2015
Record 1 of 243 | ||||||||||||||||||||||||
Title: A level set method with shape priors by using locality preserving projections | ||||||||||||||||||||||||
Author(s): Wang, B (Wang, Bin); Gao, XB (Gao, Xinbo); Li, J (Li, Jie); Li, XL (Li, Xuelong); Tao, DC (Tao, Dacheng) | ||||||||||||||||||||||||
Source: NEUROCOMPUTING Volume: 170 Pages: 188-200 DOI: 10.1016/j.neucom.2014.07.086 Published: DEC 25 2015 | ||||||||||||||||||||||||
Abstract: A novel level set method (LSM) with the constraint of shape priors is proposed to implement a selective image segmentation. Firstly, the shape priors are aligned by using image moment to deprive the spatial related information. Secondly, the aligned shape priors are projected into the subspace expanded by using locality preserving projection to measure the similarity between the shapes. Finally, a new energy functional is built by combing data-driven and shape-driven energy items to implement a selective image segmentation method. We assess the proposed method and some representative LSMs on the synthetic, medical and natural images, the results suggest that the proposed one is superior to the pure data-driven LSMs and the representative LSMs with shape priors. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||||||||||||||
Accession Number: WOS:000361256000019 | ||||||||||||||||||||||||
Conference Title: International Conference on Intelligent Science and Intelligent Data Engineering (IScIDE) | ||||||||||||||||||||||||
Conference Date: JUL 31-AUG 02, 2013 | ||||||||||||||||||||||||
Conference Location: Beijing, PEOPLES R CHINA | ||||||||||||||||||||||||
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ISSN: 0925-2312 | ||||||||||||||||||||||||
eISSN: 1872-8286 |
Record 2 of 243 | |||||||||||||||
Title: Generation and three-dimensional characterization of complex nondiffracting optical beams | |||||||||||||||
Author(s): Yu, XH (Yu Xiang-Hua); Yao, BL (Yao Bao-Li); Lei, M (Lei Ming); Yan, SH (Yan Shao-Hui); Yang, YL (Yang Yan-Long); Li, RZ (Li Run-Ze); Cai, YN (Cai Ya-Nan) | |||||||||||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 24 Article Number: 244203 DOI: 10.7498/aps.64.244203 Published: DEC 20 2015 | |||||||||||||||
Abstract: Nondiffracting optical beams play an important role in contemporary optics due to their special propagation characteristics, i.e., nondiffracting in a diffraction-free zone, shape recovering behind obstacles or self-healing property. Liquid crystal spatial light modulators (LC-SLM) are widely used for generating nondiffracting optical beams in virtue of programmable and dynamic features. In this paper, we propose a complex amplitude modulation technique that can encode any scalar complex fields for generating the complex nondiffracting beams. Before experiment, the phase modulation curve of the phase-only LC-SLM is optimized into being linear in a range of 0-2 pi by gamma correction in the way of variable binary phase gratings. Then, we experimentally generate the nonaccelerating beams, e.g., two zero-order Bessel beams with variable intensity distributions, and the nondiffracting petal-like beams generated by interfering with two coaxial Bessel beams. By scanning a reflection mirror near the focal region along the optical axis, a stack of two-dimensional images is acquired, and then a three-dimensional intensity profile of the beam is reconstructed with a software. We also experimentally demonstrate a new kind of multi-main-lobe accelerating beam with parabolic accelerating trajectory by modifying the spatial spectrum of classical Airy beam. Compared with the so-called vectorial accelerating beam with multiple main lobes in spheroidal coordinates, our generated two-main-lobe accelerating beam has a very high energy efficiency. The self-healing property of the two-main-lobe accelerating beam is also demonstrated. The presented technique can generate a variety of complex nondiffracting optical beams rapidly and obtain their three-dimensional intensity distributions accurately, which has potential applications in the fields of optical microscope, optical date storage, optical trapping, optical micromachining, etc. | |||||||||||||||
Accession Number: WOS:000368828600024 | |||||||||||||||
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ISSN: 1000-3290 |
Record 3 of 243 | ||||||||||||||||||
Title: Hydrothermal synthesis of TiO<sub>2</sub> nanostructure films and their photoelectrochemical properties | ||||||||||||||||||
Author(s): Miao, H (Miao, Hui); Hu, XY (Hu, Xiaoyun); Fan, J (Fan, Jun); Li, CB (Li, Chaoben); Sun, Q (Sun, Qian); Hao, YY (Hao, Yuanyuan); Zhang, GW (Zhang, Guowei); Bai, JT (Bai, Jintao); Hou, X (Hou, Xun) | ||||||||||||||||||
Source: APPLIED SURFACE SCIENCE Volume: 358 Pages: 418-424 DOI: 10.1016/j.apsusc.2015.08.212 Part: A Published: DEC 15 2015 | ||||||||||||||||||
Abstract: In this study, anatase TiO2 nanostructured films were successfully prepared via Ti foil-assisted hydrothermal synthesis method without any surfactants. With the increase of hydrothermal time from 3 to 12 h, the surface morphologies of the films changed from nanotubes to nanoflowers and the thickness of the films increased from 2.5 to 4.2 mu m. The nanoflowers were seated on a layer of oriented nanotubes and consisted of nanosheets. Both nanotubes and nanosheets were multi-walled, comprising interconnected [TiO6] octahedra. Ti foil and acid-treated Ti foil both formed pieces of thin films on the surface with nanotubes and nanoflowers, respectively. Photoelectrochemistry tests showed that the photocurrent response of the nanotube film was nearly 13.8 mu A/cm(2), which was approximately three times higher than that of nanoflowers film. This indicates that the nanotubes more successfully transferred electrons to the surface of the film as a result of nanotubes providing direct pathways for electrons from the point of injection to the Ti foil electrode. The ultraviolet (UV)-visible-near infrared (NIR) absorption spectra indicated that the nanotube film had a narrower band gap as compared to the nanoflower film. In other words, a relatively low hydrothermal treatment temperature or relatively short hydrothermal treatment time is better for preparing excellent photocurrent response films. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||||||||
Accession Number: WOS:000366220400052 | ||||||||||||||||||
Conference Title: 1st International Workshop on Graphene and C3N4-based Photocatalysts (IWGCP) | ||||||||||||||||||
Conference Date: JUN 05-08, 2015 | ||||||||||||||||||
Conference Location: Wuhan Univ Technology, Wuhan, PEOPLES R CHINA | ||||||||||||||||||
Conference Sponsors: Jianghan Univ, Changsha Univ | ||||||||||||||||||
Conference Host: Wuhan Univ Technology | ||||||||||||||||||
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ISSN: 0169-4332 | ||||||||||||||||||
eISSN: 1873-5584 |
Record 4 of 243 | |||||||||
Title: Plasmon-induced transparency in terahertz planar metamaterials | |||||||||
Author(s): Chen, X (Chen, Xu); Fan, WH (Fan, Wen-Hui) | |||||||||
Source: OPTICS COMMUNICATIONS Volume: 356 Pages: 84-89 DOI: 10.1016/j.optcom.2015.07.063 Published: DEC 1 2015 | |||||||||
Abstract: A planar metamaterial structure with plasmon-induced transparency effect in terahertz region is proposed and systematic numerical study is presented in this paper. The metamaterial structure is comprised of two different spilt-ring resonators in the same plane. With the destructive interference coupling between these two split-ring resonators, the proposed metamaterial structure exhibits a large transparency window within a broad absorption spectra. Moreover, the origin of transparency window with extremely low absorption and strong dispersion is clarified by two coupled Lorentzian resonators analytical model, and verified by accurate simulation of the electromagnetic wave propagation in the metamaterial structure. The proposed metamaterial opens up the avenue to design micro-sized functional devices used in switching, modulation, and slowing down terahertz waves. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||
Accession Number: WOS:000362603600016 | |||||||||
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ISSN: 0030-4018 | |||||||||
eISSN: 1873-0310 |
Record 5 of 243 | ||||||||||||||||||
Title: Mining Spatial-Temporal Patterns and Structural Sparsity for Human Motion Data Denoising | ||||||||||||||||||
Author(s): Feng, YF (Feng, Yinfu); Ji, MM (Ji, Mingming); Xiao, J (Xiao, Jun); Yang, XS (Yang, Xiaosong); Zhang, JJ (Zhang, Jian J.); Zhuang, YT (Zhuang, Yueting); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 12 Pages: 2693-2706 DOI: 10.1109/TCYB.2014.2381659 Published: DEC 2015 | ||||||||||||||||||
Abstract: Motion capture is an important technique with a wide range of applications in areas such as computer vision, computer animation, film production, and medical rehabilitation. Even with the professional motion capture systems, the acquired raw data mostly contain inevitable noises and outliers. To denoise the data, numerous methods have been developed, while this problem still remains a challenge due to the high complexity of human motion and the diversity of real-life situations. In this paper, we propose a data-driven-based robust human motion denoising approach by mining the spatial-temporal patterns and the structural sparsity embedded in motion data. We first replace the regularly used entire pose model with a much fine-grained partlet model as feature representation to exploit the abundant local body part posture and movement similarities. Then, a robust dictionary learning algorithm is proposed to learn multiple compact and representative motion dictionaries from the training data in parallel. Finally, we reformulate the human motion denoising problem as a robust structured sparse coding problem in which both the noise distribution information and the temporal smoothness property of human motion have been jointly taken into account. Compared with several state-of-the-art motion denoising methods on both the synthetic and real noisy motion data, our method consistently yields better performance than its counterparts. The outputs of our approach are much more stable than that of the others. In addition, it is much easier to setup the training dataset of our method than that of the other data-driven-based methods. | ||||||||||||||||||
Accession Number: WOS:000365320300006 | ||||||||||||||||||
PubMed ID: 25561602 | ||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||
eISSN: 2168-2275 |
Record 6 of 243 | ||||||||||||||||||
Title: Efficient Video Stitching Based on Fast Structure Deformation | ||||||||||||||||||
Author(s): Li, J (Li, Jing); Xu, W (Xu, Wei); Zhang, JG (Zhang, Jianguo); Zhang, MJ (Zhang, Maojun); Wang, ZM (Wang, Zhengming); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 12 Pages: 2707-2719 DOI: 10.1109/TCYB.2014.2381774 Published: DEC 2015 | ||||||||||||||||||
Abstract: In computer vision, video stitching is a very challenging problem. In this paper, we proposed an efficient and effective wide-view video stitching method based on fast structure deformation that is capable of simultaneously achieving quality stitching and computational efficiency. For a group of synchronized frames, firstly, an effective double-seam selection scheme is designed to search two distinct but structurally corresponding seams in the two original images. The seam location of the previous frame is further considered to preserve the inter-frame consistency. Secondly, along the double seams, 1-D feature detection and matching is performed to capture the structural relationship between the two adjacent views. Thirdly, after feature matching, we propose an efficient algorithm to linearly propagate the deformation vectors to eliminate structure misalignment. At last, image intensity misalignment is corrected by rapid gradient fusion based on the successive over relaxation iteration (SORI) solver. A principled solution to the initialization of the SORI significantly reduced the number of iterations required. We have compared favorably our method with seven state-of-the-art image and video stitching algorithms as well as traditional ones. Experimental results show that our method outperforms the existing ones compared in terms of overall stitching quality and computational efficiency. | ||||||||||||||||||
Accession Number: WOS:000365320300007 | ||||||||||||||||||
PubMed ID: 25561603 | ||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||
eISSN: 2168-2275 |
Record 7 of 243 | ||||||
Title: Yb-doped passively mode-locked fiber laser with Bi<sub>2</sub>Te<sub>3</sub>-deposited | ||||||
Author(s): Li, L (Li Lu); Yan, PG (Yan Pei-Guang); Wang, YG (Wang Yong-Gang); Duan, LN (Duan Li-Na); Sun, H (Sun Hang); Si, JH (Si Jin-Hai) | ||||||
Source: CHINESE PHYSICS B Volume: 24 Issue: 12 Article Number: 124204 DOI: 10.1088/1674-1056/24/12/124204 Published: DEC 2015 | ||||||
Abstract: In this study we present an all-normal-dispersion Yb-doped fiber laser passively mode-locked with topological insulator (Bi2Te3) saturable absorber. The saturable absorber device is fabricated by depositing Bi2Te3 on a tapered fiber through using pulsed laser deposition (PLD) technology, which can give rise to less non-saturable losses than most of the solution processing methods. Owing to the long interaction length, Bi2Te3 is not exposed to high optical power, which allows the saturable absorber device to work in a high power regime. The modulation depth of this kind of saturable absorber is measured to be 10%. By combining the saturable absorber device with Yb-doped fiber laser, a mode-locked pulse operating at a repetition rate of 19.8 MHz is achieved. The 3-dB spectral width and pulse duration are measured to be 1.245 nm and 317 ps, respectively. | ||||||
Accession Number: WOS:000366977800026 | ||||||
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ISSN: 1674-1056 | ||||||
eISSN: 1741-4199 |
Record 8 of 243 | ||||||||||||||||||||||||||||||||||||
Title: Fraunhofer diffraction of Laguerre-Gaussian beam caused by a dynamic superposed dual-triangular aperture | ||||||||||||||||||||||||||||||||||||
Author(s): Li, XZ (Li, Xinzhong); Tai, YP (Tai, Yuping); Nie, ZG (Nie, Zhaogang); Wang, H (Wang, Hui); Li, HH (Li, Hehe); Wang, JG (Wang, Jingge); Tang, J (Tang, Jie); Wang, YS (Wang, Yishan) | ||||||||||||||||||||||||||||||||||||
Source: OPTICAL ENGINEERING Volume: 54 Issue: 12 Article Number: 123113 DOI: 10.1117/1.OE.54.12.123113 Published: DEC 2015 | ||||||||||||||||||||||||||||||||||||
Abstract: We investigate the Fraunhofer diffraction of a Laguerre-Gaussian (LG) beam incident on a dynamic superposed dual-triangular aperture. The evolution of the diffraction pattern from this aperture is analyzed experimentally and theoretically. A special aperture, called the hex-star triangular aperture, demonstrates interesting diffraction patterns. Further, the diffraction properties of integer, half-integer, and fractional orders of topological charges at the Fraunhofer zone are studied by using the hex-star triangular aperture. This study can provide additional information to enhance the understanding of the diffraction properties of the LG beam transmitted through a complex aperture. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) | ||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000368418300016 | ||||||||||||||||||||||||||||||||||||
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ISSN: 0091-3286 | ||||||||||||||||||||||||||||||||||||
eISSN: 1560-2303 |
Record 9 of 243 | |||||||||
Title: Passively Q-switched Nd:YAG laser with a MoS<sub>2</sub> solution saturable absorber | |||||||||
Author(s): Lin, T (Lin, Tao); Sun, H (Sun, Hang); Wang, X (Wang, Xi); Mao, D (Mao, Dong); Wang, YG (Wang, Yonggang); Li, L (Li, Lu); Duan, LN (Duan, Lina) | |||||||||
Source: LASER PHYSICS Volume: 25 Issue: 12 Article Number: 125805 DOI: 10.1088/1054-660X/25/12/125805 Published: DEC 2015 | |||||||||
Abstract: This study presents a passively Q-switched Nd:YAG laser using a MoS2 solution as a saturable absorber. The prepared MoS2 solution saturable absorber features adjustable optical absorption, high heat dissipation, and non-contact damage. By inserting the MoS2 solution saturable absorber into a Z-type Nd:YAG laser cavity, a stable Q-switched laser with the maximum repetition rate of 20.8 KHz centered at 1064.24 nm was achieved, with the shortest pulse width at 2.8 mu s. The results experimentally confirm the potential application of a MoS2 solution saturable absorber for high performance Q-switched solid-state lasers. | |||||||||
Accession Number: WOS:000365351200020 | |||||||||
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ISSN: 1054-660X | |||||||||
eISSN: 1555-6611 |
Record 10 of 243 | ||||||||||||
Title: Highly efficient nonlinear ellipse rotation in bulk SrTiO<sub>3</sub> crystal and its applications | ||||||||||||
Author(s): Sun, QB (Sun, Qibing); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu); Li, SP (Li, Shaopeng); Han, J (Han, Jing) | ||||||||||||
Source: LASER PHYSICS Volume: 25 Issue: 12 Article Number: 125403 DOI: 10.1088/1054-660X/25/12/125403 Published: DEC 2015 | ||||||||||||
Abstract: We investigated the highly efficient, nonlinear ellipse rotation (NER) effect in bulk SrTiO3 crystal, which provides practical application as a pulse cleaner for ultrashort pulses. A highly stable, ultrafast NER effect was realized by using a bulk SrTiO3 crystal with a fast response time, strong optical Kerr effect, high damage threshold, and wide transmission wavelength range. Transmissivity higher than 30% was obtained at a level of several mJ, in which the temporal contrast can be enhanced by about three orders of magnitude. This provides a simple and feasible technology for improving the temporal contrast for the ultrahigh power laser system. | ||||||||||||
Accession Number: WOS:000365351200012 | ||||||||||||
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ISSN: 1054-660X | ||||||||||||
eISSN: 1555-6611 |
Record 11 of 243 | ||||||||||||||||||
Title: Linkage of Dual Frequency Combs Based on All Polarization-Maintaining Femtosecond Fiber Lasers | ||||||||||||||||||
Author(s): Xu, X (Xu, Xin); Feng, Y (Feng, Ye); Liu, YS (Liu, Yuanshan); Hu, XH (Hu, Xiaohong); Li, FT (Li, Feitao); Zhang, T (Zhang, Ting); Zhang, W (Zhang, Wei); Yang, Z (Yang, Zhi); Cheng, Z (Cheng, Zhao); Zhao, W (Zhao, Wei); Wang, YS (Wang, Yishan) | ||||||||||||||||||
Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 27 Issue: 23 Pages: 2421-2424 DOI: 10.1109/LPT.2015.2462080 Published: DEC 1 2015 | ||||||||||||||||||
Abstract: Perfect linkage of dual frequency combs based on all polarization-maintaining femtosecond fiber lasers is demonstrated. By employing two independent tracking feedback controlling circuits, the repetition frequency (f(r)) and the carrier-envelope offset frequency (f(ceo)) of the slave frequency comb track the master's f(r) and f(ceo), respectively. The correlation coefficients of the dual f(r)'s and the dual f(ceo)'s are up to 0.99 and 0.98, which indicate an ideal linkage between the dual frequency combs. To the best of our knowledge, this is the first report about linkage of dual frequency combs. | ||||||||||||||||||
Accession Number: WOS:000363209500001 | ||||||||||||||||||
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ISSN: 1041-1135 | ||||||||||||||||||
eISSN: 1941-0174 |
Record 12 of 243 | |||||||||||||||
Title: Degradation of high power single emitter laser modules using nanosilver paste in continuous pulse conditions | |||||||||||||||
Author(s): Yan, HD (Yan, Haidong); Mei, YH (Mei, Yunhui); Li, X (Li, Xin); Zhang, P (Zhang, Pu); Lu, GQ (Lu, Guo-Quan) | |||||||||||||||
Source: MICROELECTRONICS RELIABILITY Volume: 55 Issue: 12 Special Issue: SI Pages: 2532-2541 DOI: 10.1016/j.microrel.2015.07.037 Part: A Published: DEC 2015 | |||||||||||||||
Abstract: This paper is mainly reported to a pulse reliability investigation of high power single emitter laser modules with nanosilver paste. Comparative experiments in continuous pulse conditions for the laser modules packaged with nanosilver paste, indium and AuSn solders were conducted. The results indicate that the laser modules attached by nanosilver paste have a longer-term lifetime than those with indium and AuSn solders in continuous pulse conditions. Transient thermal behavior and coupled thermo-mechanical behavior in continuous pulse conditions are simulated by finite element method (FEM). A semi-empirical model based on Arrhenius relationship is established to provide relative reliability assessments for laser modules by combining with the simulating results. (C) 2015 Elsevier Ltd. All rights reserved. | |||||||||||||||
Accession Number: WOS:000367773000010 | |||||||||||||||
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ISSN: 0026-2714 |
Record 13 of 243 | ||||||||||||||||||
Title: A Class of Manifold Regularized Multiplicative Update Algorithms for Image Clustering | ||||||||||||||||||
Author(s): Yang, SM (Yang, Shangming); Yi, Z (Yi, Zhang); He, XF (He, Xiaofei); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON IMAGE PROCESSING Volume: 24 Issue: 12 Pages: 5302-5314 DOI: 10.1109/TIP.2015.2457033 Published: DEC 2015 | ||||||||||||||||||
Abstract: Multiplicative update algorithms are important tools for information retrieval, image processing, and pattern recognition. However, when the graph regularization is added to the cost function, different classes of sample data may be mapped to the same subspace, which leads to the increase of data clustering error rate. In this paper, an improved nonnegative matrix factorization (NMF) cost function is introduced. Based on the cost function, a class of novel graph regularized NMF algorithms is developed, which results in a class of extended multiplicative update algorithms with manifold structure regularization. Analysis shows that in the learning, the proposed algorithms can efficiently minimize the rank of the data representation matrix. Theoretical results presented in this paper are confirmed by simulations. For different initializations and data sets, variation curves of cost functions and decomposition data are presented to show the convergence features of the proposed update rules. Basis images, reconstructed images, and clustering results are utilized to present the efficiency of the new algorithms. Last, the clustering accuracies of different algorithms are also investigated, which shows that the proposed algorithms can achieve state-of-the-art performance in applications of image clustering. | ||||||||||||||||||
Accession Number: WOS:000362488900015 | ||||||||||||||||||
PubMed ID: 26186793 | ||||||||||||||||||
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ISSN: 1057-7149 | ||||||||||||||||||
eISSN: 1941-0042 |
Record 14 of 243 | ||||||
Title: Attitude Disturbance Correction for Binocular Vision Cameras in Rendezvous and Docking | ||||||
Author(s): Zhai, Y (Zhai, You); Zeng, L (Zeng, Luan); Xiong, W (Xiong, Wei); Shan, QS (Shan, Qiusha) | ||||||
Source: IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE Volume: 30 Issue: 12 Pages: 34-40 DOI: 10.1109/MAES.2015.150019 Published: DEC 2015 | ||||||
Accession Number: WOS:000368406300004 | ||||||
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ISSN: 0885-8985 | ||||||
eISSN: 1557-959X |
Record 15 of 243 | ||||||||||||||||||
Title: Tracking Human Pose Using Max-Margin Markov Models | ||||||||||||||||||
Author(s): Zhao, L (Zhao, Lin); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON IMAGE PROCESSING Volume: 24 Issue: 12 Pages: 5274-5287 DOI: 10.1109/TIP.2015.2473662 Published: DEC 2015 | ||||||||||||||||||
Abstract: We present a new method for tracking human pose by employing max-margin Markov models. Representing a human body by part-based models, such as pictorial structure, the problem of pose tracking can be modeled by a discrete Markov random field. Considering max-margin Markov networks provide an efficient way to deal with both structured data and strong generalization guarantees, it is thus natural to learn the model parameters using the max-margin technique. Since tracking human pose needs to couple limbs in adjacent frames, the model will introduce loops and will be intractable for learning and inference. Previous work has resorted to pose estimation methods, which discard temporal information by parsing frames individually. Alternatively, approximate inference strategies have been used, which can overfit to statistics of a particular data set. Thus, the performance and generalization of these methods are limited. In this paper, we approximate the full model by introducing an ensemble of two tree-structured sub-models, Markov networks for spatial parsing and Markov chains for temporal parsing. Both models can be trained jointly using the max-margin technique, and an iterative parsing process is proposed to achieve the ensemble inference. We apply our model on three challengeable data sets, which contains highly varied and articulated poses. Comprehensive experimental results demonstrate the superior performance of our method over the state-of-the-art approaches. | ||||||||||||||||||
Accession Number: WOS:000362488900013 | ||||||||||||||||||
PubMed ID: 26336122 | ||||||||||||||||||
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ISSN: 1057-7149 | ||||||||||||||||||
eISSN: 1941-0042 |
Record 16 of 243 | ||||||||||||||||||
Title: Learning a Tracking and Estimation Integrated Graphical Model for Human Pose Tracking | ||||||||||||||||||
Author(s): Zhao, L (Zhao, Lin); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 12 Pages: 3176-3186 DOI: 10.1109/TNNLS.2015.2411287 Published: DEC 2015 | ||||||||||||||||||
Abstract: We investigate the tracking of 2-D human poses in a video stream to determine the spatial configuration of body parts in each frame, but this is not a trivial task because people may wear different kinds of clothing and may move very quickly and unpredictably. The technology of pose estimation is typically applied, but it ignores the temporal context and cannot provide smooth, reliable tracking results. Therefore, we develop a tracking and estimation integrated model (TEIM) to fully exploit temporal information by integrating pose estimation with visual tracking. However, joint parsing of multiple articulated parts over time is difficult, because a full model with edges capturing all pairwise relationships within and between frames is loopy and intractable. In previous models, approximate inference was usually resorted to, but it cannot promise good results and the computational cost is large. We overcome these problems by exploring the idea of divide and conquer, which decomposes the full model into two much simpler tractable submodels. In addition, a novel two-step iteration strategy is proposed to efficiently conquer the joint parsing problem. Algorithmically, we design TEIM very carefully so that: 1) it enables pose estimation and visual tracking to compensate for each other to achieve desirable tracking results; 2) it is able to deal with the problem of tracking loss; and 3) it only needs past information and is capable of tracking online. Experiments are conducted on two public data sets in the wild with ground truth layout annotations, and the experimental results indicate the effectiveness of the proposed TEIM framework. | ||||||||||||||||||
Accession Number: WOS:000365312800017 | ||||||||||||||||||
PubMed ID: 25826809 | ||||||||||||||||||
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ISSN: 2162-237X | ||||||||||||||||||
eISSN: 2162-2388 |
Record 17 of 243 | ||||||||||||||||||
Title: Sparse kernel entropy component analysis for dimensionality reduction of biomedical data | ||||||||||||||||||
Author(s): Shi, J (Shi, Jun); Jiang, QK (Jiang, Qikun); Zhang, Q (Zhang, Qi); Huang, QH (Huang, Qinghua); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: NEUROCOMPUTING Volume: 168 Pages: 930-940 DOI: 10.1016/j.neucom.2015.05.032 Published: NOV 30 2015 | ||||||||||||||||||
Abstract: Dimensionality reduction is ubiquitous in biomedical applications. A newly proposed spectral dimensionality reduction method, named kernel entropy component analysis (KECA), can reveal the structure related to Renyi entropy of an input space data set. However, each principal component in the Hilbert space depends on all training samples in KECA, causing degraded performance. To overcome this drawback, a sparse KECA (SKECA) algorithm based on a recursive divide-and-conquer (DC) method is proposed in this work. The original large and complex problem of KECA is decomposed into a series of small and simple sub-problems, and then they are solved recursively. The performance of SKECA is evaluated on four biomedical datasets, and compared with KECA, principal component analysis (PCA), kernel PCA (KPCA), sparse PCA and sparse KPCA. Experimental results indicate that the SKECA outperforms conventional dimensionality reduction algorithms, even for high order dimensional features. It suggests that SKECA is potentially applicable to biomedical data processing. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||||||||
Accession Number: WOS:000359165000091 | ||||||||||||||||||
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ISSN: 0925-2312 | ||||||||||||||||||
eISSN: 1872-8286 |
Record 18 of 243 | ||||||||||||||||||||||||
Title: Video-based road detection via online structural learning | ||||||||||||||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Jiang, ZY (Jiang, Zhiyu); Wang, Q (Wang, Qi) | ||||||||||||||||||||||||
Source: NEUROCOMPUTING Volume: 168 Pages: 336-347 DOI: 10.1016/j.neucom.2015.05.092 Published: NOV 30 2015 | ||||||||||||||||||||||||
Abstract: Video-based road detection is a crucial enabler for the successful development of driver assistant and robot navigation systems. But reliable detection is still on its infancy and deserves further research. In order to adapt to the situation consisting of environmental varieties, an online framework is proposed focusing on exploring the structure cue of the feature vectors. Through the structural support vector machine, the road boundary and non-boundary instances are firstly discriminated. Then they are utilized to fit a complete road boundary. After that, the road region is accordingly inferred and the obtained results are treated as ground truth to update the learned model. Three contributions are claimed in this work: online-learning updating, structural information consideration, and targeted sampling selection. The proposed method is finally evaluated on several challenging videos captured by ourselves. Qualitative and quantitative results show that it outperforms the other competitors. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||||||||||||||
Accession Number: WOS:000359165000034 | ||||||||||||||||||||||||
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ISSN: 0925-2312 | ||||||||||||||||||||||||
eISSN: 1872-8286 |
Record 19 of 243 |
Title: Improved multiple-wavelength Brillouin-Raman fiber laser assisted by four-wave mixing with a micro-air cavity |
Author(s): Li, XJ (Li, Xuejiao); Ren, LY (Ren, Liyong); Lin, X (Lin, Xiao); Ju, HJ (Ju, Haijuan); Chen, N (Chen, Nana); Liang, J (Liang, Jian); Ren, KL (Ren, Kaili); Xu, YP (Xu, Yiping) |
Source: APPLIED OPTICS Volume: 54 Issue: 33 Pages: 9919-9924 DOI: 10.1364/AO.54.009919 Published: NOV 20 2015 |
Abstract: In this paper, a multiple-wavelength Brillouin-Raman fiber laser (MBRFL) with enhanced performance is presented. This is attributed to the improved Fresnel reflection, thus strengthening four-wave mixing in the fiber laser cavity due to the insertion of a micro-air cavity. As a result, compared with the conventional MBRFL without a micro-air cavity, the thresholds of Brillouin Stokes (BS) lines are observed to be reduced, and more BS lines can be generated. In the experiment, a MBRFL having 40 BS lines is achieved with good stability on laser wavelengths and output power. In view of the fact that more BS lines can be established with a simple scheme and low pump power, our MBRFL promises to be employed as a multiwavelength source for optical communication. (C) 2015 Optical Society of America |
Accession Number: WOS:000364988100040 |
PubMed ID: 26836558 |
ISSN: 1559-128X |
eISSN: 2155-3165 |
Record 20 of 243 | ||||||
Title: Combined analysis of tunable phase mask within spatial and frequency domain | ||||||
Author(s): Zhou, L (Zhou Liang); Liu, ZH (Liu Zhao-Hui); She, WJ (She Wen-Ji) | ||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 22 Article Number: 224207 DOI: 10.7498/aps.64.224207 Published: NOV 20 2015 | ||||||
Abstract: Wavefront coding technique is a powerful technique which overcomes the defects of traditional way to extend depth of field. By inserting a phase mask into the traditional incoherent imaging system, wavefront coding technique does not reduce the resolution and the light gathering power of the optical system but enlarges the depth of field of incoherent imaging system. Although several kinds of phase masks have been reported, cubic phase mask is still of a classical type which has been investigated widely both in spatial and frequency domain. Since the phase profiles of phase masks adopted in classical wavefront coding systems are predefined with specific optical systems, the extension of depth of field is not tunable. Tunable wavefront coding systems are introduced by using a pair of detachable phase masks, which is possible to control the depth of field and bandwidth of system by changing the position of each component with respect to the pupil center. Ojeda-Castaneda [Ojeda-Castaneda J, Rodriguez M, Naranjo R 2010 Proceedings of Progress in Electronics Research Symposium, Cambridge, July 5-8, 2010 p531] proposed to use a pair of cosine phase masks to make defocus sensitivity tunable. Zhao [Zhao H, Wei J X 2014 Opt. Commun. 326 35] investigated an improved version of Ojeda-Castaneda's design in frequency domain and found that the proposed system realized tunable bandwidth. The present study, based on the work of Zhao, analyzes the tunable characteristics of a pair of simple modified detachable cubic phase masks in spatial domain and frequency domain. Firstly, the ray aberration theory is adopted to give mathematical analyses and ray aberration maps of the proposed tunable phase mask. Based on the mathematical derivations, the size of point spread function (PSF) of system can be changed not only by profile of each cubic mask but also by the each mask displacement relative to pupil center. Secondly, a mathematical PSF based on the stationary phase method is derived in spatial domain. Simulations indicate that the positions of PSF translate in the image plane with the displacements of phase mask profile and the position of each component with respect to the pupil center. By analyzing the oscillations of PSF, the effective bandwidth is obtained. Through the expression, we can conclude that the effective bandwidth can be changed by the position, mask profile of each component and defocus. Only when the addition of two mask profiles is large enough, can the effective bandwidth be simplified without adding the influence of defocus. In addition, though the approximate expression of magnitude transfer of function (MTF) has been given by adopting stationary phase method in the appendix of previous work, it cannot give an intuitive grasp of the effective bandwidth in MTF map. Unlike the MTF expression derived before, the exact optical transfer function (OTF) expression is derived by adopting Fresnel integral in frequency domain. Exact MTF and phase transfer function (PTF) can be derived from OTF. Based on the exact MTF expression, simulations give an intuitive effective bandwidth in MTF map. Simulations also show the nonlinear property of PTF. The effective bandwidth and MTF can be changed by different phase mask profiles and positions, which indicate that the effective bandwidth and defocus sensitivity can be tuned. Analyses are conducted both in spatial domain and in frequency domain to verify the tunable property of the proposed phase mask, which provides theoretical foundation for tunable wavefront coding system design. | ||||||
Accession Number: WOS:000368824600016 | ||||||
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ISSN: 1000-3290 |
Record 21 of 243 |
Title: Metal-dielectric-metal based narrow band absorber for sensing applications |
Author(s): Lu, XY (Lu, Xiaoyuan); Wan, RG (Wan, Rengang); Zhang, TY (Zhang, Tongyi) |
Source: OPTICS EXPRESS Volume: 23 Issue: 23 Pages: 29842-29847 DOI: 10.1364/OE.23.029842 Published: NOV 16 2015 |
Abstract: We have investigated numerically the narrowband absorption property of a metal-dielectric-metal based structure which includes a top metallic nanoring arrays, a metal backed plate, and a middle dielectric spacer. Its absorption is up to 90% with linewidth narrower than 10 nm. This can be explained in terms of surface lattice resonance of the periodic structure. The spectrum with the sharp absorption dip, i.e. the lattice resonance, strongly depends on the refractive index of media surrounding the nanorings. This feature can be explored to devise a refractive index sensor, of which the bulk sensitivity factor is one order larger than that based on gap resonance mode, while the surface sensitivity factor can be two times larger. The proposed narrowband absorber has potential in applications of plasmonic biosensors. (C) 2015 Optical Society of America |
Accession Number: WOS:000366611500053 |
PubMed ID: 26698467 |
ISSN: 1094-4087 |
Record 22 of 243 | ||||||
Title: Design of short wave infrared imaging spectrometer system based on CDP | ||||||
Author(s): Zhang, ZF (Zhang, Zhoufeng); Hu, BL (Hu, Bingliang); Yin, QY (Yin, Qinye); Yu, T (Yu, Tao); Li, SY (Li, Siyuan); Gao, XH (Gao, Xiaohui); Zhang, HJ (Zhang, Hongjian) | ||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 23 Pages: 29758-29763 DOI: 10.1364/OE.23.029758 Published: NOV 16 2015 | ||||||
Abstract: A compact static infrared snapshot imaging spectrometer (ISIS) is designed in order to satisfy the application requirements of real-time spectral imaging for the moving targets. It consists of a CDP (crossed dispersion prism), an imaging lens, and a detector. Here we describe the spectral imaging principle, and design a short wave infrared imaging spectrometer with 4.8 degrees field of view, the measured spectrum is from 0.9 mu m to 2.5 mu m and is sampled by 40 spectral channels. This instrument has a large potential for detecting, locating and identifying unknown energetic events in real-time. (C) 2014 Optical Society of America | ||||||
Accession Number: WOS:000366611500044 | ||||||
PubMed ID: 26698458 | ||||||
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ISSN: 1094-4087 |
Record 23 of 243 | |||||||||||||||
Title: Extracting nanosecond pulse signals via stochastic resonance generated by surface plasmon bistability | |||||||||||||||
Author(s): Han, J (Han, Jing); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu); Li, SP (Li, Shaopeng) | |||||||||||||||
Source: OPTICS LETTERS Volume: 40 Issue: 22 Pages: 5367-5370 DOI: 10.1364/OL.40.005367 Published: NOV 15 2015 | |||||||||||||||
Abstract: A technology is investigated to extract nanosecond pulse noise hidden signals via stochastic resonance, which is based on surface plasmon bistability. A theoretical model for recovering nanosecond pulse signals is derived to describe the nonlinear process. It is found that the incident angle, polarization state, medium properties, and input noise intensity all determine the efficiency and fidelity of the output signal. The bistable behavior of the output intensity can be accurately controlled to obtain a cross-correlation gain larger than 6 in a wide range of input signal-to-noise ratio from 1:5 to 1:30. Meanwhile, the distortion in the time domain induced by phase shift can be reduced to a negligible level. This work provides a potential method for detecting low-level or hidden pulse signals in various communication fields. (C) 2015 Optical Society of America | |||||||||||||||
Accession Number: WOS:000366133400060 | |||||||||||||||
PubMed ID: 26565876 | |||||||||||||||
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ISSN: 0146-9592 | |||||||||||||||
eISSN: 1539-4794 |
Record 24 of 243 | |||||||||||||||
Title: Subwavelength beam focusing via multiple-metal slits arranged along a triangle surface | |||||||||||||||
Author(s): Jia, S (Jia, Sen); Wu, YM (Wu, Yiming); Si, JH (Si, Jinhai); Chen, F (Chen, Feng); Hou, X (Hou, Xun) | |||||||||||||||
Source: OPTICS COMMUNICATIONS Volume: 355 Pages: 586-590 DOI: 10.1016/j.optcom.2015.06.024 Published: NOV 15 2015 | |||||||||||||||
Abstract: A compact plasmonic structure is proposed to actualize the subwavelength beam focusing, through a metal slit array arranged along a triangular or trapezium surface profile. The incident light passes through the metal slits in the form of surface plasmon polaritons (SPPs) and then scattered into radiation fields. The constructive interference of radiation fields from individual slits with different depths and widths gives rise to beam focusing. The advantages of the proposed plasmonic lens are having a much smaller lateral dimension and broad working wavelength range. This is of importance for realizing densely integrated photonic circuits. The finite-difference time-domain (FDTD) method is employed to verify the proposed design. The simulation results indicate that the focal spot is beyond the diffraction limit. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||
Accession Number: WOS:000362861400089 | |||||||||||||||
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ISSN: 0030-4018 | |||||||||||||||
eISSN: 1873-0310 |
Record 25 of 243 | ||||||||||||
Title: Coherence in ultrafast laser-induced periodic surface structures | ||||||||||||
Author(s): Zhang, H (Zhang, Hao); Colombier, JP (Colombier, Jean-Philippe); Li, C (Li, Chen); Faure, N (Faure, Nicolas); Cheng, GH (Cheng, Guanghua); Stoian, R (Stoian, Razvan) | ||||||||||||
Source: PHYSICAL REVIEW B Volume: 92 Issue: 17 Article Number: 174109 DOI: 10.1103/PhysRevB.92.174109 Published: NOV 13 2015 | ||||||||||||
Abstract: Ultrafast laser irradiation can trigger anisotropically structured nanoscaled gratinglike arrangements of matter, the laser-induced periodic surface structures (LIPSSs). We demonstrate here that the formation of LIPSS is intrinsically related to the coherence of the laser field. Employing several test materials that allow large optical excursions, we observe the effect of randomizing spatial phase in generating finite domains of ripples. Using three-dimensional finite-difference time-domain methods, we evaluate energy deposition patterns below a material's rough surface and show that modulated pattern, i.e., a spatially ordered electromagnetic solution, results from the coherent superposition of waves. By separating the field scattered from a surface rough topography from the total field, the inhomogeneous energy absorption problem is reduced to a simple interference equation. We further distinguish the contribution of the scattered near field and scattered far field on various types of inhomogeneous energy absorption features. It is found that the inhomogeneous energy absorption which could trigger the low-spatial-frequency LIPSSs (LSFLs) and high-spatial-frequency LIPSSs (HSFLs) of periodicity Lambda > lambda/Re((n) over tilde) are due to coherent superposition between the scattered far field (propagation) and the refracted field, while HSFLs of Lambda > lambda/Re((n) over tilde) are triggered by coherent superposition between the scattered near field (evanescent) and the refracted field. This is a general scenario that involves a topography-induced scattering phenomenon and stationary evanescent fields, being applied to two model case materials that exhibit large optical excursions upon excitation (W, Si) and nonplasmonic to plasmonic transitions. We indicate the occurrence of a general light interference phenomenon that does not necessarily involve wavelike surface plasmonic excitation. Finally, we discuss the role of interference field and scattered field on the enhancement of LIPSSs by simulating interpulse feedback effects and provide the electromagnetic origin of grooves (Lambda > lambda) related to a feedback-driven topography evolution. Those results strongly suggest the electromagnetic interpretation of LIPSSs in interplay with an evolving surface topography. | ||||||||||||
Accession Number: WOS:000368094200001 | ||||||||||||
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ISSN: 2469-9950 | ||||||||||||
eISSN: 2469-9969 |
Record 26 of 243 |
Title: Effect of nano-sized cerium zirconium oxide solid solution on far-infrared emission properties of tourmaline powders |
Author(s): Guo, B (Guo, Bin); Yang, LQ (Yang, Liqing); Hu, WJ (Hu, Weijie); Li, WL (Li, Wenlong); Wang, HJ (Wang, Haojing) |
Source: MODERN PHYSICS LETTERS B Volume: 29 Issue: 30 Article Number: 1550183 DOI: 10.1142/S0217984915501833 Published: NOV 10 2015 |
Abstract: Far-infrared functional nanocomposites were prepared by the co-precipitation method using natural tourmaline (XY(3)Z(6)Si(6)O(18)(BO3)(3)V3W, where X is Na+, Ca2+, K+, or vacancy; Y is Mg2+, Fe2+, Mn2+, Al3+, Fe3+, Mn3+, Cr3+, Li+, or Ti4+; Z is Al3+, Mg2+, Cr3+, or V3+; V is O2-, OH-; and W is O2-, OH-, or F-) powders, ammonium cerium(IV) nitrate and zirconium(IV) nitrate pentahydrate as raw materials. The reference sample, tourmaline modified with ammonium cerium(IV) nitrate alone was also prepared by a similar precipitation route. The results of Fourier transform infrared spectroscopy show that tourmaline modified with Ce and Zr has a better far-infrared emission property than tourmaline modified with Ce alone. Through characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the mechanism for oxygen evolution during the heat process in the two composite materials was systematically studied. The XPS spectra show that Fe3+ ratio inside tourmaline modified with Ce alone can be raised by doping Zr. Moreover, it is showed that there is a higher Ce3+ ratio inside the tourmaline modified with Ce and Zr than tourmaline modified with Ce alone. In addition, XRD results indicate the formation of CeO2 and Ce1-xZrxO2 crystallites during the heat treatment and further TEM observations show they exist as nanoparticles on the surface of tourmaline powders. Based on these results, we attribute the improved far-infrared emission properties of Ce-Zr doped tourmaline to the enhanced unit cell shrinkage of the tourmaline arisen from much more oxidation of Fe2+ to Fe3+ inside the tourmaline caused by the change in the catalyst redox properties of CeO2 brought about by doping with Zr4+. In all samples, tourmaline modified with 7.14 wt.% Ce and 1.86 wt.% Zr calcined at 800 degrees C for 5 h has the best far-infrared emission property with the maximum emissivity value of 98%. |
Accession Number: WOS:000364504900002 |
ISSN: 0217-9849 |
eISSN: 1793-6640 |
Record 27 of 243 | |||||||||||||||||||||
Title: Prediction of nested complementary pattern in argon dielectric-barrier discharge at atmospheric pressure | |||||||||||||||||||||
Author(s): Jiang, WM (Jiang, Weiman); Li, J (Li, Jing); Tang, J (Tang, Jie); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Duan, YX (Duan, Yixiang) | |||||||||||||||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 16391 DOI: 10.1038/srep16391 Published: NOV 10 2015 | |||||||||||||||||||||
Abstract: A two-dimensional self-consistent fluid model was employed to investigate the spatiotemporal nonlinear behavior in an argon glow-like/Townsend-like dielectric-barrier discharge (DBD) at atmospheric pressure. The discharge is characterized by a major current pulse with a residual one ahead per half cycle of the external voltage. The two current pulses are operated in glow mode, but with Townsend mode between them. Contrasting spatial discharge structures are complementarily presented not only at two current pulses in the same half cycle but also during the discharge in the two adjacent-half cycles, resulting in the formation of a unique nested complementary pattern each cycle. This peculiar behavior mainly lies in the fact that sufficient charged particles are trapped in the gas gap due to the last discharge and able to dominate the subsequent discharge through the "spatial memory effect". The charge transport regime reveals that this nested complementary pattern is presented only in a limited range of driving frequency. | |||||||||||||||||||||
Accession Number: WOS:000364380400001 | |||||||||||||||||||||
PubMed ID: 26552714 | |||||||||||||||||||||
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ISSN: 2045-2322 |
Record 28 of 243 | ||||||||||||
Title: Nonlinear restoration of pulse and high noisy images via stochastic resonance | ||||||||||||
Author(s): Sun, QB (Sun, Qibing); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu); Han, J (Han, Jing); Li, SP (Li, Shaopeng) | ||||||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 16183 DOI: 10.1038/srep16183 Published: NOV 4 2015 | ||||||||||||
Abstract: We propose a novel scheme for restoring pulse and high noisy images using stochastic resonance, which is based on the modulation instability and provides a cross-correlation gain higher than 8. As opposed to previously reported designs, this unique approach employs a continuous noise and pulse signal for the generation of modulation instability. The visibility and quality of output images can be improved by appropriately adjusting the system parameters. This provides a simple and feasible method for detecting low-level or hidden pulse images in various imaging applications. | ||||||||||||
