Record 1 of 263

Title: Toward solving the Steiner travelling salesman problem on urban road maps using the branch decomposition of graphs

Author(s): Xia, YJ (Xia, Yingjie); Zhu, MZ (Zhu, Mingzhe); Gu, QP (Gu, Qianping); Zhang, LM (Zhang, Luming); Li, XL (Li, Xuelong)

Source: INFORMATION SCIENCES  Volume: 374  Pages: 164-178  DOI: 10.1016/j.ins.2016.09.043  Published: DEC 20 2016  

Abstract: The Steiner travelling salesman problem (STSP) is an important issue in intelligent transportation systems and has various practical applications, such as travelling and parcel delivery. In this study, we consider the STSP in real-world road maps, i.e., given a road map with a set of service points or intersections, selection of the representative vertices of a graph G to determine a closed route so a vehicle can visit each service point at least once with the minimum cost. It has been theoretically proved that the STSP and its ancestor, travelling salesman problem, are NP-hard. However, it has been empirically demonstrated that they can be solved efficiently on planar graphs with small branchwidths. Therefore, we propose a branch decomposition-based extraction algorithm for the STSP in planar graphs. Our algorithm can solve the STSP in a planar graph G with a time complexity of 2(O(bw(G))) n(O(1)), where bw(G) is the branchwidth of G. In the case of planar graphs with a small branchwidth, our algorithm performs efficiently. We evaluated our algorithm by applying it to real-world urban road maps, which demonstrated the suitability of our method for real-world applications. (C) 2016 Elsevier Inc. All rights reserved.

Accession Number: WOS:000386645800011

Author Identifiers:

ISSN: 0020-0255

eISSN: 1872-6291

Record 2 of 263

Title: Two-Photon Laser Scanning Stereomicroscopy for Fast Volumetric Imaging

Author(s): Yang, YL (Yang, Yanlong); Yao, BL (Yao, Baoli); Lei, M (Lei, Ming); Dan, D (Dan, Dan); Li, RZ (Li, Runze); Van Horn, M (Van Horn, Mark); Chen, X (Chen, Xun); Li, Y (Li, Yang); Ye, T (Ye, Tong)

Source: PLOS ONE  Volume: 11  Issue: 12  Article Number: e0168885  DOI: 10.1371/journal.pone.0168885  Published: DEC 20 2016  

Abstract: Bessel beams have been successfully used in two-photon laser scanning fluorescence microscopy to extend the depth of field (EDF), which makes it possible to observe fast events volumetrically. However, the depth information is lost due to integration of fluorescence signals along the propagation direction. We describe the design and implementation of two-photon lasers scanning stereomicroscopy, which allows viewing dynamic processes in three-dimensional (3D) space stereoscopically in real-time with shutter glasses at the speed of 1.4 volumes per second. The depth information can be appreciated by human visual system or be recovered with correspondence algorithms for some cases.

Accession Number: WOS:000392842900083

PubMed ID: 27997624

Author Identifiers:

ISSN: 1932-6203

Record 3 of 263

Title: Ultrafast destructuring of laser-irradiated tungsten: Thermal or nonthermal process

Author(s): Zhang, H (Zhang, H.); Li, C (Li, C.); Bevillon, E (Bevillon, E.); Cheng, G (Cheng, G.); Colombier, JP (Colombier, J. P.); Stoian, R (Stoian, R.)

Source: PHYSICAL REVIEW B  Volume: 94  Issue: 22  Article Number: 224103  DOI: 10.1103/PhysRevB.94.224103  Published: DEC 16 2016  

Abstract: The time needed for metals to respond structurally to electronic excitation is usually considered to be set by picosecond-long electron-phonon coupling, hence limiting the rapid achievement of structural phase changes. Via time-resolved ellipsometry, we show that fs laser excitation of tungsten determines unexpectedly fast optical and structural transformations, almost on the time scale of the laser pulse, with sub-ps destructuring of matter. If at low energies, below the damage threshold, Fermi redistribution within the d-band pseudogap populates localized states that screen ions, in ablative ranges, at electronic energies above 4 eV, a charge deficit appears on bonding orbitals generating bond-softening and ionic repulsion in spite of the metallic environment. Along pressure gradients, this rapidly destabilizes the structure. Sub-ps ablation occurs, challenging thermally driven scenarios of phonon activation. First-principles and hydrodynamic models show that ablation interrelates nonclassical charge distortions, electronic stress, and classical electron-phonon dynamics, with the coexistence of thermal and nonthermal effects on scales believed to be prohibitive for the former.

Accession Number: WOS:000390251300002

Author Identifiers:

ISSN: 2469-9950

eISSN: 2469-9969

Record 4 of 263

Title: Modeling the encoding structure and spatial resolution of photon counting imagers with Vernier anode readout

Author(s): Yang, H (Yang, Hao); Zhao, BS (Zhao, Baosheng); Yan, QR (Yan, Qiurong); Liu, YA (Liu, Yong'an)

Source: CHINESE OPTICS LETTERS  Volume: 14  Issue: 12  Article Number: 121102  DOI: 10.3788/COL201614.121102  Published: DEC 10 2016  

Abstract: We present the spatial resolution estimation methods for a photon counting system with a Vernier anode. A limiting resolution model is provided according to discussions of surface encoding structure and quantized noise. The limiting resolution of a Vernier anode is revealed to be significantly higher than that of a microchannel plate. The relationship between the actual spatial resolution and equivalent noise charge of a detector is established by noise analysis and photon position reconstruction. The theoretical results are demonstrated to be in good agreement with the experimental results for a 1.2 mm pitch Vernier anode.

Accession Number: WOS:000391128900015

Author Identifiers:

ISSN: 1671-7694

Record 5 of 263

Title: A target detection method for hyperspectral image based on mixture noise model

Author(s): Zheng, XT (Zheng, Xiangtao); Yuan, Y (Yuan, Yuan); Lu, XQ (Lu, Xiaoqiang)

Source: NEUROCOMPUTING  Volume: 216  Pages: 331-341  DOI: 10.1016/j.neucom.2016.08.015  Published: DEC 5 2016  

Abstract: Subpixel hyperspectral detection is a kind of method which tries to locate targets in a hyperspectral image when the spectrum of the targets is given. Due to its subpixel nature, targets are often smaller than one pixel, which increases the difficulty of detection. Many algorithms have been proposed to tackle this problem, most of which model the noise in all spatial points of hyperspectral image by multivariate normal distribution. However, this model alone may not be an appropriate description of the noise distribution in hyperspectral image. After carefully studying the distribution of hyperspectral image, it is concluded that the gradient of noise also obeys normal distribution. In this paper two detectors are proposed: mixture gradient structured detector (MGSD) and mixture gradient unstructured detector (MGUD). These detectors are based on a new model which takes advantage of the distribution of the gradient of the noise. This makes the detectors more accordant with the practical situation. To evaluate the performance of the proposed detectors, three different data sets, including one synthesized data set and two real-world data sets, are used in the experiments. Results show that the proposed detectors have better performance than current subpixel detectors. (C) 2016 Elsevier B.V. All rights reserved.

Accession Number: WOS:000388777400031

Author Identifiers:

ISSN: 0925-2312

eISSN: 1872-8286

Record 6 of 263

Title: Pedestrian Detection Inspired by Appearance Constancy and Shape Symmetry

Author(s): Cao, JL (Cao, Jiale); Pang, YW (Pang, Yanwei); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON IMAGE PROCESSING  Volume: 25  Issue: 12  Pages: 5538-5551  DOI: 10.1109/TIP.2016.2609807  Published: DEC 2016  

Abstract: Most state-of-the-art methods in pedestrian detection are unable to achieve a good trade-off between accuracy and efficiency. For example, ACF has a fast speed but a relatively low detection rate, while checkerboards have a high detection rate but a slow speed. Inspired by some simple inherent attributes of pedestrians (i.e., appearance constancy and shape symmetry), we propose two new types of non-neighboring features: side-inner difference features (SIDF) and symmetrical similarity features (SSFs). SIDF can characterize the difference between the background and pedestrian and the difference between the pedestrian contour and its inner part. SSF can capture the symmetrical similarity of pedestrian shape. However, it is difficult for neighboring features to have such above characterization abilities. Finally, we propose to combine both non-neighboring features and neighboring features for pedestrian detection. It is found that non-neighboring features can further decrease the log-average miss rate by 4.44%. The relationship between our proposed method and some state-of-the-art methods is also given. Experimental results on INRIA, Caltech, and KITTI data sets demonstrate the effectiveness and efficiency of the proposed method. Compared with the state-of-the-art methods without using CNN, our method achieves the best detection performance on Caltech, outperforming the second best method (i.e., checkerboards) by 2.27%. Using the new annotations of Caltech, it can achieve 11.87% miss rate, which outperforms other methods.

