Record 1 of 244

Title: Frequency non-degenerate phase-sensitive optical parametric amplification based on fourwave-mixing in width-modulated silicon waveguides

Author(s): Wang, ZL (Wang, Zhaolu); Liu, HJ (Liu, Hongjun); Sun, QB (Sun, Qibing); Huang, N (Huang, Nan); Li, XF (Li, Xuefeng)

Source: OPTICS EXPRESS  Volume: 22  Issue: 25  Pages: 31486-31495  DOI: 10.1364/OE.22.031486  Published: DEC 15 2014  

Abstract: A width-modulated silicon waveguide is proposed to realize nondegenerate phase sensitive optical parametric amplification. It is found that the relative phase at the input of the phase sensitive amplifier (PSA) theta(In-PSA) can be tuned by tailoring the width and length of the second segment of the width-modulated silicon waveguide, which will influence the gain in the parametric amplification process. The maximum gain of PSA is larger by 9 dB compared with the phase insensitive amplifier (PIA) gain, and the gain bandwidth of PSA is larger by 35 nm compared with the gain bandwidth of PIA. Our on-chip PSA can find important potential applications in highly integrated optical circuits for optical chip-to-chip communication and computers. (C)2014 Optical Society of America

Accession Number: WOS:000346368800143

PubMed ID: 25607099

Author Identifiers:

ISSN: 1094-4087

Record 2 of 244

Title: Sub-100 ns passively Q-switched Nd:LuAG laser with multi-walled carbon nanotube

Author(s): Chen, XT (Chen, X. T.); Zhao, SZ (Zhao, S. Z.); Zhao, J (Zhao, J.); Yang, KJ (Yang, K. J.); Li, GQ (Li, G. Q.); Li, DC (Li, D. C.); Qiao, WC (Qiao, W. C.); Li, T (Li, T.); Zhang, HJ (Zhang, H. J.); Feng, TL (Feng, T. L.); Xu, XD (Xu, X. D.); Zheng, LH (Zheng, L. H.); Xu, J (Xu, J.); Wang, YG (Wang, Y. G.); Wang, YS (Wang, Y. S.)

Source: OPTICS AND LASER TECHNOLOGY  Volume: 64  Pages: 7-10  DOI: 10.1016/j.optlastec.2014.04.019  Published: DEC 2014  

Abstract: We report the first demonstration of a diode-pumped passively Q-switched Nd:LuAG laser with a multi-walled carbon nanotube (MWCNT) as saturable absorber. A maximum average output power of 844 mW and pulses as short as 78 ns under a repetition rate of about 100 kHz were generated. A MWCNT Q-switched Nd:YAG laser was comparatively investigated, in comparison with which the Nd:LuAG laser showed lower threshold absorbed pump power and higher pulse energy, indicating a better energy storage ability of Nd:LuAG crystal than Nd:YAG. (C) 2014 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000340336100002

Author Identifiers:

ISSN: 0030-3992

eISSN: 1879-2545

Record 3 of 244

Title: Flowing on Riemannian Manifold: Domain Adaptation by Shifting Covariance

Author(s): Cui, Z (Cui, Zhen); Li, W (Li, Wen); Xu, D (Xu, Dong); Shan, SG (Shan, Shiguang); Chen, XL (Chen, Xilin); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 44  Issue: 12  Pages: 2264-2273  DOI: 10.1109/TCYB.2014.2305701  Published: DEC 2014  

Abstract: Domain adaptation has shown promising results in computer vision applications. In this paper, we propose a new unsupervised domain adaptation method called domain adaptation by shifting covariance (DASC) for object recognition without requiring any labeled samples from the target domain. By characterizing samples from each domain as one covariance matrix, the source and target domain are represented into two distinct points residing on a Riemannian manifold. Along the geodesic constructed from the two points, we then interpolate some intermediate points (i.e., covariance matrices), which are used to bridge the two domains. By utilizing the principal components of each covariance matrix, samples from each domain are further projected into intermediate feature spaces, which finally leads to domain-invariant features after the concatenation of these features from intermediate points. In the multiple source domain adaptation task, we also need to effectively integrate different types of features between each pair of source and target domains. We additionally propose an SVM based method to simultaneously learn the optimal target classifier as well as the optimal weights for different source domains. Extensive experiments demonstrate the effectiveness of our method for both single source and multiple source domain adaptation tasks.

Accession Number: WOS:000345629000003

PubMed ID: 25415937

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 4 of 244

Title: LED-based digital holographic microscopy with slightly off-axis interferometry

Author(s): Guo, RL (Guo, Rongli); Yao, BL (Yao, Baoli); Min, JW (Min, Junwei); Zhou, ML (Zhou, Meiling); Yu, XH (Yu, Xianghua); Lei, M (Lei, Ming); Yan, SH (Yan, Shaohui); Yang, YL (Yang, Yanlong); Dan, D (Dan, Dan)

Source: JOURNAL OF OPTICS  Volume: 16  Issue: 12  Article Number: 125408  DOI: 10.1088/2040-8978/16/12/125408  Published: DEC 2014  

Abstract: An LED illuminated Linnik-type digital holographic microscope (DHM) for high-quality phase imaging is presented by the adoption of slightly off-axis two-step blind-phase-shifting interferometry (TB-PSI). Slightly off-axis interferometry lowers the requirement on the angle between the object and the reference waves as well as the requirement on the resolving power of the charge-coupled device (CCD) camera. In addition, the apparatus is cost-effective and offers ease of alignment. The phase-shifting DHM is simply implemented by mechanically moving the reference mirror while disposing of a precise phase modulator such as a piezoelectric transducer (PZT). The phase shift between the two interferograms is extracted by Fourier transformation analysis, and then the phase image is reconstructed. The performance of the TB-PSI used in the scheme is analyzed. The phase imaging for nanostructured specimens is conducted, and the results demonstrate the feasibility of the scheme. The phase noise is reduced by 73% when compared to the result obtained with coherent illumination.

Accession Number: WOS:000344915000028

Author Identifiers:

ISSN: 2040-8978

eISSN: 2040-8986

Record 5 of 244

Title: Optical properties of SrAl₂O₄: Eu<SUP>2+</SUP> phosphor in glass

Author(s): He, QL (He, Quanlong); Hu, CC (Hu, Changchuan)

Source: OPTICAL MATERIALS  Volume: 38  Pages: 286-289  DOI: 10.1016/j.optmat.2014.10.055  Published: DEC 2014  

Abstract: Phosphor-in-glass (PiG) typed robust color converters were fabricated using pb-free silicate glasses for luminescence materials applications. The PiG based on a SiO2-B2O3-BaCO3 ternary system and SrAl2O4: Eu2+ phosphor showed good transparency reached 99.50%, even if the GTP ratio is 25:1. By simply changing the mixing ratio of glass to SrAl2O4: Eu2+ phosphor, the emission color of PiG can be controlled from blue to bluish green. The results reveal that the luminescence properties of SrAl2O4: Eu2+ distinct from the phosphor in glass significantly. These suggest that PIG could provide potential application in a variety of luminescence materials. (C) 2014 Elsevier B.V. All rights reserved.

Accession Number: WOS:000346228800050

ISSN: 0925-3467

eISSN: 1873-1252

Record 6 of 244

Title: Facial Skin Beautification Using Adaptive Region-Aware Masks

Author(s): Liang, LY (Liang, Lingyu); Jin, LW (Jin, Lianwen); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 44  Issue: 12  Pages: 2600-2612  DOI: 10.1109/TCYB.2014.2311033  Published: DEC 2014  

Abstract: In this paper, we propose a unified facial beautification framework with respect to skin homogeneity, lighting, and color. A novel region-aware mask is constructed for skin manipulation, which can automatically select the edited regions with great precision. Inspired by the state-of-the-art edit propagation techniques, we present an adaptive edge-preserving energy minimization model with a spatially variant parameter and a high-dimensional guided feature space for mask generation. Using region-aware masks, our method facilitates more flexible and accurate facial skin enhancement while the complex manipulations are simplified considerably. In our beautification framework, a portrait is decomposed into smoothness, lighting, and color layers by an edge-preserving operator. Next, facial landmarks and significant features are extracted as input constraints for mask generation. After three region-aware masks have been obtained, a user can perform facial beautification simply by adjusting the skin parameters. Furthermore, the combinations of parameters can be optimized automatically, depending on the data priors and psychological knowledge. We performed both qualitative and quantitative evaluation for our method using faces with different genders, races, ages, poses, and backgrounds from various databases. The experimental results demonstrate that our technique is superior to previous methods and comparable to commercial systems, for example, PicTreat, Portrait+, and Portraiture.