Accession Number: WOS:000364091900001 | ||||||||||||
PubMed ID: 26530885 | ||||||||||||
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ISSN: 2045-2322 |
Record 29 of 243 | ||||||||||||
Title: WS<sub>2</sub>/fluorine mica (FM) saturable absorbers for all-normal-dispersion mode-locked fiber laser | ||||||||||||
Author(s): Li, L (Li, Lu); Jiang, SZ (Jiang, Shouzhen); Wang, YG (Wang, Yonggang); Wang, X (Wang, Xi); Duan, LN (Duan, Lina); Mao, D (Mao, Dong); Li, Z (Li, Zhen); Man, BY (Man, Baoyuan); Si, JH (Si, Jinhai) | ||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 22 Pages: 28698-28706 DOI: 10.1364/OE.23.028698 Published: NOV 2 2015 | ||||||||||||
Abstract: The report firstly propose a new WS2 absorber based on fluorine mica (FM) substrate. The WS2 material was fabricated by thermal decomposition method. The FM was stripped into one single layer as thin as 20 mu m and deposited WS2 on it, which can be attached to the fiber flank without causing the laser deviation. Similar to quartz, the transmission rate of FM is as high as 90% at near infrared wavelength from one to two micrometers. Furthermore, FM is a highly elastic material so that it is not easy to break off even its thickness was only 20 mu m. On the contrary, quartz is hard to be processed and easy to break off when its thickness is less than 100 mu m. Compared to organic matrix such as polyvinyl alcohol (PVA), FM has higher softening temperature, heat dissipation and laser damage threshold than those of organic composites. In our work, the modulation depth (MD) and non-saturable losses (NLs) of this kind of saturable absorber were measured to be 5.8% and 14.8%, respectively. The WS2/FM absorber has a high damage threshold of 406 MW/cm(2), two times higher than that of WS2/PVA. By incorporating the saturable absorber into Yb-doped fiber laser cavity, a mode-locked fiber laser was achieved with central wavelength of 1052.45 nm. The repetition rate was 23.26 MHz and the maximum average output power was 30 mW. The long term stability of working was proved to be good too. The results indicate that WS2/FM film is a practical nonlinear optical material for photonic applications. (C) 2015 Optical Society of America | ||||||||||||
Accession Number: WOS:000366578900058 | ||||||||||||
PubMed ID: 26561138 | ||||||||||||
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ISSN: 1094-4087 |
Record 30 of 243 | |||||||||||||||
Title: Relevance Preserving Projection and Ranking for Web Image Search Reranking | |||||||||||||||
Author(s): Ji, Z (Ji, Zhong); Pang, YW (Pang, Yanwei); Li, XL (Li, Xuelong) | |||||||||||||||
Source: IEEE TRANSACTIONS ON IMAGE PROCESSING Volume: 24 Issue: 11 Pages: 4137-4147 DOI: 10.1109/TIP.2015.2437198 Published: NOV 2015 | |||||||||||||||
Abstract: An image search reranking (ISR) technique aims at refining text-based search results by mining images' visual content. Feature extraction and ranking function design are two key steps in ISR. Inspired by the idea of hypersphere in one-class classification, this paper proposes a feature extraction algorithm named hypersphere-based relevance preserving projection (HRPP) and a ranking function called hypersphere-based rank (H-Rank). Specifically, an HRPP is a spectral embedding algorithm to transform an original high-dimensional feature space into an intrinsically low-dimensional hypersphere space by preserving the manifold structure and a relevance relationship among the images. An H-Rank is a simple but effective ranking algorithm to sort the images by their distances to the hypersphere center. Moreover, to capture the user's intent with minimum human interaction, a reversed k-nearest neighbor (KNN) algorithm is proposed, which harvests enough pseudorelevant images by requiring that the user gives only one click on the initially searched images. The HRPP method with reversed KNN is named one-click-based HRPP (OC-HRPP). Finally, an OC-HRPP algorithm and the H-Rank algorithm form a new ISR method, H-reranking. Extensive experimental results on three large real-world data sets show that the proposed algorithms are effective. Moreover, the fact that only one relevant image is required to be labeled makes it has a strong practical significance. | |||||||||||||||
Accession Number: WOS:000359563500010 | |||||||||||||||
PubMed ID: 26011885 | |||||||||||||||
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ISSN: 1057-7149 | |||||||||||||||
eISSN: 1941-0042 |
Record 31 of 243 | |||||||||||||||||||||
Title: Event-Based Media Enrichment Using an Adaptive Probabilistic Hypergraph Model | |||||||||||||||||||||
Author(s): Liu, XL (Liu, Xueliang); Wang, M (Wang, Meng); Yin, BC (Yin, Bao-Cai); Huet, B (Huet, Benoit); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 11 Pages: 2461-2471 DOI: 10.1109/TCYB.2014.2374755 Published: NOV 2015 | |||||||||||||||||||||
Abstract: Nowadays, with the continual development of digital capture technologies and social media services, a vast number of media documents are captured and shared online to help attendees record their experience during events. In this paper, we present a method combining semantic inference and multimodal analysis for automatically finding media content to illustrate events using an adaptive probabilistic hypergraph model. In this model, media items are taken as vertices in the weighted hypergraph and the task of enriching media to illustrate events is formulated as a ranking problem. In our method, each hyperedge is constructed using the K-nearest neighbors of a given media document. We also employ a probabilistic representation, which assigns each vertex to a hyperedge in a probabilistic way, to further exploit the correlation among media data. Furthermore, we optimize the hypergraph weights in a regularization framework, which is solved as a second-order cone problem. The approach is initiated by seed media and then used to rank the media documents using a transductive inference process. The results obtained from validating the approach on an event dataset collected from EventMedia demonstrate the effectiveness of the proposed approach. | |||||||||||||||||||||
Accession Number: WOS:000363233000008 | |||||||||||||||||||||
PubMed ID: 26470061 | |||||||||||||||||||||
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ISSN: 2168-2267 | |||||||||||||||||||||
eISSN: 2168-2275 |
Record 32 of 243 | ||||||
Title: Development of intelligent control system for X-ray streak camera in diagnostic instrument manipulator | ||||||
Author(s): Pei, CQ (Pei, Chengquan); Wu, SL (Wu, Shengli); Tian, JS (Tian, Jinshou); Liu, Z (Liu, Zhen); Fang, YM (Fang, Yuman); Gao, GL (Gao, Guilong); Liang, LL (Liang, Lingliang); Wen, WL (Wen, Wenlong) | ||||||
Source: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT Volume: 799 Pages: 124-131 DOI: 10.1016/j.nima.2015.07.049 Published: NOV 1 2015 | ||||||
Abstract: An intelligent control system for an X ray streak camera in a diagnostic instrument manipulator (DIM) is proposed and implemented, which can control time delay, electric focusing, image gain adjustment, switch of sweep voltage, acquiring environment parameters etc. The system consists of 16 A/D converters and 16 D/A converters, a 32-channel general purpose input/output (GPIO) and two sensors. An isolated DC/DC converter with multi-outputs and a single mode filer were adopted to reduce the interference generated by the common ground among the A/D, D/A and I/O. The software was designed using graphical programming language and can remotely access the corresponding instrument from a website. The entire intelligent control system can acquire the desirable data at a speed of 30 Mb/s and store 11 for later analysis. The intelligent. system was implemented on a streak camera in a DIM and it shows a temporal resolution of 11.25 ps, spatial distortion of less than 10% and dynamic range of 279:1. The intelligent control system has been successfully used in a streak camera to verify the synchronization of multi-channel laser on the Confinement Fusion (C) 2015 Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000361877300019 | ||||||
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ISSN: 0168-9002 | ||||||
eISSN: 1872-9576 |
Record 33 of 243 | |||||||||||||||
Title: High-Pulse-Energy All-Normal-Dispersion Yb-Doped Fiber Laser Based on Nonlinear Polarization Evolution | |||||||||||||||
Author(s): Wang, JL (Wang Jun-Li); Wang, XL (Wang Xue-Ling); He, BR (He Bo-Rong); Wang, YG (Wang Yong-Gang); Zhu, JF (Zhu Jiang-Feng); Wei, ZY (Wei Zhi-Yi) | |||||||||||||||
Source: CHINESE PHYSICS LETTERS Volume: 32 Issue: 11 Article Number: 114202 DOI: 10.1088/0256-307X/32/11/114202 Published: NOV 2015 | |||||||||||||||
Abstract: We report an all-normal-dispersion ytterbium fiber laser mode locked by nonlinear polarization evolution. With a 347-m-long all-fiber ring cavity, a pulse energy of 263 nJ at a repetition rate of 613 kHz is achieved, which is the highest per-pulse energy directly obtained from an all-fiber mode-locked laser doped by ytterbium ions. The compact and operation-robust laser yields a well-shaped spectrum centered at 1032nm with a bandwidth (FWHM) of 4 nm, and the slope efficiency is as high as 27.5%. The proposed low-repetition-rate high-pulse-energy mode-locked fiber laser will be a promising seed for all-fiber chirped pulsed amplification systems. | |||||||||||||||
Accession Number: WOS:000365178900012 | |||||||||||||||
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ISSN: 0256-307X | |||||||||||||||
eISSN: 1741-3540 |
Record 34 of 243 | ||||||||||||
Title: Compact multi-band fluorescent microscope with an electrically tunable lens for autofocusing | ||||||||||||
Author(s): Wang, ZJ (Wang, Zhaojun); Lei, M (Lei, Ming); Yao, BL (Yao, Baoli); Cai, Y (Cai, Yanan); Liang, YS (Liang, Yansheng); Yang, YL (Yang, Yanlong); Yang, XB (Yang, Xibin); Li, H (Li, Hui); Xiong, DX (Xiong, Daxi) | ||||||||||||
Source: BIOMEDICAL OPTICS EXPRESS Volume: 6 Issue: 11 Pages: 4353-4364 DOI: 10.1364/BOE.6.004353 Published: NOV 1 2015 | ||||||||||||
Abstract: Autofocusing is a routine technique in redressing focus drift that occurs in time-lapse microscopic image acquisition. To date, most automatic microscopes are designed on the distance detection scheme to fulfill the autofocusing operation, which may suffer from the low contrast of the reflected signal due to the refractive index mismatch at the water/glass interface. To achieve high autofocusing speed with minimal motion artifacts, we developed a compact multi-band fluorescent microscope with an electrically tunable lens (ETL) device for autofocusing. A modified searching algorithm based on equidistant scanning and curve fitting is proposed, which no longer requires a single-peak focus curve and then efficiently restrains the impact of external disturbance. This technique enables us to achieve an autofocusing time of down to 170 ms and the reproductivity of over 97%. The imaging head of the microscope has dimensions of 12 cm x 12 cm x 6 cm. This portable instrument can easily fit inside standard incubators for real-time imaging of living specimens. (C) 2015 Optical Society of America | ||||||||||||
Accession Number: WOS:000366122400015 | ||||||||||||
PubMed ID: 26601001 | ||||||||||||
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ISSN: 2156-7085 |
Record 35 of 243 | ||||||||||||||||||||||||
Title: Research progress of chelate precursor doping method to fabricate Yb-doped large-mode-area silica fibers for kW-level laser | ||||||||||||||||||||||||
Author(s): Wang, Z (Wang, Zhen); Zhan, H (Zhan, Huan); Ni, L (Ni, Li); Peng, K (Peng, Kun); Wang, XL (Wang, Xiaolong); Wang, JJ (Wang, Jianjun); Jing, F (Jing, Feng); Lin, AX (Lin, Aoxiang) | ||||||||||||||||||||||||
Source: LASER PHYSICS Volume: 25 Issue: 11 Article Number: 115103 DOI: 10.1088/1054-660X/25/11/115103 Published: NOV 2015 | ||||||||||||||||||||||||
Abstract: With continuous efforts and practical managing experiences, the chelate precursor doping method has been justified as an effective way to dope rare-earth ions into silica host materials, a key technique in making large-mode-area silica fibers for high power laser applications. It is characterized by good controllability, stability and repeatability to accomplish different refractive index profiles. Different preforms with a large core, designed refractive index profile, good symmetrical shape and homogeneous elemental distribution were successfully fabricated. The home-made standard 20/400-type double-cladding Yb-doped large-mode-area silica fiber was drawn and presented a 1.6 kW laser output at 1064 nm, the highest power record publically reported with this method. With further optimization, chelate precusor doping method has potential to manufacture high power laser fibers for the next generation. | ||||||||||||||||||||||||
Accession Number: WOS:000365350800004 | ||||||||||||||||||||||||
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ISSN: 1054-660X | ||||||||||||||||||||||||
eISSN: 1555-6611 |
Record 36 of 243 | ||||||||||||||||||
Title: Panoramic camera on the Yutu lunar rover of the Chang'e-3 mission | ||||||||||||||||||
Author(s): Yang, JF (Yang, Jian-Feng); Li, CL (Li, Chun-Lai); Xue, B (Xue, Bin); Ruan, P (Ruan, Ping); Gao, W (Gao, Wei); Qiao, WD (Qiao, Wei-Dong); Lu, D (Lu, Di); Ma, XL (Ma, Xiao-Long); Li, F (Li, Fu); He, YH (He, Ying-Hong); Li, T (Li, Ting); Ren, X (Ren, Xin); Yan, XT (Yan, Xing-Tao) | ||||||||||||||||||
Source: RESEARCH IN ASTRONOMY AND ASTROPHYSICS Volume: 15 Issue: 11 Pages: 1867-1880 DOI: 10.1088/1674-4527/15/11/009 Published: NOV 2015 | ||||||||||||||||||
Abstract: The Chang'e-3 panoramic camera, which is composed of two cameras with identical functions, performances and interfaces, is installed on the lunar rover mast. It can acquire 3D images of the lunar surface based on the principle of binocular stereo vision. By rotating and pitching the mast, it can take several photographs of the patrol area. After stitching these images, panoramic images of the scenes will be obtained. Thus the topography and geomorphology of the patrol area and the impact crater, as well as the geological structure of the lunar surface, will be analyzed and studied. In addition, it can take color photographs of the lander using the Bayer color coding principle. It can observe the working status of the lander by switching between static image mode and dynamic video mode with automatic exposure time. The focal length of the lens on the panoramic camera is 50 mm and the field of view is 19.7 degrees x 14.5 degrees. Under the best illumination and viewing conditions, the largest signal-to-noise ratio of the panoramic camera is 44 dB. Its static modulation transfer function is 0.33. A large number of ground testing experiments and on-orbit imaging results show that the functional interface of the panoramic camera works normally. The image quality of the panoramic camera is satisfactory. All the performance parameters of the panoramic camera satisfy the design requirements. | ||||||||||||||||||
Accession Number: WOS:000365467400009 | ||||||||||||||||||
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ISSN: 1674-4527 |
Record 37 of 243 | |||||||||
Title: Optical properties of a binuclear neodymium complex in phosphorus oxychloride for liquid laser | |||||||||
Author(s): Zhang, GF (Zhang, Guofang); She, JB (She, Jiangbo); Han, K (Han, Kai); Nie, RZ (Nie, Rongzhi); Li, DD (Li, Dongdong); Peng, B (Peng, Bo) | |||||||||
Source: OPTICAL MATERIALS Volume: 49 Pages: 343-347 DOI: 10.1016/j.optmat.2015.10.002 Published: NOV 2015 | |||||||||
Abstract: A novel binuclear neodymium complex Nd(CF3COO)(3)center dot(Ph3PO)(2) (Ph3PO: triphenylphosphine oxide) with high stimulated emission cross-section was presented. The molecular structure of the complex was characterized by single-crystal X-ray diffraction. The optical properties of the complex in liquid medium were studied. From the absorption and luminescence spectra, the Judd-Ofelt parameters of Nd (CF3COO)(3)center dot(Ph3PO)(2) in phosphorus oxychloride were obtained. Based on the crystal structure, the effects of crystal field and bonding valence properties on three intensity parameters Omega(t)(t = 2, 4, 6) and emission cross-section were analyzed in detail. The emission cross-section of E-4(3/2) -> I-4(11/2) fluorescence transition (2.78 x 10(-2) cm(2)) of the new neodymium compound was higher than those of other Nd(III) complexes and even comparable with some laser glasses. (C) 2015 Elsevier BM. All rights reserved. | |||||||||
Accession Number: WOS:000364255100054 | |||||||||
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ISSN: 0925-3467 | |||||||||
eISSN: 1873-1252 |
Record 38 of 243 | |||||||||||||||||||||
Title: Robust Visual Tracking Using Structurally Random Projection and Weighted Least Squares | |||||||||||||||||||||
Author(s): Zhang, SP (Zhang, Shengping); Zhou, HY (Zhou, Huiyu); Jiang, F (Jiang, Feng); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY Volume: 25 Issue: 11 Pages: 1749-1760 DOI: 10.1109/TCSVT.2015.2406194 Published: NOV 2015 | |||||||||||||||||||||
Abstract: Sparse representation-based visual tracking approaches have attracted increasing interests in the community in recent years. The main idea is to linearly represent each target candidate using a set of target and trivial templates, while imposing a sparsity constraint onto the representation coefficients. After we obtain the coefficients using l(1)-norm minimization methods, the candidate with the lowest error, when it is reconstructed using only the target templates and the associated coefficients, is considered as the tracking result. In spite of promising system performance widely reported, it is unclear if the performance of these trackers can be maximized. In addition, computational complexity caused by the dimensionality of the feature space limits these algorithms in real-time applications. In this paper, we propose a real-time visual tracking method based on structurally random projection (RP) and weighted least squares (WLS) techniques. In particular, to enhance the discriminative capability of the tracker, we introduce background templates to the linear representation framework. To handle appearance variations over time, we relax the sparsity constraint using a WLS method to obtain the representation coefficients. To further reduce the computational complexity, structurally RP is used to reduce the dimensionality of the feature space, while preserving the pairwise distances between the data points in the feature space. Experimental results show that the proposed approach outperforms several state-of-the-art tracking methods. | |||||||||||||||||||||
Accession Number: WOS:000364230600003 | |||||||||||||||||||||
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ISSN: 1051-8215 | |||||||||||||||||||||
eISSN: 1558-2205 |
Record 39 of 243 | |||||||||||||||||||||||||||
Title: In situ optical measurements of Chang'E-3 landing site in Mare Imbrium: 2. Photometric properties of the regolith | |||||||||||||||||||||||||||
Author(s): Jin, WD (Jin, Weidong); Zhang, H (Zhang, Hao); Yuan, Y (Yuan, Ye); Yang, YZ (Yang, Yazhou); Shkuratov, YG (Shkuratov, Yuriy G.); Lucey, PG (Lucey, Paul G.); Kaydash, VG (Kaydash, Vadim G.); Zhu, MH (Zhu, Meng-Hua); Xue, B (Xue, Bin); Di, KC (Di, Kaichang); Xu, B (Xu, Bin); Wan, WH (Wan, Wenhui); Xiao, L (Xiao, Long); Wang, ZW (Wang, Ziwei) | |||||||||||||||||||||||||||
Source: GEOPHYSICAL RESEARCH LETTERS Volume: 42 Issue: 20 Pages: 8312-8319 DOI: 10.1002/2015GL065789 Published: OCT 28 2015 | |||||||||||||||||||||||||||
Abstract: The panorama cameras onboard the Yutu Rover of the Chang'E-3 lunar mission acquired hundreds of high-resolution color images of the lunar surface and captured the first in situ lunar opposition effect (OE) since the Apollo era. We extracted the phase curve and the color ratio in three bands with the phase angle range from 2 degrees to 141 degrees. Photometric inversions using the Hapke model reveal that submicroscopic dusts are present in the landing area and both the coherent backscattering and the shadow hiding are responsible for the strong OE. Compared with spaceborne measurements, the grains in the landing site are brighter, more transparent, and appear to be better crystallized than the average maria basaltic grains. The results show that the phase-reddening effect appears to be present in the in situ phase curves. The current phase curve can be used as the ground-truth validations of any future spaceborne phase curve measurement over the landing site region. | |||||||||||||||||||||||||||
Accession Number: WOS:000364782500007 | |||||||||||||||||||||||||||
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ISSN: 0094-8276 | |||||||||||||||||||||||||||
eISSN: 1944-8007 |
Record 40 of 243 |
Title: Multifocus color image sequence fusion based on mean shift segmentation |
Author(s): Hao, XX (Hao, Xingxing); Zhao, H (Zhao, Hui); Liu, J (Liu, Jing) |
Source: APPLIED OPTICS Volume: 54 Issue: 30 Pages: 8982-8989 DOI: 10.1364/AO.54.008982 Published: OCT 20 2015 |
Abstract: This paper presents a region-based technique for fusion of a multifocus color image sequence in the LUV color space. First, mean shift segmentation was applied on the weighted average image of the image sequence to obtain the fusion reference areas. Second, for each segmented area, the well-known modified Laplacian (LAP2) was used as a focus measure to select the clearest parts within the image sequence and then a final image focused with all parts can be generated. Mutual information, QAB/F metric, entropy, standard deviation, image sharpness metric, image contrast metric, average gradient, and spatial frequency were adopted to assess the quality of the fused image. Experiments carried out using standard image sequences from HeliconSoft demonstrated that the results obtained through our technique offer good performance. The proposed technique can be used to extend the depth of field (DOF) of a camera system effectively. (C) 2015 Optical Society of America |
Accession Number: WOS:000363311400024 |
PubMed ID: 26560388 |
ISSN: 1559-128X |
eISSN: 2155-3165 |
Record 41 of 243 | ||||||||||||
Title: Picosecond resolving detection method and experiment for ultrafast X-ray by modulation of an optical probe | ||||||||||||
Author(s): Wang, B (Wang Bo); Bai, YL (Bai Yong-Lin); Cao, WW (Cao Wei-Wei); Xu, P (Xu Peng); Liu, BY (Liu Bai-Yu); Gou, YS (Gou Yong-Sheng); Zhu, BL (Zhu Bing-Li); Hou, X (Hou Xun) | ||||||||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 20 Article Number: 200701 DOI: 10.7498/aps.64.200701 Published: OCT 20 2015 | ||||||||||||
Abstract: Diagnostic measurement of single picosecond event in high energy density physics, laser fusion, plasma radiation, and combustion, is of great importance. However, the measuring of the shape of the single X-ray pulse and the synchronization of X-ray and the laser pulse in picosecond resolution is still a great challenge. Restricted by the transit time of electrons, the time-resolution limit of a conventional framing camera based on the microchannel plate is 40 ps. Centered on the full-optical modulation effect of the light-probe, a novel method for X-ray detection of picoseconds temporal resolution based on low temperature GaAs is proposed in this work. The basic physical mechanism of the detector can be explained in both macroscopical and microcosmic ways. In the macroscopical way, the X-ray radiation absorption in the sensor material produces a transient, non-equilibrium electron-hole pair distribution that results in a transient differential change of the local refractive index, which is then sensed by the reflectivity changes of the optical probe beam. In the microcosmic way, X-ray absorption creates photoelectrons and the core level holes are subsequently filled through Auger or fluorescence processes. These excitations ultimately increase conduction and valence band carriers that perturb optical reflectivity. | ||||||||||||
Accession Number: WOS:000368822000009 | ||||||||||||
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ISSN: 1000-3290 |
Record 42 of 243 | ||||||
Title: Direct welding of glass and metal by 1 kHz femtosecond laser pulses | ||||||
Author(s): Zhang, GD (Zhang, Guodong); Cheng, GH (Cheng, Guanghua) | ||||||
Source: APPLIED OPTICS Volume: 54 Issue: 30 Pages: 8957-8961 DOI: 10.1364/AO.54.008957 Published: OCT 20 2015 | ||||||
Abstract: In the welding process between similar or dissimilar materials, inserting an intermediate layer and pressure assistance are usually thought to be necessary. In this paper, the direct welding between alumina-silicate glass and metal (aluminum, copper, and steel), under exposure from 1 kHz femtosecond laser pulses without any auxiliary processes, is demonstrated. The micron/nanometer-sized metal particles induced by laser ablation were considered to act as the adhesive in the welding process. The welding parameters were optimized by varying the pulse energy and the translation velocity of the sample. The shear joining strength characterized by a shear force testing equipment was as high as 2.34 MPa. This direct bonding technology has potential for applications in medical devices, sensors, and photovoltaic devices. (C) 2015 Optical Society of America | ||||||
Accession Number: WOS:000363311400021 | ||||||
PubMed ID: 26560385 | ||||||
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ISSN: 1559-128X | ||||||
eISSN: 2155-3165 |
Record 43 of 243 | ||||||||||||||||||||||||||||||||||||||||||
Title: WS<sub>2</sub> saturable absorber for dissipative soliton mode locking at 1.06 and 1.55 μm | ||||||||||||||||||||||||||||||||||||||||||
Author(s): Mao, D (Mao, Dong); Zhang, SL (Zhang, Shengli); Wang, YD (Wang, Yadong); Gan, XT (Gan, Xuetao); Zhang, WD (Zhang, Wending); Mei, T (Mei, Ting); Wang, YG (Wang, Yonggang); Wang, YS (Wang, Yishan); Zeng, HB (Zeng, Haibo); Zhao, JL (Zhao, Jianlin) | ||||||||||||||||||||||||||||||||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 21 Pages: 27509-27519 DOI: 10.1364/OE.23.027509 Published: OCT 19 2015 | ||||||||||||||||||||||||||||||||||||||||||
Abstract: Transition-metal dichalcogenides, such as tungsten disulfide (WS2) and molybdenium disulfide (MoS2), are highly anisotropic layered materials and have attracted growing interest from basic research to practical applications due to their exotic physical property that may complement graphene and other semiconductor materials. WS2 nanosheets are found to exhibit broadband nonlinear saturable absorption property, and saturable absorbers (SAs) are fabricated by depositing WS2 nanosheets on side-polished fibers. Attributing to the weak evanescent field and long interaction length, the WS2 nanosheets are not exposed to large optical intensity, which allows the SA to work at the high-power regime. The SAs are used to mode lock erbium- and ytterbium-doped fiber lasers with normal dispersion, producing trains of dissipative soliton at 1.55 and 1.06 mu m respectively. Simulations show that the bandgap of WS2 nanosheets decreases from 1.18 to 0.02 and 0.65 eV by introducing W and S defects respectively, which may contribute to the broadband saturable absorption property of the WS2. (C) 2015 Optical Society of America | ||||||||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000366574400062 | ||||||||||||||||||||||||||||||||||||||||||
PubMed ID: 26480411 | ||||||||||||||||||||||||||||||||||||||||||
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ISSN: 1094-4087 |
Record 44 of 243 | ||||||||||||
Title: Transparent and Dense Ladder-Like Alkylene-Bridged Polymethylsiloxane Coating with Enhanced Water Vapor Barrier Property | ||||||||||||
Author(s): Zhang, C (Zhang, Ce); Zhang, C (Zhang, Cong); Cui, XM (Cui, Xinmin); Sun, JH (Sun, Jinghua); Ding, RM (Ding, Ruimin); Zhang, QH (Zhang, Qinghua); Xu, Y (Xu, Yao) | ||||||||||||
Source: ACS APPLIED MATERIALS & INTERFACES Volume: 7 Issue: 40 Pages: 22157-22165 DOI: 10.1021/acsami.5b08084 Published: OCT 14 2015 | ||||||||||||
Abstract: Organic-inorganic hybrid composites have been well-studied as water vapor barrier materials for their long diffusion length of water vapor in coatings which can be realized by improving the aspect ratio of inorganic components and regularity of nanostructure in coatings. In this paper, dense organic-inorganic hybrid coating based on ladder-like alkylene-bridged polymethylsiloxane (ABPMS) was successfully fabricated through the hydrosilylation reaction between polymethylhydrosiloxane and diene (1,5-hexadiene or 1,7-octadiene) in toluene under Pt/C catalysis. Its ladder-like structure was verified by Si-29 magic angle spinning (MAS) NMR, C-18 MAS NMR, and in-plane and out-of-plane glance-incident X-ray diffraction (GIXRD) techniques. Its corresponding coating showed excellent water vapor barrier ability for a typical water-soluble crystal, potassium dihydrogen phosphate (KDP). When treated in 50% relative humidity (RH) condition at 25 degrees C for 8 months, the ABPMS coating with 100 run thickness displayed a very low transmittance loss of 1.6% compared with the high transmittance loss of 10% for uncoated KDP. Moreover, the ABPMS coating showed good ultraviolet radiation resistance, thermal stability, low mechanical property, and excellent compatibility with hydrophobic antireflective (AR) coatings. | ||||||||||||
Accession Number: WOS:000363001500006 | ||||||||||||
PubMed ID: 26393288 | ||||||||||||
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ISSN: 1944-8244 |
Record 45 of 243 | ||||||||||||
Title: Digital holographic shape measurement using Fizeau microscopy | ||||||||||||
Author(s): Abdelsalam, DG (Abdelsalam, D. G.); Min, JW (Min, Junwei); Kim, D (Kim, Daesuk); Yao, BL (Yao, Baoli) | ||||||||||||
Source: CHINESE OPTICS LETTERS Volume: 13 Issue: 10 Article Number: 100701 DOI: 10.3788/COL201513.100701 Published: OCT 10 2015 | ||||||||||||
Abstract: We present a Fizeau interferometer using a microscopic objective as a tool for surface contouring without the need for a numerical lens for reconstruction. The interferometer is associated with a telescope system to feature the object with collimated light. The experiment is conducted on two objects possessing different step heights. The phase maps from the captured off-axis holograms are calculated numerically, which allows us to deduce the contours of the objects. The great advantages of the presented technique are that it can be done in real time and there is no need for numerical lenses for micro-objects reconstruction. | ||||||||||||
Accession Number: WOS:000362847900009 | ||||||||||||
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ISSN: 1671-7694 |
Record 46 of 243 | ||||||||||||||||||||||||
Title: Spatiotemporal evolution of a cosine-modulated stationary field and Kerr frequency comb generation in a microresonator | ||||||||||||||||||||||||
Author(s): Hu, XH (Hu, Xiaohong); Liu, YS (Liu, Yuanshan); Xu, X (Xu, Xin); Feng, Y (Feng, Ye); Zhang, WF (Zhang, Wenfu); Wang, WQ (Wang, Weiqiang); Song, JZ (Song, Jiazheng); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei) | ||||||||||||||||||||||||
Source: APPLIED OPTICS Volume: 54 Issue: 29 Pages: 8751-8757 DOI: 10.1364/AO.54.008751 Published: OCT 10 2015 | ||||||||||||||||||||||||
Abstract: Based on the normalized spatiotemporal Lugiato-Lefever equation, the evolutions of cosine-modulated stationary fields relating to the generation of single-free spectral range (FSR) or multi-FSR Kerr frequency combs in a microresonator with anomalous dispersion are studied numerically. The research results show that a single-FSR comb arises when a dissipative soliton pulse or multiple nonequidistant soliton pulses form in the cavity. Compared with the smooth and regular spectral structure of a single soliton pulse, the comb corresponding to the uneven distribution of multiple soliton pulses exhibits a complex and irregular profile. When the stable intracavity field consists of a "roll" Turing pattern or N(N > 1) evenly distributed soliton pulses separated by 2 pi/N, multi-FSR combs can be generated. In the case of the "roll" Turing pattern solution, it is found that third-order dispersion could modify the comb mode spacing and decrease the intensity of high-order comb modes. For the situation of multiple soliton pulse generation, the simulation results indicate that both the number and locations of the soliton pulses can be actively controlled through the careful selection of modulation frequency. In addition, for the selected cosine-modulated initial field profile, only those modes with the mode numbers being equal to an integer multiple of N can be greatly amplified by the parametric gain during propagation in the microresonator. This process eventually leads to the formation of a N-FSR frequency comb. (c) 2015 Optical Society of America | ||||||||||||||||||||||||
Accession Number: WOS:000362667200026 | ||||||||||||||||||||||||
PubMed ID: 26479815 | ||||||||||||||||||||||||
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ISSN: 1559-128X | ||||||||||||||||||||||||
eISSN: 2155-3165 |
Record 47 of 243 | ||||||||||||||||||
Title: Fast frame scanning camera system for light-sheet microscopy | ||||||||||||||||||
Author(s): Wu, D (Wu, Di); Zhou, X (Zhou, Xing); Yao, BL (Yao, Baoli); Li, RZ (Li, Runze); Yang, YL (Yang, Yanlong); Peng, T (Peng, Tong); Lei, M (Lei, Ming); Dan, D (Dan, Dan); Ye, T (Ye, Tong) | ||||||||||||||||||
Source: APPLIED OPTICS Volume: 54 Issue: 29 Pages: 8632-8636 DOI: 10.1364/AO.54.008632 Published: OCT 10 2015 | ||||||||||||||||||
Abstract: In the interest of improving the temporal resolution for light-sheet microscopy, we designed a fast frame scanning camera system that incorporated a galvanometer scanning mirror into the imaging path of a home-built light-sheet microscope. This system transformed a temporal image sequence to a spatial one so that multiple images could be acquired during one exposure period. The improvement factor of the frame rate was dependent on the number of sub-images that could be tiled on the sensor without overlapping each other and was therefore a trade-off with the image size. As a demonstration, we achieved 960 frames/s (fps) on a CCD camera that was originally capable of recording images at only 30 fps (full frame). This allowed us to observe millisecond or sub-millisecond events with ordinary CCD cameras. (c) 2015 Optical Society of America | ||||||||||||||||||
Accession Number: WOS:000362667200008 | ||||||||||||||||||
PubMed ID: 26479797 | ||||||||||||||||||
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ISSN: 1559-128X | ||||||||||||||||||
eISSN: 2155-3165 |
Record 48 of 243 | ||||||
Title: Polarimetric dehazing method for dense haze removal based on distribution analysis of angle of polarization | ||||||
Author(s): Liang, J (Liang, Jian); Ren, LY (Ren, Liyong); Ju, HJ (Ju, Haijuan); Zhang, WF (Zhang, Wenfei); Qu, ES (Qu, Enshi) | ||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 20 Pages: 26146-26157 DOI: 10.1364/OE.23.026146 Published: OCT 5 2015 | ||||||
Abstract: Many dehazing methods have proven to be effective in removing haze out of the hazy image, but few of them are adaptive in handling the dense haze. In this paper, based on the angle of polarization (AOP) distribution analysis we propose a kind of polarimetric dehazing method, which is verified to be capable of enhancing the contrast and the range of visibility of images taken in dense haze substantially. It is found that the estimating precision of the intensity of airlight is a key factor which determines the dehazing quality, and fortunately our method involves a high precision estimation inherently. In the experiments a good dehazing performance is demonstrated, especially for dense haze removal. We find that the visibility can be enhanced at least 74%. Besides, the method can be used not only in dense haze but also in severe sea fog. (C)2015 Optical Society of America | ||||||
Accession Number: WOS:000365077900071 | ||||||
PubMed ID: 26480129 | ||||||
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ISSN: 1094-4087 |
Record 49 of 243 | |||||||||||||||
Title: Effect of geometrical parameters on flow and heat transfer performances in multi-stream spiral-wound heat exchangers | |||||||||||||||
Author(s): Lu, X (Lu, Xing); Zhang, GP (Zhang, Gaopeng); Chen, YT (Chen, Yi-tung); Wang, QW (Wang, Qiuwang); Zeng, M (Zeng, Min) | |||||||||||||||
Source: APPLIED THERMAL ENGINEERING Volume: 89 Pages: 1104-1116 DOI: 10.1016/j.applthermaleng.2015.04.084 Published: OCT 5 2015 | |||||||||||||||
Abstract: The influences of the changes in geometrical factors, including the space bar thickness, the tube pitch in the first layer, the tube external diameter, the number of layers and the centre core diameter on flow and heat transfer performances in multi-stream spiral-wound heat exchangers are numerical investigated. The shell-side and tube-side Nusselt number and pressure drop per unit length increase with the increase of number of layers, centre core diameter, and tube external diameter, but decrease with the increase of space bar thickness and tube pitch in the first layer. Quantitatively estimation of the affecting performances of these five geometrical parameters is implemented by using the Taguchi method, and the result shows that the contribution rate of them are more than 5%. Thus, the multivariate correlations with the main geometrical parameters considered are developed for shell-side Nusselt number and friction coefficient. (C) 2015 Elsevier Ltd. All rights reserved. | |||||||||||||||
Accession Number: WOS:000362862100105 | |||||||||||||||
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ISSN: 1359-4311 | |||||||||||||||
eISSN: 1873-5606 |
Record 50 of 243 | |||||||||||||||
Title: Tunable photonic nanojet formed by generalized Luneburg lens | |||||||||||||||
Author(s): Mao, XR (Mao, Xiurun); Yang, Y (Yang, Yang); Dai, HT (Dai, Haitao); Luo, D (Luo, Dan); Yao, BL (Yao, Baoli); Yan, SH (Yan, Shaohui) | |||||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 20 Pages: 26426-26433 DOI: 10.1364/OE.23.026426 Published: OCT 5 2015 | |||||||||||||||
Abstract: Nanojet has been emerging as an interesting topic in variety photonics applications. In this paper, inspired by the properties of generalized Luneburg lens (GLLs), a two-dimensional photonic nanojet system has been developed, which focal distance can be tuned by engineering the refractive index profile of GLLs. Simulation and analysis results show that the maximum light intensity, transverse and longitudinal dimensions of the photonic nanojet are dependent on the focal distance of the GLLs, thereby, by simply varying the focal distance, it is possible to obtain localized photon fluxes with different power characteristics and spatial dimensions. This can be of interest for many promising applications, such as high-resolution optical detection, optical manipulation, technology of direct-write nano-patterning and nano-lithography. (C) 2015 Optical Society of America | |||||||||||||||
Accession Number: WOS:000365077900097 | |||||||||||||||
PubMed ID: 26480155 | |||||||||||||||
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ISSN: 1094-4087 |
Record 51 of 243 | ||||||||||||||||||
Title: Nonnegative Multiresolution Representation-Based Texture Image Classification | ||||||||||||||||||
Author(s): Dong, YS (Dong, Yongsheng); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: ACM TRANSACTIONS ON INTELLIGENT SYSTEMS AND TECHNOLOGY Volume: 7 Issue: 1 Article Number: 4 DOI: 10.1145/2738050 Published: OCT 2015 | ||||||||||||||||||
Abstract: Effective representation of image texture is important for an image-classification task. Statistical modelling in wavelet domains has been widely used to image texture representation. However, due to the intraclass complexity and interclass diversity of textures, it is hard to use a predefined probability distribution function to fit adaptively all wavelet subband coefficients of different textures. In this article, we propose a novel modelling approach, Heterogeneous and Incrementally Generated Histogram (HIGH), to indirectly model the wavelet coefficients by use of four local features in wavelet subbands. By concatenating all the HIGHs in all wavelet subbands of a texture, we can construct a nonnegative multiresolution vector (NMV) to represent a texture image. Considering the NMV's high dimensionality and nonnegativity, we further propose a Hessian regularized discriminative nonnegative matrix factorization to compute a low-dimensional basis of the linear subspace of NMVs. Finally, we present a texture classification approach by projecting NMVs on the low-dimensional basis. Experimental results show that our proposed texture classification method outperforms seven representative approaches. | ||||||||||||||||||
Accession Number: WOS:000363900100004 | ||||||||||||||||||
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ISSN: 2157-6904 | ||||||||||||||||||
eISSN: 2157-6912 |
Record 52 of 243 | |||||||||
Title: Investigations on the photoluminescence spectra and its defect-related nature for the ultraviolet transmitting fluoride-containing phosphate-based glasses | |||||||||
Author(s): Feng, DD (Feng, Dandan); He, QL (He, Quanlong); Lu, M (Lu, Min); Li, WN (Li, Weinan); Song, WW (Song, Weiwei); Wang, PF (Wang, Pengfei); Peng, B (Peng, Bo) | |||||||||
Source: JOURNAL OF NON-CRYSTALLINE SOLIDS Volume: 425 Pages: 130-137 DOI: 10.1016/j.jnoncrysol.2015.06.009 Published: OCT 1 2015 | |||||||||
Abstract: Two types of fluoride-containing phosphate-based glasses were prepared under the reducing and ambient air atmosphere, respectively. And the interrelation between the micro-defects and luminescence for these glasses was investigated by studying their absorption, photoluminescence emission (PL) and excitation (PLE) spectra as well as electron spin resonance (ESR) spectra. The emission spectra under the excitation at 351 nm and the excitation spectra by monitoring the emission wavelength at 433 nm, 454 nm, 505 nm, 645 nm and 780 nm, together with the absorption spectra of these two types of glasses were investigated through Gaussian peak fitting method. Their photoluminescence spectra exhibit a general character with a broadband emission at around 430 nm and a minor band at around 645 nm. The photoluminescence excitation spectra and absorption spectra indicate that the Gaussian peak fitting of the emission spectra with the maximum at about 433,455, 505 and 645 nm, respectively, are closely associated with phosphate-related oxygen hole center defects and fluorine-related color centers. In addition, the emission and excitation spectra of the glass samples after the thermal treatment process in hydrogen atmosphere manifest that the reducing conditions promote the formation of phosphate-related oxygen hole center defects, oxygen related hole center defects and fluorine-related non-paramagnetic color centers as well as PO43- defects, while decrease the concentration level of Fe-3 and PO32- defects, The investigations on the glasses' photoluminescence properties and their changes with the glass melting and thermal treatment atmosphere will promote the further development in preparation technology of the fluoride-containing phosphate-based glasses. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||
Accession Number: WOS:000359958700018 | |||||||||
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ISSN: 0022-3093 | |||||||||
eISSN: 1873-4812 |
Record 53 of 243 | ||||||||||||||||||
Title: Learning to Rank for Blind Image Quality Assessment | ||||||||||||||||||
Author(s): Gao, F (Gao, Fei); Tao, DC (Tao, Dacheng); Gao, XB (Gao, Xinbo); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 10 Pages: 2275-2290 DOI: 10.1109/TNNLS.2014.2377181 Published: OCT 2015 | ||||||||||||||||||
Abstract: Blind image quality assessment (BIQA) aims to predict perceptual image quality scores without access to reference images. State-of-the-art BIQA methods typically require subjects to score a large number of images to train a robust model. However, subjective quality scores are imprecise, biased, and inconsistent, and it is challenging to obtain a large-scale database, or to extend existing databases, because of the inconvenience of collecting images, training the subjects, conducting subjective experiments, and realigning human quality evaluations. To combat these limitations, this paper explores and exploits preference image pairs (PIPs) such as the quality of image I-a is better than that of image I-b for training a robust BIQA model. The preference label, representing the relative quality of two images, is generally precise and consistent, and is not sensitive to image content, distortion type, or subject identity; such PIPs can be generated at a very low cost. The proposed BIQA method is one of learning to rank. We first formulate the problem of learning the mapping from the image features to the preference label as one of classification. In particular, we investigate the utilization of a multiple kernel learning algorithm based on group lasso to provide a solution. A simple but effective strategy to estimate perceptual image quality scores is then presented. Experiments show that the proposed BIQA method is highly effective and achieves a performance comparable with that of state-of-the-art BIQA algorithms. Moreover, the proposed method can be easily extended to new distortion categories. | ||||||||||||||||||
Accession Number: WOS:000362358800005 | ||||||||||||||||||
PubMed ID: 25616080 | ||||||||||||||||||
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ISSN: 2162-237X | ||||||||||||||||||
eISSN: 2162-2388 |
Record 54 of 243 |
Title: Nanotube-mode-locked fiber laser delivering dual-wavelength conventional and dissipative solitons |
Author(s): Han, XX (Han, X. X.) |
Source: LASER PHYSICS Volume: 25 Issue: 10 Article Number: 105101 DOI: 10.1088/1054-660X/25/10/105101 Published: OCT 2015 |
Abstract: We propose a novel passively nanotube-mode-locked fiber laser, which consists of a linear oscillator generating conventional solitons (CSs) and a ring oscillator delivering dissipative solitons (DSs) simultaneously. The CSs exhibit distinct spectral sidebands with a bandwidth of similar to 0.53 nm and duration of similar to 5.47 ps, while the DSs have a quasi-rectangular spectral profile with a bandwidth of similar to 11.9 nm. The pulse duration of chirped DSs is similar to 5.30 ps and can be further compressed to similar to 0.55 ps external to the cavity. The experimental observations are well confirmed by numerical results. This compact all-fiber laser delivering two different types of ultrafast soliton simultaneously is quite cost-efficient for practical applications, such as optical communications, nonlinear optics and ultrafast optics. |
Accession Number: WOS:000365350500002 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 55 of 243 | ||||||||||||||||||||||||
Title: Biclustering Learning of Trading Rules | ||||||||||||||||||||||||
Author(s): Huang, QH (Huang, Qinghua); Wang, T (Wang, Ting); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 10 Pages: 2287-2298 DOI: 10.1109/TCYB.2014.2370063 Published: OCT 2015 | ||||||||||||||||||||||||
Abstract: Technical analysis with numerous indicators and patterns has been regarded as important evidence for making trading decisions in financial markets. However, it is extremely difficult for investors to find useful trading rules based on numerous technical indicators. This paper innovatively proposes the use of biclustering mining to discover effective technical trading patterns that contain a combination of indicators from historical financial data series. This is the first attempt to use biclustering algorithm on trading data. The mined patterns are regarded as trading rules and can be classified as three trading actions (i.e., the buy, the sell, and no-action signals) with respect to the maximum support. A modified K nearest neighborhood (K-NN) method is applied to classification of trading days in the testing period. The proposed method [called biclustering algorithm and the K nearest neighbor (BIC-K-NN)] was implemented on four historical datasets and the average performance was compared with the conventional buy-and-hold strategy and three previously reported intelligent trading systems. Experimental results demonstrate that the proposed trading system outperforms its counterparts and will be useful for investment in various financial markets. | ||||||||||||||||||||||||
Accession Number: WOS:000361751900023 | ||||||||||||||||||||||||
PubMed ID: 25494520 | ||||||||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||||||||
eISSN: 2168-2275 |
Record 56 of 243 | |||||||||||||||||||||
Title: A novel visual codebook model based on fuzzy geometry for large-scale image classification | |||||||||||||||||||||
Author(s): Li, YS (Li, Yanshan); Huang, QH (Huang, Qinghua); Xie, WX (Xie, Weixin); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: PATTERN RECOGNITION Volume: 48 Issue: 10 Pages: 3125-3134 DOI: 10.1016/j.patcog.2015.02.010 Published: OCT 2015 | |||||||||||||||||||||
