2015
2015
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Record 301 of
Title:Polarization modulation of parallel circular polarization recorded grating in bacteriorhodopsin induced by polarized violet light
Author(s):Huang, Hai-Kun(1); Yang, Chen-Xiao(1); Li, Ruo-Ping(1); Huang, Ming-Ju(1); Yao, Bao-Li(2); Han, Jun-He(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 44 Issue: 8 DOI: 10.3788/gzxb20154408.0805002 Published: August 1, 2015Abstract:A theoretical model for calculating the diffraction efficiency kinetics of the grating recorded by two parallel circular polarized recording beams was proposed, based on Jones-matrix and photochromic two-state theory. The diffraction efficiency of bacteriorhodopsin grating was measured by system of four-wave coupled light path. The theoreical analysis and the experimental results show that, in the condition of adding linearly polarized auxiliary violet light, when linearly polarized reconstruction light parallel with linearly polarized auxiliary violet light, the diffraction efficiency of bacteriorhodopsin grating is maximum; when linearly polarized reconstruction light perpendicular to linearly polarized auxiliary violet light, the diffraction efficiency of bacteriorhodopsin grating is minimum. The angle between linearly polarized reconstruction light and linearly polarized auxiliary violet light produces a cosine modulation on the kinetics of the diffraction efficiency. It indicates that parallel circular polarization recorded grating in bacteriorhodopsin induced by polarized violet light became polarizing grating. ?, 2015, Chinese Optical Society. All right reserved.Accession Number: 20153901310774 -
Record 302 of
Title:Observation and interpretation of energy efficient, diffuse direct current glow discharge at atmospheric pressure
Author(s):Tang, Jie(1); Jiang, Weiman(1); Li, Jing(1,2); Wang, Yishan(1); Zhao, Wei(1); Duan, Yixiang(1,3)Source: Applied Physics Letters Volume: 107 Issue: 8 DOI: 10.1063/1.4929606 Published: August 24, 2015Abstract:A diffuse direct-current glow discharge was realized with low energy consumption and high energy utilization efficiency at atmospheric pressure. The formation of diffuse discharge was demonstrated by examining and comparing the electrical properties and optical emissions of plasmas. In combination with theoretical derivation and calculation, we draw guidelines that appearance of nitrogen ions at low electron density is crucial to enhance the ambipolar diffusion for the expansion of discharge channel and the increasing ambipolar diffusion near the cathode plays a key role in the onset of diffuse discharge. An individual-discharge-channel expansion model is proposed to explain the diffuse discharge formation. ? 2015 AIP Publishing LLC.Accession Number: 20153601232608 -
Record 303 of
Title:Adaptive road detection via context-aware label transfer
Author(s):Wang, Qi(1); Fang, Jianwu(2,3); Yuan, Yuan(2)Source: Neurocomputing Volume: 158 Issue: DOI: 10.1016/j.neucom.2015.01.054 Published: June 22, 2015Abstract:The vision ability is fundamentally important for a mobile robot. Many aspects have been investigated during the past few years, but there still remain questions to be answered. This work mainly focuses on the task of road detection, which is considered as the first step for a robot to become moveable. The proposed method combines the depth clue with traditional RGB information and is divided into three steps: depth recovery and superpixel generation, weakly supervised SVM classification and context-aware label transfer. The main contributions made in this paper are (1) Design a novel superpixel based context-aware descriptor by utilizing depth map. (2) Conduct label transfer in an efficient nearest neighbor search and a temporal MRF model. (3) Update the learned model adaptively with the changing scene. Experimental results on a publicly available dataset justify the effectiveness of the proposed method. ? 2015 Elsevier B.V.Accession Number: 20150900578238 -
Record 304 of
Title:Design and analysis of supporting structure between the primary mirror and the secondary mirror on a space telescope
Author(s):Wang, Chenjie(1); Chai, Wenyi(1); Feng, Liangjie(1); Yang, Wengang(1); Wang, Wei(1); Fan, Xuewu(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9678 Issue: DOI: 10.1117/12.2199672 Published: 2015Abstract:Mechanical stability is a significant segment for an on-axis space telescope to assure its assembly accuracy as well as the image quality in the rigorous space environment, supporting structure between the primary mirror and the secondary mirror as a main structure of the on-axis space telescope must be designed reasonably to meet the mission requirements of the space telescope. Meanwhile, in view of the limitation of the satellite launching cost, it is necessary to reduce the weight and power compensation during the supporting structure design based on the satisfaction of telescope performance. Two types of supporting structure for a space telescope are designed, one is three-tripod structure which has three tripods located on the optical bench to support the secondary mirror assemblies and keep the distance between the primary mirror and the secondary mirror, the other is barrel supporting structure which includes a tube and a secondary mirror support with four spider struts. To compare the mechanical performance and launching cost of the two kinds of supporting structure, both structural and thermal analysis model are established. The analysis results indicates that the three-tripod support is lighter, has better mechanical performance and needs less power compensation than the barrel support. ? 2015 SPIE.Accession Number: 20161602271458 -