Accession Number: WOS:000345629000029

PubMed ID: 24710839

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 7 of 244

Title: Realistic action recognition via sparsely-constructed Gaussian processes

Author(s): Liu, L (Liu, Li); Shao, L (Shao, Ling); Zheng, F (Zheng, Feng); Li, XL (Li, Xuelong)

Source: PATTERN RECOGNITION  Volume: 47  Issue: 12  Pages: 3819-3827  DOI: 10.1016/j.patcog.2014.07.006  Published: DEC 2014  

Abstract: Realistic action recognition has been one of the most challenging research topics in computer vision. The existing methods are commonly based on non-probabilistic classification, predicting category labels but not providing an estimation of uncertainty. In this paper, we propose a probabilistic framework using Gaussian processes (GPs), which can tackle regression problems with explicit uncertain models, for action recognition. A major challenge for GPs when applied to large-scale realistic data is that a large covariance matrix needs to be inverted during inference. Additionally, from the manifold perspective, the intrinsic structure of the data space is only constrained by a local neighborhood and data relationships with far-distance usually can be ignored. Thus, we design our GPs covariance matrix via the proposed l(1) construction and a local approximation (LA) covariance weight updating method, which are demonstrated to be robust to data noise, automatically sparse and adaptive to the neighborhood. Extensive experiments on four realistic datasets, i.e., UCF YouTube, UCF Sports, Hollywood2 and HMDB51, show the competitive results of l(1)-GPs compared with state-of-the-art methods on action recognition tasks. (C) 2014 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000342870900007

Author Identifiers:

ISSN: 0031-3203

eISSN: 1873-5142

Record 8 of 244

Title: Effect of energy density and feeding speed on micro-hole drilling in C/SiC composites by picosecond laser

Author(s): Liu, YS (Liu, Yongsheng); Wang, CH (Wang, Chunhui); Li, WN (Li, Weinan); Zhang, LT (Zhang, Litong); Yang, XJ (Yang, Xiaojun); Cheng, GH (Cheng, Guanghua); Zhang, Q (Zhang, Qing)

Source: JOURNAL OF MATERIALS PROCESSING TECHNOLOGY  Volume: 214  Issue: 12  Pages: 3131-3140  DOI: 10.1016/j.jmatprotec.2014.07.016  Published: DEC 2014  

Abstract: The effect of energy density and feeding speed on micro-holes was investigated, which were machined in C/SiC composites by picosecond laser. Morphologies and elemental compositions of the machined holes in 2 mm and 3 mm thickness specimens were analyzed. The results indicated that both energy density and feeding speed had remarkable effect on the quality of micro-holes, especially on the exit side and cross-section of micro-holes. While the circularity of drilling holes on the entry side was affected by the energy density and feeding speed slightly. Additionally, the machining debris also played an important role in the quality of micro-holes. The micro-holes were consisted with three elements C, Si, and O, and those predominantly attributed to C-C (sp(2)), C-C (sp(3)) and Si-O bonds. Moreover, the laser machining process was discussed, which was responsible for the formation of the debris. (C) 2014 Elsevier B.V. All rights reserved.

Accession Number: WOS:000342245500032

Author Identifiers:

ISSN: 0924-0136

Record 9 of 244

Title: Mid-infrared emissions of Pr<SUP>3+</SUP>-doped GeS₂-Ga₂S₃-CdI₂ chalcohalide glasses

Author(s): Lu, CF (Lu, Chunfeng); Guo, HT (Guo, Haitao); Xu, YT (Xu, Yantao); Hou, CQ (Hou, Chaoqi); Lu, M (Lu, Min); He, X (He, Xin); Wang, PF (Wang, Pengfei); Li, WN (Li, Weinan); Peng, B (Peng, Bo)

Source: MATERIALS RESEARCH BULLETIN  Volume: 60  Pages: 391-396  DOI: 10.1016/j.materresbull.2014.09.003  Published: DEC 2014  

Abstract: For elucidation of the glass composition's influence on the spectroscopic properties in the chalcohalide system and the discovery of a new material for applications in mid-infrared fiber-lasers, a serial Pr3+-doped (100-x)(0.8GeS(2).0.2Ga(2)S(3))xCdI(2) (x = 5, 10, 15 and 20) chalcohalide glasses were prepared. similar to 4.6 mu m mid-infrared fluorescence emission from Pr3+ in the sulfide glass is successfully observed at room temperature excited by a 2.01 mu m Tm3+:YAG ceramic laser system, and the effective line-width of fluorescence band is 106-227 nm. Intense compositional dependence of mid-infrared emissions is found. The radiative rates of Pr3+ ions in these glasses were calculated by using the Judd-Ofelt theory. (C) 2014 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000347583100056

Author Identifiers:

ISSN: 0025-5408

eISSN: 1873-4227

Record 10 of 244

Title: Phase retrieval without unwrapping by single-shot dual-wavelength digital holography

Author(s): Min, JW (Min, Junwei); Yao, BL (Yao, Baoli); Zhou, ML (Zhou, Meiling); Guo, RL (Guo, Rongli); Lei, M (Lei, Ming); Yang, YL (Yang, Yanlong); Dan, D (Dan, Dan); Yan, SH (Yan, Shaohui); Peng, T (Peng, Tong)

Source: JOURNAL OF OPTICS  Volume: 16  Issue: 12  Article Number: 125409  DOI: 10.1088/2040-8978/16/12/125409  Published: DEC 2014  

Abstract: A phase retrieval method by using single-shot dual-wavelength digital holography is proposed. Each single wavelength hologram is extracted from the color CCD recorded hologram at one exposure, and the unwrapped phase image of object can be reconstructed directly. Different from the traditional multiple wavelength phase unwrapping techniques, any single complex wave-fronts at different wavelengths have no need to be calculated any more. Thus, the phase retrieval is computationally fast and straightforward, and the limitations on the total optical path difference are significantly relaxed. The practicability of the proposed method is demonstrated by both simulated and experimental results.

Accession Number: WOS:000344915000029

Author Identifiers:

ISSN: 2040-8978

eISSN: 2040-8986

Record 11 of 244

Title: Learning Regularized LDA by Clustering

Author(s): Pang, YW (Pang, Yanwei); Wang, S (Wang, Shuang); Yuan, Y (Yuan, Yuan)

Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS  Volume: 25  Issue: 12  Pages: 2191-2201  DOI: 10.1109/TNNLS.2014.2306844  Published: DEC 2014  

Abstract: As a supervised dimensionality reduction technique, linear discriminant analysis has a serious overfitting problem when the number of training samples per class is small. The main reason is that the between-and within-class scatter matrices computed from the limited number of training samples deviate greatly from the underlying ones. To overcome the problem without increasing the number of training samples, we propose making use of the structure of the given training data to regularize the between- and within-class scatter matrices by between-and within-cluster scatter matrices, respectively, and simultaneously. The within-and between-cluster matrices are computed from unsupervised clustered data. The within-cluster scatter matrix contributes to encoding the possible variations in intraclasses and the between-cluster scatter matrix is useful for separating extra classes. The contributions are inversely proportional to the number of training samples per class. The advantages of the proposed method become more remarkable as the number of training samples per class decreases. Experimental results on the AR and Feret face databases demonstrate the effectiveness of the proposed method.

Accession Number: WOS:000345518900006

PubMed ID: 25420242

Author Identifiers:

ISSN: 2162-237X

eISSN: 2162-2388

Record 12 of 244

Title: A method and results of color calibration for the Chang'e-3 terrain camera and panoramic camera

Author(s): Ren, X (Ren, Xin); Li, CL (Li, Chun-Lai); Liu, JJ (Liu, Jian-Jun); Wang, FF (Wang, Fen-Fei); Yang, JF (Yang, Jian-Feng); Liu, EH (Liu, En-Hai); Xue, B (Xue, Bin); Zhao, RJ (Zhao, Ru-Jin)

Source: RESEARCH IN ASTRONOMY AND ASTROPHYSICS  Volume: 14  Issue: 12  Pages: 1557-1566  DOI: 10.1088/1674-4527/14/12/005  Published: DEC 2014  

Abstract: The terrain camera (TCAM) and panoramic camera (PCAM) are two of the major scientific payloads installed on the lander and rover of the Chang'e 3 mission respectively. They both use a Bayer color filter array covering CMOS sensor to capture color images of the Moon's surface. RGB values of the original images are related to these two kinds of cameras. There is an obvious color difference compared with human visual perception. This paper follows standards published by the International Commission on Illumination to establish a color correction model, designs the ground calibration experiment and obtains the color correction coefficient. The image quality has been significantly improved and there is no obvious color difference in the corrected images. Ground experimental results show that: (1) Compared with uncorrected images, the average color difference of TCAM is 4.30, which has been reduced by 62.1%. (2) The average color differences of the left and right cameras in PCAM are 4.14 and 4.16, which have been reduced by 68.3% and 67.6% respectively.