Abstract: The codebook model has been developed as an effective means for image classification. However, the inherent operation of assigning visual words to image feature vectors in traditional codebook approaches causes serious ambiguities in image classification. In particular, the nearest word may not be the best fit to a feature, and multiple words may be equally appropriate for one specific feature. To resolve these ambiguities, we propose a novel visual codebook model based on the n-dimensional fuzzy geometry (n-D FG) theory, where all visual words and features are modeled as fuzzy points in the n-D FG space, and appropriate uncertainty is introduced to each fuzzy point to enhance the representation capacity. This n-D FG-codebook model not only inherits advantages from the fuzzy set theory, but also facilitates the analysis and determination of the relationship between visual words and features in geometric form. By explicitly taking into account the ambiguities, we propose a novel measure of similarity between the visual words and fuzzy features. Following the proposed codebook model and the novel similarity measure, we develop two useful image classification algorithms by modifying popular image coding algorithms (i.e. SPM and LLC). Finally, experimental results demonstrate that the classification accuracy of the proposed algorithms is dramatically improved for a standard large-scale image database. For example, with a codebook size of 256, the proposed algorithms achieve similar performance as traditional algorithms with a codebook size of 1024, indicating that the proposed algorithms reduce the computational cost by 75% while achieving almost identical classification accuracy to traditional algorithms. Thus, the proposed algorithms represent a more efficient and appropriate scheme for big image data. (C) 2015 Elsevier Ltd. All rights reserved. | |||||||||||||||||||||
Accession Number: WOS:000357246100015 | |||||||||||||||||||||
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ISSN: 0031-3203 | |||||||||||||||||||||
eISSN: 1873-5142 |
Record 57 of 243 | |||||||||||||||||||||||||||
Title: Visual Tracking Using Strong Classifier and Structural Local Sparse Descriptors | |||||||||||||||||||||||||||
Author(s): Ma, B (Ma, Bo); Shen, JB (Shen, Jianbing); Liu, YB (Liu, Yangbiao); Hu, HW (Hu, Hongwei); Shao, L (Shao, Ling); Li, XL (Li, Xuelong) | |||||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON MULTIMEDIA Volume: 17 Issue: 10 Pages: 1818-1828 DOI: 10.1109/TMM.2015.2463221 Published: OCT 2015 | |||||||||||||||||||||||||||
Abstract: Sparse coding methods have achieved great success in visual tracking, and we present a strong classifier and structural local sparse descriptors for robust visual tracking. Since the summary features considering the sparse codes are sensitive to occlusion and other interfering factors, we extract local sparse descriptors from a fraction of all patches by performing a pooling operation. The collection of local sparse descriptors is combined into a boosting-based strong classifier for robust visual tracking using a discriminative appearance model. Furthermore, a structural reconstruction error based weight computation method is proposed to adjust the classification score of each candidate for more precise tracking results. To handle appearance changes during tracking, we present an occlusion-aware template update scheme. Comprehensive experimental comparisons with the state-of-the-art algorithms demonstrated the better performance of the proposed method. | |||||||||||||||||||||||||||
Accession Number: WOS:000361685400011 | |||||||||||||||||||||||||||
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ISSN: 1520-9210 | |||||||||||||||||||||||||||
eISSN: 1941-0077 |
Record 58 of 243 | |||||||||||||||
Title: Truncation Error Analysis on Reconstruction of Signal From Unsymmetrical Local Average Sampling | |||||||||||||||
Author(s): Pang, YW (Pang, Yanwei); Song, ZJ (Song, Zhanjie); Li, XL (Li, Xuelong); Pan, J (Pan, Jing) | |||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 10 Pages: 2100-2104 DOI: 10.1109/TCYB.2014.2365513 Published: OCT 2015 | |||||||||||||||
Abstract: The classical Shannon sampling theorem is suitable for reconstructing a band-limited signal from its sampled values taken at regular instances with equal step by using the well-known sinc function. However, due to the inertia of the measurement apparatus, it is impossible to measure the value of a signal precisely at such discrete time. In practice, only unsymmetrically local averages of signal near the regular instances can be measured and used as the inputs for a signal reconstruction method. In addition, when implemented in hardware, the traditional sinc function cannot be directly used for signal reconstruction. We propose using the Taylor expansion of sinc function to reconstruct signal sampled from unsymmetrically local averages and give the upper bound of the reconstruction error (i.e., truncation error). The convergency of the reconstruction method is also presented. | |||||||||||||||
Accession Number: WOS:000361751900007 | |||||||||||||||
PubMed ID: 25415996 | |||||||||||||||
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ISSN: 2168-2267 | |||||||||||||||
eISSN: 2168-2275 |
Record 59 of 243 |
Title: Tubular depressed cladding waveguide laser realized in Yb: YAG by direct inscription of femtosecond laser |
Author(s): Tang, WL (Tang, Wenlong); Zhang, WF (Zhang, Wenfu); Liu, X (Liu, Xin); Liu, S (Liu, Shuang); Stoian, R (Stoian, Razvan); Cheng, GH (Cheng, Guanghua) |
Source: JOURNAL OF OPTICS Volume: 17 Issue: 10 Article Number: 105803 DOI: 10.1088/2040-8978/17/10/105803 Published: OCT 2015 |
Abstract: We report on the fabrication of tubular depressed cladding waveguides in single crystalline Yb: YAG by the direct femtosecond laser writing technique. Full control over the confined light spatial distribution is demonstrated by the photoinscription of high index contrast waveguides with tubular configuration. Under optical pumping, highly efficient laser oscillation in depressed cladding waveguide at 1030 nm is demonstrated. The maximum output power obtained is 68 mW with a slope efficiency of 35% for an outcoupling transmission of 50%. A slope efficiency as high as 44% is realized when the coupling output ratio is 91% and a low lasing threshold of 70 mW is achieved with the output coupling mirror of 10%. |
Accession Number: WOS:000366161700043 |
ISSN: 2040-8978 |
eISSN: 2040-8986 |
Record 60 of 243 | ||||||||||||
Title: Image Pair Analysis With Matrix-Value Operator | ||||||||||||
Author(s): Tang, Y (Tang, Yi); Yuan, Y (Yuan, Yuan) | ||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 10 Pages: 2042-2050 DOI: 10.1109/TCYB.2014.2363882 Published: OCT 2015 | ||||||||||||
Abstract: Image pair analysis provides significant image pair priori which describes the dependency between training image pairs for various learning-based image processing. For avoiding the information loss caused by vectorizing training images, a novel matrix-value operator learning method is proposed for image pair analysis. Sample-dependent operators, named image pair operators (IPOs) by us, are employed to represent the local image-to-image dependency defined by each of the training image pairs. A linear combination of IPOs is learned via operator regression for representing the global dependency between input and output images defined by all of the training image pairs. The proposed operator learning method enjoys the image-level information of training image pairs because IPOs enable training images to be used without vectorizing during the learning and testing process. By applying the proposed algorithm in learning-based super-resolution, the efficiency and the effectiveness of the proposed algorithm in learning image pair information is verified by experimental results. | ||||||||||||
Accession Number: WOS:000361751900002 | ||||||||||||
PubMed ID: 25616089 | ||||||||||||
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ISSN: 2168-2267 | ||||||||||||
eISSN: 2168-2275 |
Record 61 of 243 | ||||||||||||
Title: Scene Recognition by Manifold Regularized Deep Learning Architecture | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Mou, LC (Mou, Lichao); Lu, XQ (Lu, Xiaoqiang) | ||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 10 Pages: 2222-2233 DOI: 10.1109/TNNLS.2014.2359471 Published: OCT 2015 | ||||||||||||
Abstract: Scene recognition is an important problem in the field of computer vision, because it helps to narrow the gap between the computer and the human beings on scene understanding. Semantic modeling is a popular technique used to fill the semantic gap in scene recognition. However, most of the semantic modeling approaches learn shallow, one-layer representations for scene recognition, while ignoring the structural information related between images, often resulting in poor performance. Modeled after our own human visual system, as it is intended to inherit humanlike judgment, a manifold regularized deep architecture is proposed for scene recognition. The proposed deep architecture exploits the structural information of the data, making for a mapping between visible layer and hidden layer. By the proposed approach, a deep architecture could be designed to learn the high-level features for scene recognition in an unsupervised fashion. Experiments on standard data sets show that our method outperforms the state-of-the-art used for scene recognition. | ||||||||||||
Accession Number: WOS:000362358800001 | ||||||||||||
PubMed ID: 25622326 | ||||||||||||
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ISSN: 2162-237X | ||||||||||||
eISSN: 2162-2388 |
Record 62 of 243 | ||||||||||||
Title: High peak power sub-nanosecond mode-locked pulse characteristics of Nd:GGG laser | ||||||||||||
Author(s): Zhao, J (Zhao, Jia); Zhao, SZ (Zhao, Shengzhi); Li, T (Li, Tao); Li, YF (Li, Yufei); Yang, KJ (Yang, Kejian); Li, GQ (Li, Guiqiu); Li, DC (Li, Dechun); Qiao, WC (Qiao, Wenchao); Feng, CS (Feng, Chuansheng); Wang, YG (Wang, Yonggang) | ||||||||||||
Source: OPTICS AND LASER TECHNOLOGY Volume: 73 Pages: 162-165 DOI: 10.1016/j.optlastec.2015.04.025 Published: OCT 2015 | ||||||||||||
Abstract: Based on the dual-loss modulation, i.e. electro-optic (E0) modulator and GaAs saturable absorber, a sub-nanosecond mode-locked pulsed Nd:GGG laser with kHz repetition rates is presented for the first time. The repetition rate (0.5-10 kHz) of this pulsed laser is controlled by the modulation rate of EO modulator, so high stability can be obtained. The sub-nanosecond pulse width depends on the mode-locked pulse underneath the Q-switched envelope in the Q-switched mode-locked (QML) laser and high peak power can be generated. The condition on the generation of sub-nanosecond pulse and the needed threshold power for different modulation rates of EO are given. The average output power, the pulse width and the peak power versus pump power for different repetition rates are demonstrated. The shortest pulse width is 426 ps and the highest peak power reaches 239.4 kW. The experimental results show that the dual-loss modulation technology with EO and GaAs saturable absorber in QML laser is an efficient method to generate sub-nanosecond mode-locked pulsed laser with kHz repetition rates. (C) 2015 Elsevier Ltd. All rights reserved. | ||||||||||||
Accession Number: WOS:000357225400026 | ||||||||||||
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ISSN: 0030-3992 | ||||||||||||
eISSN: 1879-2545 |
Record 63 of 243 | |||||||||||||||||||||||||||
Title: Full-color structured illumination optical sectioning microscopy | |||||||||||||||||||||||||||
Author(s): Qian, J (Qian, Jia); Lei, M (Lei, Ming); Dan, D (Dan, Dan); Yao, BL (Yao, Baoli); Zhou, X (Zhou, Xing); Yang, YL (Yang, Yanlong); Yan, SH (Yan, Shaohui); Min, JW (Min, Junwei); Yu, XH (Yu, Xianghua) | |||||||||||||||||||||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 14513 DOI: 10.1038/srep14513 Published: SEP 29 2015 | |||||||||||||||||||||||||||
Abstract: In merits of super-resolved resolution and fast speed of three-dimensional (3D) optical sectioning capability, structured illumination microscopy (SIM) has found variety of applications in biomedical imaging. So far, most SIM systems use monochrome CCD or CMOS cameras to acquire images and discard the natural color information of the specimens. Although multicolor integration scheme are employed, multiple excitation sources and detectors are required and the spectral information is limited to a few of wavelengths. Here, we report a new method for full-color SIM with a color digital camera. A data processing algorithm based on HSV (Hue, Saturation, and Value) color space is proposed, in which the recorded color raw images are processed in the Hue, Saturation, Value color channels, and then reconstructed to a 3D image with full color. We demonstrated some 3D optical sectioning results on samples such as mixed pollen grains, insects, micro-chips and the surface of coins. The presented technique is applicable to some circumstance where color information plays crucial roles, such as in materials science and surface morphology. | |||||||||||||||||||||||||||
Accession Number: WOS:000361878800002 | |||||||||||||||||||||||||||
PubMed ID: 26415516 | |||||||||||||||||||||||||||
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ISSN: 2045-2322 |
Record 64 of 243 | ||||||||||||||||||||||||
Title: Evolutionary compact embedding for large-scale image classification | ||||||||||||||||||||||||
Author(s): Liu, L (Liu, Li); Shao, L (Shao, Ling); Li, XL (Li, Xuelong) | ||||||||||||||||||||||||
Source: INFORMATION SCIENCES Volume: 316 Pages: 567-581 DOI: 10.1016/j.ins.2014.06.030 Published: SEP 20 2015 | ||||||||||||||||||||||||
Abstract: Effective dimensionality reduction is a classical research area for many large-scale analysis tasks in computer vision. Several recent methods attempt to learn either graph embedding or binary hashing for fast and accurate applications. In this paper, we propose a novel framework to automatically learn the task-specific compact coding, called evolutionary compact embedding (ECE), which can be regarded as an optimization algorithm combining genetic programming (GP) and a boosting trick. As an evolutionary computation methodology, GP can solve problems inspired by natural evolution without any prior knowledge of the solutions. In our evolutionary architecture, each bit of ECE is iteratively computed using a binary classification function, which is generated through GP evolving by jointly minimizing its empirical risk with the AdaBoost strategy on a training set. We address this as greedy optimization leading to small Hamming distances for similar samples and large distances for dissimilar samples. We then evaluate ECE on four image datasets: USPS digital hand-writing, CMU PIE face, CIFAR-10 tiny image and SUN397 scene, showing the accurate and robust performance of our method for large-scale image classification. (C) 2014 Elsevier Inc. All rights reserved. | ||||||||||||||||||||||||
Accession Number: WOS:000356732600032 | ||||||||||||||||||||||||
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ISSN: 0020-0255 | ||||||||||||||||||||||||
eISSN: 1872-6291 |
Record 65 of 243 | |||||||||||||||||||||||||||
Title: In situ optical measurements of Chang'E-3 landing site in Mare Imbrium: 1. Mineral abundances inferred from spectral reflectance | |||||||||||||||||||||||||||
Author(s): Zhang, H (Zhang, Hao); Yang, YZ (Yang, Yazhou); Yuan, Y (Yuan, Ye); Jin, WD (Jin, Weidong); Lucey, PG (Lucey, Paul G.); Zhu, MH (Zhu, Meng-Hua); Kaydash, VG (Kaydash, Vadim G.); Shkuratov, YG (Shkuratov, Yuriy G.); Di, KC (Di, Kaichang); Wan, WH (Wan, Wenhui); Xu, B (Xu, Bin); Xiao, L (Xiao, Long); Wang, ZW (Wang, Ziwei); Xue, B (Xue, Bin) | |||||||||||||||||||||||||||
Source: GEOPHYSICAL RESEARCH LETTERS Volume: 42 Issue: 17 Pages: 6945-6950 DOI: 10.1002/2015GL065273 Published: SEP 16 2015 | |||||||||||||||||||||||||||
Abstract: The visible and near-infrared imaging spectrometer on board the Yutu Rover of Chinese Chang'E-3 mission measured the lunar surface reflectance at a close distance (similar to 1m) and collected four spectra at four different sites. These in situ lunar spectra have revealed less mature features than that measured remotely by spaceborne sensors such as the Moon Mineralogy Mapper instrument on board the Chandrayaan-1 mission and the Spectral Profiler on board the Kaguya over the same region. Mineral composition analysis using a spectral lookup table populated with a radiative transfer mixing model has shown that the regolith at the landing site contains high abundance of olivine. Themineral abundance results are consistent with that inferred from the compound measurement made by the on board alpha-particle X-ray spectrometer. | |||||||||||||||||||||||||||
Accession Number: WOS:000363411200010 | |||||||||||||||||||||||||||
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ISSN: 0094-8276 | |||||||||||||||||||||||||||
eISSN: 1944-8007 |
Record 66 of 243 | |||||||||||||||||||||||||||||||||
Title: Hybrid tilted fiber grating based refractive index and liquid level sensing system | |||||||||||||||||||||||||||||||||
Author(s): Yan, ZJ (Yan, Zhijun); Mou, CB (Mou, Chengbo); Sun, ZY (Sun, Zhongyuan); Zhou, KM (Zhou, Kaimin); Wang, HS (Wang, Hushan); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Zhang, L (Zhang, Lin) | |||||||||||||||||||||||||||||||||
Source: OPTICS COMMUNICATIONS Volume: 351 Pages: 144-148 DOI: 10.1016/j.optcom.2015.04.038 Published: SEP 15 2015 | |||||||||||||||||||||||||||||||||
Abstract: We report a refractive index (RI) and liquid level sensing system based on a hybrid grating structure comprising of a 45 and an 81 tilted fiber gratings (TFGs) that have been inscribed into a single mode fiber in series. In this structure, the 45 degrees-TFG is used as a polarizer to filter out the transverse electric (TE) component and enable the 81 degrees-TFG operating at single polarization for RI and level sensing. The experiment results show a lower temperature cross-sensitivity, only about 7.33 pm/degrees C, and a higher RI sensitivity, being around 180 nm/RIU at RI=1345 and 926 nm/RIU at RI=1.412 region, which are significantly improved in comparison with long period fiber gratings. The hybrid grating structure has also been applied as a liquid level sensor, showing 3.06 dB/mm linear peak ratio sensitivity. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||||||||||||||||||||
Accession Number: WOS:000357552200024 | |||||||||||||||||||||||||||||||||
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ISSN: 0030-4018 | |||||||||||||||||||||||||||||||||
eISSN: 1873-0310 |
Record 67 of 243 | |||||||||||||||||||||
Title: Learning a Nonnegative Sparse Graph for Linear Regression | |||||||||||||||||||||
Author(s): Fang, XZ (Fang, Xiaozhao); Xu, Y (Xu, Yong); Li, XL (Li, Xuelong); Lai, ZH (Lai, Zhihui); Wong, WK (Wong, Wai Keung) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON IMAGE PROCESSING Volume: 24 Issue: 9 Pages: 2760-2771 DOI: 10.1109/TIP.2015.2425545 Published: SEP 2015 | |||||||||||||||||||||
Abstract: Previous graph-based semisupervised learning (G-SSL) methods have the following drawbacks: 1) they usually predefine the graph structure and then use it to perform label prediction, which cannot guarantee an overall optimum and 2) they only focus on the label prediction or the graph structure construction but are not competent in handling new samples. To this end, a novel nonnegative sparse graph (NNSG) learning method was first proposed. Then, both the label prediction and projection learning were integrated into linear regression. Finally, the linear regression and graph structure learning were unified within the same framework to overcome these two drawbacks. Therefore, a novel method, named learning a NNSG for linear regression was presented, in which the linear regression and graph learning were simultaneously performed to guarantee an overall optimum. In the learning process, the label information can be accurately propagated via the graph structure so that the linear regression can learn a discriminative projection to better fit sample labels and accurately classify new samples. An effective algorithm was designed to solve the corresponding optimization problem with fast convergence. Furthermore, NNSG provides a unified perceptiveness for a number of graph-based learning methods and linear regression methods. The experimental results showed that NNSG can obtain very high classification accuracy and greatly outperforms conventional G-SSL methods, especially some conventional graph construction methods. | |||||||||||||||||||||
Accession Number: WOS:000355760300001 | |||||||||||||||||||||
PubMed ID: 25910093 | |||||||||||||||||||||
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ISSN: 1057-7149 | |||||||||||||||||||||
eISSN: 1941-0042 |
Record 68 of 243 | |||||||||||||||||||||
Title: Toward an SDN-Enabled Big Data Platform for Social TV Analytics | |||||||||||||||||||||
Author(s): Hu, H (Hu, Han); Wen, YG (Wen, Yonggang); Gao, Y (Gao, Yue); Chua, TS (Chua, Tat-Seng); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE NETWORK Volume: 29 Issue: 5 Pages: 43-49 Published: SEP-OCT 2015 | |||||||||||||||||||||
Abstract: The TV experience is being transformed with online social networks. TV audiences are sharing their opinions (i.e., social response) about video programs on OSNs (e.g., Twitter and Sina Weibo), thus providing a great opportunity for mining these data for stakeholders in TV value chains. This new paradigm is touted as social TV analytics, integrating the emerging big data research into TV. In this article, we envision and develop a unified big data platform for social TV analytics, extracting valuable insights from TV social response in a real-time manner. Such a platform presents tremendous challenges in networking architecture for our big data platform. We propose to build a cloud-centric platform with SDN support, providing on-demand virtual machines and reconfigurable networks. The architecture of our system consists of three key components, including a robust data crawler system, an SDN-enabled big data processing system, and a social media analytics system. The data crawler system adopts a distributed architecture to circumvent the access constraints of OSNs to crawl sufficient data about each TV program of interest; the SDN-enabled big data processing system integrates SDN and Hadoop, and exploits the SDN benefit to transfer intermediate data between different processing units to accelerate the data processing rate; and the social media analytics system extracts the public perception and knowledge related to TV programs based on microblog data. We have built a proof-of-concept demo over a private cloud at Nanyang Technological University. Feature verification and performance comparisons demonstrate the feasibility and effectiveness of the system. | |||||||||||||||||||||
Accession Number: WOS:000362910400010 | |||||||||||||||||||||
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ISSN: 0890-8044 | |||||||||||||||||||||
eISSN: 1558-156X |
Record 69 of 243 | |||||||||||||||||||||||||||
Title: Automatic segmentation of breast lesions for interaction in ultrasonic computer-aided diagnosis | |||||||||||||||||||||||||||
Author(s): Huang, QH (Huang, Qinghua); Yang, FB (Yang, Feibin); Liu, LZ (Liu, Longzhong); Li, XL (Li, Xuelong) | |||||||||||||||||||||||||||
Source: INFORMATION SCIENCES Volume: 314 Pages: 293-310 DOI: 10.1016/j.ins.2014.08.021 Published: SEP 1 2015 | |||||||||||||||||||||||||||
Abstract: Breast cancer is one of the most commonly diagnosed cancer types among women. Sonography has been regarded as an important imaging modality for diagnosis of breast lesions. Due to the speckle and the variance in shape and appearance of sonographic lesions, fully automatic segmentation of the breast tumor regions still remains a challenging task. In this paper, we propose an automatic interaction scheme based on an object recognition method to segment the lesions in breast ultrasound images. In this scheme, a 2D ultrasound image is firstly filtered with a total-variation model to reduce the speckle noise. A robust graphbased segmentation method is then used to segment the image into a number of subregions. An object recognition method incorporating the procedures of image feature extraction, feature selection and classification is proposed to automatically identify the regions which are associated with breast tumors. Finally, an active contour model is used to refine the contours of the regions that are recognized as tumors. This scheme is validated on a database of 46 breast ultrasound images with diagnosed tumors. The experimental results show that our scheme can segment the breast ultrasound images automatically, indicating its good performance in real applitations. (C) 2014 Elsevier Inc. All rights reserved. | |||||||||||||||||||||||||||
Accession Number: WOS:000355050200019 | |||||||||||||||||||||||||||
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ISSN: 0020-0255 | |||||||||||||||||||||||||||
eISSN: 1872-6291 |
Record 70 of 243 | |||||||||||||||
Title: Scene Parsing From an MAP Perspective | |||||||||||||||
Author(s): Li, XL (Li, Xuelong); Mou, LC (Mou, Lichao); Lu, XQ (Lu, Xiaoqiang) | |||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 9 Pages: 1876-1886 DOI: 10.1109/TCYB.2014.2361489 Published: SEP 2015 | |||||||||||||||
Abstract: Scene parsing is an important problem in the field of computer vision. Though many existing scene parsing approaches have obtained encouraging results, they fail to overcome within-category inconsistency and intercategory similarity of superpixels. To reduce the aforementioned problem, a novel method is proposed in this paper. The proposed approach consists of three main steps: 1) posterior category probability density function (PDF) is learned by an efficient low-rank representation classifier (LRRC); 2) prior contextual constraint PDF on the map of pixel categories is learned by Markov random fields; and 3) final parsing results are yielded up to the maximum a posterior process based on the two learned PDFs. In this case, the nature of being both dense for within-category affinities and almost zeros for intercategory affinities is integrated into our approach by using LRRC to model the posterior category PDF. Meanwhile, the contextual priori generated by modeling the prior contextual constraint PDF helps to promote the performance of scene parsing. Experiments on benchmark datasets show that the proposed approach outperforms the state-of-the-art approaches for scene parsing. | |||||||||||||||
Accession Number: WOS:000360019000014 | |||||||||||||||
PubMed ID: 25376051 | |||||||||||||||
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ISSN: 2168-2267 | |||||||||||||||
eISSN: 2168-2275 |
Record 71 of 243 | ||||||||||||
Title: A Robust Gradient-Based Algorithm to Correct Bias Fields of Brain MR Images | ||||||||||||
Author(s): Ling, Q (Ling, Qiang); Li, ZH (Li, Zhaohui); Huang, QH (Huang, Qinghua); Liu, XL (Liu, Xuelong) | ||||||||||||
Source: IEEE TRANSACTIONS ON AUTONOMOUS MENTAL DEVELOPMENT Volume: 7 Issue: 3 Special Issue: SI Pages: 256-264 DOI: 10.1109/TAMD.2015.2416976 Published: SEP 2015 | ||||||||||||
Abstract: We developed a novel algorithm to estimate bias fields from brain magnetic resonance (MR) images using a gradient-based method. The bias field is modeled as a multiplicative and slowly varying surface. We fit the bias field by a low-order polynomial. The polynomial's parameters are directly obtained by minimizing the sum of square errors between the gradients of MR images (both in the x-direction and y-direction) and the partial derivatives of the desired polynomial in the log domain. Compared to the existing retrospective algorithms, our algorithm combines the estimation of the gradient of the bias field and the reintegration of the obtained gradient polynomial together so that it is more robust against noise and can achieve better performance, which are demonstrated through experiments with both real and simulated brain MR images. | ||||||||||||
Accession Number: WOS:000364875000011 | ||||||||||||
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ISSN: 1943-0604 | ||||||||||||
eISSN: 1943-0612 |
Record 72 of 243 | |||||||||||||||||||||
Title: Large-Scale Unsupervised Hashing with Shared Structure Learning | |||||||||||||||||||||
Author(s): Liu, XL (Liu, Xianglong); Mu, YD (Mu, Yadong); Zhang, DC (Zhang, Danchen); Lang, B (Lang, Bo); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 9 Pages: 1811-1822 DOI: 10.1109/TCYB.2014.2360856 Published: SEP 2015 | |||||||||||||||||||||
Abstract: Hashing methods are effective in generating compact binary signatures for images and videos. This paper addresses an important open issue in the literature, i.e., how to learn compact hash codes by enhancing the complementarity among different hash functions. Most of prior studies solve this problem either by adopting time-consuming sequential learning algorithms or by generating the hash functions which are subject to some deliberately-designed constraints (e.g., enforcing hash functions orthogonal to one another). We analyze the drawbacks of past works and propose a new solution to this problem. Our idea is to decompose the feature space into a subspace shared by all hash functions and its complementary subspace. On one hand, the shared subspace, corresponding to the common structure across different hash functions, conveys most relevant information for the hashing task. Similar to data de-noising, irrelevant information is explicitly suppressed during hash function generation. On the other hand, in case that the complementary subspace also contains useful information for specific hash functions, the final form of our proposed hashing scheme is a compromise between these two kinds of subspaces. To make hash functions not only preserve the local neighborhood structure but also capture the global cluster distribution of the whole data, an objective function incorporating spectral embedding loss, binary quantization loss, and shared subspace contribution is introduced to guide the hash function learning. We propose an efficient alternating optimization method to simultaneously learn both the shared structure and the hash functions. Experimental results on three well-known benchmarks CIFAR-10, NUS-WIDE, and a-TRECVID demonstrate that our approach significantly outperforms state-of-the-art hashing methods. | |||||||||||||||||||||
Accession Number: WOS:000360019000009 | |||||||||||||||||||||
PubMed ID: 25420275 | |||||||||||||||||||||
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ISSN: 2168-2267 | |||||||||||||||||||||
eISSN: 2168-2275 |
Record 73 of 243 | |||||||||||||||
Title: Semi-Supervised Multitask Learning for Scene Recognition | |||||||||||||||
Author(s): Lu, XQ (Lu, Xiaoqiang); Li, XL (Li, Xuelong); Mou, LC (Mou, Lichao) | |||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 9 Pages: 1967-1976 DOI: 10.1109/TCYB.2014.2362959 Published: SEP 2015 | |||||||||||||||
Abstract: Scene recognition has been widely studied to understand visual information from the level of objects and their relationships. Toward scene recognition, many methods have been proposed. They, however, encounter difficulty to improve the accuracy, mainly due to two limitations: 1) lack of analysis of intrinsic relationships across different scales, say, the initial input and its down-sampled versions and 2) existence of redundant features. This paper develops a semi-supervised learning mechanism to reduce the above two limitations. To address the first limitation, we propose a multitask model to integrate scene images of different resolutions. For the second limitation, we build a model of sparse feature selection-based manifold regularization (SFSMR) to select the optimal information and preserve the underlying manifold structure of data. SFSMR coordinates the advantages of sparse feature selection and manifold regulation. Finally, we link the multitask model and SFSMR, and propose the semi-supervised learning method to reduce the two limitations. Experimental results report the improvements of the accuracy in scene recognition. | |||||||||||||||
Accession Number: WOS:000360019000021 | |||||||||||||||
PubMed ID: 25423664 | |||||||||||||||
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ISSN: 2168-2267 | |||||||||||||||
eISSN: 2168-2275 |
Record 74 of 243 | ||||||||||||||||||||||||
Title: Dual-loss-modulated passively Q-switched Tm:LuAG laser with multi-walled carbon nanotube and monolayer graphene | ||||||||||||||||||||||||
Author(s): Luan, C (Luan, C.); Yang, KJ (Yang, K. J.); Zhao, J (Zhao, J.); Zhao, SZ (Zhao, S. Z.); Li, GQ (Li, G. Q.); Li, DC (Li, D. C.); Li, T (Li, T.); Qiao, WC (Qiao, W. C.); Zheng, LH (Zheng, L. H.); Xu, J (Xu, J.); Wang, QG (Wang, Q. G.); Xu, XD (Xu, X. D.); Su, LB (Su, L. B.); Wang, YG (Wang, Y. G.) | ||||||||||||||||||||||||
Source: APPLIED PHYSICS B-LASERS AND OPTICS Volume: 120 Issue: 4 Pages: 759-763 DOI: 10.1007/s00340-015-6193-y Published: SEP 2015 | ||||||||||||||||||||||||
Abstract: By simultaneously using a multi-walled carbon nanotube (MWCNT) and a monolayer graphene saturable absorber (SA) in the cavity, a laser-diode-pumped dual-loss-modulated passively Q-switched Tm:LuAG laser at 2 mu m is demonstrated for the first time. In comparison with the singly passively Q-switched laser with MWCNT or monolayer graphene SA, the doubly passively Q-switched laser with both MWCNT and monolayer graphene SA can generate shorter pulse width and higher peak power. A maximum pulse width compression ratio of 2.8 and a highest peak power enhancement factor of 4 were obtained at the incident pump power of 5.8 W, respectively. The experimental results show that the dual-loss modulation is an efficient method to compress the pulse widths and improve the peak powers of the Q-switched lasers at 2 mu m. | ||||||||||||||||||||||||
Accession Number: WOS:000359814800023 | ||||||||||||||||||||||||
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ISSN: 0946-2171 | ||||||||||||||||||||||||
eISSN: 1432-0649 |
Record 75 of 243 | ||||||||||||||||||||||||||||||||||||||||||
Title: Cross-polarized photon-pair generation and bi-chromatically pumped optical parametric oscillation on a chip | ||||||||||||||||||||||||||||||||||||||||||
Author(s): Reimer, C (Reimer, Christian); Kues, M (Kues, Michael); Caspani, L (Caspani, Lucia); Wetzel, B (Wetzel, Benjamin); Roztocki, P (Roztocki, Piotr); Clerici, M (Clerici, Matteo); Jestin, Y (Jestin, Yoann); Ferrera, M (Ferrera, Marcello); Peccianti, M (Peccianti, Marco); Pasquazi, A (Pasquazi, Alessia); Little, BE (Little, Brent E.); Chu, ST (Chu, Sai T.); Moss, DJ (Moss, David J.); Morandotti, R (Morandotti, Roberto) | ||||||||||||||||||||||||||||||||||||||||||
Source: NATURE COMMUNICATIONS Volume: 6 Article Number: 8236 DOI: 10.1038/ncomms9236 Published: SEP 2015 | ||||||||||||||||||||||||||||||||||||||||||
Abstract: Nonlinear optical processes are one of the most important tools in modern optics with a broad spectrum of applications in, for example, frequency conversion, spectroscopy, signal processing and quantum optics. For practical and ultimately widespread implementation, on-chip devices compatible with electronic integrated circuit technology offer great advantages in terms of low cost, small footprint, high performance and low energy consumption. While many on-chip key components have been realized, to date polarization has not been fully exploited as a degree of freedom for integrated nonlinear devices. In particular, frequency conversion based on orthogonally polarized beams has not yet been demonstrated on chip. Here we show frequency mixing between orthogonal polarization modes in a compact integrated microring resonator and demonstrate a bi-chromatically pumped optical parametric oscillator. Operating the device above and below threshold, we directly generate orthogonally polarized beams, as well as photon pairs, respectively, that can find applications, for example, in optical communication and quantum optics. | ||||||||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000363017500007 | ||||||||||||||||||||||||||||||||||||||||||
PubMed ID: 26364999 | ||||||||||||||||||||||||||||||||||||||||||
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ISSN: 2041-1723 |
Record 76 of 243 |
Title: RELATIVE ORIENTATION DEPENDENT ON DUAL QUATERNIONS |
Author(s): Sheng, QH (Sheng, Qing H.); Shao, S (Shao, Sa); Xiao, H (Xiao, Hui); Zhu, F (Zhu, Feng); Wang, Q (Wang, Qing); Zhang, B (Zhang, Bin) |
Source: PHOTOGRAMMETRIC RECORD Volume: 30 Issue: 151 Pages: 300-317 DOI: 10.1111/phor.12111 Published: SEP 2015 |
Abstract: A new approach to relative orientation based on dual quaternions is proposed. Dual quaternions are used to express a unified description of the relative position and orientation of two images in a stereopair. The coplanarity condition equation and its linearised model based on dual quaternions are established. According to the principle of least squares adjustment with constraints, a dual quaternion can be identified and the relative-orientation parameters can then be obtained by a nonlinear transformation of the components of the dual quaternion. Experimental results show that the proposed approach is feasible and more reliable and efficient than the conventional approach based on Euler angles. |
Accession Number: WOS:000366837800004 |
ISSN: 0031-868X |
eISSN: 1477-9730 |
Record 77 of 243 | |||||||||||||||
Title: High-energy pulse generation using Yb-doped Q-switched fiber laser based on single-walled carbon nanotubes | |||||||||||||||
Author(s): Wang, JL (Wang Jun-Li); Wang, XL (Wang Xue-Ling); He, BR (He Bo-Rong); Zhu, JF (Zhu Jiang-Feng); Wei, ZY (Wei Zhi-Yi); Wang, YG (Wang Yong-Gang) | |||||||||||||||
Source: CHINESE PHYSICS B Volume: 24 Issue: 9 Article Number: 097601 DOI: 10.1088/1674-1056/24/9/097601 Published: SEP 2015 | |||||||||||||||
Abstract: An all-fiber laser using a single-walled carbon nanotube (SWCNT) as the saturable absorber (SA) for Q-switched operation in the 1031 nm region is demonstrated in this work. A lasing threshold as low as 17 mW was realized for continuous wave operation. By further increasing the pump power, stable Q-switched pulse trains are obtained when the pump power ranges from 38 mW to 125 mW, corresponding to repetition rate varying from 40.84 kHz to 66.24 kHz, the pulse width from 2.0 mu s to 1.0 mu s, and the highest single pulse energy of 40.6 nJ respectively. | |||||||||||||||
Accession Number: WOS:000363325200089 | |||||||||||||||
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ISSN: 1674-1056 | |||||||||||||||
eISSN: 1741-4199 |
Record 78 of 243 | ||||||
Title: Enhanced slow light in microfiber double-knot resonator with a Sagnac loop reflector | ||||||
Author(s): Xu, YP (Xu, Yiping); Ren, LY (Ren, Liyong); Wang, YL (Wang, Yingli); Kong, XD (Kong, Xudong); Liang, J (Liang, Jian); Ren, KL (Ren, Kaili); Lin, X (Lin, Xiao) | ||||||
Source: OPTICS COMMUNICATIONS Volume: 350 Pages: 148-153 DOI: 10.1016/j.optcom.2015.04.027 Published: SEP 1 2015 | ||||||
Abstract: We propose a theoretical model to describe the light-propagation property of the microfiber double-knot resonator with a Sagnac loop reflector. The mathematical relationships between the reflection light field and the input one of this structure are deduced. Numerical simulations indicate that, comparing with the group time delay in the microfiber double-knot resonator, the one in the same resonator but with a Sagnac loop reflector can be enhanced considerably. For comparison, microfiber double-knot resonators with and without a Sagnac loop reflector are both fabricated. Corresponding comparison experiments are performed, which indeed demonstrates the theoretical prediction. A group time delay of about 61 ps is achieved experimentally in the resonator with a Sagnac loop reflector, while in the same resonator but without a Sagnac loop reflector it is only about 30 ps. (C) 2015 Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000357552000023 | ||||||
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ISSN: 0030-4018 | ||||||
eISSN: 1873-0310 |
Record 79 of 243 | ||||||||||||
Title: MR image super-resolution via manifold regularized sparse learning | ||||||||||||
Author(s): Lu, XQ (Lu, Xiaoqiang); Huang, ZH (Huang, Zihan); Yuan, Y (Yuan, Yuan) | ||||||||||||
Source: NEUROCOMPUTING Volume: 162 Pages: 96-104 DOI: 10.1016/j.neucom.2015.03.065 Published: AUG 25 2015 | ||||||||||||
Abstract: Single image super-resolution (SR) has been shown useful in Magnetic Resonance (MR) image based diagnosis, where the image resolution is still limited. The basic goal of single image SR is to produce a high-resolution (HR) image from corresponding low-resolution (LR) image. However, most existing SR algorithms often fail to: (1) reflect the intrinsic structure between MR images and (2) exploit the intra-patient information of MR images. In fact, MR images are more likely to vary along a low dimensional submanifold, which can be embedded in the high dimensional space. It has also been shown that the structure information of MR images and the priors of the MR images of different modality are important for improving the image resolution. To take full advantage of manifold structure information and intra-patient prior of MR images, a novel single image super-resolution algorithm for MR images is proposed in this paper. Compared with the existing works, the proposed algorithm has the following merits: (1) the proposed sparse coding based algorithm integrates manifold constraints to handle the inverse problem in MR image SR; (2) the manifold structure of the intra-patient MR image is considered for image SR; and (3) the topological structure of the intra-patient MR image can be preserved to improve the reconstructed result. Experiments show that the proposed algorithm is more effective than the state-of-the-art algorithms. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||
Accession Number: WOS:000356125200010 | ||||||||||||
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ISSN: 0925-2312 | ||||||||||||
eISSN: 1872-8286 |
Record 80 of 243 | ||||||||||||||||||||||||
Title: Integrated frequency comb source based Hilbert transformer for wideband microwave photonic phase analysis | ||||||||||||||||||||||||
Author(s): Nguyen, TG (Nguyen, Thach G.); Shoeiby, M (Shoeiby, Mehrdad); Chu, ST (Chu, Sai T.); Little, BE (Little, Brent E.); Morandotti, R (Morandotti, Roberto); Mitchell, A (Mitchell, Arnan); Moss, DJ (Moss, David J.) | ||||||||||||||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 17 Pages: 22087-22097 DOI: 10.1364/OE.23.022087 Published: AUG 24 2015 | ||||||||||||||||||||||||
Abstract: We demonstrate a photonic RF Hilbert transformer for broadband microwave in-phase and quadrature-phase generation based on an integrated frequency optical comb, generated using a nonlinear microring resonator based on a CMOS compatible, high-index contrast, doped-silica glass platform. The high quality and large frequency spacing of the comb enables filters with up to 20 taps, allowing us to demonstrate a quadrature filter with more than a 5-octave (3 dB) bandwidth and an almost uniform phase response. (C) 2015 Optical Society of America | ||||||||||||||||||||||||
Accession Number: WOS:000362418300048 | ||||||||||||||||||||||||
PubMed ID: 26368182 | ||||||||||||||||||||||||
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ISSN: 1094-4087 |
Record 81 of 243 | ||||||||||||||||||||||||
Title: Observation and interpretation of energy efficient, diffuse direct current glow discharge at atmospheric pressure | ||||||||||||||||||||||||
Author(s): Tang, J (Tang, Jie); Jiang, WM (Jiang, Weiman); Li, J (Li, Jing); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Duan, YX (Duan, Yixiang) | ||||||||||||||||||||||||
Source: APPLIED PHYSICS LETTERS Volume: 107 Issue: 8 Article Number: 083505 DOI: 10.1063/1.4929606 Published: AUG 24 2015 | ||||||||||||||||||||||||
Abstract: A diffuse direct-current glow discharge was realized with low energy consumption and high energy utilization efficiency at atmospheric pressure. The formation of diffuse discharge was demonstrated by examining and comparing the electrical properties and optical emissions of plasmas. In combination with theoretical derivation and calculation, we draw guidelines that appearance of nitrogen ions at low electron density is crucial to enhance the ambipolar diffusion for the expansion of discharge channel and the increasing ambipolar diffusion near the cathode plays a key role in the onset of diffuse discharge. An individual-discharge-channel expansion model is proposed to explain the diffuse discharge formation. (C) 2015 AIP Publishing LLC. | ||||||||||||||||||||||||
Accession Number: WOS:000360593900072 | ||||||||||||||||||||||||
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ISSN: 0003-6951 | ||||||||||||||||||||||||
eISSN: 1077-3118 |
Record 82 of 243 | |||||||||
Title: Curved optical tubes in a 4Pi focusing system | |||||||||
Author(s): Yan, SH (Yan, Shaohui); Yu, XH (Yu, Xianghua); Li, MM (Li, Manman); Yao, BL (Yao, Baoli) | |||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 17 Pages: 22890-22897 DOI: 10.1364/OE.23.022890 Published: AUG 24 2015 | |||||||||
Abstract: We demonstrate the possibility of creating curved optical tubes in a 4Pi focusing system. The focal fields of such optical tubes have interesting properties: the energy is concentered in the neighborhood of a prescribed three-dimensional (3D) curve while the cross section is of hollow shape. The creation of these optical tubes is based on the annular focal spot of a vortex beam, which is employed as a building block. An optical tube is thus obtained by covering the central-axis curve of the tube by various such building blocks. Each building block has a certain orientation and position, realized by a rotation plus a certain translation. The spatial spectrum (the input field as well) of the optical tube is obtained by linearly superposing the spectrum of each transformed building block. The curve is rather arbitrary. Three examples of optical tubes: a torus, a solenoid and a trefoil knot are given, showing a good agreement with the expected results. (C) 2015 Optical Society of America | |||||||||
Accession Number: WOS:000362418300122 | |||||||||
PubMed ID: 26368256 | |||||||||
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ISSN: 1094-4087 |
Record 83 of 243 | ||||||||||||
Title: Wideband slow light in microfiber double-knot resonator with a parallel structure | ||||||||||||
Author(s): Xu, YP (Xu, Yi-Ping); Ren, LY (Ren, Li-Yong); Liang, J (Liang, Jian); Ma, CJ (Ma, Cheng-Ju); Wang, YL (Wang, Ying-Li); Kong, XD (Kong, Xu-Dong); Lin, X (Lin, Xiao) | ||||||||||||
Source: JOURNAL OF APPLIED PHYSICS Volume: 118 Issue: 7 Article Number: 073105 DOI: 10.1063/1.4928967 Published: AUG 21 2015 | ||||||||||||
Abstract: The characteristics of slow light in the microfiber double-knot resonator with a parallel structure are investigated both theoretically and experimentally. It is predicted that a wide bandwidth of about 20 GHz and flat-top group delay of about 70 ps can be generated in this resonator by changing the coupling coefficient. In the experiment, such a resonator was fabricated and the slow-light effect was demonstrated. As a result, when a pulse with a bandwidth of 3.35 GHz (equivalent to the temporal width of 299 ps) was launched into the resonator, a large group delay, whose average value was about 69.4 ps with a flat-top wavelength bandwidth of about 190 pm, was achieved. (C) 2015 AIP Publishing LLC. | ||||||||||||
Accession Number: WOS:000360441900023 | ||||||||||||
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ISSN: 0021-8979 | ||||||||||||
eISSN: 1089-7550 |
Record 84 of 243 |
Title: Influence of earth's reflective radiation on space target for space based imaging |
Author(s): Yan, PP (Yan Pei-Pei); Ma, CW (Ma Cai-Wen); She, WJ (She Wen-Ji) |
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 16 Special Issue: SI Article Number: 169501 DOI: 10.7498/aps.64.169501 Published: AUG 20 2015 |
Abstract: The space-based surveillance, which would mainly use the space-based visible, has great value for civil and military applications currently and for a fairly long future period. In space-based surveillance, the visible and near-infrared radiation characteristics of the space target are influenced by its attitude variation. This influence is especially prominent in space-based imaging. In some ways, solar radiation cannot arrive at the surface of the space target, or the arriving radiation is not uniformly distributed because of the space target's strong reflection at a particular position. In order to solve these problems, the visible and near-infrared illumination characteristics of the space target surface are analyzed. Moreover, a notion that earth's reflective radiation can be used as illumination for space target imaging is given, and an accurate modeling method is proposed. Firstly, based on diffuse reflectance model, a method of mathematically calculating the illumination at space target's position from earth's reflective radiation is established. And a formula for calculating illumination is derived. Secondly, the coordinates of sun and space target at any time can be obtained by the Satellite tool kit software, in which the complicated multiplying matrix and coordinate transformation algorithm introduced in some references are avoided. Thirdly, the method of estimating earth's reflective radiation region at arbitrary moment is introduced. The grid division method is generated and the uniform sampling is used in each small area. Fourthly, the position of a surface cell is transformed from the sphere reference frame into the J2000.0 inertial frame. The earth's reflective radiation can be calculated through numerical integration. Finally, the illumination from earth's reflective radiation to a sun synchronous orbit satellite in an imaging mission based on space is calculated by the given parameters. The results show that the earth's reflective radiation is luminous enough for space target imaging when the satellite passes through arctic. When the satellite moves on the orbit, we can obtain more detailed information about target satellites' bottom then the ground simulation imaging. The on-orbit imaging results demonstrate the validity of the modeling method, which could support the foundation of our space-based surveillance system theoretically and technically and could be used as a reference of space-based orbit measurement and determination in deep space exploration. |
