2012
2012
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Record 145 of
Title:Particle filter with fine resampling for Bearings-Only Tracking
Author(s):Cao, Bei(1,2); Ma, Caiwen(1); Liu, Zhentao(3)Source: Procedia Engineering Volume: 29 Issue: DOI: 10.1016/j.proeng.2012.01.553 Published: 2012Abstract:To solve the nonlinear filtering problem in the Bearings-Only Tracking (BOT), an improved particle filter with fine resampling is proposed, called as PF-FR (Particle Filter with Fine Resampling). By introducing distance-comparing process and generating new particle based on optimized combination scheme, PF-FR filter performs better than generic PF-SIR filter both in terms of effectiveness and diversity of the particle system, hence, evidently enhancing tracking accuracy in bearings-only tracking problem. Simulations indicate that the proposed PF-FR algorithm is effective. ? 2011 Published by Elsevier Ltd.Accession Number: 20121214883199 -
Record 146 of
Title:Design of optical system in solar blind ultraviolet and study on the detection distance
Author(s):Jiang, Bo(1,2); Zhou, Sizhong(1); Jiang, Kai(1,2); Duan, Jing(1); Deng, Xiaoguo(1); Guo, Zhili(1)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 32 Issue: SUPPL.1 DOI: 10.3788/AOS201232.s122003 Published: December 2012Abstract:Ultraviolet (UV) detection principle and configuration of UV detection system are introduced. The experimental system is designed and established. The system wording at 240~280 nm achieves the focal length of 200 mm and F number of 6. The UV image is converted to visible image at the CCD through the relay system. The estimation method and model are proposed according to the formula of image plane irradiance and imaging, which are based on the UV radiation performance of typical targets and atmospheric transmission performance of UV radiation, combined with the performance parameters of UV warning system. The detection distance of UV warning system for a typical target at different angles is computed and validated. The analysis and conclusion show that the detection distance of UV warning system can increase by changing the performance parameters of detector, such as CCD minimum illuminance, image intensifier's gain, optical system's transmittance and relative aperture.Accession Number: 20131016087853 -
Record 147 of
Title:Similarity learning for object recognition based on derived kernel
Author(s):Li, Hong(1); Wei, Yantao(2); Li, Luoqing(3); Yuan, Yuan(4)Source: Neurocomputing Volume: 83 Issue: DOI: 10.1016/j.neucom.2011.12.005 Published: April 15, 2012Abstract:Recently, derived kernel method which is a hierarchical learning method and leads to an effective similarity measure has been proposed by Smale. It can be used in a variety of application domains such as object recognition, text categorization and classification of genomic data. The templates involved in the construction of the derived kernel play an important role. To learn more effective similarity measure, a new template selection method is proposed in this paper. In this method, the redundancy is reduced and the label information of the training images is used. In this way, the proposed method can obtain compact template sets with better discrimination ability. Experiments on four standard databases show that the derived kernel based on the proposed method achieves high accuracy with low computational complexity. ? 2012 Elsevier B.V.Accession Number: 20120614753604 -
Record 148 of
Title:Observation of linewidth narrowing due to a spontaneously generated coherence effect
Author(s):Tian, Si-Cong(1,2); Wang, Chun-Liang(3); Kang, Zhi-Hui(1,2); Yang, Xiu-Bin(5); Wan, Ren-Gang(4); Zhang, Xiao-Jun(1,2); Zhang, Hang(3); Jiang, Yun(1,2); Cui, Hai-Ning(1,2); Gao, Jin-Yue(1,2)Source: Chinese Physics B Volume: 21 Issue: 6 DOI: 10.1088/1674-1056/21/6/064206 Published: June 2012Abstract:We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields. We show that such a system emulates to a large degree a V-type atom with parallel dipole moments-the latter being a system that exhibits spontaneously generated coherence and can display ultrasharp spectral lines. We find a suitable energy scheme in a 85Rb atom and experimentally observe the narrowing of the central peak in a rubidium atomic beam. The corresponding spectrum can convincingly demonstrate the existence of spontaneously generated coherence. ? 2012 Chinese Physical Society and IOP Publishing Ltd.Accession Number: 20122615155147 -
Record 149 of
Title:Unsteady heat transfer process analysis of thermoelectric cooling system on CCD sensor
