2017
2017
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Record 505 of
Title:Collective Representation for Abnormal Event Detection
Author(s):Ye, Renzhen(1,2); Li, Xuelong(1)Source: Journal of Computer Science and Technology Volume: 32 Issue: 3 DOI: 10.1007/s11390-017-1737-8 Published: May 1, 2017Abstract:Abnormal event detection in crowded scenes is a hot topic in computer vision and information retrieval community. In this paper, we study the problems of detecting anomalous behaviors within the video, and propose a robust collective representation with multi-feature descriptors for abnormal event detection. The proposed method represents different features in an identical representation, in which different features of the same topic will show more common properties. Then, we build the intrinsic relation between different feature descriptors and capture concept drift in the video sequence, which can robustly discriminate between abnormal events and normal events. Experimental results on two benchmark datasets and the comparison with the state-of-the-art methods validate the effectiveness of our method. ? 2017, Springer Science+Business Media New York.Accession Number: 20172003667282 -
Record 506 of
Title:Proton-implanted optical waveguides fabricated in Er3+-doped phosphate glasses
Author(s):Liu, Chun-Xiao(1); Shen, Xiao-Liang(1); Guo, Hai-Tao(2); Li, Wei-Nan(2); Wei, Wei(1)Source: Optik Volume: 131 Issue: DOI: 10.1016/j.ijleo.2016.11.080 Published: February 1, 2017Abstract:Er3+-doped phosphate glass is suitable to design and develop integrated photonic structures. Ion implantation is one of the most promising fabrication techniques for producing optical waveguides. In this work, we have combined Er3+-doped phosphate glass and ion implantation in order to improve the performances of waveguides. The proton-implanted Er3+-doped phosphate glass waveguides have been fabricated under implantation parameters with energies of (500 +550) keV and fluences of (1.0 + 2.0) × 1016 ions/cm2. The guiding properties of the planar waveguide have been investigated at the wavelength of 632.8 nm through the prism-coupling system and the end-face coupling arrangement. Irradiation-induced damage and refractive index modulation have been simulated by the stopping and range of ions in matter 2010 and the intensity calculation method, respectively. It is an important step to the fabrication of rare-earth-doped optical integrated devices. ? 2016 Elsevier GmbHAccession Number: 20164803052067 -
Record 507 of
Title:Visible and near-infrared waveguides formed by double-energy proton implantation in magneto-optical glasses
Author(s):Liu, Chun-Xiao(1); Shen, Xiao-Liang(1); Zheng, Rui-Lin(1); Guo, Hai-Tao(2); Li, Wei-Nan(2); Wei, Wei(1)Source: Applied Physics B: Lasers and Optics Volume: 123 Issue: 2 DOI: 10.1007/s00340-017-6644-8 Published: February 1, 2017Abstract:Ion implantation is one of the most competitive methods for the fabrication of optical waveguide structures in optoelectronic materials. Tb3+-doped aluminum borosilicate glass has been demonstrated to be a type of magneto-optical glass with high Verdet constant. In this work, the proton implantation technique with energies of (500 + 550) keV and fluences of (1.0 + 2.0) × 1016 ions/cm2 is performed to form planar waveguides in the Tb3+-doped aluminum borosilicate glass. The guiding modes of the fabricated waveguide were measured by the prism-coupling method at wavelengths of 632.8 and 1539?nm. The near-field light intensity distribution was measured by the end-face coupling method at the wavelength of 632.8?nm and calculated by the finite-difference beam propagation method at both 632.8 and 1539?nm. The optical properties of the double-energy proton-implanted magneto-optical glass waveguides show promise for use as multi-functional integrated optical devices in the visible and near-infrared bands. ? 2017, Springer-Verlag Berlin Heidelberg.Accession Number: 20170603337865 -
Record 508 of
Title:Effect of substrate temperature and sputtering pressure on the microstructure and photoluminescence performance of ZnO films by magnetron sputtering