Accession Number: WOS:000362976800056 |
ISSN: 1000-3290 |
Record 85 of 243 | ||||||||||||
Title: Nanoslit-microcavity-based narrow band absorber for sensing applications | ||||||||||||
Author(s): Lu, XY (Lu, Xiaoyuan); Zhang, LX (Zhang, Lingxuan); Zhang, TY (Zhang, Tongyi) | ||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 16 Pages: 20715-20720 DOI: 10.1364/OE.23.020715 Published: AUG 10 2015 | ||||||||||||
Abstract: We propose an ultranarrow bandwidth perfect infrared absorber consisting of a metal periodic structured surface with nanoslits, a spacer dielectric, and a metal back plate. Its bandwidth and aborption are respectively about 8 nm and 95%. The thickness of the nanobars and the spacer, and the width of the nanoslits are primary factors determining the absorption performance. This structure not only has narrow bandwidth but also can obtain the giant electric field enhancement in the tiny volume of the nanoslits. Operated as a refractive index sensor, this structure has figure of merit as high as 25. It has potential in biomedical and sensing applications. (C) 2015 Optical Society of America | ||||||||||||
Accession Number: WOS:000361036400047 | ||||||||||||
PubMed ID: 26367923 | ||||||||||||
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ISSN: 1094-4087 |
Record 86 of 243 |
Title: Adaptive nonuniformity correction algorithm based on multiscale temporal moment matching |
Author(s): Leng, HB (Leng Han-Bing); Hu, BL (Hu Bing-Liang); Zhou, ZF (Zhou Zuo-Feng); Tang, LN (Tang Li-Nao); Zhang, J (Zhang Jian); Yan, AQ (Yan A-Qi) |
Source: JOURNAL OF INFRARED AND MILLIMETER WAVES Volume: 34 Issue: 4 Pages: 401-405 Published: AUG 2015 |
Abstract: The fixed pattern noise of uncooled infrared focal plane arrays has the similar characteristics with the stripe noise. By researching the moment matching and temporal high-pass filter, a novel multiscale temporal moment matching nonuniformity correction algorithm was proposed. In the proposed algorithm, global motion was first identified by the Gaussian pyramid of the adjacent uncorrected images. Then the temporal moment matching was performed in all levels of Gaussian pyramids and Laplacian pyramids. The experimental results with the real infrared video sequences have shown that the proposed algorithm can significantly increase the convergence speed and reduce the ghosting artifacts. |
Accession Number: WOS:000361260100004 |
ISSN: 1001-9014 |
Record 87 of 243 |
Title: High-resolution, low-injection-signal-power optical sampling |
Author(s): Li, FT (Li, Feitao); Liu, YS (Liu, Yuanshan); Zhao, W (Zhao, Wei) |
Source: OPTICAL AND QUANTUM ELECTRONICS Volume: 47 Issue: 8 Pages: 2881-2888 DOI: 10.1007/s11082-015-0177-3 Published: AUG 2015 |
Abstract: We have demonstrated a high-resolution, low-injection-signal-power optical sampling system using a 20-m-length dispersion-flattened photonics crystal fiber as optical sampling gate, and employing bridge-form low noise optical fiber amplifier. Optical pulse trains with -35 dBm input power and 1.25 ps interval were clearly displayed by using our all optical sampling system. To measure the temporal resolution of system accurately, optical pulse trains from a commercial 40 GHz actively mode-locked fiber laser, were injected into the optical sampling system and an autocorrelator with 5-fs resolution, respectively. 1.02 and 0.83 ps pulse-width were obtained by using our optical sampling system and the autocorrelator, respectively. These measured results show that the resolution of the system is as high as 0.6 ps. |
Accession Number: WOS:000360091100043 |
ISSN: 0306-8919 |
eISSN: 1572-817X |
Record 88 of 243 | ||||||
Title: Single-walled carbon nanotube solution-based saturable absorbers for mode-locked fiber laser | ||||||
Author(s): Li, L (Li, Lu); Wang, YG (Wang, Yonggang); Sun, H (Sun, Hang); Duan, LN (Duan, Lina); Wang, X (Wang, Xi); Si, JH (Si, Jinhai) | ||||||
Source: OPTICAL ENGINEERING Volume: 54 Issue: 8 Article Number: 086103 DOI: 10.1117/1.OE.54.8.086103 Published: AUG 2015 | ||||||
Abstract: The report proposed a saturable absorber based on a D-shaped fiber embedded in a single-walled carbon nanotube solution. Such a saturable absorber solution method with a D-shaped fiber has the virtues of good antioxidant capacity, excellent scattering resistance, high heat dissipation, and high damage threshold. The nonsaturable loss of this kind of saturable absorber was evaluated to be 3%. To the best of our knowledge, this is the lowest value compared with other carbon nanotube saturable absorbers. By incorporating the saturable absorber into a Yb-doped fiber laser cavity, a mode-locked fiber laser was achieved with a central wavelength of 1054.16 nm. The repetition rate was 23 MHz with a signal-to-noise ratio of 60 dB, and the pulse duration was measured to be 194 ps. The long-term working stability of working is also good. The results indicated that the solution method with a D-shaped fiber possesses a potential for fiber laser stability applications. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) | ||||||
Accession Number: WOS:000362507000036 | ||||||
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ISSN: 0091-3286 | ||||||
eISSN: 1560-2303 |
Record 89 of 243 | ||||||||||||||||||||||||
Title: Robust Match Fusion Using Optimization | ||||||||||||||||||||||||
Author(s): Qin, XM (Qin, Xiameng); Shen, JB (Shen, Jianbing); Mao, XY (Mao, Xiaoyang); Li, XL (Li, Xuelong); Jia, YD (Jia, Yunde) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 8 Pages: 1549-1560 DOI: 10.1109/TCYB.2014.2355140 Published: AUG 2015 | ||||||||||||||||||||||||
Abstract: In this paper, we present a novel patch-based match and fusion algorithm by taking account of moving scene in a multiple exposure image sequence using optimization. A uniform iterative approach is developed to match and find the corresponding patches in different exposure images, which are then fused in each iteration. Our approach does not need to align the input multiple exposure images before the fusion process. Considering that the pixel values are affected by various exposure time, we design a new patch-based energy function that will be optimized to improve the matching accuracy. An efficient patch-based exposure fusion approach using the random walker algorithm is developed to preserve the moving objects from the input multiple exposure images. To the best of our knowledge, our algorithm is the first patch-based exposure fusion work to preserve the moving objects of dynamic scenes that does not need the registration process of different exposure images. Experimental results of moving scenes demonstrate that our algorithm achieves visually pleasing fusion results without ghosting artifacts, while the results produced by the state-of-the-art exposure fusion and tone mapping algorithms exhibit different levels of ghosting artifacts. | ||||||||||||||||||||||||
Accession Number: WOS:000358213100014 | ||||||||||||||||||||||||
PubMed ID: 25248209 | ||||||||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||||||||
eISSN: 2168-2275 |
Record 90 of 243 | ||||||||||||||||||||||||||||||
Title: A Variational Approach to Simultaneous Image Segmentation and Bias Correction | ||||||||||||||||||||||||||||||
Author(s): Zhang, KH (Zhang, Kaihua); Liu, QS (Liu, Qingshan); Song, HH (Song, Huihui); Li, XL (Li, Xuelong) | ||||||||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 8 Pages: 1426-1437 DOI: 10.1109/TCYB.2014.2352343 Published: AUG 2015 | ||||||||||||||||||||||||||||||
Abstract: This paper presents a novel variational approach for simultaneous estimation of bias field and segmentation of images with intensity inhomogeneity. We model intensity of inhomogeneous objects to be Gaussian distributed with different means and variances, and then introduce a sliding window to map the original image intensity onto another domain, where the intensity distribution of each object is still Gaussian but can be better separated. The means of the Gaussian distributions in the transformed domain can be adaptively estimated by multiplying the bias field with a piecewise constant signal within the sliding window. A maximum likelihood energy functional is then defined on each local region, which combines the bias field, the membership function of the object region, and the constant approximating the true signal from its corresponding object. The energy functional is then extended to the whole image domain by the Bayesian learning approach. An efficient iterative algorithm is proposed for energy minimization, via which the image segmentation and bias field correction are simultaneously achieved. Furthermore, the smoothness of the obtained optimal bias field is ensured by the normalized convolutions without extra cost. Experiments on real images demonstrated the superiority of the proposed algorithm to other state-of-the-art representative methods. | ||||||||||||||||||||||||||||||
Accession Number: WOS:000358213100004 | ||||||||||||||||||||||||||||||
PubMed ID: 25347891 | ||||||||||||||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||||||||||||||
eISSN: 2168-2275 |
Record 91 of 243 | ||||||||||||||||||||||||
Title: Learning a Probabilistic Topology Discovering Model for Scene Categorization | ||||||||||||||||||||||||
Author(s): Zhang, LM (Zhang, Luming); Ji, RR (Ji, Rongrong); Xia, YJ (Xia, Yingjie); Zhang, Y (Zhang, Ying); Li, XL (Li, Xuelong) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 8 Pages: 1622-1634 DOI: 10.1109/TNNLS.2014.2347398 Published: AUG 2015 | ||||||||||||||||||||||||
Abstract: A recent advance in scene categorization prefers a topological based modeling to capture the existence and relationships among different scene components. To that effect, local features are typically used to handle photographing variances such as occlusions and clutters. However, in many cases, the local features alone cannot well capture the scene semantics since they are extracted from tiny regions (e.g., 4 x 4 patches) within an image. In this paper, we mine a discriminative topology and a low-redundant topology from the local descriptors under a probabilistic perspective, which are further integrated into a boosting framework for scene categorization. In particular, by decomposing a scene image into basic components, a graphlet model is used to describe their spatial interactions. Accordingly, scene categorization is formulated as an intergraphlet matching problem. The above procedure is further accelerated by introducing a probabilistic based representative topology selection scheme that makes the pairwise graphlet comparison trackable despite their exponentially increasing volumes. The selected graphlets are highly discriminative and independent, characterizing the topological characteristics of scene images. A weak learner is subsequently trained for each topology, which are boosted together to jointly describe the scene image. In our experiment, the visualized graphlets demonstrate that the mined topological patterns are representative to scene categories, and our proposed method beats state-of-the-art models on five popular scene data sets. | ||||||||||||||||||||||||
Accession Number: WOS:000358224200004 | ||||||||||||||||||||||||
PubMed ID: 25203998 | ||||||||||||||||||||||||
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ISSN: 2162-237X | ||||||||||||||||||||||||
eISSN: 2162-2388 |
Record 92 of 243 | ||||||||||||
Title: Autofocusing and resolution enhancement in digital holographic microscopy by using speckle-illumination | ||||||||||||
Author(s): Zheng, JJ (Zheng, Juanjuan); Pedrini, G (Pedrini, Giancarlo); Gao, P (Gao, Peng); Yao, BL (Yao, Baoli); Osten, W (Osten, Wolfgang) | ||||||||||||
Source: JOURNAL OF OPTICS Volume: 17 Issue: 8 Article Number: 085301 DOI: 10.1088/2040-8978/17/8/085301 Published: AUG 2015 | ||||||||||||
Abstract: Sequential speckle illumination has been incorporated into digital holographic microscopy (DHM) for autofocusing and resolution enhancement. For autofocusing, the image plane is numerically determined by searching for the minimal deviation among the reconstructed images obtained by different speckle illuminations and propagating the object wave to the image plane accordingly. Furthermore, an iterative method is used to synthesize the numerical aperture from the reconstructed object waves obtained by different speckle illuminations, in order to achieve resolution enhancement. The feasibility of the proposed method is demonstrated by both simulation and experiment. | ||||||||||||
Accession Number: WOS:000362167700009 | ||||||||||||
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ISSN: 2040-8978 | ||||||||||||
eISSN: 2040-8986 |
Record 93 of 243 | |||||||||||||||||||||
Title: Ffluorescence X-ray source used for calibrating the detector of X-ray navigation | |||||||||||||||||||||
Author(s): Dai, JF (Dai Jin-Fei); Zhao, BS (Zhao Bao-Sheng); Sheng, LZ (Sheng Li-Zhi); Zhou, YN (Zhou Yan-Nan); Chen, C (Chen Chen); Song, J (Song Juan); Liu, YA (Liu Yong-An); Li, LS (Li Lin-Sen) | |||||||||||||||||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 14 Article Number: 149701 DOI: 10.7498/aps.64.149701 Published: JUL 20 2015 | |||||||||||||||||||||
Abstract: Lots of research work on the X-ray pulsar navigation detector has been carried out, but the rigorous quantitative calibration results of these detectors have never been given out. In order to further promote the research process in X-ray pulsar navigation field, a kind of high-precision X-ray source which could be tunable in energy distribution and photon flux is necessary. A new method has been proposed to generate such an X-ray source, in which a conventional X-ray tube which is called the original level tube is used to excite a special fluorescence target to generate fluorescence X-ray source. Firstly, the primary experiment system is built, with which the intensity of the fluorescence X-ray source is measured in atmospheric environment. The result indicates that the fluorescence X-ray source can be implemented in vacuum system to calibrate the detectors. Then an integral fluorescence X-ray source is fabricated which can be used in vacuum system and its intensity is measured under the condition of D-x = 300 cm and I-a = 200 mu A. The photo fluxes are obtained to be 19.57 phs/s at 4.51 keV, 25.22 phs/s at 5.41 keV, and 33.27 phs/s at 8.05 keV. These data demonstrate the correctness of our method and that this new fluorescence X-ray source can be used to calibrate the x-ray pulsar navigation detector. | |||||||||||||||||||||
Accession Number: WOS:000362976400055 | |||||||||||||||||||||
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ISSN: 1000-3290 |
Record 94 of 243 | |||||||||||||||||||||||||||||||||||||||||||||
Title: Numerical and Experimental Analysis of Sensitivity-Enhanced RI Sensor Based on Ex-TFG in Thin Cladding Fiber | |||||||||||||||||||||||||||||||||||||||||||||
Author(s): Yan, ZJ (Yan, Zhijun); Sun, ZY (Sun, Zhongyuan); Zhou, KM (Zhou, Kaiming); Luo, BB (Luo, Binbin); Li, JF (Li, Jianfeng); Wang, HS (Wang, Hushan); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Zhang, L (Zhang, Lin) | |||||||||||||||||||||||||||||||||||||||||||||
Source: JOURNAL OF LIGHTWAVE TECHNOLOGY Volume: 33 Issue: 14 Pages: 3023-3027 DOI: 10.1109/JLT.2015.2422076 Published: JUL 15 2015 | |||||||||||||||||||||||||||||||||||||||||||||
Abstract: We report a highly sensitive refractive index (RI) sensor in the aqueous solution, which is based on an 81 degrees-tilted fiber grating structure inscribed into a thin cladding fiber with 40 mu m cladding radius. The numerical analysis has indicated that the RI sensitivity of cladding resonance mode of the grating can be significantly enhanced with reducing cladding size. This has been proved by the experimental results as the RI sensitivities of TM and TE resonance peaks in the index region of 1.345 have been increased to 1180 nm/RIU and 1150 nm/RIU, respectively, from only 200 and 170 nm/RIU for the same grating structure inscribed in standard telecom fiber with 62.5-mu m cladding radius. Although the temperature sensitivity has also increased, the change in temperature sensitivity is still insignificant in comparison with RI sensitivity enhancement. | |||||||||||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000358526200012 | |||||||||||||||||||||||||||||||||||||||||||||
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ISSN: 0733-8724 | |||||||||||||||||||||||||||||||||||||||||||||
eISSN: 1558-2213 |
Record 95 of 243 |
Title: Observation of dual-wavelength solitons and bound states in a nanotube/microfiber mode-locking fiber laser |
Author(s): Zeng, C (Zeng, C.); Cui, YD (Cui, Y. D.); Guo, J (Guo, J.) |
Source: OPTICS COMMUNICATIONS Volume: 347 Pages: 44-49 DOI: 10.1016/j.optcom.2015.02.054 Published: JUL 15 2015 |
Abstract: We report on the experimental observation of dual-wavelength soliton and the phase-locked bound state in an all-fiber laser mode-locked by a carbon nanotubes/microfiber saturable absorber. The operation wavelengths are strongly dependent on the intracavity loss. By adjusting an attenuator to increase the intracavity loss, mode-locking wavelength shifts from 1557 to 1531 nm. With the appropriate pump power and intracavity loss, dual-wavelength solitons are achieved simultaneously. In addition, the phase-locked bound-state solitons are also observed at the two wavelengths. The pulse separation and phase difference are related to the first-order Kelly sidebands. (C) 2015 Elsevier B.V. All rights reserved. |
Accession Number: WOS:000357551700008 |
ISSN: 0030-4018 |
eISSN: 1873-0310 |
Record 96 of 243 | ||||||
Title: 400 mW narrow-linewidth Tm-doped silica fiber laser output near 1750 nm with volume Bragg grating | ||||||
Author(s): Quan, Z (Quan, Zhao); Gao, CX (Gao, Cunxiao); Guo, HT (Guo, Haitao); Wang, N (Wang, Ning); Cui, XX (Cui, Xiaoxia); Xu, YT (Xu, Yantao); Peng, B (Peng, Bo); Wei, W (Wei, Wei) | ||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 12034 DOI: 10.1038/srep12034 Published: JUL 13 2015 | ||||||
Abstract: A type of Tm-doped silica fiber laser with narrow-linewidth and output wavelength near 1750 nm was firstly presented, by using a 1550 nm Er-doped fiber laser pump source and a volume Bragg grating (VBG). By means of a 15 cm Tm-doped fiber, a 400 mW continuous wave (cw) at similar to 1750 nm with FWHW of similar to 54 pm was generated, corresponding to an average slope efficiency up to 23.5% with respect to absorbed pump power. The influence of gain fiber length on the spectrum wavelength has been investigated in detail. All experimental results demonstrate that this fiber laser will be an effective and promising pump source for mid-IR laser output. | ||||||
Accession Number: WOS:000357847900001 | ||||||
PubMed ID: 26166411 | ||||||
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ISSN: 2045-2322 |
Record 97 of 243 | ||||||||||||
Title: Image quality assessment: A sparse learning way | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Guo, Q (Guo, Qun); Lu, XQ (Lu, Xiaoqiang) | ||||||||||||
Source: NEUROCOMPUTING Volume: 159 Pages: 227-241 DOI: 10.1016/j.neucom.2015.01.066 Published: JUL 2 2015 | ||||||||||||
Abstract: Full reference image quality assessment is very important for many image processing applications. The challenge of image quality assessment lies in two aspects: (1) formulating perceptual meaningful features and (2) finding a way to pool them into a single quality score. A novel two-step approach is proposed to address these problems. In. the first step, sparse representations of local image patches are computed to simulate the low level characteristic of the human vision system (HVS) and represent the meaningful image structures. The differences between the representations of distorted and undistorted patches are utilized to measure the local distortion. In the second step, these local distortion measurements are fused into a single image quality score by using kernel ridge regression (KRR). Kernel ridge regression can mimic the complex high level behaviors of human vision system and is shown to be an effective way to learn the relationship between local quality measurements and quality score. The contributions of this paper would be summarized as follows: (I) extracting approximate perceptual meaningful features in image quality assessment is transformed as a sparse representation problem. In this case, the sparse representation coefficients can reflect the salient local structures and give local quality assessments. (2) The KRR is utilized to pool the local quality assessments into a single image quality score. Thus, the nonlinear relationship between the objective model outputs and the subjective quality ratings can be learned by exploiting the KRR. (3) Extensive experiments are conducted on six public databases. Compared with other approaches, the proposed approach has achieved the best performance, which demonstrates the effectiveness and robustness of the proposed approach. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||
Accession Number: WOS:000353094600025 | ||||||||||||
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ISSN: 0925-2312 | ||||||||||||
eISSN: 1872-8286 |
Record 98 of 243 | |||||||||||||||
Title: Efficient object detection by prediction in 3D space | |||||||||||||||
Author(s): Pang, YW (Pang, Yanwei); Jiang, XH (Jiang, Xiaoheng); Li, XL (Li, Xuelong); Pan, J (Pan, Jing) | |||||||||||||||
Source: SIGNAL PROCESSING Volume: 112 Special Issue: SI Pages: 64-73 DOI: 10.1016/j.sigpro.2014.08.039 Published: JUL 2015 | |||||||||||||||
Abstract: Because the scale, horizontal and vertical coordinates of an object in an image are arbitrary, so object detection can be viewed as a process of searching the object in the 3D space spanned by the scale, horizontal, and vertical factors. Traditional sliding window based method has to exhaustively search and check the 3D space, resulting in prohibitive computation cost. To deal with this problem, in this paper, we propose to explore both the scaling capacity and translation capacity of object detector to accelerate detection speed, without loss of detection accuracy. In our paradigm, scaling capacity can relieve the use of all possible sizes of templates at the first stage, i.e., only a few number of templates that can cover a large range of target object size are used to coarsely find the targets. Similarly, translation capacity can avoid dense grid sampling at the very beginning. After initial estimation, further evaluations with templates of finer scales are carried out around the candidates to verify the existence of target objects. Moreover, different from traditional uniform grid scanning, we present an interlaced scanning method called diamond grid scanning which can reduce redundant evaluation. Experimental results on face detection demonstrate the advantage of our method. (C) 2014 Elsevier B.V. All rights reserved. | |||||||||||||||
Accession Number: WOS:000351976400008 | |||||||||||||||
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ISSN: 0165-1684 | |||||||||||||||
eISSN: 1872-7557 |
Record 99 of 243 | ||||||
Title: Partial sparse shape constrained sector-driven bladder wall segmentation | ||||||
Author(s): Qin, XJ (Qin, Xianjing); Lu, HB (Lu, Hongbing); Tian, Y (Tian, Yan); Yan, PK (Yan, Pingkun) | ||||||
Source: MACHINE VISION AND APPLICATIONS Volume: 26 Issue: 5 Pages: 593-606 DOI: 10.1007/s00138-015-0684-z Published: JUL 2015 | ||||||
Abstract: Bladder wall segmentation from Magnetic Resonance (MR) images plays a crucial role in clinical applications. Level set-based methods are often used to extract the bladder boundaries. When suffering from the fuzzy boundaries, it often results in confused and leaking boundaries. It has been proved that an accurate shape prior can generate an effective force to address these problems. However, the shape prior estimation for the bladder is difficult due to the complex shape variations. Moreover, how to constrain the level set is another challenge. In this paper, we first propose a partial sparse shape model to construct a robust shape prior. Specifically, the partial reliable contour is encoded by the corresponding partial shape dictionary and decoded on the complete shape dictionary to obtain a complete reliable shape prior. Second, we propose a novel sector-driven level set model for locally constraining the evolution to address the problems caused by fuzzy boundaries. Our method was validated on 167 T2 FSE MR images acquired from 15 different patients, better results were obtained compared to the state-of-the-art methods. | ||||||
Accession Number: WOS:000356094700003 | ||||||
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ISSN: 0932-8092 | ||||||
eISSN: 1432-1769 |
Record 100 of 243 |
Title: A tilt-compensated Fourier transform spectrometer with an image rotator |
Author(s): Wei, RY (Wei, Ruyi); Yin, BS (Yin, Bangsheng) |
Source: OPTICS COMMUNICATIONS Volume: 346 Pages: 115-119 DOI: 10.1016/j.optcom.2015.02.028 Published: JUL 1 2015 |
Abstract: Due to the moving plane mirror, tilt compensation is crucial and challenging in designing high precision Michelson-type interferometers. In this paper, we propose an optical configuration design using an image rotator and plane mirrors, including a movable double-sided mirror (DSM) to balance out the tilt of the mirror. We analysed the optical path differences (OPD) caused by the tilt of the DSM and their effects on interferogram under different tilt cases. Analyses demonstrate that this design is able to cancel out the offset of the OPD introduced by the tilt pitch angle. For different incident rays in parallel, the position of the tilt centre has no relationship with the change of the OPD, implying that the OPD could be self-compensated, and the modulation of the interferogram will not be degraded due to the tilt. This configuration effectively relaxes the requirements on the control of the precision of the postures of the moving mirror and thus may have broad applications. (C) 2015 Elsevier B.V. All rights reserved. |
Accession Number: WOS:000353087800020 |
ISSN: 0030-4018 |
eISSN: 1873-0310 |
Record 101 of 243 | |||||||||||||||
Title: High-speed quantum-random number generation by continuous measurement of arrival time of photons | |||||||||||||||
Author(s): Yan, QR (Yan, Qiurong); Zhao, BS (Zhao, Baosheng); Hua, Z (Hua, Zhang); Liao, QH (Liao, Qinghong); Yang, H (Yang, Hao) | |||||||||||||||
Source: REVIEW OF SCIENTIFIC INSTRUMENTS Volume: 86 Issue: 7 Article Number: 073113 DOI: 10.1063/1.4927320 Published: JUL 2015 | |||||||||||||||
Abstract: We demonstrate a novel high speed and multi-bit optical quantum random number generator by continuously measuring arrival time of photons with a common starting point. To obtain the unbiased and post-processing free random bits, the measured photon arrival time is converted into the sum of integral multiple of a fixed period and a phase time. Theoretical and experimental results show that the phase time is an independent and uniform random variable. A random bit extraction method by encoding the phase time is proposed. An experimental setup has been built and the unbiased random bit generation rate could reach 128 Mb/s, with random bit generation efficiency of 8 bits per detected photon. The random numbers passed all tests in the statistical test suite. (C) 2015 AIP Publishing LLC. | |||||||||||||||
Accession Number: WOS:000358934400024 | |||||||||||||||
PubMed ID: 26233362 | |||||||||||||||
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ISSN: 0034-6748 | |||||||||||||||
eISSN: 1089-7623 |
Record 102 of 243 | ||||||
Title: Diffusion emission model for solid-state photon-enhanced thermionic emission solar energy converters | ||||||
Author(s): Yang, Y (Yang, Yang); Yang, WZ (Yang, Wenzheng); Sun, CD (Sun, Chuandong) | ||||||
Source: MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING Volume: 35 Pages: 120-126 DOI: 10.1016/j.mssp.2015.03.002 Published: JUL 2015 | ||||||
Abstract: Solid-state photon-enhanced thermionic emission (PETE) solar energy converters are new devices that can directly convert solar energy into electrical power at elevated temperatures. This study proposes a new solid-state PETE device structure with a p-type doped semiconductor as the absorber. A model based on a 1D steady-state continuity equation is presented to simulate the diffusion and emission of photogenerated carriers and to calculate the efficiencies. This model, can evaluate the effect of device structure and material parameters on performance and efficiency. Calculation results show that the new device is more efficient compared with the original device. A longer electron diffusion length is favourable for enhancing efficiency. Moreover, the optimal absorber thickness is predicted. Our analyses also show that the front interface strongly affects conversion efficiency, which emphasises the need to reduce interface recombination losses. The results of this study may serve as bases for the optimum design of practical solid-state PETE devices. (C) 2015 Elsevier Ltd. All rights reserved. | ||||||
Accession Number: WOS:000353855400017 | ||||||
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ISSN: 1369-8001 | ||||||
eISSN: 1873-4081 |
Record 103 of 243 |
Title: Three types of pulses delivered from a nanotube-mode-locked fiber laser |
Author(s): Yao, XK (Yao, X. K.) |
Source: LASER PHYSICS Volume: 25 Issue: 7 Article Number: 075101 DOI: 10.1088/1054-660X/25/7/075101 Published: JUL 2015 |
Abstract: Three types of pulses are experimentally investigated in a switchable normal-dispersion nanotube-mode-locked fiber laser by adjusting polarizer controller and pump power. They are a standard dissipative-soliton (DS), conventional soliton (CS)-like pulse, and noiselike pulse, which correspond to three mode-locking states. The standard DS with a rectangular spectrum possesses a Gaussian-shape pulse. The CS-like operation has a Lorenz shape, and the spectrum involves several sidebands similar to the CS case. For the noiselike pulse with a bell-shaped spectrum, a 317 fs peak rides upon the 132.5 ps pedestal in the autocorrelation trace. The spectra of these three pulse operations are centered at three close wavelengths. The generation of three such different types of pulses in one identical normal-dispersion laser cavity may find an important application for the future of mode-locked laser research. |
Accession Number: WOS:000357180200004 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 104 of 243 | |||||||||||||||
Title: Spectral-Spatial Kernel Regularized for Hyperspectral Image Denoising | |||||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Zheng, XT (Zheng, Xiangtao); Lu, XQ (Lu, Xiaoqiang) | |||||||||||||||
Source: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Volume: 53 Issue: 7 Pages: 3815-3832 DOI: 10.1109/TGRS.2014.2385082 Published: JUL 2015 | |||||||||||||||
Abstract: Noise contamination is a ubiquitous problem in hyperspectral images (HSIs), which is a challenging and promising theme in many remote sensing applications. A large number of methods have been proposed to remove noise. Unfortunately, most denoising methods fail to take full advantages of the high spectral correlation and to simultaneously consider the specific noise distributions in HSIs. Recently, a spectral-spatial adaptive hyperspectral total variation (SSAHTV) was proposed and obtained promising results. However, the SSAHTV model is insensitive to the image details, which makes the edges blur. To overcome all of these drawbacks, a spectral-spatial kernel method for HSI denoising is proposed in this paper. The proposed method is inspired by the observation that the spectral-spatial information is highly redundant in HSIs, which is sufficient to estimate the clear images. In this paper, a spectral-spatial kernel regularization is proposed to maintain the spectral correlations in spectral dimension and to match the original structure between two spatial dimensions. Moreover, an adaptive mechanism is developed to balance the fidelity term according to different noise distributions in each band. Therefore, it cannot only suppress noise in the high-noise band but also preserve information in the low-noise band. The reliability of the proposed method in removing noise is experimentally proved on both simulated data and real data. | |||||||||||||||
Accession Number: WOS:000351461000021 | |||||||||||||||
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ISSN: 0196-2892 | |||||||||||||||
eISSN: 1558-0644 |
Record 105 of 243 | ||||||||||||
Title: Low-rank representation for 3D hyperspectral images analysis from map perspective | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Fu, M (Fu, Min); Lu, XQ (Lu, Xiaoqiang) | ||||||||||||
Source: SIGNAL PROCESSING Volume: 112 Special Issue: SI Pages: 27-33 DOI: 10.1016/j.sigpro.2014.06.018 Published: JUL 2015 | ||||||||||||
Abstract: Hyperspectral images naturally stand as 3D data, which carry semantic information in remote sending applications. To well utilize 3D hyperspectral images, signal processing and learning techniques have been widely exploited, and the basis is to divide a given hyperspectral data into a set of semantic classes for analysis, i.e., segmentation. To segment given hyperspectral data is an important and challenging research theme. Recently, to reduce the amount of human labor required to label samples in hyperspectral image segmentation, many approaches have been proposed and achieved good performance with a few labeled samples. However, most of them fail to exploit the high spectral correlation in distinct bands and utilize the spatial information of hyperspectral data. In order to overcome these drawbacks, a novel framework jointing the maximum a posteriori (MAP) model and low-rank representation (LRR) is proposed. In this paper, low-rank representation, conducted as a latent variables, can exploit the high spectral correlation in distinct bands and obtain a more compact and discriminative representation. On the other hand, a novel MAP framework is driven by using low-rank representation coefficient as latent variables, which will improve the probability that the closer pixels can be divided into the same class. The experiment results and quantitative analysis demonstrate that the proposed approach is effective and can obtain high segmentation accuracy compared with state-of-the-art approaches. (C) 2014 Elsevier B.V. All rights reserved. | ||||||||||||
Accession Number: WOS:000351976400004 | ||||||||||||
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ISSN: 0165-1684 | ||||||||||||
eISSN: 1872-7557 |
Record 106 of 243 | ||||||||||||||||||||||||
Title: Simultaneous Bidirectional Link Selection in Full Duplex MIMO Systems | ||||||||||||||||||||||||
Author(s): Zhou, MX (Zhou, Mingxin); Song, LY (Song, Lingyang); Li, YH (Li, Yonghui); Li, XL (Li, Xuelong) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Volume: 14 Issue: 7 Pages: 4052-4062 DOI: 10.1109/TWC.2015.2416187 Published: JUL 2015 | ||||||||||||||||||||||||
Abstract: In this paper, we consider a point to point full duplex (FD) MIMO communication system. We assume that each node is equipped with an arbitrary number of antennas which can be used for transmission or reception. With FD radios, bidirectional information exchange between two nodes can be achieved at the same time. In this paper, we design bidirectional link selection schemes by selecting a pair of transmit and receive antenna at both ends for communications in each direction to maximize the weighted sum rate or minimize the weighted sum symbol error rate (SER). The optimal selection schemes require exhaustive search, so they are highly complex. To tackle this problem, we propose a Serial-Max selection algorithm, which approaches the exhaustive search methods with much lower complexity. In the Serial-Max method, the antenna pairs with maximum "obtainable SINR" at both ends are selected in a two-step serial way. The performance of the proposed Serial-Max method is analyzed, and the closed-form expressions of the average weighted sum rate and the weighted sum SER are derived. The analysis is validated by simulations. Both analytical and simulation results show that as the number of antennas increases, the Serial-Max method approaches the performance of the exhaustive-search schemes in terms of sum rate and sum SER. | ||||||||||||||||||||||||
Accession Number: WOS:000357805200041 | ||||||||||||||||||||||||
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ISSN: 1536-1276 | ||||||||||||||||||||||||
eISSN: 1558-2248 |
Record 107 of 243 | |||||||||||||||||||||||||||||||||
Title: Environmental-adaptability analysis of an all polarization-maintaining fiber-based optical frequency comb | |||||||||||||||||||||||||||||||||
Author(s): Feng, Y (Feng, Ye); Xu, X (Xu, Xin); Hu, XH (Hu, Xiaohong); Liu, YS (Liu, Yuanshan); Wang, YS (Wang, Yishan); Zhang, W (Zhang, Wei); Yang, Z (Yang, Zhi); Duan, LN (Duan, Lina); Zhao, W (Zhao, Wei); Cheng, Z (Cheng, Zhao) | |||||||||||||||||||||||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 13 Pages: 17549-17559 DOI: 10.1364/OE.23.017549 Published: JUN 29 2015 | |||||||||||||||||||||||||||||||||
Abstract: We demonstrate an all polarization-maintaining (PM) fiberbased optical frequency comb and provide the detailed environmental stability analysis results. The frequency comb has been built by commercial available PM fiber completely, and its static uncertainty in optical domain is 350 Hz in 1 s when referenced to a low noise oven controlled crystal oscillator. The acoustic resonant frequencies of the system have been measured. It is proved that acoustic-vibration induced phase noise could be eliminated by low pass vibration-isolation structure. Further, the existence of the optimum working temperature is illustrated. At this temperature (289.6 K), the out-loop integrated phase noise of f(r) and the temperature-drift induced instability of f(CEO) reach the lowest level 31.6 mu rad and 0 kHz/(mW center dot K) respectively. Finally, the system is proved to be stable under different humidity (18% similar to 80%) by a 240-day-long record of the f(CEO). (C) 2015 Optical Society of America | |||||||||||||||||||||||||||||||||
Accession Number: WOS:000358543300102 | |||||||||||||||||||||||||||||||||
PubMed ID: 26191762 | |||||||||||||||||||||||||||||||||
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ISSN: 1094-4087 |
Record 108 of 243 | ||||||||||||
Title: Soliton dynamics in a PT-symmetric optical lattice with a longitudinal potential barrier | ||||||||||||
Author(s): Zhou, KY (Zhou, Keya); Wei, TT (Wei, Tingting); Sun, HP (Sun, Haipeng); He, YJ (He, Yingji); Liu, ST (Liu, Shutian) | ||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 13 Pages: 16903-16911 DOI: 10.1364/OE.23.016903 Published: JUN 29 2015 | ||||||||||||
Abstract: We present dynamics of spatial solitons propagating through a PT symmetric optical lattice with a longitudinal potential barrier. We find that a spatial soliton evolves a transverse drift motion after transmitting through the lattice barrier. The gain/loss coefficient of the PT symmetric potential barrier plays an essential role on such soliton dynamics. The bending angle of solitons depends on the lattice parameters including the modulation frequency, incident position, potential depth and the barrier length. Besides, solitons tend to gain a certain amount of energy from the barrier, which can also be tuned by barrier parameters. (C) 2015 Optical Society of America | ||||||||||||
Accession Number: WOS:000358543300041 | ||||||||||||
PubMed ID: 26191701 | ||||||||||||
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ISSN: 1094-4087 |
Record 109 of 243 | |||||||||||||||||||||
Title: Adaptive road detection via context-aware label transfer | |||||||||||||||||||||
Author(s): Wang, Q (Wang, Qi); Fang, JW (Fang, Jianwu); Yuan, Y (Yuan, Yuan) | |||||||||||||||||||||
Source: NEUROCOMPUTING Volume: 158 Pages: 174-183 DOI: 10.1016/j.neucom.2015.01.054 Published: JUN 22 2015 | |||||||||||||||||||||
Abstract: The vision ability is fundamentally important for a mobile robot. Many aspects have been investigated during the past few years, but there still remain questions to be answered. This work mainly focuses on the task of road detection, which is considered as the first step for a robot to become moveable. The proposed method combines the depth clue with traditional RGB information and is divided into three steps: depth recovery and superpixel generation, weakly supervised SVM classification and context-aware label transfer. The main contributions made in this paper are (I) Design a novel superpixel based context-aware descriptor by utilizing depth map. (2) Conduct label transfer in an efficient nearest neighbor search and a temporal MRF model. (3) Update the learned model adaptively with the changing scene. Experimental results on a publicly available dataset justify the effectiveness of the proposed method. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||||||||
Accession Number: WOS:000352173100019 | |||||||||||||||||||||
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ISSN: 0925-2312 | |||||||||||||||||||||
eISSN: 1872-8286 |
Record 110 of 243 | ||||||
Title: All-phase target reconstruction method for coherent field imaging | ||||||
Author(s): Cao, B (Cao Bei); Luo, XJ (Luo Xiu-Juan); Chen, ML (Chen Ming-Lai); Zhang, Y (Zhang Yu) | ||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 12 Article Number: 124205 DOI: 10.7498/aps.64.124205 Published: JUN 20 2015 | ||||||
Abstract: Received signal processing and target reconstruction technique plays a key role in coherent field imaging, and directly influences the quality of the reconstructed image of a target. Based on all-phase fast Fourier transformation (FFT) spectrum analysis theory, a new processing and reconstruction method is proposed. By directly extracting the phase and amplitude information from all-phase FFT spectrum of the return signal, the proposed all-phase target reconstruction method is capable of inhibiting the frequency error caused by many factors, thus reconstructing the target image more precisely. The validity of the proposed method is proved by a coherent field imaging system in outdoor environments, and it has a better reconstruction performance than a traditional method. The resolution of the reconstructed target is close to a theoretical diffraction limit. | ||||||
Accession Number: WOS:000356793900018 | ||||||
Author Identifiers: | ||||||
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ISSN: 1000-3290 |
Record 111 of 243 |
Title: Improving coherent field imaging quality by suppressing the influence of transmitting aperture spacing error |
Author(s): Cheng, ZY (Cheng Zhi-Yuan); Ma, CW (Ma Cai-Wen); Luo, XJ (Luo Xiu-Juan); Zhang, Y (Zhang Yu); Zhu, XP (Zhu Xiang-Ping); Xia, AL (Xia Ai-Li) |
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 12 Article Number: 124203 DOI: 10.7498/aps.64.124203 Published: JUN 20 2015 |
Abstract: Coherent field imaging is based on the assumption of equal transmitting apertures spacing and equal spectrum of laser, and high-resolution image is reconstructed by iteratively computing the frequency spectrum. However, the inevitable transmitting aperture spacing error of laser is a key factor to affect the coherent field imaging quality in the application. Aiming at the problem of degrading imaging quality caused by the transmitting aperture spacing error, we discuss the mechanism of influence of aperture spacing error on imaging quality and propose a novel method of improving imaging quality from the perspective of suppressing the influence of transmitting aperture spacing error. Firstly, the mechanism of the influence of aperture spacing error on imaging quality and laser echo spectrum is analyzed in detail. Then we derive a frequency spectrum error propagation model. Based on the model, the iterative effect of frequency spectrum error is investigated and the trend of variation in imaging quality with frequency spectrum error is given. We propose a theoretical equation, in which the transmitting aperture spacing error has no influence on frequency spectrum nor imaging quality. To solve the above equation, an optimized method of linear programming is proposed and the optimized matrix of aperture spacing error is obtained. In practice, the influence of aperture spacing error on imaging quality can be largely counteracted by reasonably allocating aperture spacing error according to the optimized spacing error matrix. The correctness and validity of the theoretical model are verified by a simulation experiment. The results show that the Strehl ratio of imaging quality index can be improved by about 100% through using the proposed method, the greater the aperture spacing error, the higher the Strehl ratio of imaging quality index obtained by the method will be. In addition, the method is easy to use practically and less costly as well. Finally, it is concluded that the proposed method can easily and effectively counteract the degrading effect of aperture spacing error on imaging quality. The research can provide a theoretical basis for improving imaging quality and reasonably assigning transmitter aperture spacing accuracy of coherent field imaging telescope. |
Accession Number: WOS:000356793900016 |
ISSN: 1000-3290 |
Record 112 of 243 | ||||||||||||
Title: Theoretical and experimental study of structural slow light in a microfiber coil resonator | ||||||||||||
Author(s): Ma, CJ (Ma, Cheng-Ju); Ren, LY (Ren, Li-Yong); Xu, YP (Xu, Yi-Ping); Wang, YL (Wang, Ying-Li); Zhou, H (Zhou, Hong); Fu, HW (Fu, Hai-Wei); Wen, J (Wen, Jin) | ||||||||||||
Source: APPLIED OPTICS Volume: 54 Issue: 18 Pages: 5619-5623 DOI: 10.1364/AO.54.005619 Published: JUN 20 2015 | ||||||||||||
Abstract: In this paper, a compact slow-light microfiber coil resonator (MCR) is fabricated and the slow-light properties of it are analyzed and tested. Based on coupled-wave theory, a theoretical model for describing the slow-light propagation in the MCR is established. Experimentally, the MCR slow-light element is fabricated and its relative slow-light time delay is measured. The group velocity of the light pulse in the MCR slow-light element can be reduced to about 0.47c (c is the speed of light in vacuum) and the shape of the light pulse passing through the MCR is well preserved. (C) 2015 Optical Society of America | ||||||||||||
Accession Number: WOS:000356783700002 | ||||||||||||
PubMed ID: 26193003 | ||||||||||||
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ISSN: 1559-128X | ||||||||||||
eISSN: 2155-3165 |
Record 113 of 243 | |||||||||||||||
Title: Bit error rate analysis of X-ray communication system | |||||||||||||||
Author(s): Wang, LQ (Wang Lu-Qiang); Su, T (Su Tong); Zhao, BS (Zhao Bao-Sheng); Sheng, LZ (Sheng Li-Zhi); Liu, YA (Liu Yong-An); Liu, D (Liu Duo) | |||||||||||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 12 Article Number: 120701 DOI: 10.7498/aps.64.120701 Published: JUN 20 2015 | |||||||||||||||
Abstract: X-ray communication, which was firstly introduced by Keithe Gendreau in 2007, is potential to compete with conventional communication methods, such as microwave and laser communication, against space surroundings. As a result, a great deal of time and effort has been devoted to making the initial idea into reality in recent years. Eventually, the X-ray communication demonstration system based on the grid-controlled X-ray source and microchannel plate detector can deliver both audio and video information in a 6-meter vacuum tunnel. The point is how to evaluate this space X-ray demonstration system in a typical experimental way. The method is to design a specific board to measure the relationship between bit-error-rate and emitting power against various communicating distances. In addition, the data should be compared with the calculation and simulation results to estimate the referred theoretical model. The concept of using X-ray as signal carriers is confirmed by our first generation X-ray communication demonstration system. Specifically, the method is to use grid-controlled emission source as a transceiver while implementing the photon counting detector which can be regarded as an important orientation of future deep-space X-ray communication applications. As the key specification of any given communication system, bit-error-rate level should be informed first. In addition, the theoretical analysis by using Poisson noise model also has been implemented to support this novel communication concept. Previous experimental results indicated that the X-ray audio demonstration system requires a 10(-4) bit-error-rate level with 25 kbps communication rate. The system bit-error-rate based on on-off keying (OOK) modulation is calculated and measured, which corresponds to the theoretical calculation commendably. Another point that should be taken into consideration is the emitting energy, which is the main restriction of current X-ray communication system. The designed experiment shows that the detected X-ray energy is 7 x 10(-5) mW/m(2). This relatively low power level not only restricts the bit rate of transceiver, but also increases the error fraction to some extent. Obviously, OOK modulation can meet the high communication rate and relatively low bit-error-rate requirement of current audio demo system. Current restriction has been pointed out and the potential improvement is also presented. | |||||||||||||||
