2011
2011
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Record 49 of
Title:Measurement research on electromagnetic pulse hazard for electroexplosive device based on optical-fiber fluorescence
Author(s):Liu, Lanshu(1,2); Du, Chong(3); Zhang, Wensong(1); He, Liangming(2,3)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 31 Issue: SUPPL.1 DOI: 10.3788/AOS201131.s100203 Published: June 2011Abstract:An optical-fiber fluorescence temperature detect system was proposed for hazard analysis and measurement of electromagnetic pulse of the electroexplosive devices(EED). The feasibility of the method was investigated in both theory and experiment. Different temperatures of EED can be obtained through different fluorescence lifetime, then the induced current is obtained, and finally the hazard of electromagnetic pulse of EED is measured. Experiment results show the system can analyze and measure the hazard of electromagnetic pulse of EED accurately and real-timely, so it is helpful to the research of security and reliability of EED.Accession Number: 20113114199074 -
Record 50 of
Title:Efficient HOG human detection
Author(s):Pang, Yanwei(1); Yuan, Yuan(2); Li, Xuelong(2); Pan, Jing(3)Source: Signal Processing Volume: 91 Issue: 4 DOI: 10.1016/j.sigpro.2010.08.010 Published: April 2011Abstract:While Histograms of Oriented Gradients (HOG) plus Support Vector Machine (SVM) (HOGSVM) is the most successful human detection algorithm, it is time-consuming. This paper proposes two ways to deal with this problem. One way is to reuse the features in blocks to construct the HOG features for intersecting detection windows. Another way is to utilize sub-cell based interpolation to efficiently compute the HOG features for each block. The combination of the two ways results in significant increase in detecting humansmore than five times better. To evaluate the proposed method, we have established a top-view human database. Experimental results on the top-view database and the well-known INRIA data set have demonstrated the effectiveness and efficiency of the proposed method. ? 2010 Elsevier B.V. All rights reserved.Accession Number: 20110213561002 -
Record 51 of
Title:Wideband slow light with ultralow dispersion in a W1 photonic crystal waveguide
Author(s):Liang, Jian(1,2); Ren, Li-Yong(1); Yun, Mao-Jin(2); Wang, Xing-Jun(3)Source: Applied Optics Volume: 50 Issue: 31 DOI: 10.1364/AO.50.000G98 Published: November 1, 2011Abstract:A dispersion tailoring scheme for obtaining slow light in a silicon-on-insulator W1-type photonic crystal waveguide, novel to our knowledge, is proposed in this paper. It is shown that, by simply shifting the first two rows of air holes adjacent to the waveguide to specific directions, slow light with large groupindex, wideband, and low group-velocity dispersion can be realized. Defining a criterion of restricting the group-index variation within a ±0.8% range as a flattened region, we obtain the ultraflat slow light with bandwidths over 5.0, 4.0, 2.5, and 1.0 nm when keeping the group index at 38.0, 48.8, 65.2, and 100.4, respectively. Numerical simulations are performed utilizing the three-dimensional (3D) plane-wave expansion method and the 3D finite-difference time-domain method. ? 2011 Optical Society of America.Accession Number: 20114514492374 -
Record 52 of
Title:Optical imaging based on compressive sensing
Author(s):Li, Shen(1); Ma, Cai-Wen(1); Xia, Ai-Li(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8194 Issue: DOI: 10.1117/12.900691 Published: 2011Abstract:Compressive Sensing (CS) is a new sampling framework that provides an alternative to the well-known Shannon sampling theory. The basic idea of CS theory is that a signal or image, unknown but supposed to be sparse or compressible in some basis, can be subjected to fewer measurements than the nominal number of pixels, and yet be accurately reconstructed. By designing optical sensors to measure inner products between the scene and a set of test functions according to CS theory, we can use sophisticated computational methods to infer critical scene structure and content for significantly economizing the resources in data acquisition store and transmit. In this paper, we investigate how CS can provide new insights into optical imaging including optical devices. We first give a brief overview of the CS theory and reviews associated fast numerical reconstruction algorithms. Next, this paper explores the potential of several different physically realizable optical systems based on CS principles. In the end, we briefly discuss possible implication in the areas of data compression and optical imaging. ? 2011 SPIE.Accession Number: 20113714325874 -
Record 53 of
Title:Holographic interfermetry based on fulgide film