Accession Number: WOS:000388205100003

PubMed ID: 27654480

Author Identifiers:

ISSN: 1057-7149

eISSN: 1941-0042

Record 7 of 263

Title: Similarity Constraints-Based Structured Output Regression Machine: An Approach to Image Super-Resolution

Author(s): Deng, C (Deng, Cheng); Xu, J (Xu, Jie); Zhang, KB (Zhang, Kaibing); Tao, DC (Tao, Dacheng); Gao, XB (Gao, Xinbo); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS  Volume: 27  Issue: 12  Pages: 2472-2485  DOI: 10.1109/TNNLS.2015.2468069  Published: DEC 2016  

Abstract: For regression-based single-image super-resolution (SR) problem, the key is to establish a mapping relation between high-resolution (HR) and low-resolution (LR) image patches for obtaining a visually pleasing quality image. Most existing approaches typically solve it by dividing the model into several single-output regression problems, which obviously ignores the circumstance that a pixel within an HR patch affects other spatially adjacent pixels during the training process, and thus tends to generate serious ringing artifacts in resultant HR image as well as increase computational burden. To alleviate these problems, we propose to use structured output regression machine (SORM) to simultaneously model the inherent spatial relations between the HR and LR patches, which is propitious to preserve sharp edges. In addition, to further improve the quality of reconstructed HR images, a nonlocal (NL) self-similarity prior in natural images is introduced to formulate as a regularization term to further enhance the SORM-based SR results. To offer a computation-effective SORM method, we use a relative small nonsupport vector samples to establish the accurate regression model and an accelerating algorithm for NL self-similarity calculation. Extensive SR experiments on various images indicate that the proposed method can achieve more promising performance than the other state-of-the-art SR methods in terms of both visual quality and computational cost.

Accession Number: WOS:000388919600002

PubMed ID: 26357410

Author Identifiers:

ISSN: 2162-237X

eISSN: 2162-2388

Record 8 of 263

Title: Graphene-induced unique polarization tuning properties of excessively tilted fiber grating

Author(s): Jiang, BQ (Jiang, Biqiang); Yin, GL (Yin, Guolu); Zhou, KM (Zhou, Kaiming); Wang, CL (Wang, Changle); Gan, XT (Gan, Xuetao); Zhao, JL (Zhao, Jianlin); Zhang, L (Zhang, Lin)

Source: OPTICS LETTERS  Volume: 41  Issue: 23  Pages: 5450-5453  DOI: 10.1364/OL.41.005450  Published: DEC 1 2016  

Abstract: By exploiting the polarization-sensitive coupling effect of graphene with the optical mode, we investigate the polarization modulation properties of a hybrid waveguide of graphene-integrated excessively tilted fiber grating (Ex-TFG). The theoretical analysis and experimental results demonstrate that the real and imaginary parts of complex refractive index of few-layer graphene exhibit different effects on transverse electric (TE) and transverse magnetic (TM) claddingmodes of the Ex-TFG, enabling stronger absorption in the TE mode and more wavelength shift in the TM mode. Furthermore, the surrounding refractive index can modulate the complex optical constant of graphene and then the polarization properties of the hybrid waveguide, such as resonant wavelength and peak intensity. Therefore, the unique polarization tuning property induced by the integration of the graphene layer with Ex-TFG may endow potential applications in all-in-one fiber modulators, fiber lasers, and biochemical sensors. (C) 2016 Optical Society of America

Accession Number: WOS:000389654000009

PubMed ID: 27906210

Author Identifiers:

ISSN: 0146-9592

eISSN: 1539-4794

Record 9 of 263

Title: Online fabrication scheme of helical long-period fiber grating for liquid-level sensing

Author(s): Ren, KL (Ren, Kaili); Ren, LY (Ren, Liyong); Liang, J (Liang, Jian); Kong, XD (Kong, Xudong); Ju, HJ (Ju, Haijuan); Xu, YP (Xu, Yiping); Wu, ZX (Wu, Zhaoxin)

Source: APPLIED OPTICS  Volume: 55  Issue: 34  Pages: 9675-9679  DOI: 10.1364/AO.55.009675  Published: DEC 1 2016  

Abstract: We present a novel online fabrication scheme of helical long-period fiber gratings (H-LPFGs) by directly twisting a standard single-mode fiber (SMF) in a microheater. This is done by taking advantage of the inherent core-cladding eccentricity in SMF. We adopt a fiber optic rotary joint to eliminate the accompanying twisting spiral for real-time spectral monitoring and a stepping mechanical system to accurately control the twisting length in fabrication. As a consequence, low-cost and high-quality H-LPFGs can be readily fabricated. Meanwhile, by using this kind of H-LPFG, we design a simple and low-cost wavelength-interrogated liquid-level sensor with a high sensitivity of 0.1 nm/mm. (C) 2016 Optical Society of America

Accession Number: WOS:000388938200031

PubMed ID: 27958456

Conference Title: Biennial Conference on Applied Optics on Advanced Infrared Technology and Applications (AITA)

Conference Date: SEP 29-OCT 02, 2015

Conference Location: Pisa, ITALY

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 10 of 263

Title: Weakly Supervised Multilabel Clustering and its Applications in Computer Vision

Author(s): Xia, YJ (Xia, Yingjie); Nie, LQ (Nie, Liqiang); Zhang, LM (Zhang, Luming); Yang, Y (Yang, Yi); Hong, RC (Hong, Richang); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 46  Issue: 12  Pages: 3220-3232  DOI: 10.1109/TCYB.2015.2501385  Published: DEC 2016  

Abstract: Clustering is a useful statistical tool in computer vision and machine learning. It is generally accepted that introducing supervised information brings remarkable performance improvement to clustering. However, assigning accurate labels is expensive when the amount of training data is huge. Existing supervised clustering methods handle this problem by transferring the bag-level labels into the instance-level descriptors. However, the assumption that each bag has a single label limits the application scope seriously. In this paper, we propose weakly supervised multilabel clustering, which allows assigning multiple labels to a bag. Based on this, the instance-level descriptors can be clustered with the guidance of bag-level labels. The key technique is a weakly supervised random forest that infers the model parameters. Thereby, a deterministic annealing strategy is developed to optimize the nonconvex objective function. The proposed algorithm is efficient in both the training and the testing stages. We apply it to three popular computer vision tasks: 1) image clustering; 2) semantic image segmentation; and 3) multiple objects localization. Impressive performance on the state-of-the-art image data sets is achieved in our experiments.

Accession Number: WOS:000388923100043

PubMed ID: 27046858

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 11 of 263

Title: Demonstration of a stable and uniform single-wavelength erbium-doped fiber laser based on microfiber knot resonator

Author(s): Xu, YP (Xu, Yiping); Ren, LY (Ren, Liyong); Ma, CJ (Ma, Chengju); Kong, XD (Kong, Xudong); Ren, KL (Ren, Kaili)

Source: OPTICAL ENGINEERING  Volume: 55  Issue: 12  Article Number: 126111  DOI: 10.1117/1.OE.55.12.126111  Published: DEC 2016  

Abstract: We propose and demonstrate an application of microfiber knot resonator (MKR) in the generation of a stable and uniform single-wavelength erbium-doped fiber laser (EDFL). An MKR was fabricated using a microfiber a few micrometers in diameter. By embedding the MKR to the ring cavity of the EDFL, a laser with a wavelength of 1558.818 nm and a 3-dB linewidth of 0.0149 nm is demonstrated. The side mode suppression ratio of the laser is about 30 dB, and the maximum power fluctuation is about 0.85 dB. The results demonstrate that the MKR can be employed as a high-performance comb filter to realize a stable and uniform fiber laser. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

Accession Number: WOS:000396372900073

Author Identifiers:

ISSN: 0091-3286

eISSN: 1560-2303

Record 12 of 263

Title: 126W fiber laser at 1018nm and its application in tandem pumped fiber amplifier

Author(s): Yang, HN (Yang, Hening); Zhao, W (Zhao, Wei); Si, JH (Si, Jinhai); Zhao, BY (Zhao, Baoyin); Zhu, YG (Zhu, Yonggang)

Source: JOURNAL OF OPTICS  Volume: 18  Issue: 12  Article Number: 125801  DOI: 10.1088/2040-8978/18/12/125801  Published: DEC 2016  

Abstract: We report on a 126W fiber laser operating at 1018 nm with an optical efficiency of 75%. The optimal length for such a fiber laser is theoretically analyzed using steady-state rate equations including amplified spontaneous emission. Excellent agreement on the maximum output power is achieved between the numerical result and the experimental counterpart. Furthermore, a monolithic tandem pumped fiber amplifier is established by using conventional 30/250 mu m double clad ytterbium-doped fiber, and 185W output power with 85% optical efficiency is realized.