Record 305 of
Title:Thermal design and Simulation of an attitude-varied Space Camera
Author(s):Wang, Chenjie(1); Yang, Wengang(1); Feng, Liangjie(1); Li, Xu Yang(1); Wang, Yinghao(1); Fan, Xuewu(1); Wen, Desheng(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9678 Issue: DOI: 10.1117/12.2199666 Published: 2015Abstract:An attitude-varied space camera changes attitude continually when it is working, its attitude changes with large angle in short time leads to the significant change of heat flux; Moreover, the complicated inner heat sources, other payloads and the satellite platform will also bring thermal coupling effects to the space camera. According to a space camera which is located on a two dimensional rotating platform, detailed thermal design is accomplished by means of thermal isolation, thermal transmission and temperature compensation, etc. Then the ultimate simulation cases of both high temperature and low temperature are chosen considering the obscuration of the satellite platform and other payloads, and also the heat flux analysis of light entrance and radiator surface of the camera. NEVEDA and SindaG are used to establish the simulation model of the camera and the analysis is carried out. The results indicate that, under both passive and active thermal control, the temperature of optical components is 20±1°C,both their radial and axial temperature gradient are less than 0.3°C, while the temperature of the main structural components is 20±2°C, and the temperature fluctuation of the focal plane assemblies is 3.0-9.5°C,. The simulation shows that the thermal control system can meet the need of the mission, and the thermal design is efficient and reasonable. ? 2015 SPIE.Accession Number: 20161602271456 -
Record 306 of
Title:Low Repetition Rate Subnanosecond Pulse Characteristics of Nd:Lu0.5Y0.5VO4/KTP Green Laser With EO and MWCNT
Author(s):Zhang, Haijuan(1); Zhao, Jia(1); Yang, Kejian(1); Zhao, Shengzhi(1); Li, Tao(1); Li, Guiqiu(1); Li, Dechun(1); Qiao, Wenchao(1); Wang, Yonggang(2); Zhao, Bin(3)Source: IEEE Journal of Selected Topics in Quantum Electronics Volume: 21 Issue: 1 DOI: 10.1109/JSTQE.2014.2345758 Published: January 1, 2015Abstract:By simultaneously employing electro-optic (EO) modulator and multiwalled carbon nanotube (MWCNT) in a doubly Q-switched mode-locked (QML) Nd:Lu0.5Y0.5VO4/KTP laser, a low repetition rate subnanosecond Nd:Lu0.5Y0.5VO4/KTP green laser with high peak power is presented. Since the repetition rate of this pulsed green laser is controlled by the EO modulator, highly stable laser pulses with low repetition rates of 1-5 kHz are obtained. As the pulse duration of this laser depends on the mode-locked pulse width underneath the Q-switched envelope, subnanosecond green laser pulses with high peak power can be generated. The average output powers, pulse widths as well as peak powers versus incident pump power under different repetition rates are measured. The shortest pulse duration of 415 ps and the highest pulse energy of 424 μJ are obtained at the repetition rate of 1 kHz, corresponding to a peak power of as high as 1022 kW. The experimental results show that the dual-loss modulation technology with EO and MWCNT in QML laser is an efficient method in generating low repetition rate subnanosecond pulse green laser. ? 1995-2012 IEEE.Accession Number: 20160701938434 -
Record 307 of
Title:Nonnegative multiresolution representation-based texture image classification
Author(s):Dong, Yongsheng(1,2); Tao, Dacheng(1); Li, Xuelong(1)Source: ACM Transactions on Intelligent Systems and Technology Volume: 7 Issue: 1 DOI: 10.1145/2738050 Published: September 1, 2015Abstract:Effective representation of image texture is important for an image-classification task. Statistical modelling in wavelet domains has been widely used to image texture representation. However, due to the intraclass complexity and interclass diversity of textures, it is hard to use a predefined probability distribution function to fit adaptively all wavelet subband coefficients of different textures. In this article, we propose a novel modelling approach, Heterogeneous and Incrementally Generated Histogram (HIGH), to indirectly model the wavelet coefficients by use of four local features in wavelet subbands. By concatenating all the HIGHs in allwavelet subbands of a texture, we can construct a nonnegative multiresolution vector (NMV) to represent a texture image. Considering the NMV's high dimensionality and nonnegativity, we further propose a Hessian regularized discriminative nonnegative matrix factorization to compute a low-dimensional basis of the linear subspace of NMVs. Finally, we present a texture classification approach by projecting NMVs on the lowdimensional basis. Experimental results show that our proposed texture classification method outperforms seven representative approaches. Copyright ? 2015 ACM.Accession Number: 20154501523497 -
Record 308 of
Title:A rotating-mirror scanning camera system for light-sheet microscopy
Author(s):Wu, Di(1); Zhou, Xing(1); Li, Runze(1); Yang, Yanlong(1); Yao, Baoli(1); Ye, Tong(2)Source: 2015 Opto-Electronics and Communications Conference, OECC 2015 Volume: Issue: DOI: 10.1109/OECC.2015.7340343 Published: November 30, 2015Abstract:We report a rotating-mirror scanning camera system based on a galvanometer and a CCD camera. This system improves the imaging speed by placing a series of paralleled images on the sensor of the camera so that multiple images are acquired during one single exposure; thus, the frame rate of the CCD camera does not limit the temporal resolution of recorded events. The camera is implemented on a custom designed light-sheet microscopy and aims to improve the imaging speed while the high spatial resolution is still retained on the light-sheet microscope. ? 2015 IEEE.Accession Number: 20161202125328 -