Accession Number: WOS:000356793900006 | |||||||||||||||
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ISSN: 1000-3290 |
Record 114 of 243 | |||||||||||||||||||||
Title: Microstructure and chemical bond evolution of diamond-like carbon films machined by femtosecond laser | |||||||||||||||||||||
Author(s): Wang, J (Wang, Jing); Wang, CH (Wang, Chunhui); Liu, YS (Liu, Yongsheng); Cheng, LF (Cheng, Laifei); Li, WN (Li, Weinan); Zhang, Q (Zhang, Qing); Yang, XJ (Yang, Xiaojun) | |||||||||||||||||||||
Source: APPLIED SURFACE SCIENCE Volume: 340 Pages: 49-55 DOI: 10.1016/j.apsusc.2015.02.169 Published: JUN 15 2015 | |||||||||||||||||||||
Abstract: Femtosecond laser is of great interest for machining high melting point and hardness materials such as diamond like carbon, SiC ceramic, et al. In present work, the microstructural and chemical bond evolution of diamond-like carbon films were investigated using electron microscopy and spectroscopy techniques after machined by diverse femtosecond laser power in air. The results showed the machining depth was essentially proportional to the laser power. The well patterned microgrooves and ripple structures with nanoparticles were formed distinctly in the channels. Considering the D and G Raman band parameters on the laser irradiation, it revealed a conversion from amorphous carbon to nanocrystalline graphite after laser treated with increasing laser power. X-ray photoelectron spectroscopy analysis showed a great decrease of sp(3)/sp(2) after laser treatment. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||||||||
Accession Number: WOS:000352213300007 | |||||||||||||||||||||
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ISSN: 0169-4332 | |||||||||||||||||||||
eISSN: 1873-5584 |
Record 115 of 243 | |||||||||
Title: Reconstruction of pulse noisy images via stochastic resonance | |||||||||
Author(s): Han, J (Han, Jing); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan) | |||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 10616 DOI: 10.1038/srep10616 Published: JUN 12 2015 | |||||||||
Abstract: We investigate a practical technology for reconstructing nanosecond pulse noisy images via stochastic resonance, which is based on the modulation instability. A theoretical model of this method for optical pulse signal is built to effectively recover the pulse image. The nanosecond noise-hidden images grow at the expense of noise during the stochastic resonance process in a photorefractive medium. The properties of output images are mainly determined by the input signal-to-noise intensity ratio, the applied voltage across the medium, and the correlation length of noise background. A high cross-correlation gain is obtained by optimizing these parameters. This provides a potential method for detecting low-level or hidden pulse images in various imaging applications. | |||||||||
Accession Number: WOS:000356150000001 | |||||||||
PubMed ID: 26067911 | |||||||||
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ISSN: 2045-2322 |
Record 116 of 243 | ||||||||||||
Title: Bessel beam CARS of axially structured samples | ||||||||||||
Author(s): Heuke, S (Heuke, Sandro); Zheng, JJ (Zheng, Juanjuan); Akimov, D (Akimov, Denis); Heintzmann, R (Heintzmann, Rainer); Schmitt, M (Schmitt, Michael); Popp, J (Popp, Juergen) | ||||||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 10991 DOI: 10.1038/srep10991 Published: JUN 5 2015 | ||||||||||||
Abstract: We report about a Bessel beam CARS approach for axial profiling of multi-layer structures. This study presents an experimental implementation for the generation of CARS by Bessel beam excitation using only passive optical elements. Furthermore, an analytical expression is provided describing the generated anti-Stokes field by a homogeneous sample. Based on the concept of coherent transfer functions, the underling resolving power of axially structured geometries is investigated. It is found that through the non-linearity of the CARS process in combination with the folded illumination geometry continuous phase-matching is achieved starting from homogeneous samples up to spatial sample frequencies at twice of the pumping electric field wave. The experimental and analytical findings are modeled by the implementation of the Debye Integral and scalar Green function approach. Finally, the goal of reconstructing an axially layered sample is demonstrated on the basis of the numerically simulated modulus and phase of the anti-Stokes far-field radiation pattern. | ||||||||||||
Accession Number: WOS:000355868400001 | ||||||||||||
PubMed ID: 26046671 | ||||||||||||
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ISSN: 2045-2322 |
Record 117 of 243 | ||||||||||||||||||
Title: Accelerating nondiffracting beams | ||||||||||||||||||
Author(s): Yan, SH (Yan, Shaohui); Li, MM (Li, Manman); Yao, BL (Yao, Baoli); Yu, XH (Yu, Xianghua); Lei, M (Lei, Ming); Dan, D (Dan, Dan); Yang, YL (Yang, Yanlong); Min, JW (Min, Junwei); Peng, T (Peng, Tong) | ||||||||||||||||||
Source: PHYSICS LETTERS A Volume: 379 Issue: 12-13 Pages: 983-987 DOI: 10.1016/j.physleta.2015.01.017 Published: JUN 5 2015 | ||||||||||||||||||
Abstract: We present a set of beams which combine the properties of accelerating beams and (conventional) diffraction-free beams. These beams can travel along a desired trajectory while keeping an approximately invariant transverse profile, which may be (higher-order) Bessel-, Mathieu- or parabolic-nondiffracting-like beams, depending on the initial complex amplitude distribution. A possible application of these beams presented here may be found in optical tapping field. For example, a higher-order Bessel-like beam, which has a hollow (transverse) pattern, is suitable for guiding low-refractive-index or metal particles along a curve. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||||||||
Accession Number: WOS:000351321800012 | ||||||||||||||||||
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ISSN: 0375-9601 | ||||||||||||||||||
eISSN: 1873-2429 |
Record 118 of 243 | ||||||||||||||||||
Title: Blind Image Quality Assessment via Deep Learning | ||||||||||||||||||
Author(s): Hou, WL (Hou, Weilong); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 6 Pages: 1275-1286 DOI: 10.1109/TNNLS.2014.2336852 Published: JUN 2015 | ||||||||||||||||||
Abstract: This paper investigates how to blindly evaluate the visual quality of an image by learning rules from linguistic descriptions. Extensive psychological evidence shows that humans prefer to conduct evaluations qualitatively rather than numerically. The qualitative evaluations are then converted into the numerical scores to fairly benchmark objective image quality assessment (IQA) metrics. Recently, lots of learning-based IQA models are proposed by analyzing the mapping from the images to numerical ratings. However, the learnt mapping can hardly be accurate enough because some information has been lost in such an irreversible conversion from the linguistic descriptions to numerical scores. In this paper, we propose a blind IQA model, which learns qualitative evaluations directly and outputs numerical scores for general utilization and fair comparison. Images are represented by natural scene statistics features. A discriminative deep model is trained to classify the features into five grades, corresponding to five explicit mental concepts, i.e., excellent, good, fair, poor, and bad. A newly designed quality pooling is then applied to convert the qualitative labels into scores. The classification framework is not only much more natural than the regression-based models, but also robust to the small sample size problem. Thorough experiments are conducted on popular databases to verify the model's effectiveness, efficiency, and robustness. | ||||||||||||||||||
Accession Number: WOS:000354957000013 | ||||||||||||||||||
PubMed ID: 25122842 | ||||||||||||||||||
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ISSN: 2162-237X | ||||||||||||||||||
eISSN: 2162-2388 |
Record 119 of 243 | |||||||||||||||||||||
Title: Bezier Interpolation for 3-D Freehand Ultrasound | |||||||||||||||||||||
Author(s): Huang, QH (Huang, Qinghua); Huang, YP (Huang, Yanping); Hu, W (Hu, Wei); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON HUMAN-MACHINE SYSTEMS Volume: 45 Issue: 3 Pages: 385-392 DOI: 10.1109/THMS.2014.2374551 Published: JUN 2015 | |||||||||||||||||||||
Abstract: Freehand 3-D ultrasound (US) produces 3-D volume data of anatomical objects from a sequence of irregularly located 2-D B-mode US images (B-scans). In 3-D US, the voxel intensities are calculated by interpolating those pixels from raw B-scans. Current interpolation algorithms do not consider sparsity of the raw data and are time consuming in computation. In this paper, we aim to perform the 3-D reconstruction of freehand US with sparse raw data in a more efficient manner. A novel interpolation algorithm takes advantage of Bezier curves. A single sweep of raw B-scans is collected, and the third-order Bezier curves are employed for approximating the voxels located in a control window. In in vitro and in vivo experiments, a fetus phantom and a subject's forearm were scanned using the freehand 3-D US system and reconstructed using the proposed Bezier interpolation algorithm and three popular interpolation algorithms, respectively. The results showed that the proposed algorithm significantly outperformed the other three algorithms when the raw B-scans were relatively sparse and the interpolation error in gray level can be reduced by 0.51-5.07. The speed for 3-D reconstruction can be improved by 90.6-97.2% because a single third-order Bezier curve using four control points (i.e., the pixel points) is able to estimate more than four voxels, whereas the estimation of a voxel value often requires a number of pixels in conventional techniques. | |||||||||||||||||||||
Accession Number: WOS:000354532400010 | |||||||||||||||||||||
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ISSN: 2168-2291 | |||||||||||||||||||||
eISSN: 2168-2305 |
Record 120 of 243 | ||||||
Title: Active control of beams by metallic nanoslit array lens with movable dielectric substrate | ||||||
Author(s): Jia, S (Jia, Sen); Wang, XH (Wang, Xianhua); Wu, YM (Wu, Yiming); Xiao, MS (Xiao, Maosen); Fan, PG (Fan, Pengge); Wang, ZY (Wang, Zhiyong) | ||||||
Source: APPLIED PHYSICS EXPRESS Volume: 8 Issue: 6 Article Number: 062001 DOI: 10.7567/APEX.8.062001 Published: JUN 2015 | ||||||
Abstract: We proposed a plasmonic structure consisting of uniform metallic nanoslits with a movable dielectric substrate for subwavelength beam manipulation. In this structure, the phase of incident light can be modulated beforehand by the substrate before bumping the metal slits; therefore, the shape of transmitted light from nanoslits can be actively controlled by changing the substrate profile. According to this idea, plasmonic lenses with different functions, such as focusing light to two points, focus length variation, and beam deflection, are designed and investigated numerically. The proposed structure has a unique advantage of multifunction and reduces the difficulty in fabrication. (C) 2015 The Japan Society of Applied Physics | ||||||
Accession Number: WOS:000358071400017 | ||||||
Author Identifiers: | ||||||
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ISSN: 1882-0778 | ||||||
eISSN: 1882-0786 |
Record 121 of 243 |
Title: Performance analysis of compressive ghost imaging based on different signal reconstruction techniques |
Author(s): Kang, Y (Kang, Yan); Yao, YP (Yao, Yin-Ping); Kang, ZH (Kang, Zhi-Hua); Ma, L (Ma, Lin); Zhang, TY (Zhang, Tong-Yi) |
Source: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION Volume: 32 Issue: 6 Pages: 1063-1067 DOI: 10.1364/JOSAA.32.001063 Published: JUN 2015 |
Abstract: We present different signal reconstruction techniques for implementation of compressive ghost imaging (CGI). The different techniques are validated on the data collected from ghost imaging with the pseudothermal light experimental system. Experiment results show that the technique based on total variance minimization gives high-quality reconstruction of the imaging object with less time consumption. The different performances among these reconstruction techniques and their parameter settings are also analyzed. The conclusion thus offers valuable information to promote the implementation of CGI in real applications. (C) 2015 Optical Society of America |
Accession Number: WOS:000355633300007 |
PubMed ID: 26367039 |
ISSN: 1084-7529 |
eISSN: 1520-8532 |
Record 122 of 243 |
Title: Carrier-Envelope Phase Measurement With Linear Optical Sampling |
Author(s): Li, FT (Li, Feitao); Hu, H (Hu, Hui); Zhao, W (Zhao, Wei); Liu, YS (Liu, Yuanshan) |
Source: IEEE PHOTONICS JOURNAL Volume: 7 Issue: 3 Article Number: 7800607 DOI: 10.1109/JPHOT.2015.2420688 Published: JUN 2015 |
Abstract: In the few-cycle pulses, the temporal evolution of the electric field sensitively depends on the carrier-envelope phase (CEP). The ability to measure and stabilize the CEP therefore becomes a crucial issue for all applications. However, few studies are focused on the measurement of CEP with coherent linear optical sampling. We propose an efficient method to measure the CEP of the frequency comb pulses by employing a high-resolution linear optical sampling technique. It is shown that constant chirp and pulsewidth of frequency comb pulses have negligible effect on the CEP measurement. |
Accession Number: WOS:000354188100023 |
ISSN: 1943-0655 |
eISSN: 1943-0647 |
Record 123 of 243 | ||||||
Title: Ultra-broadband and polarization-insensitive wide-angle terahertz metamaterial absorber | ||||||
Author(s): Li, XW (Li, Xinwang); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan) | ||||||
Source: PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS Volume: 15 Pages: 81-88 DOI: 10.1016/j.photonics.2015.04.002 Published: JUN 2015 | ||||||
Abstract: In this paper, an ultra-broadband and polarization insensitive terahertz (THz) metamaterial absorber is presented and investigated. With the optimization of the structural parameters, resonant peaks are merged into a broadband absorption spectrum. The simulation results demonstrate that a wide bandwidth of 3.1 THz is obtained in the range from 2.6 to 5.7 THz, where the absorption is higher than 90% for the normal incident THz waves. The full width at half maximum (FWHM) of absorption spectrum is 95% with respect to central frequency (similar to 4 THz), which is five times greater than the FWHM of a single layer structure. Furthermore, this structure can keep the absorption above 88% over a large frequency range (>2.5 THz) when the incident angle is smaller than 50 degrees. This metamaterial absorber can find potential applications in terahertz imaging and stealth technology. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000358812700010 | ||||||
Author Identifiers: | ||||||
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ISSN: 1569-4410 | ||||||
eISSN: 1569-4429 |
Record 124 of 243 | |||||||||
Title: Fabrication and characterization of carbon/oxygen-implanted waveguides in Nd<SUP>3+</SUP>-doped phosphate glasses | |||||||||
Author(s): Liu, CX (Liu, Chun-Xiao); Xu, J (Xu, Jun); Fu, LL (Fu, Li-Li); Zheng, RL (Zheng, Rui-Lin); Zhou, ZG (Zhou, Zhi-Guang); Li, WN (Li, Wei-Nan); Guo, HT (Guo, Hai-Tao); Lin, SB (Lin, She-Bao); Wei, W (Wei, Wei) | |||||||||
Source: OPTICAL ENGINEERING Volume: 54 Issue: 6 Article Number: 067106 DOI: 10.1117/1.OE.54.6.067106 Published: JUN 2015 | |||||||||
Abstract: Optical planar waveguides in Nd-3-Hdoped phosphate glasses are fabricated by a 6.0-MeV carbon ion implantation with a dose of 6.0 x 1014 ions/cm2 and a 6.0-MeV oxygen ion implantation at a fluence of 6.0 x 1014 ions/cm(2), respectively. The guided modes and the corresponding effective refractive indices were measured by a modal 2010 prism coupler. The refractive index profiles of the waveguides were analyzed based on the stopping and range of ions in matter and the RCM reflectivity calculation method. The near-field light intensity distributions were measured and simulated by an end-face coupling method and a finite-difference beam propagation method, respectively. The comparison of optical properties between the carbon-implanted waveguide and the oxygen-implanted waveguide was carried out. The microluminescence and Raman spectroscopy investigations reveal that fluorescent properties of Nd3- ions and glass microstructure are well preserved in the waveguide region, which suggests that the carbon/oxygen-implanted waveguide is a good candidate for integrated photonic devices. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) | |||||||||
Accession Number: WOS:000358261000024 | |||||||||
Author Identifiers: | |||||||||
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ISSN: 0091-3286 | |||||||||
eISSN: 1560-2303 |
Record 125 of 243 | |||||||||||||||||||||||||||
Title: Narrow-linewidth double-peak figure-eight passively mode-locked fiber laser | |||||||||||||||||||||||||||
Author(s): Liu, XL (Liu, Xianglian); Li, XH (Li, Xiaohui); Zhang, W (Zhang, Wei); Wang, YS (Wang, Yishan) | |||||||||||||||||||||||||||
Source: LASER PHYSICS Volume: 25 Issue: 6 Article Number: 065105 DOI: 10.1088/1054-660X/25/6/065105 Published: JUN 2015 | |||||||||||||||||||||||||||
Abstract: We report on the experimental observation of narrow-linewidth double-peak dissipative solitons in a figure-eight Yb-doped passively mode-locked fiber laser in the large net normal cavity dispersion regime. Without any physical bandpass filters in the cavity, stable mode-locking pulses with a duration of 416 ps and a 3 dB bandwidth of 0.3 nm can be directly generated from the laser cavity. The edge-to-edge bandwidth of the spectrum is about 5 nm. The repetition rate of the dissipative solitons is 3.9 MHz. With the increase of pump power, the central wavelength of the dissipative solitons shifts toward a short wavelength and edge-to-edge spectral widths are widened gradually. These phenomena are theoretically explained. | |||||||||||||||||||||||||||
Accession Number: WOS:000355083000011 | |||||||||||||||||||||||||||
Author Identifiers: | |||||||||||||||||||||||||||
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ISSN: 1054-660X | |||||||||||||||||||||||||||
eISSN: 1555-6611 |
Record 126 of 243 | ||||||||||||||||||||||||||||||||||||||||||
Title: Single-polarization, dual-wavelength mode-locked Yb-doped fiber laser by a 45°-tilted fiber grating | ||||||||||||||||||||||||||||||||||||||||||
Author(s): Liu, XL (Liu, Xianglian); Wang, HS (Wang, Hushan); Wang, YS (Wang, Yishan); Yan, ZJ (Yan, Zhijun); Zhang, L (Zhang, Lin) | ||||||||||||||||||||||||||||||||||||||||||
Source: LASER PHYSICS LETTERS Volume: 12 Issue: 6 Article Number: 065102 DOI: 10.1088/1612-2011/12/6/065102 Published: JUN 2015 | ||||||||||||||||||||||||||||||||||||||||||
Abstract: We experimentally demonstrate an all-fiber single-polarization dual-wavelength Yb-doped fiber laser passively mode-locked with a 45 degrees-tilted fiber grating for the first time. Stable dual-wavelength operation exhibits double-rectangular spectral profile centered at 1033 and 1053 nm, respectively. The 3 dB bandwidth of each rectangular optical spectrum is estimated as 10 nm. The separation of two fundamental repetition rates is 6 kHz. By employing the 45 degrees TFG with the polarization-dependent loss of 33 dB, output pulses with 27 dB polarization extinction ratio are implemented in the experiment. The single pulse centered at 1053 nm is researched by using a filter at the output port of the laser, and the experimental results denote that the output ps pulses are highly chirped. The formation mechanism of dual-wavelength operation is investigated. | ||||||||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000356489100003 | ||||||||||||||||||||||||||||||||||||||||||
Author Identifiers: | ||||||||||||||||||||||||||||||||||||||||||
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ISSN: 1612-2011 | ||||||||||||||||||||||||||||||||||||||||||
eISSN: 1612-202X |
Record 127 of 243 | ||||||
Title: Yb-doped large-mode-area laser fiber fabricated by halide-gas-phase-doping technique | ||||||
Author(s): Peng, K (Peng, Kun); Wang, YY (Wang, Yuying); Ni, L (Ni, Li); Wang, Z (Wang, Zhen); Gao, C (Gao, Cong); Zhan, H (Zhan, Huan); Wang, JJ (Wang, Jianjun); Jing, F (Jing, Feng); Lin, AX (Lin, Aoxiang) | ||||||
Source: LASER PHYSICS Volume: 25 Issue: 6 Article Number: 065801 DOI: 10.1088/1054-660X/25/6/065801 Published: JUN 2015 | ||||||
Abstract: In this manuscript, we designed a rare-earth-halide gas-phase-doping setup to fabricate a large-mode-area fiber for high power laser applications. YbCl3 and AlCl3 halides are evaporated, carried respectively and finally mixed with usual host gas material SiCl4 at the hot zone of MCVD system. Owing to the all-gas-phasing reaction process and environment, the home-made Yb-doped fiber preform has a homogeneous large core and modulated refractive index profile to keep high beam quality. The drawn fiber core has a small numerical aperture of 0.07 and high Yb concentration of 9500 ppm. By using a master oscillator power amplifier system, nearly kW-level (951 W) laser output power was obtained with a slope efficiency of 83.3% at 1063.8 nm, indicating the competition and potential of the halide-gas-phase-doping technique for high power laser fiber fabrication. | ||||||
Accession Number: WOS:000355083000022 | ||||||
Author Identifiers: | ||||||
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ISSN: 1054-660X | ||||||
eISSN: 1555-6611 |
Record 128 of 243 | |||||||||||||||
Title: Label Image Constrained Multiatlas Selection | |||||||||||||||
Author(s): Yan, PK (Yan, Pingkun); Cao, YH (Cao, Yihui); Yuan, Y (Yuan, Yuan); Turkbey, B (Turkbey, Baris); Choyke, PL (Choyke, Peter L.) | |||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 6 Pages: 1158-1168 DOI: 10.1109/TCYB.2014.2346394 Published: JUN 2015 | |||||||||||||||
Abstract: Multiatlas based method is commonly used in medical image segmentation. In multiatlas based image segmentation, atlas selection and combination are considered as two key factors affecting the performance. Recently, manifold learning based atlas selection methods have emerged as very promising methods. However, due to the complexity of prostate structures in raw images, it is difficult to get accurate atlas selection results by only measuring the distance between raw images on the manifolds. Although the distance between the regions to be segmented across images can be readily obtained by the label images, it is infeasible to directly compute the distance between the test image (gray) and the label images (binary). This paper tries to address this problem by proposing a label image constrained atlas selection method, which exploits the label images to constrain the manifold projection of raw images. Analyzing the data point distribution of the selected atlases in the manifold subspace, a novel weight computation method for atlas combination is proposed. Compared with other related existing methods, the experimental results on prostate segmentation from T2w MRI showed that the selected atlases are closer to the target structure and more accurate segmentation were obtained by using our proposed method. | |||||||||||||||
Accession Number: WOS:000354532000005 | |||||||||||||||
PubMed ID: 25415994 | |||||||||||||||
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ISSN: 2168-2267 | |||||||||||||||
eISSN: 2168-2275 |
Record 129 of 243 | ||||||||||||
Title: Projection-Based NMF for Hyperspectral Unmixing | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Feng, YC (Feng, Yachuang); Lu, XQ (Lu, Xiaoqiang) | ||||||||||||
Source: IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING Volume: 8 Issue: 6 Special Issue: SI Pages: 2632-2643 DOI: 10.1109/JSTARS.2015.2427656 Published: JUN 2015 | ||||||||||||
Abstract: As a widely concerned research topic, many advanced algorithms have been proposed for hyperspectral unmixing. However, they may fail to accurately identify endmember signatures when coming across insufficient spatial resolution. To deal with this problem, an algorithm based on semisupervised linear sparse regression is proposed, in which unmixing procedure is reduced to seeking an optimal subset from the spectral library to best model mixed pixels in the scene. However, the number of the spectra with nonzero abundance is much more than that of the true endmember signatures. Furthermore, the selection of library spectra as endmember signatures is undesirable due to the divergent imaging conditions. In this paper, a novel projection-based nonnegative matrix factorization (NMF) (PNMF) algorithm is proposed by importing spectra library into the NMF framework. The main novelties of this paper are listed as follows. 1) By introducing the spectral library, the extraction of endmember signatures is no longer restricted by spatial resolution. 2) Related spectra are selected and projected onto a subspace containing the endmember signatures. So that the number of endmember signatures is controlled by dimension of the subspace. 3) In PNMF, the endmember signatures are adaptively generated from the spectral library, and are matched with the observed hyperspectral images. This overcomes the difficulty caused by diverse imaging conditions, and makes the proposed algorithm more practical for real applications. The experimental results, conducted on both synthetic and real hyperspectral data, illustrate the advantages of the proposed algorithm when compared with the state-of-the-art algorithms. | ||||||||||||
Accession Number: WOS:000359264000028 | ||||||||||||
Conference Title: 6th Workshop on Hyperspectral Image and Signal Processing - Evolution in Remote Sensing (WHISPERS) | ||||||||||||
Conference Date: JUN 24-27, 2014 | ||||||||||||
Conference Location: Lausanne, SWITZERLAND | ||||||||||||
Author Identifiers: | ||||||||||||
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ISSN: 1939-1404 | ||||||||||||
eISSN: 2151-1535 |
Record 130 of 243 | ||||||||||||
Title: Substance Dependence Constrained Sparse NMF for Hyperspectral Unmixing | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Fu, M (Fu, Min); Lu, XQ (Lu, Xiaoqiang) | ||||||||||||
Source: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Volume: 53 Issue: 6 Pages: 2975-2986 DOI: 10.1109/TGRS.2014.2365953 Published: JUN 2015 | ||||||||||||
Abstract: Hyperspectral unmixing is one of the most important problems in analyzing remote sensing images, which aims to decompose a mixed pixel into a collection of constituent materials named endmembers and their corresponding fractional abundances. Recently, various methods have been proposed to incorporate sparse constraints into hyperspectral unmixing and achieve advanced performance. However, most of them ignore the complex distribution of substances in hyperspectral data so that they are only effective in limited cases. In this paper, the concept of substance dependence is introduced to help hyperspectral unmixing. Generally, substance dependence can be considered in a local region by K-nearest neighbors method. However, since substances of hyperspectral images are complicatedly distributed, number K of the most similar substances to each substance is difficult to decide. In this case, substance dependence should be considered in the whole data space, and the number of the K most similar substances to each substance can be adaptively determined by searching from the whole space. Through maintaining the substance dependence during unmixing, the abundances resulted from the proposed method are closer to the real fractions, which lead to better unmixing performance. The following contributions can be summarized. 1) The concept of substance dependence is proposed to describe the complicated relationship between substances in the hyperspectral image. 2) We propose substance dependence constrained sparse nonnegative matrix factorization ( SDSNMF) for hyperspectral unmixing. Using SDSNMF, we meet or exceed state-of-the-art unmixing performance. 3) Adequate experiments on both synthetic and real hyperspectral data have been tested. Compared with the state-of-the-art methods, the experimental results prove the superiority of the proposed method. | ||||||||||||
Accession Number: WOS:000351063800001 | ||||||||||||
Author Identifiers: | ||||||||||||
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ISSN: 0196-2892 | ||||||||||||
eISSN: 1558-0644 |
Record 131 of 243 | ||||||||||||
Title: Generation of low repetition rate sub-nanosecond pulses in doubly QML Nd:Lu<sub>0.5</sub>Y<sub>0.5</sub>VO<sub>4</sub> and Nd:YVO<sub>4</sub> lasers with EO and transmission SSA | ||||||||||||
Author(s): Zhang, HJ (Zhang, Haijuan); Zhao, SZ (Zhao, Shengzhi); Zhao, J (Zhao, Jia); Yang, KJ (Yang, Kejian); Li, GQ (Li, Guiqiu); Li, DC (Li, Dechun); Li, T (Li, Tao); Qiao, WC (Qiao, Wenchao); Wang, YG (Wang, Yonggang) | ||||||||||||
Source: OPTICS AND LASER TECHNOLOGY Volume: 69 Pages: 39-43 DOI: 10.1016/j.optlastec.2014.12.017 Published: JUN 2015 | ||||||||||||
Abstract: By employing the mixed crystal Nd:Lu0.5Y0.5VO4 and the single crystal Nd:YVO4 as the laser media, the characteristics of the QML laser doubly modulated by electro-optic (BO) modulator and transmission semiconductor saturable absorber (T-SSA) are studied. Under the Same cavity parameters, the properties of the low repetition rate sub-nanosecond pulses generated from Nd:Lu0.5Y0.5VO4 and Nd:YVO4 laser are compared. The experimental results show that Nd:Lu0.5Y0.5VO4 laser can generate shorter pulse width than Nd:YVO4 laser, and meanwhile, needs lower pump power to generate low repetition rate sub-nanosecond pulses. The shortest pulse durations obtained from the doubly QML Nd:Lu0.5Y0.5VO4 and Nd:YVO4 lasers are estimated to be 204 and 294 ps, with the corresponding peak power of 3.4 and 3.04 MW, respectively. (C) 2014 Elsevier Ltd. All rights reserved. | ||||||||||||
Accession Number: WOS:000350521400007 | ||||||||||||
Author Identifiers: | ||||||||||||
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ISSN: 0030-3992 | ||||||||||||
eISSN: 1879-2545 |
Record 132 of 243 | |||||||||||||||||||||||||||||||||||||||
Title: Low-Loss Slow-Light in Periodic Plasmonic Waveguides | |||||||||||||||||||||||||||||||||||||||
Author(s): Zhang, LX (Zhang, Lingxuan); Lu, XY (Lu, Xiaoyuan); Gong, YK (Gong, Yongkang); Copner, N (Copner, Nigel); Zhao, W (Zhao, Wei); Wang, GX (Wang, Guoxi); Zhang, WF (Zhang, Wenfu) | |||||||||||||||||||||||||||||||||||||||
Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 27 Issue: 11 Pages: 1208-1211 DOI: 10.1109/LPT.2015.2414939 Published: JUN 1 2015 | |||||||||||||||||||||||||||||||||||||||
Abstract: We have proposed and investigated two kinds of waveguide systems (i.e., dielectric-dielectric-metal and dielectric-metal-dielectric waveguides) which are able to support low-loss slow-light guided mode at telecommunication regime of 1.55 mu m. Simulation results demonstrate that the propagation length of the proposed waveguides is as long as tens or even hundreds of micrometers, which is more than ten times higher than that of the traditional metal-dielectric-metal waveguides. Moreover, the proposed waveguides have better slow light performance and a figure of merit that can reach a value as high as 18 000. In addition, the slow-down factor can be flexibly tuned by adjusting the geometrical parameters. The proposed waveguide have advantages of low loss and compact configuration, which can find potential applications, such as optical buffers, in highly integrated optical communication systems. | |||||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000354457400018 | |||||||||||||||||||||||||||||||||||||||
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ISSN: 1041-1135 | |||||||||||||||||||||||||||||||||||||||
eISSN: 1941-0174 |
Record 133 of 243 | ||||||||||||||||||
Title: Picosecond Laser Machining of Deep Holes in Silicon Infiltrated Silicon Carbide Ceramics | ||||||||||||||||||
Author(s): Zhang, Q (Zhang Qing); Wang, CH (Wang Chunhui); Liu, YS (Liu Yongsheng); Zhang, LT (Zhang Litong); Cheng, GH (Cheng Guanghua) | ||||||||||||||||||
Source: JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION Volume: 30 Issue: 3 Pages: 437-441 DOI: 10.1007/s11595-015-1167-9 Published: JUN 2015 | ||||||||||||||||||
Abstract: Silicon infiltrated silicon carbide (Si-SiC) ceramics, as high hardness materials, are difficult to machine, especially drilling micro-holes. In this study, the interaction of picosecond laser pulses (1 ps at 1 030 nm) with Si-SiC ceramics was investigated. Variations of the diameter and depth of circular holes with the growth of the laser energy density were obtained. The results indicate that the increase of machining depth follows a nonlinear relation with the increasing of laser energy density, while the diameter has little change with that. Moreover, it is found that some debris and particles are deposited around and inside the holes and waviness is in the entrance and at walls of the holes after laser processing. | ||||||||||||||||||
Accession Number: WOS:000357860000001 | ||||||||||||||||||
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ISSN: 1000-2413 | ||||||||||||||||||
eISSN: 1993-0437 |
Record 134 of 243 | ||||||
Title: Micromachining features of TiC ceramic by femtosecond pulsed laser | ||||||
Author(s): Zhang, Y (Zhang, Ying); Wang, YQ (Wang, Yuqian); Zhang, JZ (Zhang, Junzhan); Liu, YS (Liu, Yongsheng); Yang, XJ (Yang, Xiaojun); Zhang, Q (Zhang, Qing) | ||||||
Source: CERAMICS INTERNATIONAL Volume: 41 Issue: 5 Pages: 6525-6533 DOI: 10.1016/j.ceramint.2015.01.095 Part: A Published: JUN 2015 | ||||||
Abstract: Femtosecond pulsed laser was employed to drill blind holes (or circle surfaces) and through holes in titanium carbide (TiC) ceramic by the helical drilling technique. The effects of spiral number, processing time, laser fluence and repetition rate on the qualities of holes (or circle surfaces) were investigated. Morphology of holes (or circle surfaces) and composition of irradiated areas were analyzed by a scanning electron microscope (SEM), a three-dimensional super depth digital microscope and energy dispersive spectroscopy (EDS), etc. The results indicated that laser fluence and repetition rate had major effects on ablation efficiency and quality. Blind holes with taper bottom were observed when the laser fluence was above 6.37 x 10(-1) J/mm(2). With the increase of laser fluence, hole depth increased firstly and then decreased. The change in hole diameter decreased when the laser fluence was above 0.51 J/mm(2). The effects of repetition rate on hole depth were similar to that of laser fluence, while it showed a faint change in hole diameter at laser fluence of 1.02 J/mm(2) and laser repetition rate ranging from 2 to 140 kHz. Furthermore, through holes were attained at narrowed laser fluence ranging from 0.51 to 1.53 J/mm(2). The drilled holes had good circular geometry for entrance and exit. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved. | ||||||
Accession Number: WOS:000353176300052 | ||||||
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ISSN: 0272-8842 | ||||||
eISSN: 1873-3956 |
Record 135 of 243 | |||||||||
Title: Supercontinuum generation in strip/slot hybrid waveguide with flat and low dispersion | |||||||||
Author(s): Zhang, YC (Zhang, Yuchao); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu) | |||||||||
Source: APPLIED OPTICS Volume: 54 Issue: 15 Pages: 4850-4856 DOI: 10.1364/AO.54.004850 Published: MAY 20 2015 | |||||||||
Abstract: A strip/slot hybrid waveguide with double horizontal silicon nanocrystals slots is proposed to achieve flat and low dispersion with four zero dispersion wavelengths. By tuning structural parameters of the waveguide, dispersion tailoring is fully characterized. The flat dispersion varying between -13 and 14 ps/(nm . km) is obtained over an 845 nm bandwidth. A broadband supercontinuum spectrum, spanning from 1.15 to 3.65 mu m in the -15 dB level, was generated in this waveguide pumped by a femtosecond pulse at 1.86 mu m. Results indicate that the waveguide has great potential in near- and mid-infrared nonlinear applications. (C) 2015 Optical Society of America | |||||||||
Accession Number: WOS:000354898100032 | |||||||||
PubMed ID: 26192523 | |||||||||
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ISSN: 1559-128X | |||||||||
eISSN: 2155-3165 |
Record 136 of 243 | ||||||
Title: Research on the high indium content InGaAs multiple quantum wells wafers for λ > 1.55 μm laser diodes | ||||||
Author(s): Lin, T (Lin, Tao); Sun, H (Sun, Hang); Zhang, HQ (Zhang, Haoqing); Wang, YG (Wang, Yonggang); Lin, N (Lin, Nan); Ma, XY (Ma, Xiaoyu) | ||||||
Source: JOURNAL OF ALLOYS AND COMPOUNDS Volume: 631 Pages: 283-287 DOI: 10.1016/j.jallcom.2015.01.120 Published: MAY 15 2015 | ||||||
Abstract: The effects of TMIn flow rate and AsH3 flow rate on the photoluminescence spectra of the high indium content InGaAs multiple quantum wells for lambda > 1.55 mu m laser diodes have been investigated both experimentally and theoretically. The wavelength peak red-shifted about 4.8 nm for increasing 1 sccm H-2 flow rate through TMIn under a AsH3 flow rate of 150 sccm, while the wavelength shift increases to 6.5 nm at a higher AsH3 flow rate of 300 sccm. Results show that more AsH3 flow rate will promote much TMGa pyrolysis than TMIn in the high indium content InGaAs growth. Considering the influence of growth parameters, the longest wavelength of 1.889 mu m among the InGaAs/InGaAsP strained MQWs samples was obtained with high crystal quality. (C) 2015 Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000350388800044 | ||||||
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ISSN: 0925-8388 | ||||||
eISSN: 1873-4669 |
Record 137 of 243 |
Title: Research on large dynamic range streak camera based on electron-bombarded CCD |
Author(s): Zhu, M (Zhu Min); Tian, JS (Tian Jin-Shou); Wen, WL (Wen Wen-Long); Wang, JF (Wang Jun-Feng); Cao, XB (Cao Xi-Bin); Lu, Y (Lu Yu); Xu, XY (Xu Xiang-Yan); Sai, XF (Sai Xiao-Feng); Liu, HL (Liu Hu-Lin); Wang, X (Wang Xing); Li, WH (Li Wei-Hua) |
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 9 Special Issue: SI Article Number: 098501 DOI: 10.7498/aps.64.098501 Published: MAY 5 2015 |
Abstract: In order to detect the weaker on greater span of light signals, the dynamic range, spatial resolution, and the signal to noise ratio of the streak camera need to be improved to meet further diagnostic requirements in scientific area of materials, biology, information, semiconductor physics and energy, etc. Therefore, we design a streak camera with a larger dynamic range based on electron-bombarded CCD. Using the rectangle-framed electrode and electric quadruple lens in the streak camera can reduce its space charge effect and shorten the space charge interaction time by improving electron accelerating voltage to minimize the electron transit time. Using a back-illuminated CCD, which is based on the electron bombardment readout technology as image device to replace the traditional intensified CCD can shorten the chain of image conversion and greatly reduce the image degradation in the conversion of ultrafast diagnostic equipment. The signal to noise ratio, spatial resolution and dynamic range of the streak camera may gain improvement. Experimental results show that the static spatial resolution is better than 35 lp/mm and the dynamic spatial resolution is up to 20 lp/mm. Deflection sensitivity is 60.76 mm/kV and dynamic range reaches 2094: 1. Nonlinear scanning speed is 5.04%. EBS gain of the streak camera can be over 3000. |
Accession Number: WOS:000354605400056 |
ISSN: 1000-3290 |
Record 138 of 243 |
Title: Quadruple-wavelength tunable and dual-wavelength switchable ultrafast fiber laser |
Author(s): Chen, GW (Chen, G. W.); Cui, YD (Cui, Y. D.) |
Source: LASER PHYSICS Volume: 25 Issue: 5 Article Number: 055103 DOI: 10.1088/1054-660X/25/5/055103 Published: MAY 2015 |
Abstract: We propose a quadruple-wavelength tunable and dual-wavelength switchable ultrafast fiber laser by incorporating four fiber Bragg gratings. The tunable operations depend on the losses induced by intracavity polarization controllers. By appropriately setting the states of PCs, quadruple-wavelength picosecond solitons can be realized at 1530, 1540, 1550 and 1560 nm, respectively. When the losses are suitable, solitons with two different wavelengths can reach the gain balance, and the dual-wavelength operations are switched among the four wavelengths. These results demonstrate that the proposed fiber laser offers potential opportunities in exploiting flexibly switchable multi-wavelength pulse sources. |
Accession Number: WOS:000355081500004 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 139 of 243 | ||||||||||||||||||
Title: A multiband THz bandpass filter based on multiple-resonance excitation of a composite metamaterial | ||||||||||||||||||
Author(s): Chen, X (Chen, Xu); Fan, WH (Fan, Wen-Hui) | ||||||||||||||||||
Source: MATERIALS RESEARCH EXPRESS Volume: 2 Issue: 5 Article Number: 055801 DOI: 10.1088/2053-1591/2/5/055801 Published: MAY 2015 | ||||||||||||||||||
Abstract: We present a systematic numerical study on a metal-dielectric-metal (MDM) sandwich structure for multiple resonance transmission in terahertz (THz) region. The designed structure consists of periodic square close ring array on both side of a flexible dielectric substrate, exhibits a multiband transmission, with low average insertion loss, steep skirts and high out-of-band rejection. In addition, due to its rotationally symmetric structure, this filter is polarization-insensitive for normal incidence of the electromagnetic waves, keeping highly transmission at a wide range of incident angles for transverse electric waves and transverse magnetic waves. The metamaterial structure can be utilized as a desirable multiband filter with many practical applications, especially for THz communication, spectroscopic detection and phase imaging. | ||||||||||||||||||
Accession Number: WOS:000370018500023 | ||||||||||||||||||
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ISSN: 2053-1591 |
Record 140 of 243 | |||||||||
Title: Effects of Cu on properties of vitrified bond and vitrified CBN composites | |||||||||
Author(s): Feng, DD (Feng, Dandan); Wu, WJ (Wu, Weijie); Wang, PF (Wang, Pengfei); Zhu, YM (Zhu, Yumei); Zhai, CX (Zhai, Chenxi); Li, ZH (Li, Zhihong) | |||||||||
Source: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS Volume: 50 Pages: 269-273 DOI: 10.1016/j.ijrmhm.2015.01.002 Published: MAY 2015 | |||||||||
Abstract: In order to obtain vitrified CBN composites, which have high performance of both thermal conductivity and mechanical strength, the effects of Cu on the properties of vitrified bond and the vitrified CBN composites were comprehensively investigated in this work. The results show that the vitrified CBN composites incorporating 6 wt.% Cu display excellent comprehensive performance including the increases by about 62.1% in thermal conductivity and 16.1% in bending strength. The substantial performance improvement of the vitrified bond and the vitrified CBN composites may be attributed to the high thermal conductivity and good ductility of metal Cu and its toughening effect on the vitrified bond, as well as formation of thermal conductive path in the vitrified bond. (C) 2015 Elsevier Ltd. All rights reserved. | |||||||||
Accession Number: WOS:000352680800039 | |||||||||
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ISSN: 0263-4368 |
Record 141 of 243 |
Title: Evanescent-field interaction with carbon nanotubes for a multi-wavelength ultrafast all-fiber laser |
Author(s): Han, XX (Han, X. X.) |
Source: LASER PHYSICS Volume: 25 Issue: 5 Article Number: 055104 DOI: 10.1088/1054-660X/25/5/055104 Published: MAY 2015 |
Abstract: We report on the experimental observation of multi-wavelength operations based on the evanescent-field interaction with carbon nanotubes (CNTs). The saturable absorber (SA) is fabricated by depositing CNTs on a D-shaped fiber (DF). In the experiment, switchable dual-wavelength picosecond solitons with central wavelengths of 1532.2, 1556.6 nm and 1529.4, 1531.0 nm are achieved. Several single wavelength operations are also delivered by the all-fiber laser. Single-and multi-wavelength pulse emissions are effectively controlled by changing the pump power and optimizing the polarization controller. Our experiment demonstrates that the DF-SA can work as a versatile mode locker in ultrafast lasers. The flexible all-fiber laser is convenient and attractive for practical applications such as fiber optic sensing and photonic component characterization. |
Accession Number: WOS:000355081500005 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 142 of 243 | |||||||||||||||
Title: Flexible sliding windows with adaptive pixel strides | |||||||||||||||
Author(s): Jiang, XH (Jiang, Xiaoheng); Pang, YW (Pang, Yanwei); Pan, J (Pan, Jing); Li, XL (Li, Xuelong) | |||||||||||||||
Source: SIGNAL PROCESSING Volume: 110 Special Issue: SI Pages: 37-45 DOI: 10.1016/j.sigpro.2014.08.004 Published: MAY 2015 | |||||||||||||||
Abstract: Detecting humans, faces, and other objects is important for pose estimation, behaviour analysis, and recognition. Most of the existing detection methods exploit sliding-window technique that typically evaluates image patches at uniform grids, with constant pixel strides along horizontal and vertical directions in an image. This approach can lead to excessively redundant computation since target object instances are relatively rare events compared to non-objects of the background. Therefore, most of the computation is unnecessarily wasted on the background. In this paper, to deal with this problem, we propose to scan the image using adaptive instead of fixed (unchanged) strides. That is, a high response of current sliding window generates small strides for the subsequent sliding windows in both horizontal and vertical directions, which means an object instance is likely to exist around. Otherwise, a low response gives large pixel strides and results in sparse sampling on the background. As a result, the areas of potential object instances are densely sampled and the areas of non-objects are sparsely sampled, leading to the reduction of total computation cost without loss of detection accuracy. Experimental results on face detection demonstrate the high efficiency and effectiveness of the proposed method. (C) 2014 Elsevier B.V. All rights reserved. | |||||||||||||||
Accession Number: WOS:000350183700005 | |||||||||||||||
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ISSN: 0165-1684 | |||||||||||||||
eISSN: 1872-7557 |
Record 143 of 243 | ||||||||||||
Title: Prediction of Length-of-day Using Gaussian Process Regression | ||||||||||||
Author(s): Lei, Y (Lei, Yu); Guo, M (Guo, Min); Cai, HB (Cai, Hongbing); Hu, DD (Hu, Dandan); Zhao, DN (Zhao, Danning) | ||||||||||||
Source: JOURNAL OF NAVIGATION Volume: 68 Issue: 3 Pages: 563-575 DOI: 10.1017/S0373463314000927 Published: MAY 2015 | ||||||||||||
Abstract: The predictions of Length-Of-Day (LOD) are studied by means of Gaussian Process Regression (GPR). The EOP C04 time-series with daily values from the International Earth Rotation and Reference Systems Service (IERS) serve as the data basis. Firstly, well known effects that can be described by functional models, for example effects of the solid Earth and ocean tides or seasonal atmospheric variations, are removed a priori from the C04 time-series. Only the differences between the modelled and actual LOD, i.e. the irregular and quasi-periodic variations, are employed for training and prediction. Different input patterns are discussed and compared so as to optimise the GPR model. The optimal patterns have been found in terms of the prediction accuracy and efficiency, which conduct the multi-step ahead predictions utilising the formerly predicted values as inputs. Finally, the results of the predictions are analysed and compared with those obtained by other prediction methods. It is shown that the accuracy of the predictions are comparable with that of other prediction methods. The developed method is easy to use. | ||||||||||||