Accession Number: WOS:000388839000001

Author Identifiers:

ISSN: 2040-8978

eISSN: 2040-8986

Record 13 of 263

Title: Hyperspectral Image Classification via Multitask Joint Sparse Representation and Stepwise MRF Optimization

Author(s): Yuan, Y (Yuan, Yuan); Lin, JZ (Lin, Jianzhe); Wang, Q (Wang, Qi)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 46  Issue: 12  Pages: 2966-2977  DOI: 10.1109/TCYB.2015.2484324  Published: DEC 2016  

Abstract: Hyperspectral image (HSI) classification is a crucial issue in remote sensing. Accurate classification benefits a large number of applications such as land use analysis and marine resource utilization. But high data correlation brings difficulty to reliable classification, especially for HSI with abundant spectral information. Furthermore, the traditional methods often fail to well consider the spatial coherency of HSI that also limits the classification performance. To address these inherent obstacles, a novel spectral-spatial classification scheme is proposed in this paper. The proposed method mainly focuses on multitask joint sparse representation (MJSR) and a stepwise Markov random filed framework, which are claimed to be two main contributions in this procedure. First, the MJSR not only reduces the spectral redundancy, but also retains necessary correlation in spectral field during classification. Second, the stepwise optimization further explores the spatial correlation that significantly enhances the classification accuracy and robustness. As far as several universal quality evaluation indexes are concerned, the experimental results on Indian Pines and Pavia University demonstrate the superiority of our method compared with the state-of-the-art competitors.

Accession Number: WOS:000388923100023

PubMed ID: 26485729

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 14 of 263

Title: Hyperspectral Anomaly Detection by Graph Pixel Selection

Author(s): Yuan, Y (Yuan, Yuan); Ma, DD (Ma, Dandan); Wang, Q (Wang, Qi)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 46  Issue: 12  Pages: 3123-3134  DOI: 10.1109/TCYB.2015.2497711  Published: DEC 2016  

Abstract: Hyperspectral anomaly detection (AD) is an important problem in remote sensing field. It can make full use of the spectral differences to discover certain potential interesting regions without any target priors. Traditional Mahalanobis-distance-based anomaly detectors assume the background spectrum distribution conforms to a Gaussian distribution. However, this and other similar distributions may not be satisfied for the real hyperspectral images. Moreover, the background statistics are susceptible to contamination of anomaly targets which will lead to a high false-positive rate. To address these intrinsic problems, this paper proposes a novel AD method based on the graph theory. We first construct a vertex- and edge-weighted graph and then utilize a pixel selection process to locate the anomaly targets. Two contributions are claimed in this paper: 1) no background distributions are required which makes the method more adaptive and 2) both the vertex and edge weights are considered which enables a more accurate detection performance and better robustness to noise. Intensive experiments on the simulated and real hyperspectral images demonstrate that the proposed method outperforms other benchmark competitors. In addition, the robustness of the proposed method has been validated by using various window sizes. This experimental result also demonstrates the valuable characteristic of less computational complexity and less parameter tuning for real applications.

Accession Number: WOS:000388923100035

PubMed ID: 26600560

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 15 of 263

Title: A robust haze-removal scheme in polarimetric dehazing imaging based on automatic identification of sky region

Author(s): Zhang, WF (Zhang, Wenfei); Liang, J (Liang, Jian); Ju, HJ (Ju, Haijuan); Ren, LY (Ren, Liyong); Qu, ES (Qu, Enshi); Wu, ZX (Wu, Zhaoxin)

Source: OPTICS AND LASER TECHNOLOGY  Volume: 86  Pages: 145-151  DOI: 10.1016/j.optlastec.2016.07.015  Published: DEC 2016  

Abstract: Quality enhancement of images acquired in hazy conditions is a significant research area in civil and military applications. The polarimetric dehazing methods have been exploited to dehaze hazy images and have proven to be effective in enhancing their quality. In this paper, by combining the polarimetric imaging technique and the dark channel prior technique, a robust haze-removal scheme is presented for the first time. On the one hand, the polarimetric imaging technique has advantages in recovering detailed information well, especially in dense hazy conditions; on the other hand, the dark channel prior technique provides a much more precise and convenient way to estimate the airlight radiance through extracting the sky region automatically. The experiments verify the practicability and effectiveness of the proposed dehazing scheme in quality enhancement of hazy images. Furthermore, comparison study demonstrates that the proposed scheme is superior to some sophisticated methods in terms of the visibility and contrast. We believe this scheme is beneficial in the image dehazing applications, especially for real-time applications. (C) 2016 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000382340900019

Author Identifiers:

ISSN: 0030-3992

eISSN: 1879-2545

Record 16 of 263

Title: Wavelength tunable CW red laser generated based on an intracavity-SFG composite cavity

Author(s): Zhang, ZN (Zhang, Z. N.); Bai, Y (Bai, Y.); Lei, GZ (Lei, G. Z.); Bai, B (Bai, B.); Sun, YX (Sun, Y. X.); Hu, MX (Hu, M. X.); Wang, C (Wang, C.); Bai, JT (Bai, J. T.)

Source: LASER PHYSICS LETTERS  Volume: 13  Issue: 12  Article Number: 125402  DOI: 10.1088/1612-2011/13/12/125402  Published: DEC 2016  

Abstract: We report a wavelength-tunable watt-level continuous wave (CW) red laser that uses a composite cavity based on an intracavity sum-frequency generation (SFG). The composite cavity is composed of a LD side-pumped Nd: GdVO4 p-polarized 1062.9 nm resonant cavity and a resonant optical parametric oscillator (SRO) of s-polarized signal light using a periodically poled crystal MgO:PPLN. Based on the temperature tuning from 30 degrees C to 200 degrees C, the CW red laser beams are obtained in a tunable waveband from 634.4 nm to 649.1 nm, corresponding to a tunable output waveband from 3278.0 nm to 2940.2 nm of the mid-infrared idler lights. The maximum CW output power of the red laser at 634.4 nm and the idler light at 3278.0 nm reach 3.03 W and 4.13 W under 30 degrees C, respectively.

Accession Number: WOS:000387909000001

ISSN: 1612-2011

eISSN: 1612-202X

Record 17 of 263

Title: Scalable Linear Visual Feature Learning via Online Parallel Nonnegative Matrix Factorization

Author(s): Zhao, XY (Zhao, Xueyi); Li, X (Li, Xi); Zhang, ZF (Zhang, Zhongfei); Shen, CH (Shen, Chunhua); Zhuang, YT (Zhuang, Yueting); Gao, LX (Gao, Lixin); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS  Volume: 27  Issue: 12  Pages: 2628-2642  DOI: 10.1109/TNNLS.2015.2499273  Published: DEC 2016  

Abstract: Visual feature learning, which aims to construct an effective feature representation for visual data, has a wide range of applications in computer vision. It is often posed as a problem of nonnegative matrix factorization (NMF), which constructs a linear representation for the data. Although NMF is typically parallelized for efficiency, traditional parallelization methods suffer from either an expensive computation or a high runtime memory usage. To alleviate this problem, we propose a parallel NMF method called alternating least square block decomposition (ALSD), which efficiently solves a set of conditionally independent optimization subproblems based on a highly parallelized fine-grained grid-based blockwise matrix decomposition. By assigning each block optimization subproblem to an individual computing node, ALSD can be effectively implemented in a MapReduce-based Hadoop framework. In order to cope with dynamically varying visual data, we further present an incremental version of ALSD, which is able to incrementally update the NMF solution with a low computational cost. Experimental results demonstrate the efficiency and scalability of the proposed methods as well as their applications to image clustering and image retrieval.