Author(s):Pan, Haijun(1,2); Ruan, Ping(1); Li, Fu(1); Bu, Fan(1,2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 41 Issue: 11 DOI: Published: November 2012Abstract:Driven by shrinking feature size and increasing functionality, thermoelectric refrigeration is widely used to precision temperature control of important components as an effective active cooling technology. In order to achieve the best refrigeration effect, a numerical analysis model was derived to identify the unsteady heat transfer process of thermoelectric cooling system on CCD sensor under the condition of constrained heat dissipation. The numerical results demonstrate that the heat transfer process in low convection coefficient of the thermoelectric cooling system is unsteady for a long time because of the limitation of heat dispersing. Increasing cooling current under the Imax can improve the refrigeration effect, but the phenomenon of temperature rise will be happened by big current. Although improving hot-side heat dissipation capability can obtain better refrigeration effect, an extreme value exists relating the figure of merit on thermoelectric cooler (TEC). Under the condition of load change, increasing refrigeration current and hot-side heat dissipation capability in reasonable range can improve the temperature stability of system. As a matter of fact, refrigeration current has a greater impact than hot-side heat dissipation capability on the temperature stability of system.Accession Number: 20130415940877 -
Record 150 of
Title:Optical aligning and measuring methods for large aperture optical system
Author(s):Zhang, Xue-Min(1,2); Wei, Ru-Yi(1,2); Duan, Jia-You(1); Yang, Jian-Feng(1); Li, Hua(1); Hou, Xiaohua(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8416 Issue: DOI: 10.1117/12.978167 Published: 2012Abstract:How to implement high accuracy measurement of large-aperture coaxial optical system is crucial to the optical alignment and optical property evaluation. The methods of image quality measurement including interferometer-collimating testing, wave front testing by using Hartmann, image processing and analysis of out-of-focus image were introduced. Both the advantages and disadvantages of the three methods were compared, which showed that the alignment method based on interferometer-collimating testing is the one with the highest accuracy. The method of computer-aided alignment (CAA) based on interferometer-collimating was discussed in detail. By using a ZYGO interferometer, interferograms with different field of views and a series of Zernike coefficients were obtained to express the disalignment of the system, and then these incorrect parameters were calculated by CAA algorithms. An alignment experiment of coaxial three-mirror system with 4m focal length and 500mm aperture was carried out. The RMS value of the system is lower than 0.07λ after iterations, which is close to the optical diffraction limit, proving the effectiveness of CAA method in alignment guidance. ? 2012 SPIE.Accession Number: 20131416168544 -
Record 151 of
Title:Study on a multi-spectral-band infrared sea surface temperature radiometer system
Author(s):Zhang, Jian(1); Qu, Enshi(1); Cao, Jianzhong(1); Fan, Zheyuan(1); Jiao, Guohua(1)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 32 Issue: 4 DOI: 10.3788/AOS201232.0401003 Published: April 2012Abstract:A multi-spectral infrared radiometer system is designed that can be used to measure sea surface temperature automatically, whose resolution ratio and accuracy are better than 0.1°C and ±0.5°C, respectively. The system adopts four spectral bands, i. e., 3.5-4.0 μm, 8-13 μm, 10.3-11.3 μm, and 11.5-12.3 μm. Its inner optical system carries out real time calibration by two blackbody reference cavities with different temperatures, which promises that the high accuracy of an infrared radiometer is maintained even when optical components are moderately contaminated by salt deposition. Moreover, a protection shutter which could be automatically triggered by a sensitive rain gauge is designed to resist against foul weather. Finally, the accuracy and stability of the system are tested by laboratory calibration and shoreside experiment.Accession Number: 20122415111271 -
Record 152 of
Title:Multifocus image fusion algorithm based on the contourlet transform
Author(s):Yang, Lei(1,2); Cao, Jianzhong(2); Wang, Hao(2); Tang, Yao(2); Wang, Hua(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8420 Issue: DOI: 10.1117/12.968604 Published: 2012Abstract:Adopting the advantages of contourlet such as multiscale, localization, directionality and anisotropy, a multifocus image fusion algorithm based on contourlet transform is developed [1]. Source images are firstly decomposed to domain of the contourlet transform. The image fusion is then implemented in subbands with different scale and direction combining. The fusion rule with maximum absolute value coefficient is used to fuse the high frequency subbands, while the rule dependent on the image's spatial frequencies and contrast are applied to the low frequency subbands. Finally the fused image is obtained through inverse transform. Experimental results show that the fused image using this algorithm has better subjective visual effect, and is better than the one using traditional Laplacian pyramid algorithm and wavelet based algorithm. ? 2012 SPIE.Accession Number: 20131416168617 -