Accession Number: WOS:000352011100010 | ||||||||||||
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ISSN: 0373-4633 | ||||||||||||
eISSN: 1469-7785 |
Record 144 of 243 | |||||||||||||||
Title: Design of a Solid-Core Large-Mode-Area Bragg Fiber | |||||||||||||||
Author(s): Li, L (Li Lu); Pang, LH (Pang Li-Hui); Zhou, ZG (Zhou Zhi-Guang); Zhang, AD (Zhang Ai-Dong); He, JL (He Jian-Li); Si, JH (Si Jin-Hai); Lin, AX (Lin Ao-Xiang) | |||||||||||||||
Source: CHINESE PHYSICS LETTERS Volume: 32 Issue: 5 Article Number: 054201 DOI: 10.1088/0256-307X/32/5/054201 Published: MAY 2015 | |||||||||||||||
Abstract: We report the design and simulation results of a solid-core Bragg fiber with 3-bilayer periodic cladding. The simulation results present single mode bandgap guidance, a large effective area of similar to 400 mu m(2) around 1.08 mu m, a very low bend loss of 0.038 dB/m at 1.08 mu m even under tight bend radius (R = 4 cm), and excellent beam quality. The results indicate that the proposed fiber could be a competitive solution for high-power fiber laser applications. | |||||||||||||||
Accession Number: WOS:000354093300013 | |||||||||||||||
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ISSN: 0256-307X | |||||||||||||||
eISSN: 1741-3540 |
Record 145 of 243 |
Title: All-fiber dual-wavelength laser delivering two types of solitons |
Author(s): Li, WL (Li, W. L.) |
Source: LASER PHYSICS Volume: 25 Issue: 5 Article Number: 055102 DOI: 10.1088/1054-660X/25/5/055102 Published: MAY 2015 |
Abstract: We have proposed a compact all-fiber dual-wavelength laser based on a fiber Bragg grating (FBG) and semiconductor saturable absorber mirror (SESAM). The proposed laser mode locked by single-walled carbon nanotubes (SWNTs) delivers two kinds of solitons with pulse durations of similar to 1 ps and similar to 20 ps. The spectral width of the longer soliton pulses is similar to 0.14 nm, which attributes to the narrow bandwidth of the FBG. Shorter pulses with a spectral width of similar to 4 nm are mainly determined by the cavity length and intracavity dispersion. Our method provides a simple, stable, low-cost, and dual-scale ultrafast-pulsed laser source suitable for practical applications in optical communications and sensing. |
Accession Number: WOS:000355081500003 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 146 of 243 | ||||||||||||||||||||||||
Title: Transfer Learning for Visual Categorization: A Survey | ||||||||||||||||||||||||
Author(s): Shao, L (Shao, Ling); Zhu, F (Zhu, Fan); Li, XL (Li, Xuelong) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 5 Pages: 1019-1034 DOI: 10.1109/TNNLS.2014.2330900 Published: MAY 2015 | ||||||||||||||||||||||||
Abstract: Regular machine learning and data mining techniques study the training data for future inferences under a major assumption that the future data are within the same feature space or have the same distribution as the training data. However, due to the limited availability of human labeled training data, training data that stay in the same feature space or have the same distribution as the future data cannot be guaranteed to be sufficient enough to avoid the over-fitting problem. In real-world applications, apart from data in the target domain, related data in a different domain can also be included to expand the availability of our prior knowledge about the target future data. Transfer learning addresses such cross-domain learning problems by extracting useful information from data in a related domain and transferring them for being used in target tasks. In recent years, with transfer learning being applied to visual categorization, some typical problems, e.g., view divergence in action recognition tasks and concept drifting in image classification tasks, can be efficiently solved. In this paper, we survey state-of-the-art transfer learning algorithms in visual categorization applications, such as object recognition, image classification, and human action recognition. | ||||||||||||||||||||||||
Accession Number: WOS:000353122400010 | ||||||||||||||||||||||||
PubMed ID: 25014970 | ||||||||||||||||||||||||
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ISSN: 2162-237X | ||||||||||||||||||||||||
eISSN: 2162-2388 |
Record 147 of 243 |
Title: Improved non-negative tensor Tucker decomposition algorithm for interference hyper-spectral image compression |
Author(s): Wen, J (Wen Jia); Zhao, JS (Zhao JunSuo); Ma, CW (Ma CaiWen); Wang, CL (Wang CaiLing) |
Source: SCIENCE CHINA-INFORMATION SCIENCES Volume: 58 Issue: 5 Article Number: 052108 DOI: 10.1007/s11432-014-5165-x Published: MAY 2015 |
Abstract: The compression method, first proposed in 2012, is based on the non-negative tensor decomposition for interference hyper-spectral image data. As a tensor is generated by a huge amount of interference hyper-spectral images, the multiplicative update algorithm is made extremely complicated, and even unfeasible. To reduce the computational cost and speed up the convergence, this paper, based on the characteristics of interference hyper-spectral images, develops a new algorithm using different down-sampling factors for different non-negative wavelet sub-band tensors. The experimental results showed that this algorithm could significantly shorten the running time, while maintaining a good compression performance compared with the conventional methods. |
Accession Number: WOS:000353818200002 |
ISSN: 1674-733X |
eISSN: 1869-1919 |
Record 148 of 243 | ||||||||||||
Title: Multi-spectral pedestrian detection | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Lu, XQ (Lu, Xiaoqiang); Chen, X (Chen, Xiao) | ||||||||||||
Source: SIGNAL PROCESSING Volume: 110 Special Issue: SI Pages: 94-100 DOI: 10.1016/j.sigpro.2014.08.003 Published: MAY 2015 | ||||||||||||
Abstract: Pedestrian detection is a crucial problem in human pose recovery and behavior analysis, especially in applications such as visual surveillance, robotics, and drive-assistance systems. Recently, most pedestrian detection approaches of machine learning and signal processing have achieved advanced performance in traditional natural images. However, there exists a limitation on the accuracy in pedestrian detection. The reason behind this is that supporting information for detecting pedestrian is limited. In fact, spectrum besides visible light can provide abundant discriminative information for pedestrian detection. Therefore, it is significative to exploit multi-spectral information for detection task. In this paper, a multi-spectral based pedestrian detection approach is proposed, which not only takes use of the information of red, green and blue (RGB) bands, but also incorporates the information of near-infrared spectrum into the detection process. Latent variable support vector machines (L-SVM) are employed to train the multi-spectral pedestrian detection model. Experiments are implemented on a new dataset containing 1826 multi-spectral image pairs. The experimental results illustrate that utilizing multi-spectral information achieves significant performance improvement in a pedestrian detection task compared with only using RGB information. (C) 2014 Elsevier B.V. All rights reserved. | ||||||||||||
Accession Number: WOS:000350183700010 | ||||||||||||
Author Identifiers: | ||||||||||||
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ISSN: 0165-1684 | ||||||||||||
eISSN: 1872-7557 |
Record 149 of 243 | ||||||
Title: 763 fs Passively mode-locked Yb:Y<sub>2</sub>SiO<sub>5</sub> laser with a graphene oxide absorber mirror | ||||||
Author(s): Zhu, HT (Zhu, Hongtong); Cai, W (Cai, Wei); Wei, JF (Wei, Jiafeng); Liu, J (Liu, Jie); Zheng, LH (Zheng, Lihe); Su, LB (Su, Liangbi); Xu, J (Xu, Jun); Wang, YG (Wang, Yonggang) | ||||||
Source: OPTICS AND LASER TECHNOLOGY Volume: 68 Pages: 120-123 DOI: 10.1016/j.optlastec.2014.11.018 Published: MAY 2015 | ||||||
Abstract: Based on a graphene oxide absorber mirror, the laser-diode pumped mode-locked Yb:Y2SiO5 (Yb:YSO) laser was demonstrated for the first time. The laser generated pulses with pulse duration as short as similar to 763 fs and average output power of 700 mW at the central wavelength of 1059 nm. The corresponding peak power and energy of a single pulse were similar to 8.6 kW and similar to 7.4 nJ, respectively. To our best knowledge, this is the shortest bulk mode-locked laser based on graphene oxide. (C) 2014 Elsevier Ltd. All rights reserved. | ||||||
Accession Number: WOS:000349728400020 | ||||||
Author Identifiers: | ||||||
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ISSN: 0030-3992 | ||||||
eISSN: 1879-2545 |
Record 150 of 243 | ||||||||||||||||||||||||||||||||||||||||||
Title: Volcanic history of the Imbrium basin: A close-up view from the lunar rover Yutu | ||||||||||||||||||||||||||||||||||||||||||
Author(s): Zhang, JH (Zhang, Jinhai); Yang, W (Yang, Wei); Hu, S (Hu, Sen); Lin, YT (Lin, Yangting); Fang, GY (Fang, Guangyou); Li, CL (Li, Chunlai); Peng, WX (Peng, Wenxi); Zhu, SY (Zhu, Sanyuan); He, ZP (He, Zhiping); Zhou, B (Zhou, Bin); Lin, HY (Lin, Hongyu); Yang, JF (Yang, Jianfeng); Liu, EH (Liu, Enhai); Xu, YC (Xu, Yuchen); Wang, JY (Wang, Jianyu); Yao, ZX (Yao, Zhenxing); Zou, YL (Zou, Yongliao); Yan, J (Yan, Jun); Ouyang, ZY (Ouyang, Ziyuan) | ||||||||||||||||||||||||||||||||||||||||||
Source: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Volume: 112 Issue: 17 Pages: 5342-5347 DOI: 10.1073/pnas.1503082112 Published: APR 28 2015 | ||||||||||||||||||||||||||||||||||||||||||
Abstract: We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of similar to 5 m of the lunar regolith layer and detected three underlying basalt units at depths of 195, 215, and 345 m. The radar measurements suggest underestimation of the global lunar regolith thickness by other methods and reveal a vast volume of the last volcano eruption. The in situ spectral reflectance and elemental analysis of the lunar soil at the landing site suggest that the young basalt could be derived from an ilmenite-rich mantle reservoir and then assimilated by 10-20% of the last residual melt of the lunar magma ocean. | ||||||||||||||||||||||||||||||||||||||||||
Accession Number: WOS:000353554000041 | ||||||||||||||||||||||||||||||||||||||||||
PubMed ID: 25870265 | ||||||||||||||||||||||||||||||||||||||||||
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ISSN: 0027-8424 |
Record 151 of 243 | ||||||||||||||||||
Title: Y<sub>2</sub>O<sub>3</sub>: Eu<SUP>3+</SUP>, Tb<SUP>3+</SUP> spherical particles based anti-reflection and wavelength conversion bi-functional films: Synthesis and application to solar cells | ||||||||||||||||||
Author(s): Miao, H (Miao, Hui); Ji, RN (Ji, Ruonan); Hu, XY (Hu, Xiaoyun); Han, LZ (Han, Linzi); Hao, YY (Hao, Yuanyuan); Sun, Q (Sun, Qian); Zhang, DK (Zhang, Dekai); Fan, J (Fan, Jun); Bai, JT (Bai, Jintao); Hou, X (Hou, Xun) | ||||||||||||||||||
Source: JOURNAL OF ALLOYS AND COMPOUNDS Volume: 629 Pages: 74-79 DOI: 10.1016/j.jallcom.2014.12.133 Published: APR 25 2015 | ||||||||||||||||||
Abstract: In this study, Eu3+ and Tb3+ co-doped Y2O3 particles were prepared via the simple, cost-effective urea homogeneous precipitation method without additives. The chosen particles were added in the SiO2 sols to get anti-reflection (AR) and wavelength conversion bi-functional films. Careful investigations were carried out to find the optimum preparation conditions and proper morphology. SEM images showed that the particle sizes reduced as metal ion/urea ratio decreased. Additionally, the extracted particles turned from sphere to lamellar type when the deionized water, which was used as solvent, reduced to a certain extent. The mechanisms of the morphology formation and diversification were proposed as well. The as prepared materials can convert UV region photos to visible photons between 460 nm and 640 nm, which just matched the spectral response of most solar cells. The spherical sample showed better luminescence performance than the one with lamellar morphology. In addition, the optical transmittance spectra indicated that the films adding spherical particles had better anti-reflective performance, and the best adding amount was 0.08 g. Finally, As a proof-of-concept application, the as prepared bi-functional films were used to test the standard monocrystalline silicon solar cell assembled with anti-reflection and wavelength conversion bi-functional films photoelectric conversion properties. As a result, the as prepared bi-functional films could effectively improve the photoelectric conversion efficiency by 0.23% compared to pure SiO2 AR coating film and 0.55% compared to glass. (C) 2015 Elsevier B.V. All rights reserved. | ||||||||||||||||||
Accession Number: WOS:000349699700014 | ||||||||||||||||||
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ISSN: 0925-8388 | ||||||||||||||||||
eISSN: 1873-4669 |
Record 152 of 243 | |||||||||||||||||||||||||||
Title: Vibrational phase imaging in wide-field CARS for nonresonant background suppression | |||||||||||||||||||||||||||
Author(s): Zheng, JJ (Zheng, Juanjuan); Akimov, D (Akimov, Denis); Heuke, S (Heuke, Sandro); Schmitt, M (Schmitt, Michael); Yao, BL (Yao, Baoli); Ye, T (Ye, Tong); Lei, M (Lei, Ming); Gao, P (Gao, Peng); Popp, J (Popp, Juergen) | |||||||||||||||||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 8 Pages: 10756-10763 DOI: 10.1364/OE.23.010756 Published: APR 20 2015 | |||||||||||||||||||||||||||
Abstract: Coherent Anti-Stokes Raman Scattering (CARS) microscopy is a valuable tool for label-free imaging of biological samples. As a major drawback quantification based on CARS images is compromised by the appearance of a nonresonant background. In this paper we propose and demonstrate a wide-field CARS vibrational phase imaging scheme that allows for nonresonant background suppression. Several CARS images at a few consecutive planes perpendicular to the propagation direction were recorded to reconstruct a phase map utilizing the iteration phase retrieval method. Experimental results verify that the CARS background is efficiently suppressed by the phase imaging approach, as compared to traditional CARS imaging without background correction. The proposed background correction method is robust against environmental disturbance, since the experimental implementation of the suggested detection scheme requires no reference beam. (C)2015 Optical Society of America | |||||||||||||||||||||||||||
Accession Number: WOS:000353299300121 | |||||||||||||||||||||||||||
PubMed ID: 25969113 | |||||||||||||||||||||||||||
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ISSN: 1094-4087 |
Record 153 of 243 | ||||||
Title: Enhanced optical properties and the origin of carrier transport in BiFeO<sub>3</sub>/TiO<sub>2</sub> heterostructures with 109° domain walls | ||||||
Author(s): Feng, HJ (Feng, Hong-Jian); Wang, M (Wang, M.); Liu, F (Liu, F.); Duan, B (Duan, B.); Tian, J (Tian, J.); Guo, X (Guo, X.) | ||||||
Source: JOURNAL OF ALLOYS AND COMPOUNDS Volume: 628 Pages: 311-316 DOI: 10.1016/j.jallcom.2014.11.211 Published: APR 15 2015 | ||||||
Abstract: The absorption coefficient in the BiFeO3/TiO2 bilayer film prepared by simple sol-gel method has been significantly improved relative to BiFeO(3)and TiO2 film. Terahertz-radiation emission presents a direct evidence for the photon-induced carrier transport in the heterostructures. First-principles calculations agree well with the experiments and present an unambiguous explanation for the charge carrier transport and the enhanced absorbance. It is induced by the large electrostatic potential drop in the interface with the 109 degrees domain walls and the reduced recombination of electron-hole pairs in the BiFeO3 side of the heterostructure. This work provides a new route toward designing novel photovoltaic heterostructures with high efficiency. (C) 2014 Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000349084100050 | ||||||
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ISSN: 0925-8388 | ||||||
eISSN: 1873-4669 |
Record 154 of 243 | |||||||||
Title: Metamaterial terahertz switch based on split-ring resonator embedded with photoconductive silicon | |||||||||
Author(s): Liu, XW (Liu, Xinwang); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan) | |||||||||
Source: APPLIED OPTICS Volume: 54 Issue: 11 Pages: 3478-3483 DOI: 10.1364/AO.54.003478 Published: APR 10 2015 | |||||||||
Abstract: In this paper, a metamaterial terahertz (THz) switch based on a split-ring resonator embedded with photoconductive silicon is presented and numerically investigated. Simulation results show that the switch works at two different resonant modes with different pump light powers and that the response time of the switch is less than 1 ps. By defining the switching window as the frequency range where the transmission magnitude of the ON state is one order of magnitude higher than the OFF state, a switching window ranging from 1.26 to 1.49 THz is obtained. The large modulation depth of the switch is due to the large separations of the maximum and minimum transmissions, which are 0.89 and 0.01, respectively. Particularly, the switch is frequency tunable by changing the thickness and permittivity of the dielectric layer. (C) 2015 Optical Society of America | |||||||||
Accession Number: WOS:000353240200050 | |||||||||
PubMed ID: 25967340 | |||||||||
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ISSN: 1559-128X | |||||||||
eISSN: 2155-3165 |
Record 155 of 243 | |||||||||
Title: Influence of laser linewidth and polarization modulator length on polarization shift keying for free space optical communication | |||||||||
Author(s): Han, BA (Han, Biao); Zhao, W (Zhao, Wei); Xie, XP (Xie, Xiaoping); Su, YL (Su, Yulong); Wang, W (Wang, Wei); Hu, H (Hu, Hui) | |||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 7 Pages: 8639-8649 DOI: 10.1364/OE.23.008639 Published: APR 6 2015 | |||||||||
Abstract: Modulating signal with polarization modulator (PolM) is the simplest method for polarization shift keying (PolSK) in free space optical communication. However, this method has an intrinsic drawback on degree of polarization (DOP) reduction for the existence of polarization mode dispersion (PMD) in PolM. In this work, we analyze this change of DOP and its influence on PolSK using coherency matrix. We demonstrate that the decrease of DOP after PolM will generate extra loss and bit error ratio (BER) for PolSK communication, while this loss and BER will aggravate with the increase of laser linewidth and PolM length. For a practical PolSK system, laser linewidth should be less than 0.008nm. (C) 2015 Optical Society of America | |||||||||
Accession Number: WOS:000352290000067 | |||||||||
PubMed ID: 25968702 | |||||||||
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ISSN: 1094-4087 |
Record 156 of 243 | |||||||||||||||||||||
Title: Nonlinear optical absorption tuning in Bi<sub>3.15</sub>Nd<sub>0.85</sub>Ti<sub>3</sub>O<sub>12</sub> ferroelectric thin films by thickness | |||||||||||||||||||||
Author(s): Li, S (Li, S.); Zhong, XL (Zhong, X. L.); Cheng, GH (Cheng, G. H.); Liu, X (Liu, X.); Zhang, Y (Zhang, Y.); Wang, JB (Wang, J. B.); Song, HJ (Song, H. J.); Tan, CB (Tan, C. B.); Li, B (Li, B.) | |||||||||||||||||||||
Source: APPLIED PHYSICS LETTERS Volume: 106 Issue: 14 Article Number: 142904 DOI: 10.1063/1.4917223 Published: APR 6 2015 | |||||||||||||||||||||
Abstract: The tunability of nonlinear optical (NLO) absorption in Bi3.15Nd0.85Ti3O12 (BNT) ferroelectric thin films was investigated through the open aperture Z-scan method with femtosecond laser pulses at the wavelength of 800 nm. NLO absorption responses of the BNT films were observed to be highly sensitive to the film thickness. As the film thickness increases from 106.8 to 139.7 nm, the NLO absorption changes from saturable absorption (SA) to reverse saturable absorption (RSA). When the film thickness further increases to 312.9 nm, the RSA effect is enhanced. A band-gap-related competition between the ground-state excitation and the two-photon absorption is responsible for the absorption switching behavior. Such a tunable NLO absorption can widen the photonic application of the BNT thin films. (C) 2015 AIP Publishing LLC. | |||||||||||||||||||||
Accession Number: WOS:000352820700034 | |||||||||||||||||||||
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ISSN: 0003-6951 | |||||||||||||||||||||
eISSN: 1077-3118 |
Record 157 of 243 | |||||||||||||||||||||||||||||||||
Title: Passively Harmonic Mode-Locked Fiber Laser With a High Signal-to-Noise Ratio via Evanescent-Light Deposition of Bismuth Telluride (Bi<sub>2</sub>Te<sub>3</sub>) Topological Insulator Based Saturable Absorber | |||||||||||||||||||||||||||||||||
Author(s): Duan, LN (Duan, L. N.); Wang, YG (Wang, Y. G.); Xu, CW (Xu, C. W.); Li, L (Li, L.); Wang, YS (Wang, Y. S.) | |||||||||||||||||||||||||||||||||
Source: IEEE PHOTONICS JOURNAL Volume: 7 Issue: 2 Article Number: 1500807 DOI: 10.1109/JPHOT.2015.2404315 Published: APR 2015 | |||||||||||||||||||||||||||||||||
Abstract: Passively harmonic mode locking (HML) operation had been demonstrated in an erbium-doped fiber laser with a microfiber-based topological insulator (TI) Bi2Te3 saturable absorber (SA). It was found that the pulse train possessed different orders of HML (with a tunable repetition rate from 232 to 390 MHz) due to different incident pump powers. The spectra exhibited typical features of conventional solitons (perfect Gaussian profile with Kelly sidebands) with no continuous wave component. The measured signal-to-noise ratio (SNR) reached 60 dB, whereas the pulse duration was kept around 1.32 ps without significant change. The experimental observation revealed that the microfiber-based TI device could indeed be employed as a high-performance SA for further applications in ultrafast photonics. | |||||||||||||||||||||||||||||||||
Accession Number: WOS:000352274100004 | |||||||||||||||||||||||||||||||||
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ISSN: 1943-0655 | |||||||||||||||||||||||||||||||||
eISSN: 1943-0647 |
Record 158 of 243 | ||||||
Title: All-normal dispersion passively mode-locked Yb-doped fiber laser with Bi<sub>2</sub>Te<sub>3</sub> absorber | ||||||
Author(s): Li, L (Li, Lu); Wang, YG (Wang, Yonggang); Sun, H (Sun, Hang); Duan, LN (Duan, Lina); Wang, X (Wang, Xi); Si, JH (Si, Jinhai) | ||||||
Source: OPTICAL ENGINEERING Volume: 54 Issue: 4 Article Number: 046101 DOI: 10.1117/1.OE.54.4.046101 Published: APR 2015 | ||||||
Abstract: An all-normal dispersion passively mode-locked Yb-doped fiber laser with a Bi2Te3 absorber is presented. The modulation depth of this kind of saturable absorber was measured to be 8.4%. By incorporating a Bi2Te3/PVA film into a Yb-doped fiber laser oscillator, a mode-locked fiber laser oscillator was achieved. The repetition rate and the central wavelength are 25.6 MHz and 1052.7 nm, respectively. The 3-dB spectral width is 0.45 nm and the pulse duration is 417 ps. The results indicate that topological insulator Bi2Te3 possesses the potential for ultrafast fiber laser application. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) | ||||||
Accession Number: WOS:000355207800024 | ||||||
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ISSN: 0091-3286 | ||||||
eISSN: 1560-2303 |
Record 159 of 243 | |||||||||
Title: A Tunable Terahertz Photonic Crystal Narrow-Band Filter | |||||||||
Author(s): Li, SP (Li, Shaopeng); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan) | |||||||||
Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 27 Issue: 7 Pages: 752-754 DOI: 10.1109/LPT.2015.2391127 Published: APR 1 2015 | |||||||||
Abstract: We theoretically propose and investigate a magnetically tunable narrow-band terahertz filter based on a triangular lattice silicon photonic crystal with a point and two line defects. The optical properties of the filter have been analyzed in detail. It is found that a single resonant peak with the central frequency of similar to 1 THz is existed in the transmission spectrum, which has a narrow full width at half maximum of <2 GHz. Moreover, under the control of an external magnetic field, transmission frequency and width of passband are adjustable, which reveals that the 2-D silicon photonic crystal waveguide with point and line defects can serve as a continuously tunable bandpass filter at the terahertz waveband. | |||||||||
Accession Number: WOS:000350877700018 | |||||||||
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ISSN: 1041-1135 | |||||||||
eISSN: 1941-0174 |
Record 160 of 243 |
Title: Coexistence of conventional solitons and stretched pulses in a fiber laser mode-locked by carbon nanotubes |
Author(s): Li, WL (Li, W. L.); Kong, YC (Kong, Y. C.); Chen, GW (Chen, G. W.); Yang, HR (Yang, H. R.) |
Source: LASER PHYSICS Volume: 25 Issue: 4 Article Number: 045103 DOI: 10.1088/1054-660X/25/4/045103 Published: APR 2015 |
Abstract: We have proposed a nanotube-mode-locking fiber laser that can generate conventional solitons and stretched pulses in the same cavity. The net cavity dispersion of laser is slightly negative. The central wavelength and bandwidth of the conventional solitons are 1584.7 and 9.2 nm, respectively. The stretched pulse locates at 1572 nm with a bandwidth of 18.8 nm. The switchable mode-locking operation is mainly attributable to the bandwidth-dependent stretching factor that is tunable due to the spectral filtering effect induced by nonlinear polarization rotation. |
Accession Number: WOS:000351843100006 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 161 of 243 | |||||||||
Title: Facile synthesis of 3D reduced graphene oxide and its polyaniline composite for super capacitor application | |||||||||
Author(s): Tang, W (Tang, Wei); Peng, L (Peng, Li); Yuan, CQ (Yuan, Chunqiu); Wang, J (Wang, Jian); Mo, SB (Mo, Shenbin); Zhao, CY (Zhao, Chunyan); Yu, YH (Yu, Youhai); Min, YG (Min, Yonggang); Epstein, AJ (Epstein, Arthur J.) | |||||||||
Source: SYNTHETIC METALS Volume: 202 Pages: 140-146 DOI: 10.1016/j.synthmet.2015.01.031 Published: APR 2015 | |||||||||
Abstract: We propose a facile and environmentally-friendly strategy for fabricating three-dimensional (3D) reduced graphene oxide (3D-rGO) porous structure with one step hydrothermal method using glucose as the reducing agent and CaCO3 as the template. The reducing process was accompanied by the self-assembly of two-dimensional graphene sheets into a 3D hydrogel which entrapped CaCO3 particle into the graphene network. After the removal of CaCO3 particle, 3D-rGO with interconnected porous structure was obtained. The 3D-rGO was further composted with PANI nanowire. The structure and the property of 3D-rGO and 3D-rGO/PANI composite have been characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, galvanostatic charge-discharge test and electrochemical impedance spectroscopy. Electrochemical test reveals that the 3D-rGO/PANI has high capacitance performance of 243 F g(-1) at current charge-discharge current density of 1 A g(-1) and an excellent capacity retention rate of 86% after 1000 cycles. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||
Accession Number: WOS:000352045800018 | |||||||||
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ISSN: 0379-6779 |
Record 162 of 243 |
Title: Switchable multi-wavelength and dual-scale soliton fiber laser incorporating cascaded chirped fiber Bragg gratings |
Author(s): Zeng, C (Zeng, C.); Cui, YD (Cui, Y. D.) |
Source: LASER PHYSICS Volume: 25 Issue: 4 Article Number: 045102 DOI: 10.1088/1054-660X/25/4/045102 Published: APR 2015 |
Abstract: A simple scheme of a switchable multi-wavelength and dual-scale soliton fiber laser is proposed by cascading three chirped fiber Bragg gratings (CFBGs). By managing the cavity dispersion and controlling the losses of attenuators, quadruple-wavelength switchable pulses are generated, including one dissipative soliton (DS) and three conventional solitons (CSs). The central wavelength of the DS is 1565 nm with a pulse duration of 12.5 ps which can be compressed to similar to 571 fs after a 70 m single mode fiber external to cavity. Three CSs are achieved at 1539.5, 1544.5, and 1549.5 nm with pulse durations of 9.6, 8.7, and 8.8 ps, corresponding to the CFBG-based comb spectral filtering. These results demonstrate that the proposed method offers potential opportunities to exploit the flexibly switchable multi-wavelength CS/DS-pulse sources at picosecond and femtosecond scales. |
Accession Number: WOS:000351843100005 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 163 of 243 |
Title: Inner scale effect on scintillation index of flat-topped beam in non-Kolmogorov weak turbulence |
Author(s): Zeng, ZH (Zeng, Zhihong); Luo, XJ (Luo, Xiujuan); Xia, AL (Xia, Aili); Zhang, Y (Zhang, Yu); Cao, B (Cao, Bei) |
Source: APPLIED OPTICS Volume: 54 Issue: 10 Pages: 2630-2638 DOI: 10.1364/AO.54.002630 Published: APR 1 2015 |
Abstract: A simpler generalized expression of irradiance fluctuation for flat-topped beams is presented based on the Born and Rytov perturbation methods. The theoretical expression of the on-axis scintillation index in non-Kolmogorov weak atmospheric optics links is developed using the generalized von Karman spectrum model, and using the equivalent structure constant that is different for all power-law exponents. The effect of the inner scale on the on-axis scintillation index is examined comprehensively. It is observed that flat- topped beams happen to possess smaller scintillation indices at larger inner scale. The effects of the power law, flat-topped order, source size of the fundamental Gaussian beam, propagation distance, and wavelength are also analyzed. (C) 2015 Optical Society of America |
Accession Number: WOS:000352152400012 |
PubMed ID: 25967169 |
ISSN: 1559-128X |
eISSN: 2155-3165 |
Record 164 of 243 | |||||||||||||||
Title: Line-plane-switching infrared bundle for push-broom sensing fiber imaging | |||||||||||||||
Author(s): Zhan, H (Zhan, Huan); Yan, XT (Yan, Xingtao); Guo, HT (Guo, Haitao); Xu, YT (Xu, Yantao); He, JL (He, Jianli); Li, F (Li, Fu); Yang, JF (Yang, Jianfeng); Si, JH (Si, Jinhai); Zhou, ZG (Zhou, Zhiguang); Lin, AX (Lin, Aoxiang) | |||||||||||||||
Source: OPTICAL MATERIALS Volume: 42 Pages: 491-494 DOI: 10.1016/j.optmat.2015.02.008 Published: APR 2015 | |||||||||||||||
Abstract: We reported line-plane-switching infrared (IR) fiber bundle with high-resolution of 0.027 mu m(-1), small numerical aperture (NA) of 0.20 (+/- 0.02), high filling-factor, and bending radius of around 5.0 mm, i.e. extremely good flexibility. This fiber bundle is made from chalcogenide glass fibers, possessing core (As40S58Se2) of 45 mu m, cladding (As40S60) of 50 mu m, and error of 1% in diameter. Based on the lens used to demonstrate IR push-broom imaging, the format of matching fiber bundle we chose is 64 x 9 in system to implement 192 x 3 format linear array imaging. By principle-demonstrating system incorporated this fiber bundle coupled with small scale Infrared Focal Plane Array (IRFPA), wide-field and long-array IR push-broom image was successfully demonstratqd. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||
Accession Number: WOS:000351800300083 | |||||||||||||||
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ISSN: 0925-3467 | |||||||||||||||
eISSN: 1873-1252 |
Record 165 of 243 | |||||||||
Title: Planar waveguides in Yb<SUP>3+</SUP>-doped tellurite glasses fabricated by ion implantation of oxygen | |||||||||
Author(s): Liu, CX (Liu, Chun-Xiao); Xut, J (Xut, Jun); Zhou, ZG (Zhou, Zhi-Guang); Fu, LL (Fu, Li-Li); Zheng, RL (Zheng, Rui-Lin); Li, WN (Li, Wei-Nan); Guo, HT (Guo, Hai-Tao); Lin, SB (Lin, She-Bao); Wei, W (Wei, Wei) | |||||||||
Source: MODERN PHYSICS LETTERS B Volume: 29 Issue: 8 Article Number: 1550021 DOI: 10.1142/S0217984915500219 Published: MAR 30 2015 | |||||||||
Abstract: A planar waveguide is demonstrated in the Yb3+-doped tellurite glass, using (5+6) MeV O3+ ion implantation with doses of (4 + 8) x 10(14) ions/cm(2). The implantation process of O3+ ions into the Yb3+-doped tellurite glass is simulated by the stopping and range of ions in matter (SRIM) 2010 code. The dark-mode spectra are measured by the prism-coupling system at lambda = 632.8 nm. The reflectivity calculation method and the finite-difference beam propagation method are used to calculate the refractive index profile and the modal profile of transverse electric (TE) mode of the fabricated waveguide, respectively. The absorption spectra show that the transmission properties are not affected by the waveguide fabrication process. | |||||||||
Accession Number: WOS:000352993300003 | |||||||||
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ISSN: 0217-9849 | |||||||||
eISSN: 1793-6640 |
Record 166 of 243 | ||||||
Title: Flexible pulse-controlled fiber laser | ||||||
Author(s): Liu, XM (Liu, Xueming); Cui, YD (Cui, Yudong) | ||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 9399 DOI: 10.1038/srep09399 Published: MAR 24 2015 | ||||||
Abstract: Controlled flexible pulses have widespread applications in the fields of fiber telecommunication, optical sensing, metrology, and microscopy. Here, we report a compact pulse-controlled all-fiber laser by exploiting an intracavity fiber Bragg grating (FBG) system as a flexible filter. The width and wavelength of pulses can be tuned independently by vertically and horizontally translating a cantilever beam, respectively. The pulse width of the laser can be tuned flexibly and accurately from similar to 7 to similar to 150 ps by controlling the bandwidth of FBG. The wavelength of pulse can be tuned precisely with the range of >20 nm. The flexible laser is precisely controlled and insensitive to environmental perturbations. This fiber-based laser is a simple, stable, and low-cost source for various applications where the width-tunable and/or wavelength-tunable pulses are necessary. | ||||||
Accession Number: WOS:000351700900001 | ||||||
PubMed ID: 25801546 | ||||||
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ISSN: 2045-2322 |
Record 167 of 243 | ||||||
Title: Graded index porous optical fibers - dispersion management in terahertz range | ||||||
Author(s): Ma, T (Ma, Tian); Markov, A (Markov, Andrey); Wang, LL (Wang, Lili); Skorobogatiy, M (Skorobogatiy, Maksim) | ||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 6 Pages: 7856-7869 DOI: 10.1364/OE.23.007856 Published: MAR 23 2015 | ||||||
Abstract: A graded index porous optical fiber incorporating an air-hole array featuring variable air-hole diameters and inter-hole separations is proposed, fabricated, and characterized in a view of the fiber potential applications in low-loss, low-dispersion terahertz guidance. The proposed fiber features simultaneously low modal and intermodal dispersions, as well as low loss in the terahertz spectral range. We experimentally demonstrate that graded index porous fibers exhibit smaller pulse distortion, larger bandwidth, and higher excitation efficiency when compared to fibers with uniform porosity. (C) 2015 Optical Society of America | ||||||
Accession Number: WOS:000351765900082 | ||||||
PubMed ID: 25837124 | ||||||
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ISSN: 1094-4087 |
Record 168 of 243 | ||||||||||||||||||||||||
Title: Double-Exposure Optical Sectioning Structured Illumination Microscopy Based on Hilbert Transform Reconstruction | ||||||||||||||||||||||||
Author(s): Zhou, X (Zhou, Xing); Lei, M (Lei, Ming); Dan, D (Dan, Dan); Yao, BL (Yao, Baoli); Qian, J (Qian, Jia); Yan, SH (Yan, Shaohui); Yang, YL (Yang, Yanlong); Min, JW (Min, Junwei); Peng, T (Peng, Tong); Ye, T (Ye, Tong); Chen, GD (Chen, Guangde) | ||||||||||||||||||||||||
Source: PLOS ONE Volume: 10 Issue: 3 Article Number: e0120892 DOI: 10.1371/journal.pone.0120892 Published: MAR 23 2015 | ||||||||||||||||||||||||
Abstract: Structured illumination microscopy (SIM) with axially optical sectioning capability has found widespread applications in three-dimensional live cell imaging in recent years, since it combines high sensitivity, short image acquisition time, and high spatial resolution. To obtain one sectioned slice, three raw images with a fixed phase-shift, normally 2 pi/3, are generally required. In this paper, we report a data processing algorithm based on the one-dimensional Hilbert transform, which needs only two raw images with arbitrary phase-shift for each single slice. The proposed algorithm is different from the previous two-dimensional Hilbert spiral transform algorithm in theory. The presented algorithm has the advantages of simpler data processing procedure, faster computation speed and better reconstructed image quality. The validity of the scheme is verified by imaging biological samples in our developed DMD-based LED-illumination SIM system. | ||||||||||||||||||||||||
Accession Number: WOS:000351987300188 | ||||||||||||||||||||||||
PubMed ID: 25799234 | ||||||||||||||||||||||||
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ISSN: 1932-6203 |
Record 169 of 243 |
Title: Metal oxide modified limestone for CO2 adsorption |
Author(s): Li, JF (Li, Jiangfeng); Li, H (Li, Hui); Meng, BL (Meng, Binglu); Yu, YH (Yu, Youhai); Min, Y (Min, Yong); Xu, DL (Xu, Delong) |
Source: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Meeting Abstract: 397 Volume: 249 Published: MAR 22 2015 |
Accession Number: WOS:000411186500390 |
ISSN: 0065-7727 |
Record 170 of 243 | ||||||
Title: Enhancement of CO2 sequestration of limestone with carbon additives | ||||||
Author(s): Meng, B (Meng, Binglu); Li, H (Li, Hui); Yang, WB (Yang, Wenbin); Li, JF (Li, Jiangfeng); Yu, YH (Yu, Youhai); Min, Y (Min, Yong); Xu, DL (Xu, Delong) | ||||||
Source: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Meeting Abstract: 398 Volume: 249 Published: MAR 22 2015 | ||||||
Accession Number: WOS:000411186500391 | ||||||
Author Identifiers: | ||||||
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ISSN: 0065-7727 |
Record 171 of 243 | |||||||||
Title: Improvement of antisintering of Ca-based sorbents by thermally treated vermiculite | |||||||||
Author(s): Meng, JJ (Meng, Jingjing); Li, H (Li, Hui); Meng, BL (Meng, Binglu); Li, JF (Li, Jiangfeng); Shan, LY (Shan, Liyuan); Yu, YH (Yu, Youhai); Min, Y (Min, Yong); Xu, DL (Xu, Delong) | |||||||||
Source: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Meeting Abstract: 395 Volume: 249 Published: MAR 22 2015 | |||||||||
Accession Number: WOS:000411186500388 | |||||||||
Author Identifiers: | |||||||||
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ISSN: 0065-7727 |
Record 172 of 243 | |||||||||
Title: Experiment on CO2 capturing capacity of attapulgite modified CaO-based sorbent in calcination/carbonation cycle | |||||||||
Author(s): Shan, L (Shan, Liyuan); Li, H (Li, Hui); Meng, JJ (Meng, Jingjing); Meng, BL (Meng, Binglu); Li, JF (Li, Jiangfeng); Yu, YH (Yu, Youhai); Min, Y (Min, Yong); Xu, DL (Xu, Delong) | |||||||||
Source: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Meeting Abstract: 396 Volume: 249 Published: MAR 22 2015 | |||||||||
Accession Number: WOS:000411186500389 | |||||||||
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ISSN: 0065-7727 |
Record 173 of 243 | |||||||||
Title: Ultra-flexible polarization-insensitive multiband terahertz metamaterial absorber | |||||||||
Author(s): Chen, X (Chen, Xu); Fan, WH (Fan, Wenhui) | |||||||||
Source: APPLIED OPTICS Volume: 54 Issue: 9 Pages: 2376-2382 DOI: 10.1364/AO.54.002376 Published: MAR 20 2015 | |||||||||
Abstract: A thin-flexible and polarization-insensitive multiband terahertz metamaterial absorber (MMA) has been investigated. Each unit cell of the MMA consists of two metallic structures, which include the top metal resonator ring and the bottom metal ground plane, separated by a thin-flexible dielectric spacer. Finite element simulation indicates that this MMA has three high absorption peaks in the terahertz region, with absorptivities of 89% at 0.72 THz, 98% at 1.4 THz, and 85% at 2.3 THz. However, because of its rotationally symmetric structure, this MMA is polarization-insensitive and can perform very well at a wide range of incident angles, namely, 30 degrees for transverse electric waves and 40 degrees for transverse magnetic waves. The thin-flexible device structure and good performance shows that this MMA is very promising to disguise objects and make them less detectable to radar in the terahertz region. (c) 2015 Optical Society of America | |||||||||
Accession Number: WOS:000351638300029 | |||||||||
PubMed ID: 25968524 | |||||||||
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ISSN: 1559-128X | |||||||||
eISSN: 2155-3165 |
Record 174 of 243 | ||||||||||||
Title: Distributed ultrafast fibre laser | ||||||||||||
Author(s): Liu, XM (Liu, Xueming); Cui, YD (Cui, Yudong); Han, DD (Han, Dongdong); Yao, XK (Yao, Xiankun); Sun, ZP (Sun, Zhipei) | ||||||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 9101 DOI: 10.1038/srep09101 Published: MAR 13 2015 | ||||||||||||
Abstract: A traditional ultrafast fibre laser has a constant cavity length that is independent of the pulse wavelength. The investigation of distributed ultrafast (DUF) lasers is conceptually and technically challenging and of great interest because the laser cavity length and fundamental cavity frequency are changeable based on the wavelength. Here, we propose and demonstrate a DUF fibre laser based on a linearly chirped fibre Bragg grating, where the total cavity length is linearly changeable as a function of the pulse wavelength. The spectral sidebands in DUF lasers are enhanced greatly, including the continuous-wave (CW) and pulse components. We observe that all sidebands of the pulse experience the same round-trip time although they have different round-trip distances and refractive indices. The pulse-shaping of the DUF laser is dominated by the dissipative processes in addition to the phase modulations, which makes our ultrafast laser simple and stable. This laser provides a simple, stable, low-cost, ultrafast-pulsed source with controllable and changeable cavity frequency. | ||||||||||||
Accession Number: WOS:000351151400002 | ||||||||||||
PubMed ID: 25765454 | ||||||||||||
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ISSN: 2045-2322 |
Record 175 of 243 |
Title: Data correction techniques for the airborne large-aperture static image spectrometer based on image registration |
Author(s): Zhang, G (Zhang, Geng); Shi, DL (Shi, Dalian); Wang, S (Wang, Shuang); Yu, T (Yu, Tao); Hu, BL (Hu, Bingliang) |
Source: JOURNAL OF APPLIED REMOTE SENSING Volume: 9 Article Number: 095088 DOI: 10.1117/1.JRS.9.095088 Published: MAR 9 2015 |
Abstract: We propose an approach to correct the data of the airborne large-aperture static image spectrometer (LASIS). LASIS is a kind of stationary interferometer which compromises flux output and device stability. It acquires a series of interferograms to reconstruct the hyperspectral image cube. Reconstruction precision of the airborne LASIS data suffers from the instability of the plane platform. Usually, changes of plane attitudes, such as yaws, pitches, and rolls, can be precisely measured by the inertial measurement unit. However, the along-track and across-track translation errors are difficult to measure precisely. To solve this problem, we propose a co-optimization approach to compute the translation errors between the interferograms using an image registration technique which helps to correct the interferograms with subpixel precision. To demonstrate the effectiveness of our approach, experiments are run on real airborne LASIS data and our results are compared with those of the state-of-the-art approaches. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) |
Accession Number: WOS:000352831700001 |
ISSN: 1931-3195 |
Record 176 of 243 | |||||||||
Title: Temporal cloak based on tunable optical delay and advance | |||||||||
Author(s): Zhou, MY (Zhou, Mingyang); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu) | |||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 5 Pages: 6543-6553 DOI: 10.1364/OE.23.006543 Published: MAR 9 2015 | |||||||||
Abstract: A temporal cloak scheme based on tunable optical delay and advance is theoretically proposed. An input optical signal is divided into two parts, and the front part is advanced while the rear part is delayed. A temporal gap which contains negligible optical energy is opened to hide events from observers, which can be closed by doing the inverse process. Different from the previous schemes that use continuous wave light, we use an optical data stream as the probe beam. Simulations have been done to investigate performance of the temporal cloak. The developed scheme can be applied in fiber-optical signal processing and secure communications. (C) 2015 Optical Society of America | |||||||||
Accession Number: WOS:000350878500100 | |||||||||
PubMed ID: 25836872 | |||||||||
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ISSN: 1094-4087 |
Record 177 of 243 | ||||||
Title: Four-phase closure algorithm for coherent field imaging | ||||||
Author(s): Cao, B (Cao Bei); Luo, XJ (Luo Xiu-Juan); Si, QD (Si Qing-Dan); Zeng, ZH (Zeng Zhi-Hong) | ||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 5 Article Number: 054204 DOI: 10.7498/aps.64.054204 Published: MAR 5 2015 | ||||||
Abstract: According to the realization principle of phase closure in coherent field imaging, a new four-phase closure (FPC) algorithm is proposed for T-array multi-beam transmitter system. A type of four-item measurement radio of closure phase is first defined, and then the validity of FPC is confirmed in cancelling out the random atmospheric phase aberrations as well as eliminating atmospheric scintillation effect on degradation of the reconstructed image. Simulations prove the effectiveness of FPC, providing a new approach in removing atmospheric aberrations for multi-beam coherence field imaging. | ||||||
Accession Number: WOS:000351749200019 | ||||||
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ISSN: 1000-3290 |
Record 178 of 243 | ||||||||||||||||||
Title: Graph-based learning for segmentation of 3D ultrasound images | ||||||||||||||||||
Author(s): Chang, HL (Chang, Huali); Chen, ZP (Chen, Zhenping); Huang, QH (Huang, Qinghua); Shi, J (Shi, Jun); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: NEUROCOMPUTING Volume: 151 Pages: 632-644 DOI: 10.1016/j.neucom.2014.05.092 Part: 2 Published: MAR 5 2015 | ||||||||||||||||||
Abstract: The analysis of 3D medical images becomes necessary since the 3D imaging techniques have been more and more widely applied in medical applications. This paper introduces a novel segmentation method for extracting objects of interest (001) in 3D ultrasound images. In the proposed method, a bilateral filtering model is first applied to a 3D ultrasound volume data set for speckle reduction. We then take advantage of graph theory to construct a 3D graph, and merge sub-graphs into larger one during the segmentation process. Therefore, the proposed method can be called a 3D graph-based segmentation algorithm. After the mergence of sub-graphs, a set of minimum spanning trees each of which corresponds to a 3D sub-region is generated. In terms of segmentation accuracy, the experiments using an ultrasound fetus phantom, a resolution phantom and human fingers demonstrate that the proposed method outperforms the 3D Snake and Fuzzy C means clustering methods, indicating improved performance for potential clinical applications. (C) 2014 Elsevier B.V. All rights reserved. | ||||||||||||||||||
Accession Number: WOS:000347753500013 | ||||||||||||||||||
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ISSN: 0925-2312 | ||||||||||||||||||
eISSN: 1872-8286 |
Record 179 of 243 | |||||||||||||||
Title: Adaptive multi-bit quantization for hashing | |||||||||||||||
Author(s): Deng, C (Deng, Cheng); Deng, HR (Deng, Huiru); Liu, XL (Liu, Xianglong); Yuan, Y (Yuan, Yuan) | |||||||||||||||
Source: NEUROCOMPUTING Volume: 151 Pages: 319-326 DOI: 10.1016/j.neucom.2014.09.033 Part: 1 Published: MAR 3 2015 | |||||||||||||||
Abstract: Recently, hashing methods which try to solve similarity-preserving approximate nearest search problem have obtained widely applications in various fields such as content-based image retrieval, object recognition and pose estimation. However, how to learn effective hash codes to describe the similarities in the large-scale database still remains as a NP-hard problem. Besides, a fatal problem lying in the existing hashing methods is that they usually threshold the real values to binary codes using single-bit quantization (SBQ) at the highest point density, which may destroy the data structure seriously. Due to this problem, double-bit quantization (DBQ) is proposed to solve the problem of SBQ by adaptively learning thresholds to quantize the real values to two bits, and achieves impressive results. However, one problem in DBQ is that it neglects the amount of the information contained in different data dimensions. In this paper, we propose a multi-bit quantization method based on bit allocation to quantize each projected dimension with variable bit numbers. Besides, different from existing methods of choosing threshold, we propose an incomplete coding manner by clustering to generate binary codes. Experiments on two large datasets demonstrate the feasibility of our method. (C) 2014 Elsevier B.V. All rights reserved. | |||||||||||||||
Accession Number: WOS:000347753400037 | |||||||||||||||
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ISSN: 0925-2312 | |||||||||||||||
eISSN: 1872-8286 |