Accession Number: WOS:000388919600014

PubMed ID: 26625429

Author Identifiers:

ISSN: 2162-237X

eISSN: 2162-2388

Record 18 of 263

Title: Super-Resolution Imaging at Mid-Infrared Waveband in Graphene-nanocavity formed on meta-surface

Author(s): Yang, JZ (Yang, Jingzhong); Wang, TS (Wang, Taisheng); Chen, ZL (Chen, Zuolong); Hu, BL (Hu, Bingliang); Yu, WX (Yu, Weixing)

Source: SCIENTIFIC REPORTS  Volume: 6  Article Number: 37898  DOI: 10.1038/srep37898  Published: NOV 29 2016  

Abstract: Plasmonic structured illumination microscopy (PSIM) is one of the promising wide filed optical imaging methods, which takes advantage of the surface plasmons to break the optical diffraction limit and thus to achieve a super-resolution optical image. To further improve the imaging resolution of PSIM, we propose in this work a so called graphene nanocavity on meta-surface structure (GNMS) to excite graphene surface plasmons with a deep sub-wavelength at mid-infrared waveband. It is found that surface plasmonic interference pattern with a period of around 52 nm can be achieved in graphene nanocavity formed on structured meta-surface for a 7 mu m wavelength incident light. Moreover, the periodic plasmonic interference pattern can be tuned by simply changing the nanostructures fabricated on meta-surface for different application purposes. At last, the proposed GNMS structure is applied for super-resolution imaging in PSIM and it is found that an imaging resolution of 26 nm can be achieved, which is nearly 100 folds higher than that can be achieved by conventional epi-fluorescence microscopy. In comparison with visible waveband, mid-infrared is more gently and safe to biological cells and thus this work opens the new possibility for optical super-resolution imaging at mid-infrared waveband for biological research field.

Accession Number: WOS:000389001900001

PubMed ID: 27897207

Author Identifiers:

ISSN: 2045-2322

Record 19 of 263

Title: Accelerating incoherent hollow beams beyond the paraxial regime

Author(s): Yang, YL (Yang, Yanlong); Yan, SH (Yan, Shaohui); Yu, XH (Yu, Xianghua); Li, MM (Li, Manman); Yao, BL (Yao, Baoli)

Source: OPTICS EXPRESS  Volume: 24  Issue: 24  Pages: 27683-27690  DOI: 10.1364/OE.24.027683  Published: NOV 28 2016  

Abstract: We propose a non-paraxial hollow accelerating beam, which is formed by incoherently superposing two well-designed coherent accelerating beams. Very interestingly, this incoherent superposition does not hamper the acceleration dynamics pertaining to the coherent ones, but results in a hollow intensity pattern in the cross section transverse to the circular accelerating trajectory. By a simple optimization, this hollow cross section pattern can be effectively extended to an angle close to 90 degrees. The magnitude and the phase of the angular spectrum of the beam are given followed by a suggested scheme to generate the beam in practice. Such highly self-bending hollow beams may find applications in some fields such as optical manipulation. (C) 2016 Optical Society of America

Accession Number: WOS:000389468200058

PubMed ID: 27906337

Author Identifiers:

ISSN: 1094-4087

Record 20 of 263

Title: Optimization of the 3-inch photomultiplier tube for the neutrino detection

Author(s): Guo, LH (Guo Le-Hui); Tian, JS (Tian Jin-Shou); Lu, Y (Lu Yu); Li, HW (Li Hong-Wei)

Source: ACTA PHYSICA SINICA  Volume: 65  Issue: 22  Article Number: 228501  DOI: 10.7498/aps.65.228501  Published: NOV 20 2016  

Abstract: Photomultiplier tubes (PMTs) widely used in neutrino detectors are critical to reconstructing the direction of the neutrino accurately. Large photocathode coverage, compact design and good time properties for single-photoelectron light are essential performances to meet the requirements for the next generation detectors. Therefore, a novel digital optical module housing 31 3-inch. diameter PMTs is developed. In order to maximize the effective photocathode area and improve the time performance, a modified PMT with a larger photocathode area and 10 dynodes is optimized with the aid of the CST Particle Studio in this paper. Based on the Monte Carlo method and finite integration theory, the main characteristics of the modified PMT, such as uniformity, collection efficiency, gain and transit-time spread, are investigated. As the earlier stages of the PMT contribute the greatest weight to the total transit time spread, the transit time spread of single-photoelectron from photocathode to the first dynode (TTSCD1) is discussed mainly in this paper. The influences of the dynodes position on collection efficiency and TTSCD1 are analyzed. The voltage ratio scheme is also optimized slightly to obtain better collection efficiency and minimum TTSCD1. By tracing the trajectories of secondary electrons from the first to the second dynode stage, dynodes are optimized for improving timing performance and secondary electrons collection efficiency. Direct collection efficiency of secondary electrons from the first dynode to the second is improved from 56.38% to 61.01%. The effective photocathode diameter of the modified PMT is increased from traditional 72 mm to 77.5 mm and the effective area of photocathode is increased by 30.87% compared with the traditional one. What is more, the length of the new PMT is reduced to 103 mm so that the available space of the multi-PMT digital optical module is increased by 63.09% compared with the traditional one containing the high-voltage power supplies, front-end and readout electronics, refrigerating equipment, etc. The simulation results show that the mean collection efficiency of the modified PMT is similar to 96.40% with the supply voltage of 1000 V and it changes little by changing the supply voltage from 900 V to 1300 V. The mean transit time spread from photocathode to the first dynode is similar to 1 ns which is better than the transit time spread of the traditional model. And the gain can reach above 10 6 with a supply voltage of above 1100 V.

Accession Number: WOS:000389598500031

Author Identifiers:

ISSN: 1000-3290

Record 21 of 263

Title: Investigations on the photoluminescence of the iron and cobalt doped fluoride-containing phosphate-based glasses and its defects-related nature

Author(s): He, QL (He, Quanlong); Wang, PF (Wang, Pengfei); Lu, M (Lu, Min); Peng, B (Peng, Bo)

Source: JOURNAL OF ALLOYS AND COMPOUNDS  Volume: 685  Pages: 153-158  DOI: 10.1016/j.jallcom.2016.05.253  Published: NOV 15 2016  

Abstract: The influence of doping iron and cobalt ions on the formation of defects in the fluoride-containing phosphate-based glasses was studied comprehensively by means of analyzing the absorption and photoluminescence (PL) spectra as well as the electron spin resonance (ESR) spectra. The absorption and ESR spectra show that the defects, including phosphate-related oxygen hole center (POHC), oxygen-related hole centers (OHC), Fe3+, Co2+, PO3-EC, PO4-EC and fluorine-related non-paramagnetic color (FD) centers were formed during the glass preparation process. In addition, the analysis on the PL and absorption as well as excitation (PLE) spectra indicate that PO4-EC and OHC defects which have large absorption in the UV region result in the emission band peaking at 780 nm under the excitation at 351 nm for the cobalt doped (2 omega absorptive) glass. Addition of small quantities of iron causes the effectively intense absorption towards the 1 omega wavelength (1053 nm) due to the presence of Fe2+, but also a distinctively observed red-shift of the UV absorption edge was dominated by the charge-transfer transition of the existence of Fe3+. The experimental results demonstrate that Fe3+ suppress the formation of FD defects in the glasses, while promotes the formation of POHC defects. Besides, introduction of Co2+ inhibits the formation of POHC and PO4-EC defects, and Fe2+ promotes forming of POHC defects. (C) 2016 Elsevier B.V. All rights reserved.

Accession Number: WOS:000382222300023

Author Identifiers:

ISSN: 0925-8388

eISSN: 1873-4669

Record 22 of 263

Title: Mode Splitter Without Changing the Mode Order in SOI Waveguide

Author(s): Liao, JW (Liao, Jianwen); Zhang, LX (Zhang, Lingxuan); Liu, ML (Liu, Mulong); Wang, LR (Wang, Leiran); Wang, WQ (Wang, Weiqiang); Wang, GX (Wang, Guoxi); Ruan, C (Ruan, Chi); Zhao, W (Zhao, Wei); Zhang, WF (Zhang, Wenfu)

Source: IEEE PHOTONICS TECHNOLOGY LETTERS  Volume: 28  Issue: 22  Pages: 2597-2600  DOI: 10.1109/LPT.2016.2606496  Published: NOV 15 2016  

Abstract: We proposed a mode splitter based on directional coupler (DC), which is capable of splitting the TE0 and TE1 modes without changing the mode order. It is found that high coupling efficiency (higher than -1 dB), low mode crosstalk (less than -16 dB), wide bandwidth (similar to 100 nm), and large fabrication tolerance (+/- 10 nm) can be obtained by a 24.4 mu m coupling length DC structure, which is composed of a strip and a slot silicon waveguide. This design represents a first step toward mode splitter without changing the mode order, which can find important potential applications, such as optical isolation and mode division multiplexing (MDM), in large-scale photonic integrated circuits (PICs).