Record 309 of
Title:Optical system design of dual-spectrum autocollimator
Author(s):Wei, Yongjing(1,2); Wu, Yiming(1); Xiao, Maosen(1); Lu, Weiguo(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9676 Issue: DOI: 10.1117/12.2200976 Published: 2015Abstract:The optical system design of a new dual-spectrum autocollimator which can measure two different spatial azimuths simultaneously is proposed. According to the principle of dual-spectrum autocollimator, ZEMAX software is used to design and optimize the optical system. Since two light sources with different wavelength are used in the autocollimator, chromatic aberration is required to reduce off in the optical system design. The experimental results demonstrate that the measuring range of the dual-spectrum autocollimator is up to ±30', the deviation is less than 1a3, and the resolution can reach 0.1. The designed autocollimator can simultaneously measure two different azimuths fastly and accurately. ? 2015 SPIE.Accession Number: 20155201717483 -
Record 310 of
Title:Modified multispectral camera out-band response base on correlation spectrum
Author(s):Li, Xu-Yang(1); Yi, Hong-Wei(1); He, Tian-Bin(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 44 Issue: 9 DOI: 10.3788/gzxb20154409.0911002 Published: September 1, 2015Abstract:Multispectral remote sense camera can obtain geometic and spectral properties of the surface scenery, and will be wildly used in optical remote sense fields, but the blue spectrum of multispectral camera is more prone to out-band response. The paper established a mathematical model of multispectral remote sense camera's spectral response, analyzed the reason of the blue band out-band response, and proposed blue spectrum out-band response correction method according to each spectral response relationship of multispectral remote sense camera used Time-Dealy-Integration Charge-Coupled-Device. Through statistics of typical objects obtain the correction formula of correction blue spectrum out-band response, the corrected residuals can be smaller than 4%, can meet the application requirement of multispectral remote sense camera. The correction results show that the correction method based on each spectral response has better applicability in correcting the blue spectrum out-band response. ?, 2015, Chinese Optical Society. All right reserved.Accession Number: 20154601533888 -
Record 311 of
Title:The design of space optical communications terminal with high efficient
Author(s):Deng, Xiaoguo(1); Li, Gang(1); Jiang, Bo(1); Yang, Xiaoxu(1); Yan, Peipei(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9449 Issue: DOI: 10.1117/12.2083003 Published: 2015Abstract:In order to improve high-speed laser space optical communications terminal receive energy and emission energy, meet the demand of mini-type and light-type for space-based bear platform, based on multiple-reflect coaxial optical receiving antenna structure, while considering the installation difficulty, a high-efficient optical system had been designed, which aperture is off-axial, both signal-receiving sub-optical system and emission sub-optical system share a same primary optical path. By the separating light lens behind the primary optical path, the received light with little energy will be filtered and shaped and then transmitted to each detector, at the same time, by the coupling element, the high-power laser will be coupling into optical antenna, and then emitted to outside. Applied the power-detected optical system evaluate principle, the optimized off-axial optical system's efficiency had been compared with the coaxial optical system. While, analyzed the Gauss beam energy distribution by numerical theory, discussed that whether off-axis optical system can be an emission terminal, verify the feasibility of the theory of the design of the system. ? 2015 SPIE.Accession Number: 20151100635532 -
Record 312 of
Title:Video-based road detection via online structural learning
Author(s):Yuan, Yuan(1); Jiang, Zhiyu(1,2); Wang, Qi(3)Source: Neurocomputing Volume: 168 Issue: DOI: 10.1016/j.neucom.2015.05.092 Published: November 30, 2015Abstract:Video-based road detection is a crucial enabler for the successful development of driver assistant and robot navigation systems. But reliable detection is still on its infancy and deserves further research. In order to adapt to the situation consisting of environmental varieties, an online framework is proposed focusing on exploring the structure cue of the feature vectors. Through the structural support vector machine, the road boundary and non-boundary instances are firstly discriminated. Then they are utilized to fit a complete road boundary. After that, the road region is accordingly inferred and the obtained results are treated as ground truth to update the learned model. Three contributions are claimed in this work: online-learning updating, structural information consideration, and targeted sampling selection. The proposed method is finally evaluated on several challenging videos captured by ourselves. Qualitative and quantitative results show that it outperforms the other competitors. ? 2015 Elsevier B.V.Accession Number: 20152400937357