Author(s):Zhu, Guanfang(1,3); Gao, Pengpeng(2); Kang, Yifan(1); Jing, Liu(1); Yao, Hebao(3); Wang, Chao(4)Source: Optoelectronics and Advanced Materials, Rapid Communications Volume: 11 Issue: 11-12 DOI: Published: November-December 2017Abstract:The strong ultraviolet stimulated emission and the weak deep energy level emission was obtained at room temperature. The mechanisms of sputtering pressure impact on growth of ZnO films was also discussed. The low energy tail emissi on of ultraviolet photoluminescence was caused by the emission of bound exciton. The effect of sputtering pressure on the growth of films were observed. The structural property and photoluminescence performance were studied at different pressures. ZnO films by magnetron sputtering on glass substrates were fabricated with XRD FWHM of only 0.12° exhibiting preferred orientation along c-axis growth at the proper substrate temperature and sputtering pressure. ? 2017, National Institute of Optoelectronics. All rights reserved.Accession Number: 20203409077481 -
Record 509 of
Title:SiC power MOSFET with monolithically integrated Schottky barrier diode for improved switching performances
Author(s):Dai, Xiaoping(1); Jiang, Huaping(2); Zheng, Changwei(2); Ke, Maolong(3)Source: PCIM Europe 2017 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management Volume: Issue: DOI: 10.1109/SBMicro.2017.7990787 Published: 2017Abstract:A power Silicon Carbide (SiC) Metal Oxide Semiconductor Field Effect Transistor (MOSFET) featuring a monolithically integrated Schottky Barrier Diode (SBD) is proposed in this paper. The proposed structure is optimized to suppress the electric field in the gate oxide under reverse blocking state, which is beneficial to enhancing the gate oxide long term reliability. Both the static and switching characteristics are studied by TCAD simulation using Sentaurus. Compared to the conventional MOSFET-SBD pair, the proposed device shows not only lower switching loss but also smaller current overshoot during the turn on process. ? VDE VERLAG GMBH · Berlin · Offenbach.Accession Number: 20180304660949 -
Record 510 of
Title:Learning Tone Mapping Function for Dehazing
Author(s):Lian, Xuhang(1); Pang, Yanwei(1); He, Yuqing(1); Li, Xuelong(2); Yang, Aiping(1)Source: Cognitive Computation Volume: 9 Issue: 1 DOI: 10.1007/s12559-016-9437-1 Published: February 1, 2017Abstract:nullAccession Number: 20164803060232 -
Record 511 of
Title:Deep temporal architecture for audiovisual speech recognition
Author(s):Tian, Chunlin(1,2); Yuan, Yuan(1); Lu, Xiaoqiang(1)Source: Communications in Computer and Information Science Volume: 771 Issue: DOI: 10.1007/978-981-10-7299-4_54 Published: 2017Abstract:The Audiovisual Speech Recognition (AVSR) is one of the applications of multimodal machine learning related to speech recognition, lipreading systems and video classification. In recent and related work, increasing efforts are made in Deep Neural Network (DNN) for AVSR, moreover some DNN models including Multimodal Deep Autoencoder, Multimodal Deep Belief Network and Multimodal Deep Boltzmann Machine perform well in experiments owing to the better generalization and nonlinear transformation. However, these DNN models have several disadvantages: (1) They mainly deal with modal fusion while ignoring temporal fusion. (2) Traditional methods fail to consider the connection among frames in the modal fusion. (3) These models aren’t end-to-end structure. We propose a deep temporal architecture, which has not only classical modal fusion, but temporal modal fusion and temporal fusion. Furthermore, the overfitting and learning with small size samples in the AVSR are also studied, so that we propose a set of useful training strategies. The experiments show the superiority of our model and necessity of the training strategies in three datasets: AVLetters, AVLetters2, AVDigits. In the end, we conclude the work. ? Springer Nature Singapore Pte Ltd. 2017.Accession Number: 20175104549161 -
Record 512 of
Title:Bidirectional adaptive feature fusion for remote sensing scene classification
Author(s):Ji, Weijun(1,2); Li, Xuelong(1); Lu, Xiaoqiang(1)Source: Communications in Computer and Information Science Volume: 772 Issue: DOI: 10.1007/978-981-10-7302-1_40 Published: 2017Abstract:Convolutional neural networks (CNN) have been excellent for scene classification in nature scene. However, directly using the pre-trained deep models on the aerial image is not proper, because of the spatial scale variability and rotation variability of the HSR remote sensing images. In this paper, a bidirectional adaptive feature fusion strategy is investigated to deal with the remote sensing scene classification. The deep learning feature and the SIFT feature are fused together to get a discriminative image presentation. The fused feature can not only describe the scenes effectively by employing deep learning feature but also overcome the scale and rotation variability with the usage of the SIFT feature. By fusing both SIFT feature and global CNN feature, our method achieves state-of-the-art scene classification performance on the UCM and the AID datasets. ? Springer Nature Singapore Pte Ltd. 2017.Accession Number: 20175104550041 -