Accession Number: WOS:000388107000031

Author Identifiers:

ISSN: 1041-1135

eISSN: 1941-0174

Record 23 of 263

Title: Yb-doped large-mode-area aluminosilicate laser fibre fabricated by chelate precursor doping technique

Author(s): Peng, K (Peng, Kun); Wang, Z (Wang, Zhen); Zhan, H (Zhan, Huan); Ni, L (Ni, Li); Gao, C (Gao, Cong); Wang, XL (Wang, Xiaolong); Wang, YY (Wang, Yuying); Wang, JJ (Wang, Jianjun); Jing, F (Jing, Feng); Lin, AX (Lin, Aoxiang)

Source: ELECTRONICS LETTERS  Volume: 52  Issue: 23  Pages: 1942-U42  DOI: 10.1049/el.2016.3350  Published: NOV 10 2016  

Abstract: A modified chelate precursor doping technique using high-purity materials and accurate gas flow control system is proposed to fabricate an efficient ytterbium-doped large-mode-area silica fibre for laser development. This technique enables to make homogeneous large-core preform with symmetrical shape, relatively low numerical aperture of approximate to 0.06 and large-core size of over 4 mm. Homemade preform was drawn into standard fibre for testing and fully characterised by electron probe microanalysis and time-of-flight secondary ion mass spectrometry. On the basis of two-stage master oscillator power amplifier system, 1 kW laser output with slope efficiency of 81.0% was realised at approximate to 1064 nm.

Accession Number: WOS:000387576200025

Author Identifiers:

ISSN: 0013-5194

eISSN: 1350-911X

Record 24 of 263

Title: Pulse noise-hidden image reconstruction and visualization 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)

Source: SCIENTIFIC REPORTS  Volume: 6  Article Number: 36678  DOI: 10.1038/srep36678  Published: NOV 8 2016  

Abstract: We investigate the nanosecond pulse noise-hidden image reconstruction and visualization using stochastic resonance implemented by modulation instability. In particular, this dynamical stochastic resonance holds with coupling between the pulse incoherent noise and pulse coherent signal, and provides a substantial enhancement of the signal-to-noise ratio and cross-correlation. This means that the pulse noise-hidden image can be effectively reconstructed with high visibility and fidelity via stochastic resonance at appropriate system parameters. Such a simple and convenient method has potential applications in image processing under noisy environment.

Accession Number: WOS:000387324000001

PubMed ID: 27824152

Author Identifiers:

ISSN: 2045-2322

Record 25 of 263

Title: Simulation of the electron collection efficiency of a PMT based on the MCP coated with high secondary yield material

Author(s): Chen, L (Chen, Lin); Tian, JS (Tian, Jinshou); Zhao, TC (Zhao, Tianchi); Liu, CL (Liu, Chunliang); Liu, HL (Liu, Hulin); Wei, YL (Wei, Yonglin); Sai, XF (Sai, Xiaofeng); Chen, P (Chen, Ping); Wang, X (Wang, Xing); Lu, Y (Lu, Yu); Hui, DD (Hui, Dandan)

Source: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT  Volume: 835  Pages: 94-98  DOI: 10.1016/j.nima.2016.08.034  Published: NOV 1 2016  

Abstract: Owning to the serious loss of photoelectrons striking at the input electrode of traditional microchannel plate (MCP), photoelectron collection efficiency (CE) of photomultiplier tubes based on MCP (MCP-PMTs) fluctuates around the MCP open area fraction and cannot make a breakthrough. Depositing a thin film of high secondary electron yield material on the MCP is proposed as an effective approach to improve the CE. The available simulation and experimental data to validate it, however, is sparse. In our work, a three-dimensional small area MCP model is developed in CST Studio Suite to evaluate the collection efficiencies of PMTs based on the traditional MCP and the coated one, respectively. Results predict that CE of the PMT based on the coated MCP has a significant increase and a better uniformity, which is expected to reach 100%. (C) 2016 Elsevier B.V. All rights reserved.

Accession Number: WOS:000386057800010

Author Identifiers:

ISSN: 0168-9002

eISSN: 1872-9576

Record 26 of 263

Title: Optically bound colloidal lattices in evanescent optical fields

Author(s): Han, X (Han, Xiang); Luo, H (Luo, Hui); Xiao, GZ (Xiao, Guangzong); Jones, PH (Jones, Philip H.)

Source: OPTICS LETTERS  Volume: 41  Issue: 21  Pages: 4935-4938  DOI: 10.1364/OL.41.004935  Published: NOV 1 2016  

Abstract: In this Letter, we demonstrate the formation of a stable two-dimensional lattice of colloidal particles in the interference pattern formed by four evanescent optical fields at a dielectric interface. The microspheres are observed to form a two-dimensional square lattice with lattice vectors inclined relative to the beam propagation directions. We use digital video microscopy and particle tracking to measure the Brownian motion of particles bound in the lattice, and use this to characterize fluctuations in the local ordering of particles using the bond orientational order parameter, the probability distribution of which is shown to be a chi-squared distribution. An explanation for the form of this distribution is presented in terms of fluctuations of the modes of a ring of particles connected by springs. (C) 2016 Optical Society of America

Accession Number: WOS:000386925800022

PubMed ID: 27805654

Author Identifiers:

ISSN: 0146-9592

eISSN: 1539-4794

Record 27 of 263

Title: Unsupervised 3D Local Feature Learning by Circle Convolutional Restricted Boltzmann Machine

Author(s): Han, ZZ (Han, Zhizhong); Liu, ZB (Liu, Zhenbao); Han, JW (Han, Junwei); Vong, CM (Vong, Chi-Man); Bu, SH (Bu, Shuhui); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON IMAGE PROCESSING  Volume: 25  Issue: 11  Pages: 5331-5344  DOI: 10.1109/TIP.2016.2605920  Published: NOV 2016  

Abstract: Extracting local features from 3D shapes is an important and challenging task that usually requires carefully designed 3D shape descriptors. However, these descriptors are hand-crafted and require intensive human intervention with prior knowledge. To tackle this issue, we propose a novel deep learning model, namely circle convolutional restricted Boltzmann machine (CCRBM), for unsupervised 3D local feature learning. CCRBM is specially designed to learn from raw 3D representations. It effectively overcomes obstacles such as irregular vertex topology, orientation ambiguity on the 3D surface, and rigid or slightly non-rigid transformation invariance in the hierarchical learning of 3D data that cannot be resolved by the existing deep learning models. Specifically, by introducing the novel circle convolution, CCRBM holds a novel ring-like multi-layer structure to learn 3D local features in a structure preserving manner. Circle convolution convolves across 3D local regions via rotating a novel circular sector convolution window in a consistent circular direction. In the process of circle convolution, extra points are sampled in each 3D local region and projected onto the tangent plane of the center of the region. In this way, the projection distances in each sector window are employed to constitute a novel local raw 3D representation called projection distance distribution (PDD). In addition, to eliminate the initial location ambiguity of a sector window, the Fourier transform modulus is used to transform the PDD into the Fourier domain, which is then conveyed to CCRBM. Experiments using the learned local features are conducted on three aspects: global shape retrieval, partial shape retrieval, and shape correspondence. The experimental results show that the learned local features outperform other state-of-the-art 3D shape descriptors.