Author(s):Ji, Ke(1); Menke, Neimule(1,2); Yao, Baoli(2); Wang, Yingli(2); Chen, Yi(3)Source: ICEOE 2011 - 2011 International Conference on Electronics and Optoelectronics, Proceedings Volume: 3 Issue: DOI: 10.1109/ICEOE.2011.6013358 Published: 2011Abstract:Holographic interfermetry was realized in a 3-indoly-benzylfulgimide/ PMMA film by using double exposure method and single exposure method for the first time. The structures of an optical wedge and an optical axicon, the rotation angle of the optical wedge and the movement distance of the optical axicon were successfully measured. It is proved that fulgide films can be used as recording medium in holographic interfermetry. As a recording medium in holographic interfermetry, the 3-indoly-benzylfulgimide/PMMA films have many advantages such as low cost, easy to use, rewritable, long life time, and higher signal to noise ratio (with small particles) and higher sensitivity etc. Then using the photoinduced anisotropy property of the 3-indoly-benzylfulgimide/PMMA film, the polarization multiplexing holographic interfermetry was realized, which can be used in particle field's dynamic measurement. This method is told for the first time, and it is proved that using this method, not only the size but also the directions of the objects' movement velocities can be got. ? 2011 IEEE.Accession Number: 20114014386473 -
Record 54 of
Title:Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics): Preface
Author(s):Suzuki, Kenji(1); Wang, Fei(2); Shen, Dinggang(3); Yan, Pingkun(4)Source: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) Volume: 7009 LNCS Issue: DOI: 10.1007/978-3-642-24319-6 Published: 2011Abstract:nullAccession Number: 20114214428935 -
Record 55 of
Title:3D adaptive spatio-temporal control of laser-induced refractive index changes in optical glasses
Author(s):Stoian, R.(1); Cheng, G.(2); Mauclair, C.(1); Mermillod-Blondin, A.(3); Mishchik, K.(1); Audouard, E.(1); Rosenfeld, A.(3); Hertel, I.V.(3)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 7921 Issue: DOI: 10.1117/12.873071 Published: 2011Abstract:The nonlinear absorption character determines a high potential of ultrafast laser pulses for 3D processing of transparent materials, particularly for optical functions. This is based on refractive index engineering involving thermo-mechanical, and structural rearrangements of the dielectric matrix. Challenges are related to the time-effectiveness of irradiation, correct beam delivery, and the influence of material properties on the exposure results. Particularly for light-guiding applications it is suitable to master positive refractive index changes in a time-efficient manner, considering that the result depends on the deposited energy and its relaxation paths. To address these challenges several irradiation concepts based on adaptive optics in spatial and temporal domains were developed. We review here some of the applications from various perspectives. A physical aspect is related to temporal pulse shaping and time-synchronized energy delivery tuned to material transient reactions, enabling thus a synergetic interaction between light and matter and, therefore, optimal results. Examples will be given concerning refractive index flip in thermally expansive glasses by thermo-mechanical regulation and energy confinement by nonlinear control. A second engineering aspect is related to processing efficiency. We give insights into beam-delivery corrections and 3D parallel complex photoinscription techniques utilizing dynamic wavefront engineering. Additionally, in energetic regimes, ultrafast laser radiation can generate an intriguing nanoscale spontaneous arrangement, leading to form birefringence and modulated index patterns. Using the birefringence properties and the deriving anisotropic optical character, polarization sensitive devices were designed and fabricated. The polarization sensitivity allows particular light propagation and confinement properties in 3D structures. ? 2011 SPIE.Accession Number: 20111313881014 -
Record 56 of
Title:Photoreaction constants of fulgide films at different wavelengths
Author(s):Du, Juan(1); Menke, Neimule(1,2); Yao, Baoli(2); Wang, Yingli(2); Chen, Yi(3)Source: 2011 International Conference on Remote Sensing, Environment and Transportation Engineering, RSETE 2011 - Proceedings Volume: Issue: DOI: 10.1109/RSETE.2011.5965760 Published: 2011Abstract:Two kinds of synthesized photochromic fulgide - pyrrylfulgide (F1) and 3-indoly-benzylfulgimide (F2) - are prepared as thin films doped in a polymethyl methacrylate (PMMA) matrix. Under irradiation by 405nm laser, the films convert from the colorless E-form (bleached state) into the C-form (colored state). When the C-forms are irradiated by 488nm, 514nm, 633nm or 650nm laser, the films returns to the E-forms. The photochromic kinetics of them under the irradiation of different wavelength lights (405nm, 488nm, 514nm, 633nm and 650nm) and the two-beam complementary suppression curve of F2 film under the irradiation of 633nm and 405nm lights are experimentally measured, which are simulated by using the first order kinetics and numerical calculation methods and the best simulating values of the photoreaction constants are obtained and compared. Under the irradiation of 633nm light, the photoreaction constants of the bleaching progress in F1 and F2 films (γC→E633nm) are 1.4×103 cm2/mJ and 2.89×103 cm2/mJ respectively. Under the irradiation of 488nm, 514nm and 650nm lights, the relative values of photoreaction constant γ c→/γC→E633nm are same with the theoretical values getting from the absorption spectra and γE→cF2,40fm =5.5×104cm 2/m. The two-beam complementary suppression curves proved that γ C →EF2,633 and γ E→cF2,405nm getting from the single beam irradiation curves are correct. And it is found that non-uniformity distribution of exciting light intensity has great affection to the deviation of the transmission curve from the first order dynamic curve. ? 2011 IEEE.Accession Number: 20113614293326 -