Record 513 of
Title:Field-induced lifetime enhancement of photorefractive gratings in a Mn:Fe:KTN crystal
Author(s):Lu, Qieni(1,2); Li, Bihua(1,2); Li, Zhen(3); Ge, Baozhen(1,2)Source: Optics Letters Volume: 42 Issue: 13 DOI: 10.1364/OL.42.002407 Published: July 1, 2017Abstract:We report the lifetime enhancement of light-induced refractive index grating by applying a bias field during writing. In comparison with the lifetime of about 10 hours of the photorefractive grating prepared without a bias field, the lifetime of the grating with a 4 kV∕cm bias field can be prolonged to 7.5 years, which is obtained from the dynamic behavior of grating visualized and monitored with digital holographic microscopy. The higher the bias field is applied, the longer the dark decay time of grating can be achieved. The enhanced lifetime of phase grating is attributed to polar nanoregions oriented by external field. This effect is of great significance for electro-holographic device applications. ? 2017 Optical Society of America.Accession Number: 20172703898659 -
Record 514 of
Title:Patch-based topic model for group detection
Author(s):Chen, Mulin(1); Wang, Qi(1,2); Li, Xuelong(3)Source: Science China Information Sciences Volume: 60 Issue: 11 DOI: 10.1007/s11432-017-9237-1 Published: November 1, 2017Abstract:Pedestrians in crowd scenes tend to connect with each other and form coherent groups. In order to investigate the collective behaviors in crowds, plenty of studies have been conducted on group detection. However, most of the existing methods are limited to discover the underlying semantic priors of individuals. By segmenting the crowd image into patches, this paper proposes the Patch-based Topic Model (PTM) for group detection. The main contributions of this study are threefold: (1) the crowd dynamics are represented by patchlevel descriptor, which provides a macroscopic-level representation; (2) the semantic topic label of each patch are inferred by integrating the Latent Dirichlet Allocation (LDA) model and the Markov Random Fields (MRF); (3) the optimal group number is determined automatically with an intro-class distance evaluation criterion. Experimental results on real-world crowd videos demonstrate the superior performance of the proposed method over the state-of-the-arts. ? 2017, Science China Press and Springer-Verlag GmbH Germany.Accession Number: 20174204284203 -
Record 515 of
Title:Optical intensity square root differentiator based on an integrated Kerr frequency comb source
Author(s):Xu, Xingyuan(1); Wu, Jiayang(1); Shoeiby, Mehrdad(2); Nguyen, Thach G.(2); Chu, Sai T.(3); Little, Brent E.(4); Morandotti, Roberto(5,6,7); Mitchell, Arnan(2); Moss, David J.(1)Source: Optics InfoBase Conference Papers Volume: Part F52-IPRSN 2017 Issue: DOI: 10.1364/IPRSN.2017.IW1A.3 Published: 2017Abstract:We propose and experimentally demonstrate an optical intensity square root differentiator based on an integrated comb source. The proposed differentiator features full reconfigurablity and compact structure. Transmission responses and temporal characterization are also experimentally demonstrated. ? OSA 2017.Accession Number: 20173504083067 -
Record 516 of
Title:Integrated Kerr comb-based reconfigurable transversal differentiator for microwave photonic signal processing
Author(s):Xu, Xingyuan(1); Wu, Jiayang(1); Shoeiby, Mehrdad(2); Nguyen, Thach G.(2); Chu, Sai T.(3); Little, Brent E.(4); Morandotti, Roberto(5,6,7); Mitchell, Arnan(2); Moss, David J.(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10456 Issue: DOI: 10.1117/12.2282642 Published: 2017Abstract:An arbitrary-order intensity differentiator for high-order microwave signal differentiation is proposed and experimentally demonstrated on a versatile transversal microwave photonic signal processing platform based on integrated Kerr combs. With a CMOS-compatible nonlinear micro-ring resonator, high quality Kerr combs with broad bandwidth and large frequency spacings are generated, enabling a larger number of taps and an increased Nyquist zone. By programming and shaping individual comb lines' power, calculated tap weights are realized, thus achieving a versatile microwave photonic signal processing platform. Arbitrary-order intensity differentiation is demonstrated on the platform. The RF responses are experimentally characterized, and systems demonstrations for Gaussian input signals are also performed. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20180404671592