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Record 277 of
Title:Research on Applications of FastICA Algorithm in the Detection of Dangerous Liquids
Author(s):Zhou, Dongmei(1); Qiu, Shi(2); Tan, Jiahai(2); Li, Xiaofeng(1); Chen, Chen(1)
Source: International Journal of Pattern Recognition and Artificial Intelligence Volume: 33 Issue: 2 DOI: 10.1142/S0218001419580035 Published: February 1, 2019
Abstract:In the actual environment of security detection, many kinds of liquids often exist in the same detection background, and their dangerous levels are difficult to identify. Therefore, it is very important to research on identifying the dangerous levels of various liquids. The paper establishes the S-parameter database of tested samples under specific detection environment with free space method. In the actual detection, ultra-wide-band (UWB) centimeter wave is used to measure the S-parameters of several detected liquids first. Then the fast independent component analysis (FastICA) algorithm is used for unmixing the mixed signal by Newton's iteration method and the negative entropy maximization search principle. The unmixed signal matches with the sample database adaptively, so the dangerous levels of the detected liquids are identified. Multiple experiments show that FastICA algorithm can reach a matching rate of 95% between water and 90# gasoline or alcohol and 90# gasoline, it also can reach a matching rate of around 73% between water and alcohol. This algorithm has a quick response and high reliability for identification of dangerous liquids. FastICA algorithm in this paper is applied for detecting the dangerous liquids for the first time, and it has high application value. ? 2019 World Scientific Publishing Company.
Accession Number: 20183705797727
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Record 278 of
Title:Optimum design of electron bombarded active pixel sensor for low-level light single photon imaging
Author(s):Bai, Jinzhou(1,2); Wang, Bo(1); Bai, Yonglin(1); Cao, Weiwei(1); Yang, Yang(1); Lei, Fanpu(1); Su, Dan(2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10843 Issue: DOI: 10.1117/12.2506350 Published: 2019
Abstract:Low-Level Light Imaging(LLLI) devices are now been widely used in military, astronomy, scientific, and even in surveillance for our daily uses. The traditional devices like ICCD, EBCCD, EMCCD, which either complicated in structure or require extra cooling system. However, a novel device called Electron Bombarded Active Pixel Sensor(EBAPS) has been developed, it is a proximity focused device which lead photoelectrons produced by photocathode hitting directly towards back illuminated CMOS and cause the semiconductor bombard phenomenon to amplification and then being readout. EBAPS is relatively small in size, less weight, with high sensitivity, and can be used to detect single photon event, etc. Although it has been proven to have excellent sensitivity in the field of LLLI, the performance today is still considered far from its maximum potential. Here, we modeled the structure of EBAPS and studied the factors influencing the performance of the device. By selecting proper parameters like proximity distance, acceleration voltage, photocathode quantum efficiency, etc., we achieved the single photon image mode with a satisfactory sensitivity. Besides, we simulated the electron scattering trajectories among the semiconducting multiplication area by using Monte Carlo method, we compared the simulation results in different conditions and successfully in finding the optimum parameter, which achieved a relatively high sensitivity. The simulation results in this paper could have a profound theoretical foundation in developing higher gain EBAPS. ? 2019 SPIE ·
Accession Number: 20191006603239
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Record 279 of
Title:Space debris positioning technology based on observation by multiple optical platforms
Author(s):Liu, Meiying(1,2); Wang, Hu(1); Yang, Shaodong(1); Du, Yun(1); Wen, Desheng(1); Xue, Yaoke(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11341 Issue: DOI: 10.1117/12.2547411 Published: 2019
Abstract:In this paper, a multi-optical platform target recognition theory based on geocentric observation is proposed by studying the space debris observation model based on multiple optical platforms, and the recognition rate is over 85%. The Gaussian minimum mean square error differential correction algorithm is used to realize the target location by multiple optical observations, and the positioning accuracy reaches 14m, and the positioning accuracy tends to the accuracy of the satellite itself. It can get rid of the disadvantage that the space debris cannot be located by single optical platform, and retain its important advantages such as high accuracy and low power consumption. which lays a solid foundation for the later debris orbit determination. ? 2019 SPIE.
Accession Number: 20200408062639
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Record 280 of
Title:Extended kalman predictive filter and its application in theodolite system
Author(s):Changming, Lu(1,3); Xin, Gao(1); Zhiguo, Li(2); Meilin, Xie(2,3); Yu, Cao(2,3); Wei, Huang(2); Xuezhen, Lian(2); Zhe, Li(2)
Source: ICEIEC 2019 - Proceedings of 2019 IEEE 9th International Conference on Electronics Information and Emergency Communication Volume: Issue: DOI: 10.1109/ICEIEC.2019.8784599 Published: July 2019
Abstract:Tracking accuracy and pointing accuracy are the core indicators of photoelectric theodolite, and the speed stationarity in the process of tracking and pointing determines the quality of target image acquisition, affects the parameters acquisition and technical and tactical indicators judgment of the target under test[2]. In order to improve the tracking accuracy, pointing accuracy and speed stability of the photoelectric theodolite in the shooting range, the prediction algorithm based on extended kalman filter (EKF) to compensate the sensor delay and the extraction speed method of the tracking differentiator are proposed in the shooting range maneuvering measurement environment. First, the EKF algorithm is analyzed and the EKF-based pointing model is established. Then, in the velocity loop of the theodolite servo control system, the tracking differentiator is used to process the Angle information of the encoder as velocity feedback[3]. Finally, the method proposed in this paper is introduced into Simulink simulation. The results show that the method in this paper improves the speed stability, tracking and pointing accuracy of the photoelectric theodolite, and meets the application requirements of the range. This method can also be transplanted to other photoelectric equipment[1]. ? 2019 IEEE.