Accession Number: WOS:000385380500001

PubMed ID: 28113374

Author Identifiers:

ISSN: 1057-7149

eISSN: 1941-0042

Record 28 of 263

Title: Block Principal Component Analysis With Nongreedy l₁-Norm Maximization

Author(s): Li, BN (Li, Bing Nan); Yu, Q (Yu, Qiang); Wang, R (Wang, Rong); Xiang, K (Xiang, Kui); Wang, M (Wang, Meng); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 46  Issue: 11  Pages: 2543-2547  DOI: 10.1109/TCYB.2015.2479645  Published: NOV 2016  

Abstract: Block principal component analysis with l(1)-norm (BPCA-L1) has demonstrated its effectiveness in a lot of visual classification and data mining tasks. However, the greedy strategy for solving the l(1)-norm maximization problem is prone to being struck in local solutions. In this paper, we propose a BPCA with nongreedy l(1)-norm maximization, which obtains better solutions than BPCA-L1 with all the projection directions optimized simultaneously. Other than BPCA-L1, the new algorithm has been evaluated against some popular principal component analysis (PCA) algorithms including PCA-L1 and 2-D PCA-L1 on a variety of benchmark data sets. The results demonstrate the effectiveness of the proposed method.

Accession Number: WOS:000386227000013

PubMed ID: 26469852

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 29 of 263

Title: Optical waveguides in magneto-optical glasses fabricated by proton implantation

Author(s): Liu, CX (Liu, Chun-Xiao); Li, YW (Li, Yu-Wen); Zheng, RL (Zheng, Rui-Lin); Fu, LL (Fu, Li-Li); Zhang, LL (Zhang, Liao-Lin); Guo, HT (Guo, Hai-Tao); Zhou, ZG (Zhou, Zhi-Guang); Li, WN (Li, Wei-Nan); Lin, SB (Lin, She-Bao); Wei, W (Wei, Wei)

Source: OPTICS AND LASER TECHNOLOGY  Volume: 85  Pages: 55-59  DOI: 10.1016/j.optlastec.2016.05.008  Published: NOV 2016  

Abstract: Planar waveguides in magneto-optical glasses (Tb3+-doped aluminum borosilicate glasses) have been produced by a 550-keV proton implantation at a dose of 4.0 x 10(16) ions/cm(2) for the first time to our knowledge. After annealing at 260 degrees C for 1.0 h, the dark-mode spectra and near-field intensity distributions are measured by the prism-coupling and end-face coupling methods. The damage profile, refractive index distribution and light propagation mode of the planar waveguide are numerically calculated by SRIM 2010, RCM and FD-BPM, respectively. The effects of implantation on the structural and optical properties are investigated by Raman and absorption spectra. It suggests that the proton-implanted Tb3+-doped aluminum borosilicate glass waveguide is a good candidate for a waveguide isolator in optical fiber communication and all-optical communication. (C) 2016 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000380597200009

Author Identifiers:

ISSN: 0030-3992

eISSN: 1879-2545

Record 30 of 263

Title: Growth of SiC nanowires by low pressure chemical vapor infiltration using different catalysts

Author(s): Men, J (Men, Jing); Liu, YS (Liu, Yongsheng); Luo, R (Luo, Rong); Li, WN (Li, Weinan); Cheng, LF (Cheng, Laifei); Zhang, LT (Zhang, Litong)

Source: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY  Volume: 36  Issue: 15  Special Issue: SI  Pages: 3615-3625  DOI: 10.1016/j.jeurceramsoc.2016.04.004  Published: NOV 2016  

Abstract: SiC nanowires were synthesized by LPCVI using different catalysts, and the influences of input gas ratio (alpha) and catalysts were investigated. The average diameter firstly decreased and then increased with increasing alpha. Under Ni-based catalysis, SiC nanowires were long and thin, and increased with increasing concentration; under Fe-based catalysis, they were short and thick, and the influence of concentration could be neglected. The growth of SiC nanowires was controlled by vapor-liquid-solid (VLS) growth mechanism and the liquid-solid interface between nanowire and metal droplet was the growth plane. At same concentration, the diameter grown under Ni-based catalyst decreased with decreasing diameter of catalyst droplet, while under Fe-based catalyst, the diameters were not affected by catalyst droplet because of the high concentration. SiC nanowires were synthesized in 2D C/SiC composites and could enhance the mechanical properties effectively because of energy consuming from the fracture, pulled up and debond of SiC nanowires. (C) 2016 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000381951200009

Conference Title: 1st Sino-German Symposium on Preparation and Application of Ultra-High Temperature Ceramic Matrix Composites

Conference Date: JUL 26-31, 2015

Conference Location: Darmstadt, GERMANY

Conference Sponsors: Tech Univ Darmstadt, Sino German Ctr Res Promot

Author Identifiers:

ISSN: 0955-2219

eISSN: 1873-619X

Record 31 of 263

Title: Multiple Representations-Based Face Sketch-Photo Synthesis

Author(s): Peng, CL (Peng, Chunlei); Gao, XB (Gao, Xinbo); Wang, NN (Wang, Nannan); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong); Li, J (Li, Jie)

Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS  Volume: 27  Issue: 11  Pages: 2201-2215  DOI: 10.1109/TNNLS.2015.2464681  Published: NOV 2016  

Abstract: Face sketch-photo synthesis plays an important role in law enforcement and digital entertainment. Most of the existing methods only use pixel intensities as the feature. Since face images can be described using features from multiple aspects, this paper presents a novel multiple representations-based face sketch-photo-synthesis method that adaptively combines multiple representations to represent an image patch. In particular, it combines multiple features from face images processed using multiple filters and deploys Markov networks to exploit the interacting relationships between the neighboring image patches. The proposed framework could be solved using an alternating optimization strategy and it normally converges in only five outer iterations in the experiments. Our experimental results on the Chinese University of Hong Kong (CUHK) face sketch database, celebrity photos, CUHK Face Sketch FERET Database, IIIT-D Viewed Sketch Database, and forensic sketches demonstrate the effectiveness of our method for face sketch-photo synthesis. In addition, cross-database and database-dependent style-synthesis evaluations demonstrate the generalizability of this novel method and suggest promising solutions for face identification in forensic science.

Accession Number: WOS:000386940300005

PubMed ID: 26357409

Author Identifiers:

ISSN: 2162-237X

eISSN: 2162-2388

Record 32 of 263

Title: Watts-level super-compact narrow-linewidth Tm-doped silica all-fiber laser near 1707 nm with fiber Bragg gratings

Author(s): Xiao, XS (Xiao, X. S.); Guo, HT (Guo, H. T.); Lu, M (Lu, M.); Yan, ZJ (Yan, Z. J.); Wang, HS (Wang, H. S.); Wang, YS (Wang, Y. S.); Xu, YT (Xu, Y. T.); Gao, CX (Gao, C. X.); Cui, XX (Cui, X. X.); Guo, Q (Guo, Q.); Peng, B (Peng, B.)

Source: LASER PHYSICS  Volume: 26  Issue: 11  Article Number: 115103  DOI: 10.1088/1054-660X/26/11/115103  Published: NOV 2016  

Abstract: Watts-level ultra-short wavelength operation of a Tm-doped all fiber laser was developed by using a 1550 nm Er-doped fiber laser pump source and a pair of fiber Bragg gratings (FBGs). The laser yielded 1.28 W of continuous-wave output at 1707.01 nm with a narrow linewidth of similar to 44 pm by means of a 20 cm Tm-doped fiber. The dependencies of the slope efficiencies and pump threshold of the Tm-doped fiber laser versus the length of active fiber and reflectivity of the output mirror (FBG) were investigated in detail, in which the maximum average slope efficiency was 36.1%. There is no doubt that this all fiber laser will be a perfect pump source for mid-IR laser output.

Accession Number: WOS:000385686900001

Author Identifiers:

ISSN: 1054-660X

eISSN: 1555-6611

Record 33 of 263

Title: Influence of Driving Frequency on the Argon Dielectric Barrier Discharge Excited by Gaussian Voltage at Atmospheric Pressure

Author(s): Xu, YG (Xu, Yonggang); Jiang, WM (Jiang, Weiman); Tang, J (Tang, Jie); Zhu, S (Zhu, Sha); Wang, YS (Wang, Yishan); Li, YF (Li, Yongfang); Zhao, W (Zhao, Wei); Duan, YX (Duan, Yixiang)

Source: IEEE TRANSACTIONS ON PLASMA SCIENCE  Volume: 44  Issue: 11  Special Issue: SI  Pages: 2553-2563  DOI: 10.1109/TPS.2016.2572733  Part: 1  Published: NOV 2016  

Abstract: A 1-D self-consistent fluid model was employed to investigate the effect of driving frequency on the discharge characters of a dielectric barrier discharge at atmospheric pressure in argon excited by a periodic Gaussian voltage. The simulation results indicate that there are two discharge modes: 1) Townsend and 2) glow modes in the multipulse discharge and different transitions between them during the discharge take place with the increase in driving frequency. When the driving frequency is 1 kHz, there is a tendency of transition from the Townsend mode through glow and finally back to the Townsend one during the positive half-circle of applied Gaussian voltage. However, the discharge in the half-circle can all along operate in the glow mode with the higher driving frequency. Moreover, when the driving frequency is sufficiently high, there are also distinct fluctuations of spatial performance of the charge densities in the positive column during the glow discharge. This is caused by the fact that a lot of charged particles created in the gas gap have not enough time to drift and diffuse to the dielectric barriers, and then these particles are preserved in the local discharge gap at such a high frequency. A comparison of the spatial and temporal evolutions of the electron density at different driving frequencies indicates that the increase in the driving frequency can enhance the plasma chemistry and also expand its volume.