Accession Number: WOS:000346124700005

Author Identifiers:

ISSN: 1674-4527

eISSN: 2397-6209

Record 13 of 244

Title: Improved adaptive control for wing rock via fuzzy neural network with randomly assigned fuzzy membership function parameters

Author(s): Rong, HJ (Rong, Hai-Jun); Han, S (Han, Sai); Bai, JM (Bai, Jian-Ming); Liang, YQ (Liang, Yong-Qi)

Source: AEROSPACE SCIENCE AND TECHNOLOGY  Volume: 39  Pages: 614-627  DOI: 10.1016/j.ast.2014.06.009  Published: DEC 2014  

Abstract: Two stable adaptive fuzzy-neural control schemes within the indirect and direct frameworks are proposed to suppress the wing rock occurring at high angles of attack. In the two control strategies, a fuzzy neural network (FNN) with any bounded nonconstant piecewise continuous membership function is used to approximate the system nonlinear dynamics and external disturbances. Differently from the existing techniques, the parameters of the fuzzy membership functions are determined based on the recently developed fuzzy-neural algorithm named online sequential fuzzy extreme learning machine (OS-Fuzzy-ELM) where the fuzzy membership function parameters need not be adjusted and could randomly be generated according to any given continuous probability distribution without any prior knowledge. This simplifies the design of the controllers. Furthermore to ensure stable control performance, the tuning laws of the consequent parameters are derived using the projection algorithm and Lyapunov stability theorem. The merits of the proposed control schemes lie in the simplicity, robustness and stability, which manifests they can be applied for online learning and real-time control. In order to evaluate the performance of the proposed two control schemes, a comparison between a neural control, a fuzzy control and a fuzzy-neural control is carried out on various initial conditions. Results indicate the performance of the proposed controllers is superior using the randomly assigned fuzzy membership function parameters. (C) 2014 Elsevier Masson SAS. All rights reserved.

Accession Number: WOS:000347743100063

Author Identifiers:

ISSN: 1270-9638

eISSN: 1626-3219

Record 14 of 244

Title: Learning Deep and Wide: A Spectral Method for Learning Deep Networks

Author(s): Shao, L (Shao, Ling); Wu, D (Wu, Di); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS  Volume: 25  Issue: 12  Pages: 2303-2308  DOI: 10.1109/TNNLS.2014.2308519  Published: DEC 2014  

Abstract: Building intelligent systems that are capable of extracting high-level representations from high-dimensional sensory data lies at the core of solving many computer vision-related tasks. We propose the multispectral neural networks (MSNN) to learn features from multicolumn deep neural networks and embed the penultimate hierarchical discriminative manifolds into a compact representation. The low-dimensional embedding explores the complementary property of different views wherein the distribution of each view is sufficiently smooth and hence achieves robustness, given few labeled training data. Our experiments show that spectrally embedding several deep neural networks can explore the optimum output from the multicolumn networks and consistently decrease the error rate compared with a single deep network.

Accession Number: WOS:000345518900016

PubMed ID: 25420251

Author Identifiers:

ISSN: 2162-237X

eISSN: 2162-2388

Record 15 of 244

Title: Efficient Closed-Loop Multiple-View Registration

Author(s): Shao, XW (Shao, Xiaowei); Shi, Y (Shi, Yun); Zhao, HJ (Zhao, Huijing); Li, XL (Li, Xuelong); Shibasaki, R (Shibasaki, Ryosuke)

Source: IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS  Volume: 15  Issue: 6  Pages: 2524-2538  DOI: 10.1109/TITS.2014.2319352  Published: DEC 2014  

Abstract: Registering multiple views is an essential and challenging problem for many intelligent transportation applications that employ a mobile sensing platform or consist of multiple stationary sensors. In this paper a novel algorithm is presented for multiple-view registration under a loop closure constraint. Different from most existing methods, which use general optimization techniques, our method studies the mechanism of adjusting the poses of views in a loop and provides a highly efficient and accurate solution. We prove that translation vectors can be decoupled if the same point set is used in each view to associate the previous and subsequent views, leading to our solution for such decouplable cases. If this condition does not hold, an exact solution of translation vectors is provided when rotation parameters are given, which results in our iterative solution for general cases by updating rotation and translation alternately. In our method, the effect of the accumulated pose error in a loop can be distributed to all views efficiently through loop factors, and only a few iterations are needed. Most important of all, in each iteration our method has linear computational complexity with respect to the number of views, which is much superior to that of state-of-the-art methods. A series of experiments was conducted, involving simulation of thousands of views and real vehicle-borne sensing data that include 65 371 point pairs in 352 views. Experimental results show that our proposed method is not only stable and highly efficient but also provides competitive accuracy relative to existing methods.

Accession Number: WOS:000345572900015

Author Identifiers:

ISSN: 1524-9050

eISSN: 1558-0016

Record 16 of 244

Title: Exact Analytical Solution for the Mutual Compensation of Astigmatism Using Curved Mirrors in a Folded Resonator Laser

Author(s): Wen, Q (Wen Qiao); Liang, GW (Liang Guowen); Zhang, XJ (Zhang Xiaojun); Liang, ZS (Liang Zongsen); Wang, YG (Wang Yonggang); Li, J (Li Ji); Niu, HB (Niu Hanben)

Source: IEEE PHOTONICS JOURNAL  Volume: 6  Issue: 6  Article Number: 1502213  DOI: 10.1109/JPHOT.2014.2366160  Published: DEC 2014  

Abstract: For the first time, to the best of our knowledge, analytical expressions for mutually compensating the curved mirror astigmatism in the two terminal arms of a folded resonator are deduced and experimentally verified. The analytical expressions are derived using the theory of the propagation and transformation of Gaussian beams under few assumptions. Our exact analytical expressions describe the necessary and sufficient conditions for simultaneously compensating astigmatism in two arms of a sequence of two off-axis curved mirrors. The theoretical results indicate that, when the astigmatism compensation expressions are satisfied, the astigmatism introduced by a folded curved mirror can be mutually compensated by another folded curved mirror, even if there is no additional Brewster element inside the cavity. The astigmatism can only be successfully eliminated by using a pair of concave mirrors or convex mirrors. Our analytical expressions can be used to design astigmatically compensated folded resonators without a Brewster element. A typical side-pumped z-shaped cavity Nd:YAG laser is employed to demonstrate the astigmatic compensation. Experimental measurements of the pattern of the laser output beam show that not only the spot intensity profile deformation but, in addition, the phase distortion in the two terminal arms can be simultaneously compensated completely in the cavity, which is in good agreement with the analytical predictions.

Accession Number: WOS:000345576700020

Author Identifiers:

ISSN: 1943-0655

eISSN: 1943-0647

Record 17 of 244

Title: Laser pulse propagation and enhanced energy coupling to fast electrons in dense plasma gradients

Author(s): Gray, RJ (Gray, R. J.); Carroll, DC (Carroll, D. C.); Yuan, XH (Yuan, X. H.); Brenner, CM (Brenner, C. M.); Burza, M (Burza, M.); Coury, M (Coury, M.); Lancaster, KL (Lancaster, K. L.); Lin, XX (Lin, X. X.); Li, YT (Li, Y. T.); Neely, D (Neely, D.); Quinn, MN (Quinn, M. N.); Tresca, O (Tresca, O.); Wahlström, CG (Wahlstrom, C-G); McKenna, P (McKenna, P.)