Record 180 of 243 | ||||||
Title: Electrochemical performance of cotton stalk based activated carbon electrodes modified by MnO<sub>2</sub> for supercapacitor | ||||||
Author(s): Chen, MD (Chen, M. D.); Wumaie, T (Wumaie, T.); Li, WL (Li, W. L.); Song, HH (Song, H. H.); Song, RR (Song, R. R.) | ||||||
Source: MATERIALS TECHNOLOGY Volume: 30 Issue: A1 Pages: A2-A7 DOI: 10.1179/1753555714Y.0000000241 Published: MAR 2015 | ||||||
Abstract: Cotton stalk based activated carbon (AC) was prepared from Xinjiang, China by H3PO4 as activating reagent. In order to improve electrochemical properties of AC, a series of AC/MnO2 (electrolytic manganese dioxide)/AC composites with different MnO2 contents were prepared. The samples specific surface area and pore distribution were characterised by Brunauer, Emmett and Teller (BET); the structure and morphology were characterised by X-ray diffraction (XRD) and scanning electron microscope (SEM) respectively. Moreover, the improvements of activated carbon modified by MnO2 were confirmed by the experiment of galvanostatic current charge/discharge, cyclic voltammograms and alternating current impedance tests respectively. The results show that the specific capacitance (169 F g(-1)) of the composite material electrode (the contents of MnO2 is 5%) would be higher in 1.0 mol L-1 Et4NBF4/AN electrolyte at 2.0 A g(-1) than other composite materials, which is 39% higher than the present study. The capacitance was kept more than 99.2% after 500 cycles and still higher than that of activated carbon materials. | ||||||
Accession Number: WOS:000351128600002 | ||||||
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ISSN: 1066-7857 | ||||||
eISSN: 1753-5557 |
Record 181 of 243 | ||||||||||||||||||||||||||||||
Title: Passively Q-switched Nd:GGG laser with a SWCNT as saturable absorber | ||||||||||||||||||||||||||||||
Author(s): Chu, HW (Chu, Hongwei); Zhao, SZ (Zhao, Shengzhi); Yang, KJ (Yang, Kejian); Li, YF (Li, Yufei); Li, DC (Li, Dechun); Li, GQ (Li, Guiqiu); Zhao, J (Zhao, Jia); Qiao, WC (Qiao, Wenchao); Li, T (Li, Tao); Wang, YG (Wang, Yonggang); Wang, YS (Wang, Yishan) | ||||||||||||||||||||||||||||||
Source: OPTICAL AND QUANTUM ELECTRONICS Volume: 47 Issue: 3 Pages: 697-703 DOI: 10.1007/s11082-014-9945-8 Published: MAR 2015 | ||||||||||||||||||||||||||||||
Abstract: A diode-pumped passively Q-switched Nd:GGG laser with a single-walled carbon nanotube as saturable absorber has been realized. A maximum average output power of 1.24 W and a minimum pulse duration of 49.8 ns were obtained at the incident pump power of 7.69 W. Corresponding to a maximum single pulse energy and a highest peak power were 4.3 and 85 W, respectively. The pulse repetition rates varied from 62 to 292 kHz versus the increase of the incident pump power. | ||||||||||||||||||||||||||||||
Accession Number: WOS:000350882000022 | ||||||||||||||||||||||||||||||
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ISSN: 0306-8919 | ||||||||||||||||||||||||||||||
eISSN: 1572-817X |
Record 182 of 243 | ||||||||||||||||||
Title: Texture Classification and Retrieval Using Shearlets and Linear Regression | ||||||||||||||||||
Author(s): Dong, YS (Dong, Yongsheng); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong); Ma, JW (Ma, Jinwen); Pu, JX (Pu, Jiexin) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 3 Pages: 358-369 DOI: 10.1109/TCYB.2014.2326059 Published: MAR 2015 | ||||||||||||||||||
Abstract: Statistical modeling of wavelet subbands has frequently been used for image recognition and retrieval. However, traditional wavelets are unsuitable for use with images containing distributed discontinuities, such as edges. Shearlets are a newly developed extension of wavelets that are better suited to image characterization. Here, we propose novel texture classification and retrieval methods that model adjacent shearlet subband dependences using linear regression. For texture classification, we use two energy features to represent each shearlet subband in order to overcome the limitation that subband coefficients are complex numbers. Linear regression is used to model the features of adjacent subbands; the regression residuals are then used to define the distance from a test texture to a texture class. Texture retrieval consists of two processes: the first is based on statistics in contourlet domains, while the second is performed using a pseudo-feedback mechanism based on linear regression modeling of shearlet subband dependences. Comprehensive validation experiments performed on five large texture datasets reveal that the proposed classification and retrieval methods outperform the current state-of-the-art. | ||||||||||||||||||
Accession Number: WOS:000350146900001 | ||||||||||||||||||
PubMed ID: 25029547 | ||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||
eISSN: 2168-2275 |
Record 183 of 243 | |||||||||||||||
Title: Trapping of Rayleigh spheroidal particles by highly focused radially polarized beams | |||||||||||||||
Author(s): Li, MM (Li, Manman); Yan, SH (Yan, Shaohui); Yao, BL (Yao, Baoli); Lei, M (Lei, Ming); Yang, YL (Yang, Yanlong); Min, JW (Min, Junwei); Dan, D (Dan, Dan) | |||||||||||||||
Source: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS Volume: 32 Issue: 3 Pages: 468-472 DOI: 10.1364/JOSAB.32.000468 Published: MAR 2015 | |||||||||||||||
Abstract: The optical forces and intrinsic optical torque of a highly focused radially polarized beam on a Rayleigh spheroidal particle are calculated with the dipole approximation. Numerical results show that the maximal trapping forces depend strongly on the orientation of the particle, and the torque is always perpendicular to the plane containing the major axis of the spheroid and the optical axis. As a result of optical mechanical and torque equilibrium, the spheroidal particle will stay at the focus with its major axis of the spheroid parallel to the optical axis. (C) 2015 Optical Society of America | |||||||||||||||
Accession Number: WOS:000351134200015 | |||||||||||||||
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ISSN: 0740-3224 | |||||||||||||||
eISSN: 1520-8540 |
Record 184 of 243 | ||||||||||||||||||||||||
Title: Structured-Patch Optimization for Dense Correspondence | ||||||||||||||||||||||||
Author(s): Qin, XM (Qin, Xiameng); Shen, JB (Shen, Jianbing); Mao, XY (Mao, Xiaoyang); Li, XL (Li, Xuelong); Jia, YD (Jia, Yunde) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON MULTIMEDIA Volume: 17 Issue: 3 Pages: 295-306 DOI: 10.1109/TMM.2015.2395078 Published: MAR 2015 | ||||||||||||||||||||||||
Abstract: This paper presents a new method to compute the dense correspondences between two images by using the energy optimization and the structured patches. In terms of the property of the sparse feature and the principle that nearest sub-scenes and neighbors are much more similar, we design a new energy optimization to guide the dense matching process and find the reliable correspondences. The sparse features are also employed to design a new structure to describe the patches. Both transformation and deformation with the structured patches are considered and incorporated into an energy optimization framework. Thus, our algorithm can match the objects robustly in complicated scenes. Finally, a local refinement technique is proposed to solve the perturbation of the matched patches. Experimental results demonstrate that our method outperforms the state-of-the-art matching algorithms. | ||||||||||||||||||||||||
Accession Number: WOS:000351585700003 | ||||||||||||||||||||||||
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ISSN: 1520-9210 | ||||||||||||||||||||||||
eISSN: 1941-0077 |
Record 185 of 243 | ||||||||||||||||||
Title: Image Classification with Densely Sampled Image Windows and Generalized Adaptive Multiple Kernel Learning | ||||||||||||||||||
Author(s): Yan, SY (Yan, Shengye); Xu, XX (Xu, Xinxing); Xu, D (Xu, Dong); Lin, S (Lin, Stephen); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 3 Pages: 395-404 DOI: 10.1109/TCYB.2014.2326596 Published: MAR 2015 | ||||||||||||||||||
Abstract: We present a framework for image classification that extends beyond the window sampling of fixed spatial pyramids and is supported by a new learning algorithm. Based on the observation that fixed spatial pyramids sample a rather limited subset of the possible image windows, we propose a method that accounts for a comprehensive set of windows densely sampled over location, size, and aspect ratio. A concise high-level image feature is derived to effectively deal with this large set of windows, and this higher level of abstraction offers both efficient handling of the dense samples and reduced sensitivity to misalignment. In addition to dense window sampling, we introduce generalized adaptive l(p)-norm multiple kernel learning (GA-MKL) to learn a robust classifier based on multiple base kernels constructed from the new image features and multiple sets of prelearned classifiers from other classes. With GA-MKL, multiple levels of image features are effectively fused, and information is shared among different classifiers. Extensive evaluation on benchmark datasets for object recognition (Caltech256 and Caltech101) and scene recognition (15Scenes) demonstrate that the proposed method outperforms the state-of-the-art under a broad range of settings. | ||||||||||||||||||
Accession Number: WOS:000350146900004 | ||||||||||||||||||
PubMed ID: 24968365 | ||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||
eISSN: 2168-2275 |
Record 186 of 243 | ||||||||||||||||||||||||
Title: Online Anomaly Detection in Crowd Scenes via Structure Analysis | ||||||||||||||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Fang, JW (Fang, Jianwu); Wang, Q (Wang, Qi) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 3 Pages: 562-575 DOI: 10.1109/TCYB.2014.2330853 Published: MAR 2015 | ||||||||||||||||||||||||
Abstract: Abnormal behavior detection in crowd scenes is continuously a challenge in the field of computer vision. For tackling this problem, this paper starts from a novel structure modeling of crowd behavior. We first propose an informative structural context descriptor (SCD) for describing the crowd individual, which originally introduces the potential energy function of particle's interforce in solid-state physics to intuitively conduct vision contextual cueing. For computing the crowd SCD variation effectively, we then design a robust multi-object tracker to associate the targets in different frames, which employs the incremental analytical ability of the 3-D discrete cosine transform (DCT). By online spatial-temporal analyzing the SCD variation of the crowd, the abnormality is finally localized. Our contribution mainly lies on three aspects: 1) the new exploration of abnormal detection from structure modeling where the motion difference between individuals is computed by a novel selective histogram of optical flow that makes the proposed method can deal with more kinds of anomalies; 2) the SCD description that can effectively represent the relationship among the individuals; and 3) the 3-D DCT multi-object tracker that can robustly associate the limited number of (instead of all) targets which makes the tracking analysis in high density crowd situation feasible. Experimental results on several publicly available crowd video datasets verify the effectiveness of the proposed method. | ||||||||||||||||||||||||
Accession Number: WOS:000350146900018 | ||||||||||||||||||||||||
PubMed ID: 24988603 | ||||||||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||||||||
eISSN: 2168-2275 |
Record 187 of 243 | |||||||||||||||||||||
Title: Learning Multiple Linear Mappings for Efficient Single Image Super-Resolution | |||||||||||||||||||||
Author(s): Zhang, KB (Zhang, Kaibing); Tao, DC (Tao, Dacheng); Gao, XB (Gao, Xinbo); Li, XL (Li, Xuelong); Xiong, ZG (Xiong, Zenggang) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON IMAGE PROCESSING Volume: 24 Issue: 3 Pages: 846-861 DOI: 10.1109/TIP.2015.2389629 Published: MAR 2015 | |||||||||||||||||||||
Abstract: Example learning-based superresolution (SR) algorithms show promise for restoring a high-resolution (HR) image from a single low-resolution (LR) input. The most popular approaches, however, are either time-or space-intensive, which limits their practical applications in many resource-limited settings. In this paper, we propose a novel computationally efficient single image SR method that learns multiple linear mappings (MLM) to directly transform LR feature subspaces into HR subspaces. In particular, we first partition the large nonlinear feature space of LR images into a cluster of linear subspaces. Multiple LR subdictionaries are then learned, followed by inferring the corresponding HR subdictionaries based on the assumption that the LR-HR features share the same representation coefficients. We establish MLM from the input LR features to the desired HR outputs in order to achieve fast yet stable SR recovery. Furthermore, in order to suppress displeasing artifacts generated by the MLM-based method, we apply a fast nonlocal means algorithm to construct a simple yet effective similarity-based regularization term for SR enhancement. Experimental results indicate that our approach is both quantitatively and qualitatively superior to other application-oriented SR methods, while maintaining relatively low time and space complexity. | |||||||||||||||||||||
Accession Number: WOS:000348458000002 | |||||||||||||||||||||
PubMed ID: 25576571 | |||||||||||||||||||||
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ISSN: 1057-7149 | |||||||||||||||||||||
eISSN: 1941-0042 |
Record 188 of 243 | |||||||||||||||||||||
Title: Machining parameter optimization of C/SiC composites using high power picosecond laser | |||||||||||||||||||||
Author(s): Zhang, RH (Zhang, Ruoheng); Li, WN (Li, Weinan); Liu, YS (Liu, Yongsheng); Wang, CH (Wang, Chunhui); Wang, J (Wang, Jing); Yang, XJ (Yang, Xiaojun); Cheng, LF (Cheng, Laifei) | |||||||||||||||||||||
Source: APPLIED SURFACE SCIENCE Volume: 330 Pages: 321-331 DOI: 10.1016/j.apsusc.2015.01.010 Published: MAR 1 2015 | |||||||||||||||||||||
Abstract: Picosecond laser is an important machining technology for high hardness materials. In this paper, high power picosecond laser was utilized to drill micro-holes in C/SiC composites, and the effects of different processing parameters including the helical line width and spacing, machining time and scanning speed were discussed. To characterize the qualities of machined holes, scanning electron microscope (SEM) was used to analyze the surface morphology, energy dispersive spectroscopy (EDS) and X-ray photoelectric spectroscopy (XPS) were employed to describe the element composition change between the untreated and laser-treated area. The experimental results indicated that all parameters mentioned above had remarkable effects on the qualities of micro-holes such as shape and depth. Additionally, the debris consisted of C, Si and 0 was observed on the machined surface. The Si C bonds of the SiC matrix transformed into Si-0 bonds after machined. Furthermore, the physical process responsible for the mechanism of debris formation was discussed as well. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||||||||
Accession Number: WOS:000349617400040 | |||||||||||||||||||||
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ISSN: 0169-4332 | |||||||||||||||||||||
eISSN: 1873-5584 |
Record 189 of 243 | ||||||||||||||||||
Title: A deep structure for human pose estimation | ||||||||||||||||||
Author(s): Zhao, L (Zhao, Lin); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: SIGNAL PROCESSING Volume: 108 Pages: 36-45 DOI: 10.1016/j.sigpro.2014.07.031 Published: MAR 2015 | ||||||||||||||||||
Abstract: Articulated human pose estimation in unconstrained conditions is a great challenge. We propose a deep structure that represents a human body in different granularity from coarse-to-fine for better detecting parts and describing spatial constrains between different parts. Typical approaches for this problem just utilize a single level structure, which is difficult to capture various body appearances and hard to model high-order part dependencies. In this paper, we build a three layer Markov network to model the body structure that separates the whole body to poselets (combined parts) then to parts representing joints. Parts at different levels are connected through a parent-child relationship to represent high-order spatial relationships. Unlike other multi-layer models, our approach explores more reasonable granularity for part detection and sophisticatedly designs part connections to model body configurations more effectively. Moreover, each part in our model contains different types so as to capture a wide range of pose modes. And our model is a tree structure, which can be trained jointly and favors exact inference. Extensive experimental results on two challenging datasets show the performance of our model improving or being on-par with state-of-the-art approaches. (C) 2014 Elsevier B.V. All rights reserved. | ||||||||||||||||||
Accession Number: WOS:000346542300005 | ||||||||||||||||||
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ISSN: 0165-1684 | ||||||||||||||||||
eISSN: 1872-7557 |
Record 190 of 243 | ||||||
Title: High-power Ho: YAG laser wing-pumped by a Tm:fiber laser at 1933 nm | ||||||
Author(s): Zhao, T (Zhao, T.); Wang, F (Wang, F.); Shen, DY (Shen, D. Y.) | ||||||
Source: APPLIED OPTICS Volume: 54 Issue: 7 Pages: 1594-1597 DOI: 10.1364/AO.54.001594 Published: MAR 1 2015 | ||||||
Abstract: We report on the high-power and efficient operation of a Ho:YAG laser wing-band-pumped by a Tm: fiber laser at 1933 nm. Using an output coupler of 10% transmission, maximum continuous-wave (CW) output power of 24.2 W at 2124 nm was generated under 42.6 W of absorbed pump power, corresponding to slope efficiency with respect to absorbed pump power of 57.6%. The operating wavelength of the Ho:YAG laser centered at 2092 or 2124 nm depending on different resonator designs. Prospects for further improvement in laser performance with this wing-pump configuration are discussed. (C) 2015 Optical Society of America | ||||||
Accession Number: WOS:000350263000005 | ||||||
Author Identifiers: | ||||||
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ISSN: 1559-128X | ||||||
eISSN: 2155-3165 |
Record 191 of 243 | |||||||||
Title: Luminescence in the fluoride-containing phosphate-based glasses: A possible origin of their high resistance to nanosecond pulse laser-induced damage | |||||||||
Author(s): Wang, PF (Wang, Pengfei); Lu, M (Lu, Min); Gao, F (Gao, Fei); Guo, HT (Guo, Haitao); Xu, YT (Xu, Yantao); Hou, CQ (Hou, Chaoqi); Zhou, ZW (Zhou, Zhiwei); Peng, B (Peng, Bo) | |||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 8593 DOI: 10.1038/srep08593 Published: FEB 26 2015 | |||||||||
Abstract: Fusion power offers the prospect of an almost inexhaustible source of energy for future generations. It was reported that fusion fuel gains exceeding unity on the National Ignition Facility (NIF) were achieved, but so far great deal of scientific and engineering challenges have to be overcome for realizing fusion power generation. There is a bottleneck for color-separation gratings in NIF and other similar inertial confinement fusion (ICF) lasers. Here we show a series of high performance phosphate-based glasses that can transmit the third harmonic frequency (3 omega) laser light with high efficiency meanwhile filter the fundamental (1 omega) and the second harmonic frequency (2 omega) laser lights through direct absorption, and especially they exhibit excellent damage threshold induced by nanosecond pulse laser compared with that of the fused silica used in NIF. Yellowish-orange fluorescence emits during the laser-material interaction process, and it can be tailored through regulating the glass structure. Study on its structural origin suggests that the fluorescence emission is a key factor that conduces to the high laser-induced damage resistance of these glasses. The results also indicated the feasibility of utilizing these high performance glasses in novel color separation optics, allowing novel design for the final optics assembly in ICF lasers. | |||||||||
Accession Number: WOS:000349964200013 | |||||||||
PubMed ID: 25716328 | |||||||||
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ISSN: 2045-2322 |
Record 192 of 243 | ||||||||||||||||||||||||
Title: Graphene-based active slow surface plasmon polaritons | ||||||||||||||||||||||||
Author(s): Lu, H (Lu, Hua); Zeng, C (Zeng, Chao); Zhang, QM (Zhang, Qiming); Liu, XM (Liu, Xueming); Hossain, MM (Hossain, Md Muntasir); Reineck, P (Reineck, Philipp); Gu, M (Gu, Min) | ||||||||||||||||||||||||
Source: SCIENTIFIC REPORTS Volume: 5 Article Number: 8443 DOI: 10.1038/srep08443 Published: FEB 13 2015 | ||||||||||||||||||||||||
Abstract: Finding new ways to control and slow down the group velocity of light in media remains a major challenge in the field of optics. For the design of plasmonic slow light structures, graphene represents an attractive alternative to metals due to its strong field confinement, comparably low ohmic loss and versatile tunability. Here we propose a novel nanostructure consisting of a monolayer graphene on a silicon based graded grating structure. An external gate voltage is applied to graphene and silicon, which are separated by a spacer layer of silica. Theoretical and numerical results demonstrate that the structure exhibits an ultra-high slowdown factor above 450 for the propagation of surface plasmon polaritons (SPPs) excited in graphene, which also enables the spatially resolved trapping of light. Slowdown and trapping occur in the mid-infrared wavelength region within a bandwidth of similar to 2.1 mu m and on a length scale less than 1/6 of the operating wavelength. The slowdown factor can be precisely tuned simply by adjusting the external gate voltage, offering a dynamic pathway for the release of trapped SPPs at room temperature. The presented results will enable the development of highly tunable optoelectronic devices such as plasmonic switches and buffers. | ||||||||||||||||||||||||
Accession Number: WOS:000349252700005 | ||||||||||||||||||||||||
PubMed ID: 25676462 | ||||||||||||||||||||||||
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ISSN: 2045-2322 |
Record 193 of 243 | ||||||
Title: Feature competition and partial sparse shape modeling for cardiac image sequences segmentation | ||||||
Author(s): Qin, XJ (Qin, Xianjing); Tian, Y (Tian, Yan); Yan, PK (Yan, Pingkun) | ||||||
Source: NEUROCOMPUTING Volume: 149 Pages: 904-913 DOI: 10.1016/j.neucom.2014.07.044 Part: B Published: FEB 3 2015 | ||||||
Abstract: The segmentation of endocardium and epicardium of left ventricle (LV) in cardiac MR image sequences play a crucial role in clinical applications. Active shape model (ASM) based methods are often used to extract the LV boundaries with the steps of searching and representation. However, due to the challenges, such as interior papillary muscles, complicated outside tissues and weak boundaries, the searching may be partially incorrect and the representation cannot reflect the reliable part of the contour. In this paper, a feature competition based searching strategy is proposed by exploiting both the information of the object and background to reduce the error of searching. Then, we propose a partial sparse shape model to effectively represent the searched shape. This representation is able to retain the partial reliable contour while reconstructing the unreliable part approximating to the real contour. Moreover, the incremental learning algorithm is exploited to construct a patient-specific appearance model to increase the accuracy and efficiency of image sequence segmentation. Experimental results on cardiac MR image sequences demonstrate that the proposed method improves the segmentation performance and also reduces the error accumulation compared to the existing methods. (C) 2014 Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000346550300042 | ||||||
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ISSN: 0925-2312 | ||||||
eISSN: 1872-8286 |
Record 194 of 243 | ||||||
Title: Adaptive neural control for a class of MIMO nonlinear systems with extreme learning machine | ||||||
Author(s): Rong, HJ (Rong, Hai-Jun); Wei, JT (Wei, Jin-Tao); Bai, JM (Bai, Jian-Ming); Zhao, GS (Zhao, Guang-She); Liang, YQ (Liang, Yong-Qi) | ||||||
Source: NEUROCOMPUTING Volume: 149 Pages: 405-414 DOI: 10.1016/j.neucom.2014.01.066 Part: A Published: FEB 3 2015 | ||||||
Abstract: This paper presents two adaptive neural control schemes for a class of uncertain continuous-time multiinput multi-output (MIMO) nonlinear dynamic systems. Within these schemes, the single-hidden layer feedforward networks (SIINs) are applied to approximate the unknown nonlinear functions of the systems and then the neural controller is built based on the approximated neural models. The parameters of the SLFNs are modified using the recently proposed neural algorithm named extreme learning machine (ELM), where the parameters of the hidden nodes are assigned randomly. Different from the original ELM algorithm, the output weights are updated using the adaptive laws derived based on the Lyapunov stability theorem and Barbalat's lemma so that the asymptotical stability of the system can be guaranteed. The robustifying control term is also constructed to compensate for approximation errors of the SLFNs. In order to avoid the requirement of the approximation error bounds, the estimation laws derived based on the Lyapunov stability theorem and Barbalat's lemma are employed to estimate the error bounds in the second adaptive control scheme. Finally the proposed control schemes are applied to control a two-link robot manipulator. The simulation results demonstrate the effectiveness of the proposed control schemes for the MIMO nonlinear system. (C) 2014 Published by Elsevier B.V. | ||||||
Accession Number: WOS:000360028800046 | ||||||
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ISSN: 0925-2312 | ||||||
eISSN: 1872-8286 |
Record 195 of 243 |
Title: Nanotube-mode-locked linear-cavity fiber laser delivering switchable ultrafast solitons |
Author(s): Han, XX (Han, X. X.) |
Source: LASER PHYSICS Volume: 25 Issue: 2 Article Number: 025104 DOI: 10.1088/1054-660X/25/2/025104 Published: FEB 2015 |
Abstract: We propose a linear-cavity switchable fiber laser based on a single-wall carbon nanotube mode-locker for the first time to the best of our knowledge. Two chirped fiber Bragg gratings (CFBGs) in series and an optical circulator are employed as end mirrors of the linear cavity. The linear-cavity fiber laser is simple and cost-efficient. By adjusting the polarization controllers, a switchable mode-locking operation is obtained at 1551.3 and 1557.9 nm respectively, corresponding to the central wavelengths of two series-wound CFBGs. The pulse duration and spectral bandwidth of ultrafast solitons are similar to 4.4 ps and similar to 0.65 nm for the short wavelength operation at 1551.3 nm and similar to 3.9 ps and similar to 0.71 nm for the long wavelength operation at 1557.9 nm, respectively. Our experimental observations are well confirmed by the numerical results. The linear-cavity all-fiber laser reduces the cost and is very attractive for ultrafast optics. |
Accession Number: WOS:000348143000007 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 196 of 243 | |||||||||||||||||||||
Title: Accurate Normal and Reflectance Recovery Using Energy Optimization | |||||||||||||||||||||
Author(s): Luo, T (Luo, Tao); Shen, JB (Shen, Jianbing); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY Volume: 25 Issue: 2 Pages: 212-224 DOI: 10.1109/TCSVT.2014.2333991 Published: FEB 2015 | |||||||||||||||||||||
Abstract: In this paper, we propose a novel energy optimization framework to accurately estimate surface normal and reflectance of an object from an input image sequence. Input images are captured from a fixed viewpoint under varying lighting conditions. In the proposed approach we combine photometric stereo and Retinex constraints into our energy function. To formulate inter-image constraints, shading information is added to the Lambertian model to account for shadows. For intra-image constraints, we moderate the strength of shading smoothness according to shadow mask and normal variations. By minimizing this energy function we are able to recover accurate surface normals and reflectance. Experimental results show that our approach yields more realistic normal map and accurate albedo map than the state-of-the-art uncalibrated photometric stereo algorithms. As for intrinsic image decomposition, results on the real and synthetic scenes show that the proposed approach outperforms previous ones. | |||||||||||||||||||||
Accession Number: WOS:000349624000004 | |||||||||||||||||||||
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ISSN: 1051-8215 | |||||||||||||||||||||
eISSN: 1558-2205 |
Record 197 of 243 | ||||||||||||||||||
Title: Person Reidentification by Minimum Classification Error-Based KISS Metric Learning | ||||||||||||||||||
Author(s): Tao, DP (Tao, Dapeng); Jin, LW (Jin, Lianwen); Wang, YF (Wang, Yongfei); Li, XL (Li, Xuelong) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON CYBERNETICS Volume: 45 Issue: 2 Pages: 242-252 DOI: 10.1109/TCYB.2014.2323992 Published: FEB 2015 | ||||||||||||||||||
Abstract: In recent years, person reidentification has received growing attention with the increasing popularity of intelligent video surveillance. This is because person reidentification is critical for human tracking with multiple cameras. Recently, keep it simple and straightforward (KISS) metric learning has been regarded as a top level algorithm for person reidentification. The covariance matrices of KISS are estimated by maximum likelihood (ML) estimation. It is known that discriminative learning based on the minimum classification error (MCE) is more reliable than classical ML estimation with the increasing of the number of training samples. When considering a small sample size problem, direct MCE KISS does not work well, because of the estimate error of small eigenvalues. Therefore, we further introduce the smoothing technique to improve the estimates of the small eigenvalues of a covariance matrix. Our new scheme is termed the minimum classification error-KISS (MCE-KISS). We conduct thorough validation experiments on the VIPeR and ETHZ datasets, which demonstrate the robustness and effectiveness of MCE-KISS for person reidentification. | ||||||||||||||||||
Accession Number: WOS:000348071500008 | ||||||||||||||||||
PubMed ID: 25486658 | ||||||||||||||||||
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ISSN: 2168-2267 | ||||||||||||||||||
eISSN: 2168-2275 |
Record 198 of 243 | ||||||||||||
Title: Facile synthesis of wheat bran-derived honeycomb-like hierarchical carbon for advanced symmetric supercapacitor applications | ||||||||||||
Author(s): Wang, DW (Wang, Dewei); Min, YG (Min, Yonggang); Yu, YH (Yu, Youhai) | ||||||||||||
Source: JOURNAL OF SOLID STATE ELECTROCHEMISTRY Volume: 19 Issue: 2 Pages: 577-584 DOI: 10.1007/s10008-014-2639-0 Published: FEB 2015 | ||||||||||||
Abstract: A novel honeycomb-like hierarchical carbon (HHC) derived from wheat bran has been obtained by the facile and environmentally friendly method via hydrothermal carbonization of wheat bran followed by KOH activation process at mild conditions without any template. The prepared carbon has a large Brunauer-Emmett-Teller (BET) surface area of 2,189.2 m(2) g(-1) and pore volumes of up to 1.1 cm(3) g(-1). The performance of the HHC as electrodes for electrochemical supercapacitors was evaluated in a symmetric two-electrode cell configuration with 6 M KOH and 1 M TEABF(4)/AN as the electrolytes. Electrochemical studies show that the supercapacitors based on the as-prepared HHC exhibit an excellent capacitive performance in both aqueous and organic electrolytes. We attribute the outstanding capacitive behavior of HHC to their unique structure and high accessible surface area. Considering that the cost-effective and feasible process, this facile technique presented here will not only provide a promising method for the production of biomass-derived hierarchical carbon but also put forward the application of carbon materials in energy storage and conversion. | ||||||||||||
Accession Number: WOS:000349030600028 | ||||||||||||
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ISSN: 1432-8488 | ||||||||||||
eISSN: 1433-0768 |
Record 199 of 243 |
Title: Bound-state fiber laser mode-locked by a graphene-nanotube saturable absorber |
Author(s): Yang, HR (Yang, H. R.); Chen, GW (Chen, G. W.); Kong, YC (Kong, Y. C.); Li, WL (Li, W. L.) |
Source: LASER PHYSICS Volume: 25 Issue: 2 Article Number: 025101 DOI: 10.1088/1054-660X/25/2/025101 Published: FEB 2015 |
Abstract: We have experimentally observed the multiple bound states in a linear-cavity fiber laser mode-locked by a mixture of graphene and single-walled carbon nanotubes. The proposed laser can deliver the fundamental frequency soliton as well as the two and three bound-state solitons at suitable conditions. The numerical simulations confirm the experimental observations. Both the theoretical predictions and experimental results reveal that the spectral filtering effect plays a key role on the lasers. |
Accession Number: WOS:000348143000004 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 200 of 243 | |||||||||||||||
Title: Fast Hyperspectral Anomaly Detection via High-Order 2-D Crossing Filter | |||||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Wang, Q (Wang, Qi); Zhu, GK (Zhu, Guokang) | |||||||||||||||
Source: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Volume: 53 Issue: 2 Pages: 620-630 DOI: 10.1109/TGRS.2014.2326654 Published: FEB 2015 | |||||||||||||||
Abstract: Anomaly detection has been an important topic in hyperspectral image analysis. This technique is sometimes more preferable than the supervised target detection because it requires no a priori information for the interested materials. Many efforts have been made in this topic; however, they usually suffer from excessive time cost and a high false-positive rate. There are two major problems that lead to such a predicament. First, the construction of the background model and affinity estimation are often overcomplicated. Second, most of these methods have to impose a stringent assumption on the spectrum distribution of background; however, these assumptions cannot hold for all practical situations. Based on this consideration, this paper proposes a novel method allowing for fast yet accurate pixel-level hyperspectral anomaly detection. We claim the following main contributions: 1) construct a high-order 2-D crossing approach to find the regions of rapid change in the spectrum, which runs without any a priori assumption; and 2) design a low-complexity discrimination framework for fast hyperspectral anomaly detection, which can be implemented by a series of filtering operators with linear time cost. Experiments on three different hyperspectral images containing several pixel-level anomalies demonstrate the superiority of the proposed detector compared with the benchmark methods. | |||||||||||||||
Accession Number: WOS:000342910800004 | |||||||||||||||
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ISSN: 0196-2892 | |||||||||||||||
eISSN: 1558-0644 |
Record 201 of 243 | ||||||||||||||||||
Title: Hyperspectral Band Selection by Multitask Sparsity Pursuit | ||||||||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Zhu, GK (Zhu, Guokang); Wang, Q (Wang, Qi) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Volume: 53 Issue: 2 Pages: 631-644 DOI: 10.1109/TGRS.2014.2326655 Published: FEB 2015 | ||||||||||||||||||
Abstract: Hyperspectral images have been proved to be effective for a wide range of applications; however, the large volume and redundant information also bring a lot of inconvenience at the same time. To cope with this problem, hyperspectral band selection is a pertinent technique, which takes advantage of removing redundant components without compromising the original contents from the raw image cubes. Because of its usefulness, hyperspectral band selection has been successfully applied to many practical applications of hyperspectral remote sensing, such as land cover map generation and color visualization. This paper focuses on groupwise band selection and proposes a new framework, including the following contributions: 1) a smart yet intrinsic descriptor for efficient band representation; 2) an evolutionary strategy to handle the high computational burden associated with groupwise-selection-based methods; and 3) a novel MTSP-based criterion to evaluate the performance of each candidate band combination. To verify the superiority of the proposed framework, experiments have been conducted on both hyperspectral classification and color visualization. Experimental results on three real-world hyperspectral images demonstrate that the proposed framework can lead to a significant advancement in these two applications compared with other competitors. | ||||||||||||||||||
Accession Number: WOS:000342910800005 | ||||||||||||||||||
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ISSN: 0196-2892 | ||||||||||||||||||
eISSN: 1558-0644 |
Record 202 of 243 | |||||||||||||||||||||
Title: Spatial-Aware Object-Level Saliency Prediction by Learning Graphlet Hierarchies | |||||||||||||||||||||
Author(s): Zhang, LM (Zhang, Luming); Xia, YJ (Xia, Yingjie); Ji, RR (Ji, Rongrong); Li, XL (Li, Xuelong) | |||||||||||||||||||||
Source: IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS Volume: 62 Issue: 2 Pages: 1301-1308 DOI: 10.1109/TIE.2014.2336602 Published: FEB 2015 | |||||||||||||||||||||
Abstract: To fill the semantic gap between the predictive power of computational saliency models and human behavior, this paper proposes to predict where people look at using spatial-aware object-level cues. While object-level saliency has been recently suggested by psychophysics experiments and shown effective with a few computational models, the spatial relationship between the objects has not yet been explored in this context. We in this work for the first time explicitly model such spatial relationship, as well as leveraging semantic information of an image to enhance object-level saliency modeling. The core computational module is a graphlet-based (i.e., graphlets are moderate-sized connected subgraphs) deep architecture, which hierarchically learns a saliency map from raw image pixels to object-level graphlets (oGLs) and further to spatial-level graphlets (sGLs). Eye tracking data are also used to leverage human experience in saliency prediction. Experimental results demonstrate that the proposed oGLs and sGLs well capture object-level and spatial-level cues relating to saliency, and the resulting saliency model performs competitively compared with the state-of-the-art. | |||||||||||||||||||||
Accession Number: WOS:000347799500062 | |||||||||||||||||||||
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ISSN: 0278-0046 | |||||||||||||||||||||
eISSN: 1557-9948 |
Record 203 of 243 | ||||||||||||
Title: Carbon-fiber-reinforced polymer variable-curvature mirror used for optical zoom imaging: prototype design and experimental demonstration | ||||||||||||
Author(s): Zhao, H (Zhao, Hui); Fan, XW (Fan, Xuewu); Pang, ZH (Pang, Zhihai); Ren, GR (Ren, Guorui); Wang, W (Wang, Wei); Xie, YJ (Xie, Yongjie); Ma, Z (Ma, Zhen); Du, YF (Du, Yunfei); Su, Y (Su, Yu); Wei, JX (Wei, Jingxuan) | ||||||||||||
Source: OPTICAL ENGINEERING Volume: 54 Issue: 2 Article Number: 025103 DOI: 10.1117/1.OE.54.2.025103 Published: FEB 2015 | ||||||||||||
Abstract: In recent years, optical zoom imaging without moving elements has received much attention. The key to realizing this technique lies in the design of the variable-curvature mirror (VCM). To obtain enough optical magnification, the VCM should be able to change its radius of curvature over a wide range. In other words, the VCM must be able to provide a large sagittal variation, which requires the mirror material to be robust during curvature variation, require little force to deform, and have high ultimate strength. Carbon-fiber-reinforced polymer (CFRP) satisfies all these requirements and is suitable for fabricating such a VCM. Therefore, in this research, a CFRP prototype VCM has been designed, fabricated, and tested. With a diameter of 100 mm, a thickness of 2 mm, and an initial radius of curvature of 1740 mm, this VCM can provide a maximum 23-mu m sagittal variation and a minimum and maximum radius of curvature of 1705 and 1760 mm. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) | ||||||||||||
Accession Number: WOS:000350481900021 | ||||||||||||
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ISSN: 0091-3286 | ||||||||||||
eISSN: 1560-2303 |
Record 204 of 243 | ||||||||||||||||||||||||
Title: Targeting Accurate Object Extraction From an Image: A Comprehensive Study of Natural Image Matting | ||||||||||||||||||||||||
Author(s): Zhu, QS (Zhu, Qingsong); Shao, L (Shao, Ling); Li, XL (Li, Xuelong); Wang, L (Wang, Lei) | ||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS Volume: 26 Issue: 2 Pages: 185-207 DOI: 10.1109/TNNLS.2014.2369426 Published: FEB 2015 | ||||||||||||||||||||||||
Abstract: With the development of digital multimedia technologies, image matting has gained increasing interests from both academic and industrial communities. The purpose of image matting is to precisely extract the foreground objects with arbitrary shapes from an image or a video frame for further editing. It is generally known that image matting is inherently an ill-posed problem because we need to output three images out of only one input image. In this paper, we provide a comprehensive survey of the existing image matting algorithms and evaluate their performance. In addition to the blue screen matting, we systematically divide all existing natural image matting methods into four categories: 1) color sampling-based; 2) propagation-based; 3) combination of sampling-based and propagation-based; and 4) learning-based approaches. Sampling-based methods assume that the foreground and background colors of an unknown pixel can be explicitly estimated by examining nearby pixels. Propagation-based methods are instead based on the assumption that foreground and background colors are locally smooth. Learning-based methods treat the matting process as a supervised or semisupervised learning problem. Via the learning process, users can construct a linear or nonlinear model between the alpha mattes and the image colors using a training set to estimate the alpha matte of an unknown pixel without any assumption about the characteristics of the testing image. With three benchmark data sets, the various matting algorithms are evaluated and compared using several metrics to demonstrate the strengths and weaknesses of each method both quantitatively and qualitatively. Finally, we conclude this paper by outlining the research trends and suggesting a number of promising directions for future development. | ||||||||||||||||||||||||
Accession Number: WOS:000348856200001 | ||||||||||||||||||||||||
PubMed ID: 25423658 | ||||||||||||||||||||||||
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ISSN: 2162-237X | ||||||||||||||||||||||||
eISSN: 2162-2388 |
Record 205 of 243 |
Title: A real-time axial activeanti-drift device with high-precision |
Author(s): Huo, YD (Huo Ying-Dong); Cao, B (Cao Bo); Yu, B (Yu Bin); Chen, DN (Chen Dan-Ni); Niu, HB (Niu Han-Ben) |
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 2 Article Number: 028701 DOI: 10.7498/aps.64.028701 Published: JAN 20 2015 |
Abstract: In a fluorescent nano-resolution microscope based on single molecular localization, drift of focal plane will bring an additional deviation to the accuracy of single molecular localization. Consequently, this will reduce the final resolution of the reconstructed image and cause image degradation. Therefore, it is vital to control the system drift to a minimum level as much as possible. In recent years, the anti-drift ways emerged in endlessly. In this paper we made a systematic study aiming at the method in which optical measurement and negative feedback control are used. The basic principle and its implementation of the system are analyzed, and possible error is also evaluated. Finally, the precision of the system is tested experimentally. With this device, axial drift can be detected and corrected automatically in time, and the axial anti-drift accuracy as high as 9.93 nm can be achieved, which is one order higher than that of the existing commercial microscopies. |
Accession Number: WOS:000349455100053 |
ISSN: 1000-3290 |
Record 206 of 243 | |||||||||||||||||||||
Title: F-state based permanent optical data storage in bacteriorhodopsin film | |||||||||||||||||||||
Author(s): Yu, XH (Yu Xiang-Hua); Yao, BL (Yao Bao-Li); Li, XY (Li Xin-Yu); Liu, SL (Liu Shi-Lei); Lei, M (Lei Ming); Li, RZ (Li Run-Ze); Liang, YS (Liang Yan-Sheng); Zhou, X (Zhou Xing); Wu, D (Wu Di); Dan, D (Dan Dan); Min, JW (Min Jun-Wei); Yan, SH (Yan Shao-Hui) | |||||||||||||||||||||
Source: ACTA PHYSICA SINICA Volume: 64 Issue: 2 Article Number: 024218 DOI: 10.7498/aps.64.024218 Published: JAN 20 2015 | |||||||||||||||||||||
Abstract: Upon excitation of high intensity linearly polarized femtosecond laser, a blue-shifted two-photon induced photoproduct named F540 state with permanent photo-induced anisotropy is observed in bacteriorhodopsin (BR) films. Based on the F-state, permanent optical data storage can be realized with spatial field modulation of femtosecond laser. By using a phase-only spatial light modulator to modulate the spatial phase distribution of the incident femtosecond laser beam, we generate spot-patterns in the focal plane of the microscopic objective lens, and the patterns are recorded in the BR film. At the same time, by varying the polarization direction of the excitation laser beam, polarization-multiplexed optical data storage in the BR film is demonstrated, which is applicable to high-density optical data storage and optical information encryption. | |||||||||||||||||||||
Accession Number: WOS:000349455100031 | |||||||||||||||||||||
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ISSN: 1000-3290 |
Record 207 of 243 | ||||||||||||
Title: Semi-supervised change detection method for multi-temporal hyperspectral images | ||||||||||||
Author(s): Yuan, Y (Yuan, Yuan); Lv, HB (Lv, Haobo); Lu, XQ (Lu, Xiaoqiang) | ||||||||||||
Source: NEUROCOMPUTING Volume: 148 Pages: 363-375 DOI: 10.1016/j.neucom.2014.06.024 Published: JAN 19 2015 | ||||||||||||
Abstract: Change detection is one of the most important open topics for multi-temporal remote sensing technology to observe the earth. Recently, many methods are proposed to detect the land-cover change information by multi-temporal hyperspectral images. However, many existing traditional change detection methods failed to utilize the spectral information effectively. Hence the models are not robust enough for more widely applications with "noise" bands. In this case, a semi-supervised distance metric learning method is proposed to detect the change areas by abundant spectral information of hyperspectral image under the "noisy" condition. This paper focuses on semi-supervised change detection method, and proposes a new distance metric learning framework for change detection in "noisy" condition with three mainly contributions: (1) Distance metric learning is demonstrated to be an effective method for revealing the change information by high spectral features. (2) An evolution regular framework is utilized to handle change detection under a "noisy" condition without removing any noise bands, which is impacted by atmosphere (or water) and always removed manually in other literatures. (3) A semi-supervised Laplacian Regularized Metric Learning method is exploited to tackle the ill-posed sample problem, and large unlabeled data is exploited in our method. The proposed method is performed on two multi-temporal hyperspectral datasets. Experimental results show that the proposed method outperforms the state-of-the-art change detection methods under both "ideal" and "noisy" conditions. (C) 2014 Elsevier B.V. All rights reserved. | ||||||||||||
Accession Number: WOS:000343840000045 | ||||||||||||
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ISSN: 0925-2312 | ||||||||||||
eISSN: 1872-8286 |
Record 208 of 243 |
Title: Low-power-threshold photonic saturable absorber in nonlinear chalcogenide glass |
Author(s): Minardi, S (Minardi, S.); Cheng, G (Cheng, G.); D'Amico, C (D'Amico, C.); Stoian, R (Stoian, R.) |
Source: OPTICS LETTERS Volume: 40 Issue: 2 Pages: 257-259 DOI: 10.1364/OL.40.000257 Published: JAN 15 2015 |
Abstract: We experimentally demonstrate controllable nonlinear modulation of optical guiding in ultrafast laser-written evanescently coupled waveguide arrays in bulk gallium lanthanum sulfide chalcogenide glass. The intensity-dependent response is validated by simulating light propagation in waveguide arrays with instantaneous Kerr nonlinearity using a discrete-continuous spatiotemporal unidirectional Maxwell equation model. The intensity-driven modulation of transmission in multicore structures acts as a potential saturable absorber at kilowatt threshold levels. (C) 2015 Optical Society of America |