Accession Number: WOS:000388793800006

Conference Title: 1st Sino-German Symposium on Atmospheric Pressure Gas Discharges and Plasma Applications

Conference Date: OCT 11-17, 2015

Conference Location: Sino German Sci Ctr, Beijing, PEOPLES R CHINA

Conference Sponsors: German Res Fdn, Sino german Ctr, Nat Sci Fdn China

Conference Host: Sino German Sci Ctr

Author Identifiers:

ISSN: 0093-3813

eISSN: 1939-9375

Record 34 of 263

Title: Action recognition by joint learning

Author(s): Yuan, Y (Yuan, Yuan); Qi, L (Qi, Lei); Lu, XQ (Lu, Xiaoqiang)

Source: IMAGE AND VISION COMPUTING  Volume: 55  Special Issue: SI  Pages: 77-85  DOI: 10.1016/j.imavis.2016.04.001  Part: 2  Published: NOV 2016  

Abstract: Due to the promising applications including video surveillance, video annotation, and interaction gaming, human action recognition from videos has attracted much research interest. Although various works have been proposed for human action recognition, there still exist many challenges such as illumination condition, viewpoint, camera motion and cluttered background. Extracting discriminative representation is one of the main ways to handle these challenges. In this paper, we propose a novel action recognition method that simultaneously learns middle-level representation and classifier by jointly training a multinomial logistic regression (MLR) model and a discriminative dictionary. In the proposed method, sparse code of low-level representation, conducting as latent variables of MLR, can capture the structure of low-level feature and thus is more discriminate. Meanwhile, the training of dictionary and MLR model are integrated into one objective function for considering the information of categories. By optimizing this objective function, we can learn a discriminative dictionary modulated by MLR and a MLR model driven by sparse coding. The proposed method is evaluated on YouTube action dataset and HMDB51 dataset. Experimental results demonstrate that our method is comparable with mainstream methods. (C) 2016 Elsevier B.V. All rights reserved.

Accession Number: WOS:000389164300005

Author Identifiers:

ISSN: 0262-8856

eISSN: 1872-8138

Record 35 of 263

Title: A discriminative representation for human action recognition

Author(s): Yuan, Y (Yuan, Yuan); Zheng, XT (Zheng, Xiangtao); Lu, XQ (Lu, Xiaoqiang)

Source: PATTERN RECOGNITION  Volume: 59  Special Issue: SI  Pages: 88-97  DOI: 10.1016/j.patcog.2016.02.022  Published: NOV 2016  

Abstract: Action recognition has been standing as an active research topic over the past years. Many efforts have been made and many methods have been proposed. However, there are still some challenges such as illumination condition, viewpoint, camera motion and cluttered background. In order to tackle these challenges, a discriminative representation is proposed by discovering key information of the input data. This task can be addressed by improvements of two major components: parameterized representation and discriminative classifier. The representation is parameterized with hidden variables and can be learned from training data. And the classifier can be trained to recognize actions based on the proposed representation. The contributions of this paper are as follows: (1) a novel probabilistic representation is utilized to capture the relative significant information of low level features; (2) a novel framework is proposed by combining the parameterized representation and discriminative classifier; (3) an alternating strategy is favorable to improve the performance of action recognition by updating the representation and the classifier alternatively. Experimental results on five well-known datasets demonstrate that the proposed method significantly improves the performance in action recognition. (C) 2016 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000383007800009

Author Identifiers:

ISSN: 0031-3203

eISSN: 1873-5142

Record 36 of 263

Title: Detection of Co-salient Objects by Looking Deep and Wide

Author(s): Zhang, DW (Zhang, Dingwen); Han, JW (Han, Junwei); Li, C (Li, Chao); Wang, JD (Wang, Jingdong); Li, XL (Li, Xuelong)

Source: INTERNATIONAL JOURNAL OF COMPUTER VISION  Volume: 120  Issue: 2  Pages: 215-232  DOI: 10.1007/s11263-016-0907-4  Published: NOV 2016  

Abstract: In this paper, we propose a unified co-salient object detection framework by introducing two novel insights: (1) looking deep to transfer higher-level representations by using the convolutional neural network with additional adaptive layers could better reflect the sematic properties of the co-salient objects; (2) looking wide to take advantage of the visually similar neighbors from other image groups could effectively suppress the influence of the common background regions. The wide and deep information are explored for the object proposal windows extracted in each image. The window-level co-saliency scores are calculated by integrating the intra-image contrast, the intra-group consistency, and the inter-group separability via a principled Bayesian formulation and are then converted to the superpixel-level co-saliency maps through a foreground region agreement strategy. Comprehensive experiments on two existing and one newly established datasets have demonstrated the consistent performance gain of the proposed approach.

Accession Number: WOS:000382092900006

Author Identifiers:

ISSN: 0920-5691

eISSN: 1573-1405

Record 37 of 263

Title: Interference data correction methods for lunar observation with a large-aperture static imaging spectrometer

Author(s): Zhang, G (Zhang, Geng); Wang, S (Wang, Shuang); Li, LB (Li, Libo); Hu, XQ (Hu, Xiuqing); Hu, BL (Hu, Bingliang)

Source: APPLIED OPTICS  Volume: 55  Issue: 31  Pages: 8770-8778  DOI: 10.1364/AO.55.008770  Published: NOV 1 2016  

Abstract: The lunar spectrum has been used in radiometric calibration and sensor stability monitoring for spaceborne optical sensors. A ground-based large-aperture static image spectrometer (LASIS) can be used to acquire the lunar spectral image for lunar radiance model improvement when the moon orbits over its viewing field. The lunar orbiting behavior is not consistent with the desired scanning speed and direction of LASIS. To correctly extract interferograms from the obtained data, a translation correction method based on image correlation is proposed. This method registers the frames to a reference frame to reduce accumulative errors. Furthermore, we propose a circle-matching-based approach to achieve even higher accuracy during observation of the full moon. To demonstrate the effectiveness of our approaches, experiments are run on true lunar observation data. The results show that the proposed approaches outperform the state-of-the-art methods. (C) 2016 Optical Society of America

Accession Number: WOS:000387101100027

PubMed ID: 27828274

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 38 of 263

Title: KW-level low photodarkening Yb/Ce codoped aluminosilicate fiber fabricated by the chelate gas phase deposition technique

Author(s): Zhang, LH (Zhang, Lihua); Li, G (Li, Gang); Li, WN (Li, Weinan); Gao, Q (Gao, Qi); Li, Z (Li, Zhe); Zhao, W (Zhao, Wei); Zhao, BY (Zhao, Baoyin); Hou, CQ (Hou, Chaoqi)

Source: OPTICAL MATERIALS EXPRESS  Volume: 6  Issue: 11  Pages: 3558-3564  DOI: 10.1364/OME.6.003558  Published: NOV 1 2016  

Abstract: A Yb/Ce codoped aluminosilicate fiber was successfully fabricated by the chelate gas phase deposition technique. Using the homemade fiber as the amplifier stage in a master oscillator power amplifier configuration laser setup, a near single mode laser output (M-2 = 1.55) with an output power of 1026 W and slope efficiency of 84.8% is obtained. In the 100 hour photodarkening experiment, the entire reduced power is less than 14 W, and the ratio, compared to the initial 1026 W output power, is less than 1.4%. The investigation of optical properties indicates that Yb/Ce codoped aluminosilicate fiber fabricated by the chelate gas phase deposition technique shows homogenous distribution, appropriate absorption coefficient, low background attenuation, high optical-to-optical efficiency and a rather low photodarkening loss, making it a promising candidate as an active fiber for a reliable and efficient fiber laser in high-power applications. (C) 2016 Optical Society of America

Accession Number: WOS:000387562700021

Author Identifiers:

ISSN: 2159-3930

Record 39 of 263

Title: Transmission volume phase holographic gratings in photo-thermo-refractive glass written with femtosecond laser Bessel beams

Author(s): Zhang, YJ (Zhang, Y. J.); Zhang, GD (Zhang, G. D.); Chen, CL (Chen, C. L.); Stoian, R (Stoian, R.); Cheng, GH (Cheng, G. H.)