Source: NEW JOURNAL OF PHYSICS  Volume: 16  Article Number: 113075  DOI: 10.1088/1367-2630/16/11/113075  Published: NOV 28 2014  

Abstract: Laser energy absorption to fast electrons during the interaction of an ultra-intense (10(20) Wcm(-2)), picosecond laser pulse with a solid is investigated, experimentally and numerically, as a function of the plasma density scale length at the irradiated surface. It is shown that there is an optimum density gradient for efficient energy coupling to electrons and that this arises due to strong self-focusing and channeling driving energy absorption over an extended length in the preformed plasma. At longer density gradients the laser filaments, resulting in significantly lower overall energy coupling. As the scale length is further increased, a transition to a second laser energy absorption process is observed experimentally via multiple diagnostics. The results demonstrate that it is possible to significantly enhance laser energy absorption and coupling to fast electrons by dynamically controlling the plasma density gradient.

Accession Number: WOS:000346764200001

Author Identifiers:

ISSN: 1367-2630

Record 18 of 244

Title: High-resolution reconstruction for terahertz imaging

Author(s): Xu, LM (Xu, Li-Min); Fan, WH (Fan, Wen-Hui); Liu, J (Liu, Jia)

Source: APPLIED OPTICS  Volume: 53  Issue: 33  Pages: 7891-7897  DOI: 10.1364/AO.53.007891  Published: NOV 20 2014  

Abstract: We present a high-resolution (HR) reconstruction model and algorithms for terahertz imaging, taking advantage of super-resolution methodology and algorithms. The algorithms used include projection onto a convex sets approach, iterative backprojection approach, Lucy-Richardson iteration, and 2D wavelet decomposition reconstruction. Using the first two HR reconstruction methods, we successfully obtain HR terahertz images with improved definition and lower noise from four low-resolution (LR) 22 x 24 terahertz images taken from our homemade THz-TDS system at the same experimental conditions with 1.0 mm pixel. Using the last two HR reconstruction methods, we transform one relatively LR terahertz image to a HR terahertz image with decreased noise. This indicates potential application of HR reconstruction methods in terahertz imaging with pulsed and continuous wave terahertz sources. (C) 2014 Optical Society of America

Accession Number: WOS:000345104200012

PubMed ID: 25607865

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 19 of 244

Title: Expanded-core waveguides written by femtosecond laser irradiation in bulk optical glasses

Author(s): Liu, X (Liu, Xin); Zhang, WF (Zhang, Wenfu); Zhao, W (Zhao, Wei); Stoian, R (Stoian, Razvan); Cheng, GH (Cheng, Guanghua)

Source: OPTICS EXPRESS  Volume: 22  Issue: 23  Pages: 28771-28782  DOI: 10.1364/OE.22.028771  Published: NOV 17 2014  

Abstract: Expanded-core structures based on layered increased index (type I) waveguiding traces are fabricated by ultrafast laser photoinscription in bulk optical glasses, with examples for fused silica and chalcogenide glasses. The expanded-core waveguides can serve for large-mode-area guiding concepts and their feasibility is experimentally investigated. A parametric study of the geometry, number of traces and index contrast indicates the possibility to design guided modes characteristics as exemplified in fused silica. A specific arrangement consisting of 8 traces of guiding layers with 6 mu m separation exhibit single-mode transport properties with mode field area of similar to 805 mu m(2). The condition of single mode operation is also discussed in the frame of the dispersion relation of light guiding in periodical dielectric structures. The supported supermode of expanded-core structures can be controlled by careful design of the refractive index change, the number of guiding layers and the thickness of the interlayers. Inspection of the propagation characteristics shows equally low loss features. A Y-branching splitter based on expanded-core concept conserving single mode characteristics is fabricated. The optical design is equally successfully tested in chalcogenide Gallium Lanthanum Sulfide glass. Ultrafast laser inscribed expanded-core waveguiding provides therefore an interesting path of fabricating large mode area waveguides usable in near infrared and mid-infrared region beneficial for applications requiring high power or large mode dimensions. (C) 2014 Optical Society of America

Accession Number: WOS:000345268500097

PubMed ID: 25402116

Author Identifiers:

ISSN: 1094-4087

Record 20 of 244

Title: Experimental and theoretical investigations of a tunable dissipative soliton fiber laser

Author(s): Han, DD (Han, D. D.)

Source: APPLIED OPTICS  Volume: 53  Issue: 32  Pages: 7629-7633  DOI: 10.1364/AO.53.007629  Published: NOV 10 2014  

Abstract: Atunable dissipative soliton fiber laser based on carbon nanotubes and the nonlinear polarization rotation (NPR) technique has been investigated experimentally and numerically for the first time to the author's best knowledge. The laser proposed delivers strongly chirped solitons with pulse duration of similar to 220 ps and a spectral width of similar to 5.6 nm. With the NPR-related filtering effect, the output pulses are wavelength tunable over the range from 1566 to 1593 nm by adjusting the polarization controller (PC). Numerical results are in good agreement with experimental observations and clearly reveal that the tunable mode-locking operation is attributed to the variation of phase delay caused by the PCs. (C) 2014 Optical Society of America

Accession Number: WOS:000345104100003

PubMed ID: 25402982

ISSN: 1559-128X

eISSN: 2155-3165

Record 21 of 244

Title: Large femtosecond third-order optical nonlinearity of Bi_3.15Nd_0.85Ti₃O₁₂ ferroelectric thin films

Author(s): Li, S (Li, S.); Zhong, XL (Zhong, X. L.); Cheng, GH (Cheng, G. H.); Liu, X (Liu, X.); Wang, JB (Wang, J. B.); Huang, J (Huang, J.); Song, HJ (Song, H. J.); Tan, CB (Tan, C. B.); Li, B (Li, B.); Zhou, YC (Zhou, Y. C.)

Source: APPLIED PHYSICS LETTERS  Volume: 105  Issue: 19  Article Number: 192901  DOI: 10.1063/1.4900758  Published: NOV 10 2014  

Abstract: Both the linear and nonlinear optical properties of Bi3.15Nd0.85Ti3O12 (BNT0.85) ferroelectric thin films deposited on quartz substrates were investigated. The fundamental optical constants were determined as a function of light wavelength by optical transmittance measurements. By performing single-beam Z-scan experiments with femtosecond laser pulses at a wavelength of 800 nm, the two-photon absorption (TPA) coefficient beta and third-order nonlinear refraction index gamma were measured to be 1.15 x 10(2) cm/GW and -8.15 x 10(-3) cm(2)/GW, respectively. The large TPA is attributed to an indirect transition process via the intermediate energy levels and the large refractive nonlinearity is the result of the electronic polarization and ferroelectric polarization arisen from the femtosecond midinfrared radiation. The results indicate that the BNT0.85 thin film is a promising candidate for applications in nonlinear photonic devices. (C) 2014 AIP Publishing LLC.

Accession Number: WOS:000345216100057

Author Identifiers:

ISSN: 0003-6951

eISSN: 1077-3118

Record 22 of 244

Title: Visibility enhancement of hazy images based on a universal polarimetric imaging method

Author(s): Liang, J (Liang, Jian); Ren, LY (Ren, Li-Yong); Ju, HJ (Ju, Hai-Juan); Qu, ES (Qu, En-Shi); Wang, YL (Wang, Ying-Li)

Source: JOURNAL OF APPLIED PHYSICS  Volume: 116  Issue: 17  Article Number: 173107  DOI: 10.1063/1.4901244  Published: NOV 7 2014  

Abstract: Enhancing the visibility of images taken in the hazy weather is important in many applications. Among many dehazing methods, those based on polarimetric imaging techniques have several advantages, such as ease of keeping detailed information, low cost, and high efficiency. In this paper, we propose a novel and robust dehazing algorithm based on polarimetric imaging. By introducing the orientation-angle information from the Stokes matrix, all the parameters used in dehazing performance can be effectively, precisely and automatically estimated, and no additional human-computer interaction is needed. Besides, this method can also be used in handling hazy images without sky region. Experimental results show that such a method can greatly enhance the visibility of hazy images. (C) 2014 AIP Publishing LLC.

Accession Number: WOS:000345152900007

Author Identifiers:

ISSN: 0021-8979

eISSN: 1089-7550

Record 23 of 244

Title: High efficient CEP-stabilized infrared optical parametric amplifier made from a BBO single crystal

Author(s): You, LF (You Lang-Fang); Ling, WJ (Ling Wei-Jun); Li, K (Li Ke); Zhang, MX (Zhang Ming-Xia); Zuo, YY (Zuo Yin-Yan); Wang, YS (Wang Yi-Shan)

Source: ACTA PHYSICA SINICA  Volume: 63  Issue: 21  Article Number: 214203  DOI: 10.7498/aps.63.214203  Published: NOV 5 2014  

Abstract: We demonstrate an efficient tunable phase-stabilized near-infrared optical parametric amplifier (OPA) made from a BBO (beta-BaB2O4) single crystal in this paper. By using the seeded white-light continuum produced by CEP(carrier envelop phase)-stabilized femtosecond laser amplifier system which is seeded into the two stages of a type II OPA system, the pump-to-signal conversion efficiency of 34% can be achieved at 1350 nm. The CEP jitter of amplified pulses measured by an f-2f interferometer is 137 mrad in 30 minutes. This paper demonstrates a simple, feasible and efficient way to produce tunable femtosecond pulses with CEP control.