Record 57 of
Title:Luminescence properties of Nd3+-doped Y2O3 nanoparticles in organic media
Author(s):Cui, Xiaoxia(1,2); Lu, Jiabao(1); Gao, Chao(1); Hou, Chaoqi(1,2); Wei, Wei(1,3); Peng, Bo(1,3)Source: Applied Physics A: Materials Science and Processing Volume: 103 Issue: 1 DOI: 10.1007/s00339-010-6015-3 Published: April 2011Abstract:Nd3+-doped yttrium oxide nanoparticles (Y2O 3:Nd) with cubic phase were obtained successfully by a glycine-nitrate solution combustion method. The results of Fourier transform infrared spectra (FTIR) showed that the -OH groups residing on the nanoparticles surfaces were reduced effectively by modifying with capping agent. The modified Y2O3:Nd nanoparticles displayed good monodispersity and excellent luminescence in N,N-dimethylformamide (DMF) solvent. Some optical parameters were calculated by Judd-Ofelt analysis based on absorption and fluorescence spectra. A relative large stimulated emission cross section, 1.7×10-20 cm2, of the 4F 3/2→4I11/2 transition was calculated. Theses results show that the modified Y2O3:Nd nanoparticles display good luminescence behavior in organic media. ? 2010 Springer-Verlag.Accession Number: 20111313874260 -
Record 58 of
Title:Segmentation of retinal blood vessels using the radial projection and semi-supervised approach
Author(s):You, Xinge(1); Peng, Qinmu(1); Yuan, Yuan(2); Cheung, Yiu-Ming(3); Lei, Jiajia(1)Source: Pattern Recognition Volume: 44 Issue: 10-11 DOI: 10.1016/j.patcog.2011.01.007 Published: October-November 2011Abstract:Automatic segmentation of retinal blood vessels has become a necessary diagnostic procedure in ophthalmology. The blood vessels consist of two types of vessels, i.e., thin vessels and wide vessels. Therefore, a segmentation method may require two different processes to treat different vessels. However, traditional segmentation algorithms hardly draw a distinction between thin and wide vessels, but deal with them together. The major problems of these methods are as follows: (1) If more emphasis is placed on the extraction of thin vessels, the wide vessels tend to be over detected; and more artificial vessels are generated, too. (2) If more attention is paid on the wide vessels, the thin and low contrast vessels are likely to be missing. To overcome these problems, a novel scheme of extracting the retinal vessels based on the radial projection and semi-supervised method is presented in this paper. The radial projection method is used to locate the vessel centerlines which include the low-contrast and narrow vessels. Further, we modify the steerable complex wavelet to provide better capability of enhancing vessels under different scales, and construct the vector feature to represent the vessel pixel by line strength. Then, semi-supervised self-training is used for extraction of the major structures of vessels. The final segmentation is obtained by the union of the two types of vessels. Our approach is tested on two publicly available databases. Experiment results show that the method can achieve improved detection of thin vessels and decrease false detection of vessels in pathological regions compared to rival solutions. ? 2011 Published by Elsevier Ltd.Accession Number: 20112514071850 -
Record 59 of
Title:Induced current measurement in bridgewire EED through infrared optical fiber image bundle
Author(s):Hu, Ya-Nan(1,3); Wang, Tao(1); Yin, Fei(1); Yang, Jin(1,3); Wang, Jing-Wei(1); Zhang, Li-Chen(1,3); Yin, Jing-Zhi(2)Source: Guangdianzi Jiguang/Journal of Optoelectronics Laser Volume: 22 Issue: 5 DOI: Published: May 2011Abstract:While the bridgewire electroexplosive device (EED) works in electromagnetic environment, conventional methods can introduce electromagnetic interference. A new method of measuring the induced current in EED is proposed in this article. The infrared optical fiber image bundle coupled with infrared CCD detector was used to detect induced current from long distance and under non-contact. At first, the thermal field images were acquired by infrared CCD detector. Then the value of weak induced current of corresponding bridgewire was further determined according to the relations between gray scale values and temperature, temperature and current. The experimental results show that the bridgewire current is accurately measured by this method. This method offers a new way to evaluate the electromagnetic effect of EED.Accession Number: 20112714112244 -
Record 60 of
Title:Enhanced low-index field confinement by radially stratified micro optical fibers
Author(s):Zhang, Wenfu(1,2); Mu, Jian-Wei(3); Huang, Wei-Ping(3); Zhao, Wei(1)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: Published: 2011Abstract:The ring micro-fiber is studied. The calculating results show that light can be concentrated in nanometer-thin low-index ring regions with very high confinement efficiency. ? OSA/ANIC/IPR/Sensors/SL/SOF/SPPCom/2011.Accession Number: 20140817360214