Source: OPTICAL MATERIALS EXPRESS  Volume: 6  Issue: 11  Pages: 3491-3499  DOI: 10.1364/OME.6.003491  Published: NOV 1 2016  

Abstract: Transmission volume phase holographic gratings were fabricated in bulk photo-thermo- refractive glass using zero-order femtosecond laser Bessel beams and subsequent thermal treatment. Microstructures composed of nano-sized crystals were observed in the exposed regions. The concentration of nano-crystals depended on the writing power, but the size of the nano-crystals was found to be quasi power-independent. Low writing power led to sparse nano-crystals, while optimized writing power achieved dense nano-crystals distribution and high refractive index change. Effects of the gratings thickness, writing laser power and thermal treatment on the diffraction efficiency were investigated. A maximum diffraction efficiency of 94.73% was achieved (at 532 nm testing wavelength) with 1 mm grating thickness at period of 5 mu m. (C) 2016 Optical Society of America

Accession Number: WOS:000387562700014

Author Identifiers:

ISSN: 2159-3930

Record 40 of 263

Title: Discrete bisoliton fiber laser

Author(s): Liu, XM (Liu, X. M.); Han, XX (Han, X. X.); Yao, XK (Yao, X. K.)

Source: SCIENTIFIC REPORTS  Volume: 6  Article Number: 34414  DOI: 10.1038/srep34414  Published: OCT 21 2016  

Abstract: Dissipative solitons, which result from the intricate balance between dispersion and nonlinearity as well as gain and loss, are of the fundamental scientific interest and numerous important applications. Here, we report a fiber laser that generates bisoliton - two consecutive dissipative solitons that preserve a fixed separation between them. Deviations from this separation result in its restoration. It is also found that these bisolitons have multiple discrete equilibrium distances with the quantized separations, as is confirmed by the theoretical analysis and the experimental observations. The main feature of our laser is the anomalous dispersion that is increased by an order of magnitude in comparison to previous studies. Then the spectral filtering effect plays a significant role in pulse-shaping. The proposed laser has the potential applications in optical communications and high-resolution optics for coding and transmission of information in higher-level modulation formats.

Accession Number: WOS:000385821900001

PubMed ID: 27767075

Author Identifiers:

ISSN: 2045-2322

Record 41 of 263

Title: Dispersion engineering of a As₂Se₃-based strip/slot hybrid waveguide for mid-infrared broadband wavelength conversion

Author(s): Hui, ZQ (Hui, Zhanqiang); Zhang, LX (Zhang, Lingxuan); Wang, LR (Wang, Leiran); Zhang, WF (Zhang, Wenfu)

Source: MODERN PHYSICS LETTERS B  Volume: 30  Issue: 28  Article Number: 1650336  DOI: 10.1142/S021798491650336X  Published: OCT 20 2016  

Abstract: An arsenic tri-selenide-based strip/slot hybrid waveguide with a single horizontal silica slot is proposed to achieve an extremely low and flat dispersion with three zero dispersion wavelengths. By adjusting the geometrical structural parameters of the hybrid waveguide, dispersion tailoring is fully obtained. The flat group velocity dispersion varying between +/- 0.08 ps(2)/(m) is obtained over a 1253 nm bandwidth. The parameters of effective area, nonlinear coefficient, and third-order dispersion are all investigated. Moreover, a compact on-chip all-optical wavelength converter is designed based on degenerate four-wave mixing in this waveguide. The dependencies of conversion efficiency and conversion bandwidth on the pump wavelength are discussed. The impact of pump power and signal power on the conversion efficiency is also investigated. The results show that a maximal conversion efficiency of 0.46 dB, and a 3-dB conversion bandwidth of 830 nm in the mid-infrared is achieved.

Accession Number: WOS:000386671500005

Author Identifiers:

ISSN: 0217-9849

eISSN: 1793-6640

Record 42 of 263

Title: Slow light and fast light in microfiber double-knot resonator with a parallel structure

Author(s): Xu, YP (Xu, Yiping); Ren, LY (Ren, Liyong); Ma, CJ (Ma, Chengju); Kong, XD (Kong, Xudong); Ren, KL (Ren, Kaili)

Source: APPLIED OPTICS  Volume: 55  Issue: 30  Pages: 8612-8617  DOI: 10.1364/AO.55.008612  Published: OCT 20 2016  

Abstract: Based on the theoretical model of a microfiber double-knot resonator with a parallel structure, numerical simulations on the transmission spectrum, the phase, and the group time delay of the resonator as a function of wavelengths are given. We find that with this kind of resonator both slow light and fast light can be obtained at different resonant wavelengths. Experimentally, such a kind of microfiber resonator was fabricated successfully. The transmission spectrum of the fabricated resonator is well consistent with the theoretical simulation. A slow-light delay of about 38 ps and a fast-light advance of about 40 ps are demonstrated at different wavelengths, which might benefit the resonator to the applications in data delay lines, optical buffers, and optical memories. (C) 2016 Optical Society of America

Accession Number: WOS:000385717100032

PubMed ID: 27828144

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 43 of 263

Title: Polarimetric dehazing method for visibility improvement based on visible and infrared image fusion

Author(s): Liang, J (Liang, Jian); Zhang, WF (Zhang, Wenfei); Ren, LY (Ren, Liyong); Ju, HJ (Ju, Haijuan); Qu, ES (Qu, Enshi)

Source: APPLIED OPTICS  Volume: 55  Issue: 29  Pages: 8221-8226  DOI: 10.1364/AO.55.008221  Published: OCT 10 2016  

Abstract: Polarimetric dehazing methods have proven effective in enhancing the quality of chromatic hazy images. Considering that the infrared radiance has a better capacity for traveling through the haze, in this paper we propose a polarimetric dehazing method based on visible and infrared image fusion to improve the visibility of hazy images, especially for dense haze conditions. Experimental results demonstrate that the visibility of hazy images can be effectively enhanced, and the color information can be finely maintained. The visibility of dehazed images can be promoted at least 100%. This kind of dehazing method can be used widely in many dehazing applications. (C) 2016 Optical Society of America

Accession Number: WOS:000385715900013

PubMed ID: 27828066

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 44 of 263

Title: Hierarchical learning of large-margin metrics for large-scale image classification

Author(s): Lei, H (Lei, Hao); Mei, KZ (Mei, Kuizhi); Xin, JM (Xin, Jingmin); Dong, PX (Dong, Peixiang); Fan, JP (Fan, Jianping)

Source: NEUROCOMPUTING  Volume: 208  Special Issue: SI  Pages: 46-58  DOI: 10.1016/j.neucom.2016.01.100  Published: OCT 5 2016  

Abstract: Large-scale image classification is a challenging task and has recently attracted active research interests. In this paper, a new algorithm is developed to achieve more effective implementation of large-scale image classification by hierarchical learning of large-margin metrics (HLMMs). A hierarchical visual tree is seamlessly integrated with metric learning to learn a set of node-specific/category-specific large margin metrics. First, a hierarchical visual tree is learned to characterize the inter-category visual correlations effectively and organize large numbers of image categories in a coarse-to-fine fashion. Second, a new algorithm is developed to support hierarchical learning of large-margin metrics by training nearest class mean (NCM) classifiers over our hierarchical visual tree. In addition, we also consider dimensionality reduction as a regularizer for high-dimensional data in our large-margin metric learning. Two top down approaches are developed for supporting hierarchical learning of large-margin metrics. We focus on learning more discriminative metrics for NCM node classifiers to identify the visually similar sub nodes (visually similar image categories) under the same parent node over our hierarchical visual tree. A mini-batch stochastic gradient descend method is used to optimize our HLMMs learning algorithm. The experimental results on ImageNet Large Scale Visual Recognition Challenge 2010 dataset (ILSVRC2010) have demonstrated that our HLMMs learning algorithm is very promising for supporting large-scale image classification. (C) 2016 Elsevier B.V. All rights reserved.

Accession Number: WOS:000382794300005