Accession Number: WOS:000344616700017

Author Identifiers:

ISSN: 1000-3290

Record 24 of 244

Title: Giant and tunable electric field enhancement in the terahertz regime

Author(s): Lu, XY (Lu, Xiaoyuan); Wan, RG (Wan, Rengang); Wang, GX (Wang, Guoxi); Zhang, TY (Zhang, Tongyi); Zhang, WF (Zhang, Wenfu)

Source: OPTICS EXPRESS  Volume: 22  Issue: 22  Pages: 27001-27006  DOI: 10.1364/OE.22.027001  Published: NOV 3 2014  

Abstract: A novel array of slits design combining the nano-slit grating and dielectric-metal is proposed to obtain giant and tunable electric field enhancement in the terahertz regime. The maximum amplitude of electric field is more than 6000 times larger than that of the incident electric field. It is found that the enhancement depends primarily on the stripe and nano-slits width of grating, as well as the thickness of spacer layer. This property is particularly beneficial for the realization of ultra-sensitive nanoparticles detection and nonlinear optics in the terahertz range, such as the second harmonic generation (SHG). (C) 2014 Optical Society of America

Accession Number: WOS:000344004900054

PubMed ID: 25401850

Author Identifiers:

ISSN: 1094-4087

Record 25 of 244

Title: Image esthetic assessment using both hand-crafting and semantic features

Author(s): Guo, LH (Guo, Lihua); Xiong, YC (Xiong, Yangchao); Huang, QH (Huang, Qinghua); Li, XL (Li, Xuelong)

Source: NEUROCOMPUTING  Volume: 143  Special Issue: SI  Pages: 14-26  DOI: 10.1016/j.neucom.2014.06.029  Published: NOV 2 2014  

Abstract: Automatically assessing the visual esthetics of images is of great interest in high-level vision research and has drawn much attention in recent years. Traditional methods heavily depend on the performance of subject region extraction. This paper proposes to use semantic features in the esthetic assessment system because they can implicitly represent the image topic and be helpful if the subject region extraction fails. Accordingly, a framework combining the hand-crafting features with semantic features is proposed to evaluate image esthetic quality. The experimental results show that the semantic features can improve the performance of image esthetic assessment. (C) 2014 Elsevier B.V. All rights reserved.

Accession Number: WOS:000340982800003

Author Identifiers:

ISSN: 0925-2312

eISSN: 1872-8286

Record 26 of 244

Title: Dayside aurora classification via BIFs-based sparse representation using manifold learning

Author(s): Han, B (Han, Bing); Zhao, XJ (Zhao, Xiaojing); Tao, DC (Tao, Dacheng); Li, XL (Li, Xuelong); Hu, ZJ (Hu, Zejun); Hu, HQ (Hu, Hongqiao)

Source: INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS  Volume: 91  Issue: 11  Special Issue: SI  Pages: 2415-2426  DOI: 10.1080/00207160.2013.831084  Published: NOV 2 2014  

Abstract: Aurora is the typical ionosphere track generated by the interaction of solar wind and magnetosphere, whose modality and variation are significant to the study of space weather activity. A new aurora classification algorithm based on biologically inspired features (BIFs) and discriminative locality alignment (DLA) is proposed in this paper. First, an aurora image is represented by the BIFs, which combines the C1 units from the hierarchical model of object recognition in cortex and the gist features from the saliency map; then, the manifold learning method called DLA is used to obtain the effective sparse representation for auroras based on BIFs; finally, classification results using support vector machine and nearest neighbour with three sets of features: the C1 unit features, the gist features and the BIFs illustrate the effectiveness and robustness of our method on the real aurora image database from Chinese Arctic Yellow River Station.

Accession Number: WOS:000345272500008

Author Identifiers:

ISSN: 0020-7160

eISSN: 1029-0265

Record 27 of 244

Title: Upgrading optical information of rotating mirror cameras

Author(s): Li, JZ (Li, Jingzhen); Sun, FS (Sun, Fengshan); Huang, HB (Huang, Hongbin); Gong, XD (Gong, Xiangdong); Chen, HY (Chen, Hongyi); Lu, XW (Lu, Xiaowei); Cai, Y (Cai, Yi)

Source: REVIEW OF SCIENTIFIC INSTRUMENTS  Volume: 85  Issue: 11  Article Number: 113701  DOI: 10.1063/1.4900404  Published: NOV 2014  

Abstract: To date, rotating mirror (RM) cameras still serve as indispensable imaging equipment for the diagnosis of microsecond transient processes due to their excellent characteristics. This paper, for upgrading the optical information capacity of the cameras, presents the new optical acceleration principle to increase the framing frequency or scanning velocity, the new design theory without principle errors instead of the classical theories with some flaws in principle to have applied to design our simultaneous streak and framing rotating mirror camera with continuous access, and the new rotating mirror with novel structure, made of an aluminum alloy, to have considerably reduced lateral deformation of the RM and improved the performance of the camera. (C) 2014 AIP Publishing LLC.

Accession Number: WOS:000345646000263

PubMed ID: 25430114

Conference Title: 20th Topical Conference on High-Temperature Plasma Diagnostics

Conference Date: JUN 01-05, 2014

Conference Location: Atlanta, GA

Author Identifiers:

ISSN: 0034-6748

eISSN: 1089-7623

Record 28 of 244

Title: Performance of diode-pumped Tm<SUP>3+</SUP> :Sc₂SiO₅ crystal passively Q-switched 2 μm laser

Author(s): Li, YQ (Li, Yaqi); Liu, J (Liu, Jie); Zhu, HT (Zhu, Hongtong); Zheng, LH (Zheng, Lihe); Su, LB (Su, Liangbi); Xu, J (Xu, Jun); Wang, YG (Wang, Yonggang)

Source: OPTICS COMMUNICATIONS  Volume: 330  Pages: 151-154  DOI: 10.1016/j.optcom.2014.05.049  Published: NOV 1 2014  

Abstract: A diode-pumped passively Q-switched Tm3+:Sc2SiO5 laser with a single-walled carbon nanotube saturable absorber is demonstrated for the first time. The maximum average output power of 189 mW has been achieved at 1970 nm under an absorbed pump power of 4 W. The minimum pulse width of 442 ns was obtained at a repetition rate of 55.6 kHz, corresponding to the highest peak power of 7.7 W and single pulse energy of 3.4 mu J, respectively. (C) 2014 Elsevier B.V. All rights reserved.

Accession Number: WOS:000343333100027

Author Identifiers:

ISSN: 0030-4018

eISSN: 1873-0310

Record 29 of 244

Title: Fabrication and annealing optimization of oxygen-implanted Yb<SUP>3+</SUP>-doped phosphate glass planar waveguides

Author(s): Liu, CX (Liu, Chun-Xiao); Xu, J (Xu, Jun); Li, WN (Li, Wei-Nan); Xu, XL (Xu, Xiao-Li); Guo, HT (Guo, Hai-Tao); Wei, W (Wei, Wei); Wu, GG (Wu, Gen-Gen); Hu, Y (Hu, Yue); Peng, B (Peng, Bo)

Source: OPTICS AND LASER TECHNOLOGY  Volume: 63  Pages: 45-49  DOI: 10.1016/j.optlastec.2014.03.014  Published: NOV 2014  

Abstract: Optical planar waveguides in Yb3+-doped phosphate glasses are fabricated by (5.0+6.0) MeV O3+ ion implantation at fluences of (4.0+8.0) x 10(14) ions/cm(2). The annealing treatment is carried out to optimize waveguide performances. The prism-coupling and end-face coupling methods are used to measure the dark-mode spectra and near-field intensity distributions before and after annealing at 350 degrees C for 60 min, respectively. The refractive index profile of the planar waveguide is obtained based on the reflectivity calculation method. The micro-Raman spectrum of the waveguide is in agreement with that of the bulk, exhibiting possible applications for integrated active photonic devices. (C) 2014 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000337876500009

Author Identifiers:

ISSN: 0030-3992

eISSN: 1879-2545

Record 30 of 244

Title: Fully immersed liquid cooling thin-disk oscillator

Author(s): Nie, RZ (Nie, R. Z.); She, JB (She, J. B.); Zhao, PF (Zhao, P. F.); Li, FL (Li, F. L.); Peng, B (Peng, B.)