Accession Number: WOS:000347939500033 |
PubMed ID: 25679858 |
ISSN: 0146-9592 |
eISSN: 1539-4794 |
Record 209 of 243 |
Title: Switchable linear-cavity nanotube-mode-locking fiber laser emitting picosecond or femtosecond pulses |
Author(s): Yao, XK (Yao, Xiankun) |
Source: OPTICS COMMUNICATIONS Volume: 335 Pages: 262-265 DOI: 10.1016/j.optcom.2014.09.036 Published: JAN 15 2015 |
Abstract: A switchable linear-cavity nanotube-mode-locking fiber laser is proposed by exploiting fiber Bragg grating for the first time to the author's best knowledge. The proposed all-fiber laser can deliver either picosecond or femtosecond pulses by controlling the polarization controllers. The durations of picosecond and femtosecond pulses are 16.4 ps and 838 is with the central wavelengths of 1529.5 and 1560 nm, respectively. The lemtosecond pulse has symmetrical spectrum sidebands, but the picosecond pulse almost has no spectral sidebands. Our work provides a simple, low-cost, dual-scale pulse source for practical applications. (C) 2014 Elsevier B.V. All rights reserved. |
Accession Number: WOS:000345641500045 |
ISSN: 0030-4018 |
eISSN: 1873-0310 |
Record 210 of 243 | |||||||||||||||||||||
Title: Towards low timing phase noise operation in fiber lasers mode locked by graphene oxide and carbon nanotubes at 1.5 μm | |||||||||||||||||||||
Author(s): Wu, K (Wu, Kan); Li, XH (Li, Xiaohui); Wang, YG (Wang, Yonggang); Wang, QJ (Wang, Qi Jie); Shum, PP (Shum, Perry Ping); Chen, JP (Chen, Jianping) | |||||||||||||||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 1 Pages: 501-511 DOI: 10.1364/OE.23.000501 Published: JAN 12 2015 | |||||||||||||||||||||
Abstract: We investigate the timing phase noise of fiber lasers mode locked by graphene oxide (GO) and carbon nanotubes (CNTs), respectively, integrated in a linear cavity fiber laser in the reflecting operation. Due to the shorter decay time of the GO and CNTs, weaker slow saturable absorber effects are expected and mode-locked lasers based on these two saturable absorbers exhibit low excess timing phase noise coupled from the laser intensity noise. Compared with a reference laser mode locked by semiconductor saturable absorber mirror (SESAM), GO based laser obtains a timing phase noise reduction of 7 dB at 1 kHz and a timing jitter reduction of 45% experimentally whereas CNTs based laser obtains a timing phase noise reduction of 3 dB and a timing jitter reduction of 29%. This finding suggests that saturable absorbers with short decay time have the potential for achieving mode locking operation with low timing phase noise, which is important for applications including frequency metrology, high-precision optical sampling, clock distribution and optical sensing. (C) 2014 Optical Society of America | |||||||||||||||||||||
Accession Number: WOS:000349162900049 | |||||||||||||||||||||
PubMed ID: 25835696 | |||||||||||||||||||||
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ISSN: 1094-4087 |
Record 211 of 243 | |||||||||
Title: Tunable multiple phase-coupled plasmon-induced transparencies in graphene metamaterials | |||||||||
Author(s): Zeng, C (Zeng, Chao); Cui, YD (Cui, Yudong); Liu, XM (Liu, Xueming) | |||||||||
Source: OPTICS EXPRESS Volume: 23 Issue: 1 Pages: 545-551 DOI: 10.1364/OE.23.000545 Published: JAN 12 2015 | |||||||||
Abstract: We demonstrate the existence of multiple electromagnetically induced transparencies (EIT)-like spectral responses in graphene metamaterials consisting of a series of self-assembled graphene Fabry-Perot (FP) cavities. By exploiting the graphene plasmon resonances and phase-coupling effects, the transfer matrix model is established to theoretically predict the EIT-like responses, and the calculated results coincide well with numerical simulations. It is found that high-contrast (similar to 90%) multiple EIT-like windows are observed over a broad range of mid-infrared. Additionally, these optical responses can be efficiently tuned by altering the Fermi level in graphene and the separations of FP cavities. The proposed scheme paves the way toward control of the multiple EIT-like responses, enabling exploration of the on-chip multifunctional electro-optic devices including multi-channel-selective filters, sensors, and modulators. (C) 2014 Optical Society of America | |||||||||
Accession Number: WOS:000349162900053 | |||||||||
PubMed ID: 25835700 | |||||||||
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ISSN: 1094-4087 |
Record 212 of 243 | ||||||||||||||||||
Title: Ionic Liquids: Not only Structurally but also Dynamically Heterogeneous | ||||||||||||||||||
Author(s): Zheng, ZP (Zheng, Zhuan-Ping); Fan, WH (Fan, Wen-Hui); Roy, S (Roy, Soham); Mazur, K (Mazur, Kamila); Nazet, A (Nazet, Andreas); Buchner, R (Buchner, Richard); Bonn, M (Bonn, Mischa); Hunger, J (Hunger, Johannes) | ||||||||||||||||||
Source: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Volume: 54 Issue: 2 Pages: 687-690 DOI: 10.1002/anie.201409136 Published: JAN 7 2015 | ||||||||||||||||||
Abstract: In recent years, the complex and heterogeneous structure of ionic liquids has been demonstrated; however, the consequences on the dynamics have remained elusive. Here, we use femtosecond IR spectroscopy to elucidate the local structural dynamics in protic alkylammonium-based ionic liquids. The structural relaxation after an ultrafast temperature increase, following vibrational excitation and subsequent relaxation of the N-D (or N-H) stretching vibration, is found to vary substantially between the ionic and hydrophobic subdomains. The dynamics in the ionic domains are virtually unaffected by the alkyl chain length and is, therefore, decoupled from viscosity. Equilibration within the hydrophobic subdomains, as evident from the dynamics of the C-H stretching vibration, is faster than that in the ionic domains and shows a remarkably low thermal activation. | ||||||||||||||||||
Accession Number: WOS:000347238800057 | ||||||||||||||||||
PubMed ID: 25411079 | ||||||||||||||||||
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ISSN: 1433-7851 | ||||||||||||||||||
eISSN: 1521-3773 |
Record 213 of 243 |
Title: Switchable dual-wavelength fiber laser mode-locked by carbon nanotubes |
Author(s): Chen, GW (Chen, G. W.); Li, WL (Li, W. L.); Yang, HR (Yang, H. R.); Kong, YC (Kong, Y. C.) |
Source: JOURNAL OF MODERN OPTICS Volume: 62 Issue: 5 Pages: 353-357 DOI: 10.1080/09500340.2014.982224 Published: 2015 |
Abstract: We have proposed a switchable mode-locked fiber laser by means of carbon nanotube saturable absorber and fiber Bragg gratings (FBGs). The single-wavelength mode-locking operation can be switched between 1549.5 and 1559.5 nm, respectively, which correspond to the central wavelengths of two FBGs. With the appropriate setting of polarization controller, the stable dual-wavelength operation can be achieved due to the high stability of saturable absorber based on carbon nanotubes. Our method provides a simple, stable, low-cost, dual-wavelength ultrafast-pulsed source. |
Accession Number: WOS:000349544800005 |
ISSN: 0950-0340 |
eISSN: 1362-3044 |
Record 214 of 243 |
Title: Carbon-nanotube-based passively mode-locked fiber lasers modulated with sub-loop |
Author(s): Cui, YD (Cui, Yudong) |
Source: OPTIK Volume: 126 Issue: 6 Pages: 618-621 DOI: 10.1016/j.ijleo.2015.02.002 Published: 2015 |
Abstract: We have proposed a carbon-nanotube-based passively mode-locked fiber laser, which consists of two fiber ring resonators, for the first time to author's best knowledge. The proposed laser in the main cavity is coupled with a fiber sub-loop, which is connected with a 2 x 2 optical coupler. Without the sub-loop, uniform-spaced conventional solitons are achieved in the fiber ring laser. With the sub-loop, the fiber laser generates a train of pulses modulated with a periodic envelop. The modulation period and pulse-pulse separation are similar to 160 and similar to 4.3 ns, which are determined by the lengths of the main cavity and the sub-loop, respectively. (C) 2015 Elsevier GmbH. All rights reserved. |
Accession Number: WOS:000355334900009 |
ISSN: 0030-4026 |
Record 215 of 243 |
Title: Device-Free Mobile Target Tracking Using Passive Tags |
Author(s): Ding, H (Ding, Han); Xi, M (Xi, Min); Li, Z (Li, Zhe); Zhao, JZ (Zhao, Jizhong) |
Source: INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS Article Number: 870204 DOI: 10.1155/2015/870204 Published: 2015 |
Abstract: We propose a low-cost device-free mobile target tracking system using passive tags, namely, DTrack, to detect and track a human object in a certain surveillance area. The idea is that when a human object moves, he may block or reflect the RF signals between the reader and tags. Based on the estimation of Doppler Shift and Tag Read Rate variations, DTrack can detect whether a human object enters in the system and further track the moving direction of the object. DTrack uses commercial readers and off-the-shelf passive tags and is scalable and easy for large-scale deployments. Experimental results show that our system is effective in detecting the direction of moving human objects with high accuracy. |
Accession Number: WOS:000364943700001 |
ISSN: 1550-1477 |
Record 216 of 243 | |||||||||
Title: The origin of enhanced optical absorption of the BiFeO<sub>3</sub>/ZnO heterojunction in the visible and terahertz regions | |||||||||
Author(s): Feng, HJ (Feng, Hong-Jian); Yang, K (Yang, Kang); Deng, W (Deng, Wan); Li, MM (Li, Mengmeng); Wang, MZ (Wang, Mingzi); Duan, B (Duan, Bi); Liu, F (Liu, Feng); Tian, JS (Tian, Jinshou); Guo, XH (Guo, Xiaohui) | |||||||||
Source: PHYSICAL CHEMISTRY CHEMICAL PHYSICS Volume: 17 Issue: 40 Pages: 26930-26936 DOI: 10.1039/c5cp04389a Published: 2015 | |||||||||
Abstract: Optical absorption is improved for the BiFeO3/ZnO heterostructure prepared by a sol-gel process, especially, in the terahertz energy region. A dipole-corrected slab model is used to describe the bilayer film, and first-principles calculations agree with the experiments which present unambiguous explanation for the enhancement of the optical properties. Two-dimensional electrons in the ZnO side of the heterostructure are found to play an essential role in forming the photoinduced carriers and the enhancement of the absorption. The conducting layers tend to penetrate into the interface and decrease the band gap, leading to the transport of carriers through the interface to the BiFeO3 side. The photoinduced carriers can be separated by the ferroelectric domains in BiFeO3, and this mechanism makes the heterostructure an ideal candidate for BiFeO3-based ferroelectric photovoltaic cells. | |||||||||
Accession Number: WOS:000362679300048 | |||||||||
PubMed ID: 26403497 | |||||||||
Author Identifiers: | |||||||||
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ISSN: 1463-9076 | |||||||||
eISSN: 1463-9084 |
Record 217 of 243 | ||||||||||||
Title: Efficient CW Dual-Wavelength and Passively <i>Q</i>-Switched Tm:LuAG Lasers | ||||||||||||
Author(s): Feng, TL (Feng, Tianli); Yang, KJ (Yang, Kejian); Zhao, SZ (Zhao, Shengzhi); Zhao, J (Zhao, Jia); Qiao, WC (Qiao, Wenchao); Li, T (Li, Tao); Zheng, LH (Zheng, Lihe); Xu, J (Xu, Jun); Wang, QG (Wang, Qingguo); Xu, XD (Xu, Xiaodong); Su, LB (Su, Liangbi); Wang, YG (Wang, Yonggang) | ||||||||||||
Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 27 Issue: 1 Pages: 7-10 DOI: 10.1109/LPT.2014.2357800 Published: JAN 1 2015 | ||||||||||||
Abstract: Efficient diode-pumped Tm:LuAG lasers operating in continuous wave, dual-wavelength, and passive Q-switching regimes have been demonstrated. A maximum output power of 4.42 W with a beam quality of M-2 <= 1.45 at 2021.2 nm was obtained, corresponding to a slope efficiency of 49.5%. Using a birefringent quartz plate, the Tm: LuAG laser emitted the highest output power of 2.3 W at dual-wavelength of 2022 and 2030 nm. With a SWCNT-SA employed as saturable absorber, passively Q-switched Tm: LuAG laser was realized, which generated the shortest pulses of 405 ns at 2021.6 nm and a maximum single pulse energy of 40.6 mu J at 2019.7 nm. | ||||||||||||
Accession Number: WOS:000349185600002 | ||||||||||||
Author Identifiers: | ||||||||||||
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ISSN: 1041-1135 | ||||||||||||
eISSN: 1941-0174 |
Record 218 of 243 | |||||||||
Title: On Laser-induced Damage Features in an Ultraviolet (UV) Fluorophosphate Glass When Irradiated with a Nanosecond Laser Beam | |||||||||
Author(s): Fu, LL (Fu, L-L.); Wei, W (Wei, W.); Zhang, CM (Zhang, C-M.); Peng, B (Peng, B.) | |||||||||
Source: LASERS IN ENGINEERING Volume: 30 Issue: 5-6 Pages: 277-285 Published: 2015 | |||||||||
Abstract: In this study a novel ultraviolet (UV) window material, fluorophosphate glass, was prepared by the melt-quenching method. The laser-induced damage (LID) feature of fluorophosphate glass was measured using laser damage experiments, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The results show that fluorophosphate glass has a high ultraviolet transmittance (88%) at 351.00 nm. And the laser-induced damage threshold (LIDT) of the fluorophosphate glass is almost 7.0 J/cm(2), which is more than 2 times higher than that of fused silica (3.2 J/cm(2)) irradiated with a 8 ns and 351.00 nm laser by the same processing method. In addition, AFM and SEM images indicate that the damage is also insensitive to the surface roughness of fluorophosphate glass. | |||||||||
Accession Number: WOS:000352114600002 | |||||||||
Author Identifiers: | |||||||||
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ISSN: 0898-1507 | |||||||||
eISSN: 1029-029X |
Record 219 of 243 |
Title: A 1.7-ps pulse mode-locked Yb<SUP>3+</SUP>:Sc<sub>2</sub>SiO<sub>5</sub> laser with a reflective graphene oxide saturable absorber |
Author(s): Ge, PG (Ge Ping-Guang); Su, LM (Su Li-Ming); Liu, J (Liu Jie); Zheng, LH (Zheng Li-He); Su, LB (Su Liang-Bi); Xu, J (Xu Jun); Wang, YG (Wang Yong-Gang) |
Source: CHINESE PHYSICS B Volume: 24 Issue: 1 Article Number: 014207 DOI: 10.1088/1674-1056/24/1/014207 Published: JAN 2015 |
Abstract: By using a reflective graphene oxide as saturable absorber, a diode-pumped passively mode-locked Yb3+:Sc2SiO5 (Yb:SSO) laser has been demonstrated for the first time. Without extra negative dispersion compensation, the minimum pulse duration of 1.7 ps with a repetition rate of 94 MHz was obtained at the central wavelength of 1062.6 nm. The average output power amounts to 355mWunder the absorbed pump power of 15W. The maximum peak power of the mode-locking laser is up to 2.2 kW, and the single pulse energy is 3.8 nJ. |
Accession Number: WOS:000350701400030 |
ISSN: 1674-1056 |
eISSN: 1741-4199 |
Record 220 of 243 |
Title: Switchable dual-wavelength all-fiber laser mode-locked by carbon nanotubes |
Author(s): Kong, YC (Kong, Y. C.); Yang, HR (Yang, H. R.); Li, WL (Li, W. L.); Chen, GW (Chen, G. W.) |
Source: LASER PHYSICS Volume: 25 Issue: 1 Article Number: 015101 DOI: 10.1088/1054-660X/25/1/015101 Published: JAN 2015 |
Abstract: We have proposed a compact dual-wavelength all-fiber pulse laser based on a single-walled carbon nanotube and chirped fiber Bragg gratings (CFBGs). A transmission filter is composed of a circulator and two CFBGs and is capable of controlling the operation of the proposed fiber laser. Mode-locking operations can be switched between 1551.2 and 1548.6 nm with the appropriate adjustment of polarization controller. Our laser delivers the pulses with the spectral bandwidth of about 0.6 nm and the pulse duration of about 7 ps. This work provides a low-cost, stable, and dual-wavelength ultrafast-pulsed laser source suitable for practical applications. |
Accession Number: WOS:000346800100004 |
ISSN: 1054-660X |
eISSN: 1555-6611 |
Record 221 of 243 | ||||||
Title: Measuring the fractional topological charge of LG beams by using interference intensity analysis | ||||||
Author(s): Li, XZ (Li, Xinzhong); Tai, YP (Tai, Yuping); Lv, FJ (Lv, Fangjie); Nie, ZG (Nie, Zhaogang) | ||||||
Source: OPTICS COMMUNICATIONS Volume: 334 Pages: 235-239 DOI: 10.1016/j.optcom.2014.08.020 Published: JAN 1 2015 | ||||||
Abstract: We demonstrate a method to measure the fractional topological charge (TC) of Laguerre-Gaussian (LG) beams by analyzing the interference intensity patterns between the vortex beam and its conjugate beam. By this method, the magnitude of integer and fractional TCs is quantitatively measured by using a simple unified formula. The proposed method can measure TCs up to 60. (C) 2014 Elsevier B.V All rights reserved. | ||||||
Accession Number: WOS:000345523600043 | ||||||
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ISSN: 0030-4018 | ||||||
eISSN: 1873-0310 |
Record 222 of 243 | ||||||
Title: Plasmonic characteristics in nanoscale graphene resonator-coupled waveguides | ||||||
Author(s): Lu, H (Lu, Hua) | ||||||
Source: APPLIED PHYSICS B-LASERS AND OPTICS Volume: 118 Issue: 1 Pages: 61-67 DOI: 10.1007/s00340-014-5954-3 Published: JAN 2015 | ||||||
Abstract: In this paper, we numerically and theoretically investigate the propagation of surface plasmon polaritons in a graphene-based resonator-coupled waveguide system, consisting of a monolayer graphene ribbon coupling to two graphene sheets. The resonance wavelength of this system can be easily tuned by adjusting the chemical potential and the width of the graphene ribbon. Both resonance bandwidth and spectral transmission characteristics of the structure strongly depend on the coupling distance and overlap length between the graphene ribbon and graphene sheets. The structural symmetry is found to be another essential parameter. The presented results may pave the way toward the dynamic control of light propagation in graphene-based structures and the realization of tunable graphene-based optoelectronic devices. | ||||||
Accession Number: WOS:000347247700008 | ||||||
Author Identifiers: | ||||||
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ISSN: 0946-2171 | ||||||
eISSN: 1432-0649 |
Record 223 of 243 | ||||||
Title: High-order topological charges measurement of LG vortex beams with a modified Mach-Zehnder interferometer | ||||||
Author(s): Lv, FJ (Lv, Fangjie); Li, XZ (Li, Xinzhong); Tai, YP (Tai, Yuping); Zhang, LP (Zhang, Liping); Nie, ZG (Nie, Zhaogang); Chen, QD (Chen, Qingdong) | ||||||
Source: OPTIK Volume: 126 Issue: 23 Pages: 4378-4381 DOI: 10.1016/j.ijleo.2015.08.145 Published: 2015 | ||||||
Abstract: We present a new method to measure the high-order topological charges (TCs) of Laguerre-Gaussian (LG) vortex beams by using a modified Mach-Zehnder interferometer. Counting the number of interference bright fringes between the LG beam and its conjugate beam determines integer and half-integer TCs through half of the bright fringe number. The proposed method can measure the order of the integer TC up to 90, which is higher than that achieved by previous methods. This technique opens up new applications for LG vortex beams. (C) 2015 Elsevier GmbH. All rights reserved. | ||||||
Accession Number: WOS:000365373400174 | ||||||
Author Identifiers: | ||||||
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ISSN: 0030-4026 |
Record 224 of 243 | ||||||||||||
Title: Enhanced properties of poly(vinyl alcohol) composite films with functionalized graphene | ||||||||||||
Author(s): Mo, SB (Mo, Shenbin); Peng, L (Peng, Li); Yuan, CQ (Yuan, Chunqiu); Zhao, CY (Zhao, Chunyan); Tang, W (Tang, Wei); Ma, CL (Ma, Cunliang); Shen, JX (Shen, Jiaxin); Yang, WB (Yang, Wenbin); Yu, YH (Yu, Youhai); Min, Y (Min, Yong); Epstein, AJ (Epstein, Arthur J.) | ||||||||||||
Source: RSC ADVANCES Volume: 5 Issue: 118 Pages: 97738-97745 DOI: 10.1039/c5ra15984a Published: 2015 | ||||||||||||
Abstract: Three types of poly(vinyl alcohol) (PVA) composite films containing graphene oxide (GO), reduced graphene oxide (RGO) and novel sulfonated graphene oxide (SRGO) as a filler were successfully prepared by a simple solution casting. The structure and properties of graphene-based PVA composites films were investigated. The results showed that the properties of the polymer composites films were sensitive to the structure of graphene. GO acted as the best reinforcing filler to enhance the mechanical property of PVA because it has many oxygen functional groups which could enhance the interfacial interactions through the formation of hydrogen bonds with PVA chains. The tensile strength and modulus of the resulting PVA/GO composites could reach 280 MPa and 13.5 GPa, respectively. RGO could improve the dielectric properties of PVA and the electrical conductivities were increased by similar to 10(11) orders of magnitude in the composites with 50 wt% of filler loadings as compared to that of neat PVA. SRGO could enhance the mechanical and dielectric properties of PVA simultaneously. The mechanical properties of PVA could be efficiently improved due to the strong interaction between the -SO3H groups on the SRGO sheets and PVA chains. The tensile strength and modulus of the resulting PVA/SRGO composites could reach 252 MPa and 8.5 GPa, respectively. Although the conductivity values of PVA/SRGO composites were less than those of the PVA/RGO composites, they were still increased by similar to 10(10) orders of magnitude in the composites with 50 wt% of filler loadings as compared to that of neat PVA. These results demonstrated that PVA films with enhancement in the mechanical and electronic properties can be fabricated with proper modified graphene. | ||||||||||||
Accession Number: WOS:000365220100079 | ||||||||||||
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ISSN: 2046-2069 |
Record 225 of 243 | |||||||||
Title: Cavity linewidth narrowing by tunneling induced double dark resonances in triple quantum dot molecules | |||||||||
Author(s): Tian, SC (Tian, Si-Cong); Wan, RG (Wan, Ren-Gang); Li, LH (Li, Lian-He); Tong, CZ (Tong, Cun-Zhu); Ning, YQ (Ning, Yong-Qiang) | |||||||||
Source: OPTICS COMMUNICATIONS Volume: 334 Pages: 94-100 DOI: 10.1016/j.optcom.2014.08.011 Published: JAN 1 2015 | |||||||||
Abstract: A scheme for obtaining a tunable ultranarrow cavity transmission controlled by two tunneling in triple quantum dots system is proposed. In such system, the tunneling can induce double dark resonances, resulting in the appearance of two transparency windows. With the steep dispersion within the narrowed transparency windows, an ultranarrow transmission peak can be obtained, compared with that of double quantum dots system. Furthermore, by varying the energy splitting, the linewidth and the position of the ultranarrow transmission peak can be engineered. Because no coupling laser is required, the scheme proposed here is more convenient for future experiments and applications in optics, and may be useful in designing novel optoelectronic devices. (C) 2014 Elsevier B.V. All rights reserved. | |||||||||
Accession Number: WOS:000345523600018 | |||||||||
Author Identifiers: | |||||||||
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ISSN: 0030-4018 | |||||||||
eISSN: 1873-0310 |
Record 226 of 243 | |||||||||
Title: Tunable continuous wave and passively Q-switched Nd:LuLiF<sub>4</sub> laser with monolayer graphene as saturable absorber | |||||||||
Author(s): Wang, F (Wang, Feng); Li, SX (Li, Shixia); Li, T (Li, Tao); Luo, JJ (Luo, Jianjun); Li, M (Li, Ming) | |||||||||
Source: LASER PHYSICS Volume: 25 Issue: 1 Article Number: 015805 DOI: 10.1088/1054-660X/25/1/015805 Published: JAN 2015 | |||||||||
Abstract: Tunable continuous wave and passively Q-switched Nd:LuLiF4 laser performances were demonstrated. Employing a 2 mm thick quartz plate as the birefringence filter, three continuous tuning ranges from 1045.2 to 1049.9 nm, 1051 to 1055.1 nm and 1072.1 to 1074.3 nm could be obtained. Q-switched laser operation was realized by using a monolayer graphene as a saturable absorber. At an incident pump power of 5.94 W, the maximum average output power was 669 mW with the pulse duration of 210 ns and the pulse repetition rate of 145 kHz at T = 10%. | |||||||||
Accession Number: WOS:000346800100019 | |||||||||
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ISSN: 1054-660X | |||||||||
eISSN: 1555-6611 |
Record 227 of 243 |
Title: Reflector designed for light-emitting-diode lighting source in three-dimensional space |
Author(s): Wang, GZ (Wang, Guangzhen); Hou, Y (Hou, Yu); Hu, LC (Hu, Lichun); Tang, WW (Tang, Wanwei); Gao, J (Gao, Jian); Wang, LL (Wang, Lili) |
Source: OPTIK Volume: 126 Issue: 23 Pages: 4534-4538 DOI: 10.1016/j.ijleo.2015.08.069 Published: 2015 |
Abstract: Reflectors used for light-emitting-diode (LED) light source are designed in three-dimensional space to produce uniform illuminance effect. Reflector's surfaces are calculated by the source-target mapping method in Geometrical Optics. Ignoring scattering and absorption loss of the material, reflectors' performances are investigated. The simulation results show that the light efficiency which is the ratio of light flux in the target surface to that from LED light source can reach above 95%. And the illuminance uniformity which is the ratio of minimum illuminance (min E) to average illuminance (aye E) also can reach above 95%. Finally, the array of reflectors is investigated and the result shows it still has good performance. (C) 2015 Elsevier GmbH. All rights reserved. |
Accession Number: WOS:000365373400203 |
ISSN: 0030-4026 |
eISSN: 1618-1336 |
Record 228 of 243 | |||||||||
Title: Tunable Slow Light Based on Plasmon-Induced Transparency in Dual-Stub-Coupled Waveguide | |||||||||
Author(s): Wang, GX (Wang, Guoxi); Zhang, WF (Zhang, Wenfu); Gong, YK (Gong, Yongkang); Liang, J (Liang, Jian) | |||||||||
Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 27 Issue: 1 Pages: 89-92 DOI: 10.1109/LPT.2014.2362293 Published: JAN 1 2015 | |||||||||
Abstract: We investigate the plasmon-induced transparency (PIT) effect in dual-stub-coupled metal-insulator-metal waveguide. The transmission line theory is employed to analyze the relationship between the transmission properties and geometrical parameters. It is found that by incorporating tunable refractive index materials with the proposed structure, a tunable PIT and slow light effect can be obtained in a constant stub separation design. The theoretical results show that a shift of 70 THz in the central wavelengths of transparency window can be obtained when the refractive index of the dielectric varies. In addition, the group index can be tuned from 24 to 36, which provides an effective method to adjust the slow light properties in the proposed waveguide. This letter opens up the possibility for the realization of tunable slow light devices in highly integrated optical circuits. | |||||||||
Accession Number: WOS:000349185600023 | |||||||||
Author Identifiers: | |||||||||
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ISSN: 1041-1135 | |||||||||
eISSN: 1941-0174 |
Record 229 of 243 | |||||||||
Title: Two types of cavities for side-pumped Nd:YAG laser mode locked by semiconductor saturable absorber mirror | |||||||||
Author(s): Wang, JL (Wang, J. L.); Jiang, ZJ (Jiang, Z. J.); Zhu, JF (Zhu, J. F.); Wang, YG (Wang, Y. G.) | |||||||||
Source: OPTIK Volume: 126 Issue: 23 Pages: 3752-3754 DOI: 10.1016/j.ijleo.2015.08.251 Published: 2015 | |||||||||
Abstract: Two types of laser cavities for mode locked solid-state laser are designed based on transmission matrix ABCD of line-style resonator and z-style resonator. By adopting these two types of cavities, mode-locked Nd:YAG laser side-pumped by diode laser was realized with semiconductor saturable absorber mirror. The highest output power is 1.5W with the repetition rate of 250 MHz in the line-style cavity. In the z-style cavity, the highest output power is 1W, and the repetition rate is about 100 MHz with the pulse duration of 200 Ps. (C) 2015 Elsevier GmbH. All rights reserved. | |||||||||
Accession Number: WOS:000365373400053 | |||||||||
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ISSN: 0030-4026 |
Record 230 of 243 | ||||||
Title: Analytical soliton solutions for the cubic-quintic nonlinear Schrodinger equation with Raman effect in the nonuniform management systems | ||||||
Author(s): Wang, P (Wang, Ping); Feng, L (Feng, Li); Shang, T (Shang, Tao); Guo, LX (Guo, Lixin); Cheng, GH (Cheng, Guanghua); Du, YJ (Du, Yingjie) | ||||||
Source: NONLINEAR DYNAMICS Volume: 79 Issue: 1 Pages: 387-395 DOI: 10.1007/s11071-014-1672-y Published: JAN 2015 | ||||||
Abstract: Based on the Kundu-Eckhaus equation with variable coefficients, the exact one-soliton and two-soliton solutions have been explicitly given by an appropriate similarity transformation method. As an example, an exponential distributed fiber control system, nonlinearity management system and dispersion management system have been considered, and the propagation characteristics of the exact soliton solutions in the three nonuniform management systems have been investigated in detail. Especially, the dynamic properties of the amplitude, pulse width and the central position of the soliton with transmission distance have been studied. The results have some guiding significance for soliton amplification, compression and control management, and can provide some theoretical analysis for carrying out optical soliton communication experiment. | ||||||
Accession Number: WOS:000348314500032 | ||||||
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ISSN: 0924-090X | ||||||
eISSN: 1573-269X |
Record 231 of 243 | |||||||||||||||||||||
Title: Pulse contrast improvement for chirped pulse amplification lasers by spectro-temporal filtering | |||||||||||||||||||||
Author(s): Wang, XL (Wang, Xianglin); Wang, YS (Wang, Yishan); Hu, XH (Hu, Xiaohong); Liu, YS (Liu, Yuanshan); Zhang, W (Zhang, Wei); Yang, Z (Yang, Zhi) | |||||||||||||||||||||
Source: JOURNAL OF MODERN OPTICS Volume: 62 Issue: 7 Pages: 576-580 DOI: 10.1080/09500340.2014.994682 Published: 2015 | |||||||||||||||||||||
Abstract: A spectro-temporal filtering method is proposed to increase the contrast ratio of chirped pulses. The advantages of this method include easy cascading, high transmission, and it can also be used in the high-energy chirped pulse amplifier (CPA) system. The effectiveness of the proposed method was experimentally verified by operating the spectro-temporal filtering method on a Ti:sapphire CPA system and then measuring the contrast ratio of pulse based on optical Kerr gate effect(OKG). The measuring result demonstrated that, after passing through one-stage spectro-temporal filtering system with transmittance up to 70%, the contrast ratio of the pulse was improved by an order of magnitude. | |||||||||||||||||||||
Accession Number: WOS:000350772400011 | |||||||||||||||||||||
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ISSN: 0950-0340 | |||||||||||||||||||||
eISSN: 1362-3044 |
Record 232 of 243 |
Title: Interval-valued intuitionistic fuzzy prioritized hybrid weighted aggregation operator and its application in decision making |
Author(s): Wu, H (Wu, Hua); Su, XQ (Su, Xiuqin) |
Source: JOURNAL OF INTELLIGENT & FUZZY SYSTEMS Volume: 29 Issue: 4 Pages: 1697-1709 DOI: 10.3233/IFS-151647 Published: 2015 |
Abstract: Interval-valued intuitionistic fuzzy numbers (IVIFNs) are usually utilized in multi-attribute decision making problems, providing an accurate description of incomplete and uncertain information. The existing IVIFN-based works mainly focus on either the prioritization relationship of attributes or both the importance and the ordered position of them. However, these aspects of attributes are all important in practical use and they should be simultaneously considered. To this end, this paper proposes an interval-valued intuitionistic fuzzy prioritized hybrid weighted aggregation (IVIF-PHWA) operator. The contribution of this paper is threefold: 1) A unit prioritized hybrid weighted aggregation (UPHWA) operator is proposed, which considers the prioritization relationship, the importance and the ordered position of attributes. 2) The UPHWA operator is extended into IVIF-PHWA operator, whose properties are all investigated. These properties illustrate that the IVIF-PHWA operator can better deal with the incomplete and imprecise information. 3) This work develops an IVIF-PHWA operator-based multi-attribute decision making method to solve the decision making problems in IVIF environment. Finally, a practical example is provided to validate the efficiency and effectiveness of the proposed approach. |
Accession Number: WOS:000364407900039 |
ISSN: 1064-1246 |
eISSN: 1875-8967 |
Record 233 of 243 | |||||||||||||||
Title: Preparation and Applications of Low-loss As-S Chalcogenide Glass Fibers | |||||||||||||||
Author(s): Xu, YT (Xu Yan-Tao); Guo, HT (Guo Hai-Tao); Yan, XT (Yan Xing-Tao); Lu, M (Lu Min); Lin, AX (Lin Ao-Xiang); Li, F (Li Fu); Yang, JF (Yang Jian-Feng); Zhan, H (Zhan Huan) | |||||||||||||||
Source: JOURNAL OF INORGANIC MATERIALS Volume: 30 Issue: 1 Pages: 97-101 DOI: 10.15541/jim20140252 Published: JAN 2015 | |||||||||||||||
Abstract: High-purity As-S glasses were prepared by repetitive distillation and open-type dynamic distillation methods. The intensities of impurities' absorptions were obviously reduced at 2.9 mu m, 4 mu m and 6.3 mu m. Chalcogenide glass tubes with precise wall thickness and fine surface properties were prepared by tube-rotating technique and the fibers with core of 40 mu m, cladding of 50 mu m and error of 1% in diameter were drawn by rod-in-tube method. The fiber had good mechanical and optical performances, which general optical loss was less than 0.5 dB/m and the bending radius was less than 4 mm based on the bending test. The line-plane-switching fiber bundle which format was 64x9 quadrate array to implement 192x3 linear array was made from these chalcogenide glass and long-array infrared push-broom image was successfully demonstrated. The results prove that the fibers and bundle have excellent properties and push-broom infrared system based on the line-plane-switching fiber bundle being feasibility. | |||||||||||||||
Accession Number: WOS:000351641500017 | |||||||||||||||
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ISSN: 1000-324X |
Record 234 of 243 |
Title: Switchable dual-wavelength fiber laser mode-locked by monolayer graphene on D-shaped fiber |
Author(s): Yang, HR (Yang, H. R.) |
Source: JOURNAL OF MODERN OPTICS Volume: 62 Issue: 17 Pages: 1363-1367 DOI: 10.1080/09500340.2015.1039616 Published: 2015 |
Abstract: A switchable mode-locking fiber laser is demonstrated by means of a monolayer graphene saturable absorber (SA) based on a D-shaped fiber. The monolayer graphene, which is grown by chemical vapor deposition, is transferred onto the D-shaped fiber and then the light-graphene interaction via the evanescent field of the fiber is enhanced greatly. Using such a graphene-based SA, the single-wavelength mode locking can be switched from 1531.5 to 1559.1 nm by appropriately adjusting the polarization controller (PC). In addition, the stable dual-wavelength mode-locking operation is also observed at the proper state of PC. |
Accession Number: WOS:000360503800001 |
ISSN: 0950-0340 |
eISSN: 1362-3044 |
Record 235 of 243 |
Title: Simultaneous Pose and Correspondence Estimation Based on Genetic Algorithm |
Author(s): Yang, HW (Yang, Haiwei); Wang, F (Wang, Fei); Li, Z (Li, Zhe); Dong, H (Dong, Hang) |
Source: INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS Article Number: 828241 DOI: 10.1155/2015/828241 Published: 2015 |
Abstract: Although several algorithms have been presented to solve the simultaneous pose and correspondence estimation problem, the correct solution may not be reached to with the traditional random-start initialization method. In this paper, we derive a novel method which estimates the initial value based on genetic algorithm, considering the influences of different initial guesses comprehensively. First, a set of random initial guesses is generated as candidate solutions. Second, the assignment matrix and the perspective projection error are computed for each candidate solution. And then each individual is modified (selection, crossover, andmutation) in current iterative process. Finally, the fittest individual is stochastically selected from the final population. With the presented initialization method, the proper initial guess could be first calculated and then the simultaneous pose and correspondence estimation problem could be solved easily. Simulation results with synthetic data and experiments on real images prove the effectiveness and robustness of our proposed method. |
Accession Number: WOS:000364943600001 |
ISSN: 1550-1477 |
Record 236 of 243 | ||||||||||||||||||
Title: An Efficient MRF Embedded Level Set Method for Image Segmentation | ||||||||||||||||||
Author(s): Yang, X (Yang, Xi); Gao, XB (Gao, Xinbo); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong); Li, J (Li, Jie) | ||||||||||||||||||
Source: IEEE TRANSACTIONS ON IMAGE PROCESSING Volume: 24 Issue: 1 Pages: 9-21 DOI: 10.1109/TIP.2014.2372615 Published: JAN 2015 | ||||||||||||||||||
Abstract: This paper presents a fast and robust level set method for image segmentation. To enhance the robustness against noise, we embed a Markov random field (MRF) energy function to the conventional level set energy function. This MRF energy function builds the correlation of a pixel with its neighbors and encourages them to fall into the same region. To obtain a fast implementation of the MRF embedded level set model, we explore algebraic multigrid (AMG) and sparse field method (SFM) to increase the time step and decrease the computation domain, respectively. Both AMG and SFM can be conducted in a parallel fashion, which facilitates the processing of our method for big image databases. By comparing the proposed fast and robust level set method with the standard level set method and its popular variants on noisy synthetic images, synthetic aperture radar (SAR) images, medical images, and natural images, we comprehensively demonstrate the new method is robust against various kinds of noises. In particular, the new level set method can segment an image of size 500 x 500 within 3 s on MATLAB R2010b installed in a computer with 3.30-GHz CPU and 4-GB memory. | ||||||||||||||||||
Accession Number: WOS:000346343400001 | ||||||||||||||||||
PubMed ID: 25420261 | ||||||||||||||||||
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ISSN: 1057-7149 | ||||||||||||||||||
eISSN: 1941-0042 |
Record 237 of 243 | ||||||
Title: Heterostructured cathode with graded bandgap window-layer for photon-enhanced thermionic emission solar energy converters | ||||||
Author(s): Yang, Y (Yang, Yang); Yang, WZ (Yang, Wenzheng); Sun, CD (Sun, Chuandong) | ||||||
Source: SOLAR ENERGY MATERIALS AND SOLAR CELLS Volume: 132 Pages: 410-417 DOI: 10.1016/j.solmat.2014.09.027 Published: JAN 2015 | ||||||
Abstract: A heterostructured cathode having a graded bandgap window-layer is proposed in this study to improve the performance of photon-enhanced thermionic emission (PETE) solar energy converters. A model based on a one-dimensional steady-state equation is developed to analyze the characteristics of the proposed device. This model is used to calculate the conversion efficiency of a PETE device with an AlxGa1-xAs/GaAs cathode. The built-in electric field induced by the bandgap gradation in the window-layer is shown to improve the efficiency because of the reduction of contact surface recombination losses and efficient collection of photogenerated electrons. This field is unaffected by temperature variation, and the improvement of efficiency is sustained at elevated temperatures. The effect of window-layer parameters and cathode thickness on efficiency is discussed. We also show that the efficiency maximizes at lower temperatures for cathodes with lower electron affinities. Moreover an optimal value exists for anode work function at a given anode temperature, thus providing guidance for the optimum design of barrier conditions for both cathode and anode. (C) 2014 Elsevier B.V. All rights reserved. | ||||||
Accession Number: WOS:000346549400057 | ||||||
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ISSN: 0927-0248 | ||||||
eISSN: 1879-3398 |
Record 238 of 243 | |||||||||
Title: Detection ability analysis of ground based imaging polarization detector | |||||||||
Author(s): Yao, DL (Yao, Dalei); Wen, DS (Wen, Desheng); Xue, JR (Xue, Jianru); Qiu, YH (Qiu, Yuehong); Xi, JB (Xi, Jiangbo); Wen, Y (Wen, Yan); Chen, Z (Chen, Zhi) | |||||||||
Source: OPTIK Volume: 126 Issue: 23 Pages: 4771-4774 DOI: 10.1016/j.ijleo.2015.08.188 Published: 2015 | |||||||||
Abstract: A ground based imaging polarization detector for astronomical observation is designed, the working principle is analyzed and the mathematical models of degree of polarization and detection ability of the detector are derived. The SNR (signal-to-noise ratio) and number of phoelectrons needed by the detector are analyzed by simulation with the detection demand of 1% or 2% degree of polarization. Then, the integration time of the detector is calculated when detecting stars with different brightness according to the parameters of the detector we designed. The theoretical basis is given through these results. (C) 2015 Elsevier GmbH. All rights reserved. | |||||||||
Accession Number: WOS:000365373400249 | |||||||||
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ISSN: 0030-4026 |
Record 239 of 243 | |||||||||||||||||||||
Title: Low Repetition Rate Subnanosecond Pulse Characteristics of Nd:Lu<sub>0.5</sub>Y<sub>0.5</sub>VO<sub>4</sub>/KTP Green Laser With EO and MWCNT | |||||||||||||||||||||
Author(s): Zhang, HJ (Zhang, Haijuan); Zhao, J (Zhao, Jia); Yang, KJ (Yang, Kejian); Zhao, SZ (Zhao, Shengzhi); Li, T (Li, Tao); Li, GQ (Li, Guiqiu); Li, DC (Li, Dechun); Qiao, WC (Qiao, Wenchao); Wang, YG (Wang, Yonggang); Zhao, B (Zhao, Bin) | |||||||||||||||||||||
Source: IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS Volume: 21 Issue: 1 Article Number: 1100506 DOI: 10.1109/JSTQE.2014.2345758 Published: JAN-FEB 2015 | |||||||||||||||||||||
Abstract: By simultaneously employing electro-optic (EO) modulator and multiwalled carbon nanotube (MWCNT) in a doubly Q-switched mode-locked (QML) Nd:Lu0.5Y0.5VO4/KTP laser, a low repetition rate subnanosecond Nd:Lu0.5Y0.5VO4/KTP green laser with high peak power is presented. Since the repetition rate of this pulsed green laser is controlled by the EO modulator, highly stable laser pulses with low repetition rates of 1-5 kHz are obtained. As the pulse duration of this laser depends on the mode-locked pulse width underneath the Q-switched envelope, subnanosecond green laser pulses with high peak power can be generated. The average output powers, pulse widths as well as peak powers versus incident pump power under different repetition rates are measured. The shortest pulse duration of 415 ps and the highest pulse energy of 424 mu J are obtained at the repetition rate of 1 kHz, corresponding to a peak power of as high as 1022 kW. The experimental results show that the dual-loss modulation technology with EO and MWCNT in QML laser is an efficient method in generating low repetition rate subnanosecond pulse green laser. | |||||||||||||||||||||
Accession Number: WOS:000353991900001 | |||||||||||||||||||||
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ISSN: 1077-260X | |||||||||||||||||||||
eISSN: 1558-4542 |
Record 240 of 243 | |||||||||||||||||||||||||||
Title: A Fine-Grained Image Categorization System by Cellet-Encoded Spatial Pyramid Modeling | |||||||||||||||||||||||||||
Author(s): Zhang, LM (Zhang, Luming); Gao, Y (Gao, Yue); Xia, YJ (Xia, Yingjie); Dai, QH (Dai, Qionghai); Li, XL (Li, Xuelong) | |||||||||||||||||||||||||||
Source: IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS Volume: 62 Issue: 1 Pages: 564-571 DOI: 10.1109/TIE.2014.2327558 Published: JAN 2015 | |||||||||||||||||||||||||||
Abstract: In this paper, a new fine-grained image categorization system that improves spatial pyramid matching is developed. In this method, multiple cells are combined into cellets in the proposed categorization model, which are highly responsive to an object's fine categories. The object components are represented by cellets that can connect spatially adjacent cells within the same pyramid level. Here, image categorization can be formulated as the matching between the cellets of corresponding images. Toward an effective matching process, an active learning algorithm that can effectively select a few representative cells for constructing the cellets is adopted. A linear-discriminant-analysis-like scheme is employed to select discriminative cellets. Then, fine-grained image categorization can be conducted with a trained linear support vector machine. Experimental results on three real-world data sets demonstrate that our proposed system outperforms the state of the art. | |||||||||||||||||||||||||||
Accession Number: WOS:000346767400058 | |||||||||||||||||||||||||||
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ISSN: 0278-0046 | |||||||||||||||||||||||||||
eISSN: 1557-9948 |
Record 241 of 243 | |||||||||||||||||||||||||||
Title: A Survey of Sparse Representation: Algorithms and Applications | |||||||||||||||||||||||||||
Author(s): Zhang, Z (Zhang, Zheng); Xu, Y (Xu, Yong); Yang, J (Yang, Jian); Li, XL (Li, Xuelong); Zhang, D (Zhang, David) | |||||||||||||||||||||||||||
Source: IEEE ACCESS Volume: 3 Pages: 490-530 DOI: 10.1109/ACCESS.2015.2430359 Published: 2015 | |||||||||||||||||||||||||||
Abstract: Sparse representation has attracted much attention from researchers in fields of signal processing, image processing, computer vision, and pattern recognition. Sparse representation also has a good reputation in both theoretical research and practical applications. Many different algorithms have been proposed for sparse representation. The main purpose of this paper is to provide a comprehensive study and an updated review on sparse representation and to supply guidance for researchers. The taxonomy of sparse representation methods can be studied from various viewpoints. For example, in terms of different norm minimizations used in sparsity constraints, the methods can be roughly categorized into five groups: 1) sparse representation with L-0-norm minimization; 2) sparse representation with L-p-norm (0 < p < 1) minimization; 3) sparse representation with L-1-norm minimization; 4) sparse representation with 12,1-norm minimization; and 5) sparse representation with 12-norm minimization. In this paper, a comprehensive overview of sparse representation is provided. The available sparse representation algorithms can also be empirically categorized into four groups: 1) greedy strategy approximation; 2) constrained optimization; 3) proximity algorithm-based optimization; and 4) homotopy algorithm-based sparse representation. The rationales of different algorithms in each category are analyzed and a wide range of sparse representation applications are summarized, which could sufficiently reveal the potential nature of the sparse representation theory. In particular, an experimentally comparative study of these sparse representation algorithms was presented. | |||||||||||||||||||||||||||
Accession Number: WOS:000371388200037 | |||||||||||||||||||||||||||
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ISSN: 2169-3536 |
Record 242 of 243 |
Title: Design and testing of infrared diffractive telescope imaging optical systems |
Author(s): Zhang, ZF (Zhang, ZhouFeng); Xie, YJ (Xie, YongJun); Yin, QY (Yin, QinYe); Kang, FZ (Kang, FuZeng) |
Source: OPTIK Volume: 126 Issue: 24 Pages: 5740-5743 DOI: 10.1016/j.ijleo.2015.09.079 Published: 2015 |
Abstract: Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different points in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light (from 8 mu m to 12 mu m) to a common focus. At last, the diffuse spot size and MTF function provide diffractive-limited performance. (C) 2015 Elsevier GmbH. All rights reserved. |
Accession Number: WOS:000368650800189 |
ISSN: 0030-4026 |
Record 243 of 243 | |||||||||||||||||||||
Title: Threshold automatic selection hybrid phase unwrapping algorithm for digital holographic microscopy | |||||||||||||||||||||
Author(s): Zhou, ML (Zhou, Meiling); Min, JW (Min, Junwei); Yao, BL (Yao, Baoli); Yu, XH (Yu, Xianghua); Lei, M (Lei, Ming); Yan, SH (Yan, Shaohui); Yang, YL (Yang, Yanlong); Dan, D (Dan, Dan) | |||||||||||||||||||||
Source: JOURNAL OF MODERN OPTICS Volume: 62 Issue: 2 Pages: 108-113 DOI: 10.1080/09500340.2014.954649 Published: 2015 | |||||||||||||||||||||
Abstract: Conventional quality-guided (QG) phase unwrapping algorithm is hard to be applied to digital holographic microscopy because of the long execution time. In this paper, we present a threshold automatic selection hybrid phase unwrapping algorithm that combines the existing QG algorithm and the flood-filled (FF) algorithm to solve this problem. The original wrapped phase map is divided into high- and low-quality sub-maps by selecting a threshold automatically, and then the FF and QG unwrapping algorithms are used in each level to unwrap the phase, respectively. The feasibility of the proposed method is proved by experimental results, and the execution speed is shown to be much faster than that of the original QG unwrapping algorithm. | |||||||||||||||||||||
Accession Number: WOS:000348035000005 | |||||||||||||||||||||
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ISSN: 0950-0340 | |||||||||||||||||||||
eISSN: 1362-3044 |