Record 153 of
Title:Design of the autocollimator tracking system based on TMS320DM642 and TMS320F2812
Author(s):Guo, Hongxiang(1); Hu, Xiaodong(1)Source: 2012 IEEE 5th International Conference on Advanced Computational Intelligence, ICACI 2012 Volume: Issue: DOI: 10.1109/ICACI.2012.6463339 Published: 2012Abstract:This paper introduces the composition of the autocollimator tracking system, and analyses in detail the image processing part and servo tracking part of the system. The image processing part uses TMS320DM642 DSP to complete the image acquisition and image display. Using RS232 serial ports to transmit each frame offset of target to the servo tracking part. According to the offset information, the servo tracking part makes use of TMS320F2812 DSP to complete real-time tracking. Autocollimator tracking system uses two rhombic prisms to ensure real-time transmission of optical path. Experiments show that the autocollimator tracking system can achieve 1HZ real-time tracking and fully meets the project needs. ? 2012 IEEE.Accession Number: 20131116105456 -
Record 154 of
Title:Multi-channel biosensor based on photonic crystal waveguide and microcavities
Author(s):Yun, Maojin(1); Wan, Yong(1); Liang, Jian(1); Xia, Feng(1); Liu, Meiling(1); Ren, Liyong(2)Source: Optik Volume: 123 Issue: 21 DOI: 10.1016/j.ijleo.2011.09.024 Published: November 2012Abstract:An ultrasensitive two-dimensional photonic crystal biosensor is theoretically demonstrated in this paper. Such device consists of a waveguide and high Q-value microcavities which are realized by introducing line and point defects into the photonic crystal respectively. The band structures and the transmission spectra are obtained from the Finite-Difference -Time-Domain (FDTD) method. The simulation results showed that such device is strongly sensitive to the refractive index of the analyte injected into the point defect. The designed device can be applied for measurements of the refractive index and detection of protein-concentrations. ? 2011 Elsevier GmbH.Accession Number: 20123915462260 -
Record 155 of
Title:Design of fore objective for wide spectrum imaging spectrometer
Author(s):Lu, Xuefeng(1,2); Bai, Qinglan(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 41 Issue: 11 DOI: Published: November 2012Abstract:An achromatic and telecentric fore objective design for a hyperspectral imaging spectrometer in the VIS-SWIR spectral range was presented in this paper. The design scheme was discussed based on the system specifications of 0.5-2.5 μm wavelength range, 750 mm focal length, F/number of 5 and ±0.8° field of view. A Ritchey-Chrétien system with a refractive corrector was designed to meet the design requirements. The properties of materials used in the visible and shortwave infrared bands were analyzed in the design of the refractive corrector. Then the F_Silica was chosen as the refractive corrector's material. The final design system has a simple structure. Chromatic aberration is well corrected as well as other aberrations. At the same time, the system is also a telecentric one. The design result meets the imaging spectrometer system requirements and the imaging quality approaches the diffraction limit within the full field of view in the specific wavebands.Accession Number: 20130415940872 -
Record 156 of
Title:Multi-atlas based image selection with label image constraint
Author(s):Cao, Yihui(1); Li, Xuelong(1); Yan, Pingkun(1)Source: Proceedings - 2012 11th International Conference on Machine Learning and Applications, ICMLA 2012 Volume: 1 Issue: DOI: 10.1109/ICMLA.2012.232 Published: 2012Abstract:Atlas selection plays an important role in multiatlas based image segmentation. In atlas selection methods, manifold learning based techniques have recently emerged as very promisingly. However, due to the complexity of anatomical structures in raw images, it is difficult to get accurate atlas selection results by measuring only the distance between raw images on the manifolds. In this paper, we tackle this problem by proposing a label image constrained atlas selection (LICAS) method to exploit the shape and size information of the regions to be segmented from the label images. Constrained by the label images, a new manifold projection method is developed to help uncover the intrinsic similarity between the regions of interest across images. Compared with other existing methods, the experimental results of segmentation on 60 Magnetic Resonance (MR) images showed that the selected atlases are closer to the target structure and more accurate segmentation can be obtained by using the proposed method. ? 2012 IEEE.Accession Number: 20130716027557