Source: LASER PHYSICS LETTERS  Volume: 11  Issue: 11  Article Number: 115808  DOI: 10.1088/1612-2011/11/11/115808  Published: NOV 2014  

Abstract: A novel Nd:YAG thin-disk laser with excellent cooling configuration is demonstrated. A maximum output energy of 653 mJ is realized, corresponding to the optical-optical efficiency of 30% and the slope efficiency of 35%. The coefficient of output instability is as low as 1.1% at a repetition rate of 1 Hz. Beam propagation analysis reveals that beam distortion caused by temperature gradient will decrease effectively with this laser configuration.

Accession Number: WOS:000345221100026

Author Identifiers:

ISSN: 1612-2011

eISSN: 1612-202X

Record 31 of 244

Title: Distributed Object Detection With Linear SVMs

Author(s): Pang, YW (Pang, Yanwei); Zhang, K (Zhang, Kun); Yuan, Y (Yuan, Yuan); Wang, KQ (Wang, Kongqiao)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 44  Issue: 11  Special Issue: SI  Pages: 2122-2133  DOI: 10.1109/TCYB.2014.2301453  Published: NOV 2014  

Abstract: In vision and learning, low computational complexity and high generalization are two important goals for video object detection. Low computational complexity here means not only fast speed but also less energy consumption. The sliding window object detection method with linear support vector machines (SVMs) is a general object detection framework. The computational cost is herein mainly paid in complex feature extraction and innerproduct-based classification. This paper first develops a distributed object detection framework (DOD) by making the best use of spatial-temporal correlation, where the process of feature extraction and classification is distributed in the current frame and several previous frames. In each framework, only subfeature vectors are extracted and the response of partial linear classifier (i.e., subdecision value) is computed. To reduce the dimension of traditional block-based histograms of oriented gradients (BHOG) feature vector, this paper proposes a cell-based HOG (CHOG) algorithm, where the features in one cell are not shared with overlapping blocks. Using CHOG as feature descriptor, we develop CHOG-DOD as an instance of DOD framework. Experimental results on detection of hand, face, and pedestrian in video show the superiority of the proposed method.

Accession Number: WOS:000343319700012

PubMed ID: 25330474

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 32 of 244

Title: Learning From Errors in Super-Resolution

Author(s): Tang, Y (Tang, Yi); Yuan, Y (Yuan, Yuan)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 44  Issue: 11  Special Issue: SI  Pages: 2143-2154  DOI: 10.1109/TCYB.2014.2301732  Published: NOV 2014  

Abstract: A novel framework of learning-based super-resolution is proposed by employing the process of learning from the estimation errors. The estimation errors generated by different learning-based super-resolution algorithms are statistically shown to be sparse and uncertain. The sparsity of the estimation errors means most of estimation errors are small enough. The uncertainty of the estimation errors means the location of the pixel with larger estimation error is random. Noticing the prior information about the estimation errors, a nonlinear boosting process of learning from these estimation errors is introduced into the general framework of the learning-based super-resolution. Within the novel framework of super-resolution, a low-rank decomposition technique is used to share the information of different super-resolution estimations and to remove the sparse estimation errors from different learning algorithms or training samples. The experimental results show the effectiveness and the efficiency of the proposed framework in enhancing the performance of different learning-based algorithms.

Accession Number: WOS:000343319700014

PubMed ID: 25099964

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 33 of 244

Title: Controlling optical bistability via interacting double dark resonances in linear quantum dot molecules

Author(s): Tian, SC (Tian, Si-Cong); Wan, RG (Wan, Ren-Gang); Tong, CZ (Tong, Cun-Zhu); Ning, YQ (Ning, Yong-Qiang)

Source: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS  Volume: 31  Issue: 11  Pages: 2681-2688  DOI: 10.1364/JOSAB.31.002681  Published: NOV 2014  

Abstract: The behavior of optical bistability (OB) in linear triple quantum dot molecules (QDMs) using double tunneling coupling by means of a unidirectional ring cavity is investigated. The linear and nonlinear susceptibilities of the system are also investigated. The double tunneling between the quantum dots can induce the interaction of double dark resonances, which can enhance the nonlinear response of the system. The type, the hysteresis loop, and the threshold of OB can be controlled by the intensity of the double tunneling and the detuning of the probe field. Our results give insights for future experiments and applications in optics using QDMs. (C) 2014 Optical Society of America

Accession Number: WOS:000344760800029

ISSN: 0740-3224

eISSN: 1520-8540

Record 34 of 244

Title: Imaging of large-area microchannel plates using phosphor screens

Author(s): Wang, X (Wang, X.); Setru, SU (Setru, S. U.); Xie, J (Xie, J.); Mane, A (Mane, A.); Demarteau, M (Demarteau, M.); Wagner, R (Wagner, R.)

Source: JOURNAL OF INSTRUMENTATION  Volume: 9  Article Number: P11011  DOI: 10.1088/1748-0221/9/11/P11011  Published: NOV 2014  

Abstract: A testing system was built, using UV illumination at 254 nm and a cathodoluminescent phosphor screen, to measure the gain uniformity of large area (20 x 20 cm(2)) microchannel plates. The phosphor screen image is captured with a wide-angle CMOS digital camera (4032 x 3024 pixels) and analyzed. First a reference MCP is illuminated and the generated phosphor screen image is captured with a CCD camera. In a second step, another image is captured with the MCP under test inserted between the reference MCP and the phosphor screen. The ratio of the two images is analyzed and provides a quantitative measure of the relative gain uniformity of the MCP under test.

Accession Number: WOS:000345026000025

Author Identifiers:

ISSN: 1748-0221

Record 35 of 244

Title: Measurements of the Concentration of Atmospheric CO₂ Based on OP/FTIR Method and Infrared Reflecting Scanning Fourier Transform Spectrometry

Author(s): Wei, RY (Wei Ru-yi); Zhou, JS (Zhou Jin-song); Zhang, XM (Zhang Xue-min); Yu, T (Yu Tao); Gao, XH (Gao Xiao-hui); Ren, XQ (Ren Xiao-qiang)

Source: SPECTROSCOPY AND SPECTRAL ANALYSIS  Volume: 34  Issue: 11  Pages: 2978-2983  DOI: 10.3964/j.issn.1000-0593(2014)11-2978-06  Published: NOV 2014  

Abstract: The present paper describes the observations and measurements of the infrared absorption spectra of CO2 on the Earth's surface with OP/FTIR method by employing a mid-infrared reflecting scanning Fourier transform spectrometry, which are the first results produced by the first prototype in China developed by the team of authors. This reflecting scanning Fourier transform spectrometry works in the spectral range 2 100 similar to 3 150 cm(-1) with a spectral resolution of 2 cm(-1). Method to measure the atmospheric molecules was described and mathematical proof and quantitative algorithms to retrieve molecular concentration were established. The related models were performed both by a direct method based on the Beer-Lambert Law and by a simulating-fitting method based on HITRAN database and the instrument functions. Concentrations of CO2 were retrieved by the two models. The results of observation and modeling analyses indicate that the concentrations have a distribution of 300 similar to 370 ppm, and show tendency that going with the variation of the environment they first decrease slowly and then increase rapidly during the observation period, and reached low points in the afternoon and during the sunset. The concentrations with measuring times retrieved by the direct method and by the simulating-fitting method agree with each other very well, with the correlation of all the data is up to 99. 79%, and the relative error is no more than 2. 00%. The precision for retrieving is relatively high. The results of this paper demonstrate that, in the field of detecting atmospheric compositions, OP/FTIR method performed by the Infrared reflecting scanning Fourier transform spectrometry is a feasible and effective technical approach, and either the direct method or the simulating-fitting method is capable of retrieving concentrations with high precision.

Accession Number: WOS:000344447700019

PubMed ID: 25752042

Author Identifiers:

ISSN: 1000-0593

Record 36 of 244

Title: Corner detection using Gabor filters

Author(s): Zhang, WC (Zhang, Wei-Chuan); Wang, FP (Wang, Fu-Ping); Zhu, L (Zhu, Lei); Zhou, ZF (Zhou, Zuo-Feng)

Source: IET IMAGE PROCESSING  Volume: 8  Issue: 11  Pages: 639-646  DOI: 10.1049/iet-ipr.2013.0641  Published: NOV 2014  

Abstract: This study proposes a contour-based corner detector using the magnitude responses of the imaginary part of the Gabor filters on contours. Unlike the traditional contour-based methods that detect corners by analysing the shape of the edge contours and searching for local curvature maxima points on planar curves, the proposed corner detector combines the pixels of the edge contours and their corresponding grey-variation information. Firstly, edge contours are extracted from the original image using Canny edge detector. Secondly, the imaginary parts of the Gabor filters are used to smooth the pixels on the edge contours. At each edge pixel, the magnitude responses at each direction are normalised by their values and the sum of the normalised magnitude response at each direction is used to extract corners from edge contours. Thirdly, both the magnitude response threshold and the angle threshold are used to remove the weak or false corners. Finally, the proposed detector is compared with five state-of-the-art detectors on some grey-level images. The results from the experiment reveal that the proposed detector is more competitive with respect to detection accuracy, localisation accuracy, affine transforms and noise-robustness.

Accession Number: WOS:000344933900003

Author Identifiers:

ISSN: 1751-9659

eISSN: 1751-9667

Record 37 of 244

Title: Adaptive fusion of particle filtering and spatio-temporal motion energy for human tracking

Author(s): Zhou, HY (Zhou, Huiyu); Fei, MR (Fei, Minrui); Sadka, A (Sadka, Abdul); Zhang, Y (Zhang, Yi); Li, XL (Li, Xuelong)

Source: PATTERN RECOGNITION  Volume: 47  Issue: 11  Pages: 3552-3567  DOI: 10.1016/j.patcog.2014.05.006  Published: NOV 2014  

Abstract: Object tracking is an active research area nowadays due to its importance in human computer interface, teleconferencing and video surveillance. However, reliable tracking of objects in the presence of occlusions, pose and illumination changes is still a challenging topic. In this paper, we introduce a novel tracking approach that fuses two cues namely colour and spatio-temporal motion energy within a particle filter based framework. We conduct a measure of coherent motion over two image frames, which reveals the spatio-temporal dynamics of the target. At the same time, the importance of both colour and motion energy cues is determined in the stage of reliability evaluation. This determination helps maintain the performance of the tracking system against abrupt appearance changes. Experimental results demonstrate that the proposed method outperforms the other state of the art techniques in the used test datasets. (C) 2014 Elsevier Ltd. All rights reserved.

Accession Number: WOS:000340335600006

Author Identifiers:

ISSN: 0031-3203

eISSN: 1873-5142

Record 38 of 244

Title: Secrecy Outage and Diversity Analysis of Cognitive Radio Systems

Author(s): Zou, YL (Zou, Yulong); Li, XL (Li, Xuelong); Liang, YC (Liang, Ying-Chang)

Source: IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS  Volume: 32  Issue: 11  Pages: 2222-2236  DOI: 10.1109/JSAC.2014.141121  Published: NOV 2014  

Abstract: In this paper, we investigate the physical-layer security of a multi-user multi-eavesdropper cognitive radio system, which is composed of multiple cognitive users (CUs) transmitting to a common cognitive base station (CBS), while multiple eavesdroppers may collaborate with each other or perform independently in intercepting the CUs-CBS transmissions, which are called the coordinated and uncoordinated eavesdroppers, respectively. Considering multiple CUs available, we propose the round-robin scheduling as well as the optimal and suboptimal user scheduling schemes for improving the security of CUs-CBS transmissions against eavesdropping attacks. Specifically, the optimal user scheduling is designed by assuming that the channel state information (CSI) of all links from CUs to CBS, to primary user (PU) and to eavesdroppers are available. By contrast, the suboptimal user scheduling only requires the CSI of CUs-CBS links without the PU's and eavesdroppers' CSI. We derive closed-form expressions of the secrecy outage probability of these three scheduling schemes in the presence of the coordinated and uncoordinated eavesdroppers. We also carry out the secrecy diversity analysis and show that the round-robin scheduling achieves the diversity order of only one, whereas the optimal and suboptimal scheduling schemes obtain the full secrecy diversity, no matter whether the eavesdroppers collaborate or not. In addition, numerical secrecy outage results demonstrate that for both the coordinated and uncoordinated eavesdroppers, the optimal user scheduling achieves the best security performance and the round-robin scheduling performs the worst. Finally, upon increasing the number of CUs, the secrecy outage probabilities of the optimal and suboptimal user scheduling schemes both improve significantly.

Accession Number: WOS:000348856700020

Author Identifiers:

ISSN: 0733-8716

eISSN: 1558-0008

Record 39 of 244

Title: GA-SIFT: A new scale invariant feature transform for multispectral image using geometric algebra

Author(s): Li, YS (Li, Yanshan); Liu, WM (Liu, Weiming); Li, XT (Li, Xiaotang); Huang, QH (Huang, Qinghua); Li, XL (Li, Xuelong)

Source: INFORMATION SCIENCES  Volume: 281  Pages: 559-572  DOI: 10.1016/j.ins.2013.12.022  Published: OCT 10 2014  

Abstract: Feature analysis plays an important role in many multispectral image applications and scale invariant feature transform (SIFT) has been successfully applied for extraction of image features. However, the existing SIFT algorithms cannot extract features from multispectral images directly. This paper puts forward a novel algorithmic framework based on the SIFT for multispectral images. Firstly, with the theory of the geometric algebra (GA), a new representation of multispectral image including spatial and spectral information is put forward and discussed. Secondly, a new method for obtaining the scale space of the multispectral image is proposed. Thirdly, following the procedures of the SIFT, the GA based difference of Gaussian images are computed and the keypoints can be detected in the GA space. Fourthly, the feature points are finally detected and described in the mathematical framework of the GA. Finally, the comparison results show that the GA-SIFT outperforms some previously reported SIFT algorithms in the feature extraction from a multispectral image, and it is comparable with its counterparts in the feature extraction of color images, indicating good performance in various applications of image analysis. (C) 2013 Elsevier Inc. All rights reserved.

Accession Number: WOS:000340315600038

Author Identifiers:

ISSN: 0020-0255

eISSN: 1872-6291

Record 40 of 244

Title: Re-texturing by intrinsic video

Author(s): Shen, JB (Shen, Jianbing); Yan, X (Yan, Xing); Chen, L (Chen, Lin); Sun, HQ (Sun, Hanqiu); Li, XL (Li, Xuelong)

Source: INFORMATION SCIENCES  Volume: 281  Pages: 726-735  DOI: 10.1016/j.ins.2014.02.134  Published: OCT 10 2014  

Abstract: In this paper, we present a novel re-texturing approach using intrinsic video. Our approach first indicates the regions of interest by contour-aware layer segmentation. The intrinsic video including reflectance and illumination components within the segmented region is recovered by our weighted energy optimization. We then compute the texture coordinates in key frames and the normals for the re-textured region using the optimization approach we develop. Meanwhile, the texture coordinates in non-key frames are optimized by our energy function. When the target sample texture is specified, the re-textured video is finally created by multiplying the re-textured reflectance component with the original illumination component within the replaced region. As shown in our experimental results, our method can produce high quality video re-texturing results with a variety of sample textures, and also the lighting and shading effects of the original videos are well preserved after re-texturing. (C) 2014 Elsevier Inc. All rights reserved.

Accession Number: WOS:000340315600051

Author Identifiers:

ISSN: 0020-0255

eISSN: 1872-6291

Record 41 of 244

Title: Action recognition by spatio-temporal oriented energies

Author(s): Zhen, XT (Zhen, Xiantong); Shao, L (Shao, Ling); Li, XL (Li, Xuelong)

Source: INFORMATION SCIENCES  Volume: 281  Pages: 295-309  DOI: 10.1016/j.ins.2014.05.021  Published: OCT 10 2014  

Abstract: In this paper, we present a unified representation based on the spatio-temporal steerable pyramid (STSP) for the holistic representation of human actions. A video sequence is viewed as a spatio-temporal volume preserving all the appearance and motion information of an action in it. By decomposing the spatio-temporal volumes into band-passed sub-volumes, the spatio-temporal Laplacian pyramid provides an effective technique for multi-scale analysis of video sequences, and spatio-temporal patterns with different scales could be well localized and captured. To efficiently explore the underlying local spatio-temporal orientation structures at multiple scales, a bank of three-dimensional separable steerable filters are conducted on each of the sub-volume from the Laplacian pyramid. The outputs of the quad-rature pair of steerable filters are squared and summed to yield a more robust oriented energy representation. To be further invariant and compact, a spatio-temporal max pooling operation is performed between responses of the filtering at adjacent scales and over spatio-temporal neighbourhoods. In order to capture the appearance, local geometric structure and motion of an action, we apply the STSP on the intensity, 3D gradients and optical flow of video sequences, yielding a unified holistic representation of human actions.
Taking advantage of multi-scale, multi-orientation analysis and feature pooling, STSP produces a compact but informative and invariant representation of human actions. We conduct extensive experiments on the KTH, UCF Sports and HMDB51 datasets, which shows the unified STSP achieves comparable results with the state-of-the-art methods. (C) 2014 Elsevier Inc. All rights reserved.

Accession Number: WOS:000340315600019

Author Identifiers:

ISSN: 0020-0255

eISSN: 1872-6291

Record 42 of 244

Title: Refraction angle extracting strategy for fan-beam differential phase contrast CT

Author(s): Ye, RZ (Ye, Renzhen); Tang, Y (Tang, Yi); Lu, XQ (Lu, Xiaoqiang)

Source: NEUROCOMPUTING  Volume: 141  Special Issue: SI  Pages: 160-169  DOI: 10.1016/j.neucom.2014.03.040  Published: OCT 2 2014  

Abstract: In this paper, the fan-beam differential phase contrast computed tomography (DPC-CT) reconstruction method is studied. We first present a new vision of how to implement the Reverse-Projection (RP) method to extract the refraction-angle data efficiently in fan-beam geometry, and then provide a Katsevich-type formula for fan-beam DPC-CT reconstruction. The proposed method has two key properties. First, it is essentially a filtered back projection (FBP) reconstruction formula. Second, it can deal with incomplete data sets. The main contributions of this paper lie in the following three aspects: First, the physical principle of the bent-grating based fan-beam DPC imaging is discussed and the RP-method is extended to the fan-beam case. Second, an implementation strategy of Katsevich algorithm for fan-beam DPC-CT is proposed. Third, a semi-quantitative research on the influence of the approximation errors introduced by the RP-method is carried out by using several numerical simulations. It should be pointed out that the RP-method will certainly introduce some errors. The effect of these errors on our reconstruction algorithm is discussed by several numerical simulations. (C) 2014 Elsevier B.V. All rights reserved.

Accession Number: WOS:000338403800018

ISSN: 0925-2312

eISSN: 1872-8286

Record 43 of 244

Title: Enhanced near infrared luminescence efficiency of ligand-free LaF₃:Nd/LaF₃ core/shell nanocrystals in solvent dispersion

Author(s): Cui, XX (Cui, Xiaoxia); Guo, HT (Guo, Haitao); Hou, CQ (Hou, Chaoqi); Gao, F (Gao, Fei); Wei, W (Wei, Wei); Peng, B (Peng, Bo)

Source: JOURNAL OF LUMINESCENCE  Volume: 154  Pages: 155-159  DOI: 10.1016/j.jlumin.2014.04.019  Published: OCT 2014  

Abstract: A variety of ligand-free LaF3:Nd/LaF3 core/shell nanocrystals with high quantum efficiency, great dispersibility and low quench ratio was prepared by a simple solvothermal method. Their phase and morphologies were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The optical properties of the samples prepared under different times were investigated. The core/shell nanocrystals have great dispersibility concentration (312 mg/mL) in dimethyl sulfoxide (DMSO)/tetrabromoethane solvents. These transparent colloidal solution exhibits enhanced high quantum efficiency (61.2%) at 1057 um. Therefore, the LaF3:Nd/LaF3 core/shell nanocrystals with excellent near infrared to near infrared (NIR-to-NIR) fluorescence are a promising candidate for luminescence material in liquid media. (C) 2014 Elsevier B.V. All rights reserved.

Accession Number: WOS:000340687600026

ISSN: 0022-2313

eISSN: 1872-7883

Record 44 of 244

Title: Recombinant proteins expressed in lettuce

Author(s): Dong, H (Dong, Hao); Zhao, YJ (Zhao, Yijun); Wang, YL (Wang, Yingli); Li, HM (Li, Hongmin)

Source: INDIAN JOURNAL OF BIOTECHNOLOGY  Volume: 13  Issue: 4  Pages: 427-436  Published: OCT 2014  

Abstract: Plant expression system has been firmly attracting researcher's attention in the past two decades and many kinds of plants were employed to express various recombinant proteins. Among those plants, lettuce has been used as a promising expression host for heterologous recombinant proteins due to its advantage of oral delivery without heating process, besides other general superiorities of plant-based expression system. Many transgenic researches on lettuce have been reported and various products have been expressed successfully in lettuce, including vaccine antigens, antibodies, bioactive peptides, therapeutic proteins, industrial products and other interesting proteins. This paper reviews the current literatures on lettuce as expression platform for heterologous proteins, as well as underlying challenges in the future application.

Accession Number: WOS:000349813000001

Author Identifiers:

ISSN: 0972-5849

eISSN: 0975-0967

Record 45 of 244

Title: Broadband high birefringence and low dispersion terahertz photonic crystal fiber

Author(s): Li, SP (Li, Shaopeng); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Sun, QB (Sun, Qibing)

Source: JOURNAL OF OPTICS  Volume: 16  Issue: 10  Article Number: 105102  DOI: 10.1088/2040-8978/16/10/105102  Published: OCT 2014  

Abstract: We propose a novel type of triangular lattice terahertz photonic crystal fiber with high birefringence and low dispersion in a wide spectrum range. The proposed structures have circular and elliptical air holes in the cladding. Properties of birefringence, confinement loss, and group velocity dispersion have been studied by using full-vector finite-element methods. Through adjusting the structural parameters of the photonic crystal fiber, birefringence up to 10(-3) could be achieved in the frequency range of 0.1-5 THz. Moreover, group velocity dispersion curve in this frequency range is flat and the values are nearly zero. Therefore, it can be used to transmit broadband THz pulses with the polarization maintained.

Accession Number: WOS:000343665200019

Author Identifiers:

ISSN: 2040-8978

eISSN: 2040-8986

Record 46 of 244

Title: Topographic NMF for Data Representation

Author(s): Xiao, YH (Xiao, Yanhui); Zhu, ZF (Zhu, Zhenfeng); Zhao, Y (Zhao, Yao); Wei, YC (Wei, Yunchao); Wei, SK (Wei, Shikui); Li, XL (Li, Xuelong)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 44  Issue: 10  Pages: 1762-1771  DOI: 10.1109/TCYB.2013.2294215  Published: OCT 2014  

Abstract: Nonnegative matrix factorization (NMF) is a useful technique to explore a parts-based representation by decomposing the original data matrix into a few parts-based basis vectors and encodings with nonnegative constraints. It has been widely used in image processing and pattern recognition tasks due to its psychological and physiological interpretation of natural data whose representation may be parts-based in human brain. However, the nonnegative constraint for matrix factorization is generally not sufficient to produce representations that are robust to local transformations. To overcome this problem, in this paper, we proposed a topographic NMF (TNMF), which imposes a topographic constraint on the encoding factor as a regularizer during matrix factorization. In essence, the topographic constraint is a two-layered network, which contains the square nonlinearity in the first layer and the square-root nonlinearity in the second layer. By pooling together the structure-correlated features belonging to the same hidden topic, the TNMF will force the encodings to be organized in a topographical map. Thus, the feature invariance can be promoted. Some experiments carried out on three standard datasets validate the effectiveness of our method in comparison to the state-of-the-art approaches. Index Terms-Data clustering, dimension reduction,

Accession Number: WOS:000342228100005

PubMed ID: 25222720

Author Identifiers:

ISSN: 2168-2267

eISSN: 2168-2275

Record 47 of 244

Title: Integrating Conventional and Inverse Representation for Face Recognition

Author(s): Xu, Y (Xu, Yong); Li, XL (Li, Xuelong); Yang, J (Yang, Jian); Lai, ZH (Lai, Zhihui); Zhang, D (Zhang, David)

Source: IEEE TRANSACTIONS ON CYBERNETICS  Volume: 44  Issue: 10  Pages: 1738-1746  DOI: 10.1109/TCYB.2013.2293391  Published: OCT 2014