Accession Number: 20193507359745
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Record 281 of
Title:Spectral Data Reconstruction Algorithm of Hadamard Transform Spectral Imager
Author(s):Li, Yun(1,2); Hu, Bing-Liang(1); Gao, Xiao-Hui(1); Sun, Xin(1); Wu, Deng-Shan(1); Yan, Peng(1); Zhang, Xiao-Rong(1)
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 48 Issue: 6 DOI: 10.3788/gzxb20194806.0630002 Published: June 1, 2019
Abstract:Based on the principle of hadamard transform spectral imager, through the mathematical modeling of its spectral imaging process, the spectral information aliasing and spatial information aliasing caused by hadamard code mask modulation are deeply analyzed, and an algorithm is proposed to remove aliasing according to the spectral offset. The target data is collected by the self-developed hadamard transform spectral imager. Data cube reconstruction is accomplished by the proposed algorithm of removing aliasing. Finally, the 3D data cube is restored successfully. The spatial information aliasing and spectral information aliasing are effectively removed, and the correctness of the proposed algorithm is verified. ? 2019, Science Press. All right reserved.
Accession Number: 20193107255131
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Record 282 of
Title:Analysis of Nitrate in Seawater of Wheat Island Based on LLE-BPNN
Author(s):Wang, Xue-Ji(1,2); Hu, Bing-Liang(1); Yu, Tao(1); Liu, Qing-Song(1,2); Li, Hong-Bo(1,2); Fan, Yao(1)
Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 39 Issue: 5 DOI: 10.3964/j.issn.1000-0593(2019)05-1503-06 Published: May 1, 2019
Abstract:Excessive nitrate in water may influence some aquatic organisms' survival and cause harm to humans, especially infants. Therefore, nitrate concentration becomes an important indicator in water quality monitoring. Due to the complexity of operation and slow response of conventional methods for measuring nitrate concentration, many researchers have begun to use ultraviolet/visible (UV-Vis) spectroscopy combined with artificial neural network (ANN) methods to measure nitrate content in water. This paper proposes a modeling method combining locally linear embedding (LLE) in manifold learning with back propagation neural network (BPNN). The relationship between the spectral curve of nitrate and the concentration was obtained, so that a rapid and accurate quantitative analysis of the nitrate concentration in the wheat island of Laoshan District, Qingdao was achieved. In the experiment, we selected 59 groups of spiked solutions with different concentrations of filtered wheat island seawater, and collected spectral measurements of these samples using a laboratory-developed spectrum analyzer, with standard normal variate (SNV) method calibrating spectral data of measured nitrate solution to reduce the noise caused by the instrument itself or the environment. First 1 500-dimensional of the pre-processed spectral data was used to avoid insufficient memory when using the entire 2 048-dimensional data to build BPNN model, and a control experiment was performed. Then the number of neighboring points k and the embedding dimension d in the LLE were optimized by the grid search combined with the ten-fold cross validation method, obtaining the optimal k=15, d=3. Then the dimension of the experimental data was reduced. The spectral information of the reduced-dimensional training set and its corresponding concentration information were modeled by the BPNN to achieve a quantitative analysis of the nitrate concentration in the prediction set. Coefficient of determination (R2) and root mean square error of prediction (RMSEP) were introduced to evaluate modeling effects. And compared with the predicted results obtained by only using BPNN modeling, R2 of our improved method increased from 0.926 3 to 0.992 8, and RMSEP decreased from 0. 442 5 to 0.280 4, and prediction modeling program run time decreased from 327 s to about 0.5 s. In addition, we used all 2 048 dimensions of the 59 data sets for LLE-BPNN modeling, with R2=0.995 7 and RMSEP=0.136 5, which was improved compared to the modeling accuracy when only using the first 1 500 dimensions, while elapsed time was similar. The analysis results above showed that using the LLE-BPNN method can achieve a rapid prediction of nitrate concentration in seawater, while significantly improving prediction accuracy and reducing prediction time. ? 2019, Peking University Press. All right reserved.
Accession Number: 20193907482105
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Record 283 of
Title:A spatial moving target recognition algorithm based on full information vector
Author(s):Du, Yun(1,2,3); Wen, Desheng(1); Liu, Guizhong(2); Yi, Hongwei(1); Liu, Meiying(1,3); Fang, Junli(4)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11052 Issue: DOI: 10.1117/12.2521938 Published: 2019
Abstract:In this paper, a full information vector recognition algorithm for moving targets is proposed on the basis of the characteristic distribution of point targets and the moving characteristic between frames. The traditional multi-frame image fusion method of moving target recognition is abandoned. We utilize the distribution characteristic of point targets extracted from single image and moving characteristic of point targets extracted from multiple images to recognize and classify moving targets with the similarity principle of feature vector. Compared with the traditional maximum likelihood estimation image processing algorithm, the proposed recognition method costs less computation and provides a novel approach for spatial moving target detection and recognition. ? 2019 SPIE.
Accession Number: 20190806534740
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Record 284 of
Title:Method for Mueller matrix acquisition based on a division-of-aperture simultaneous polarimetric imaging technique
Author(s):Ju, Haijuan(1,2); Ren, Liyong(1); Liang, Jian(1); Qu, Enshi(1); Bai, Zhaofeng(1)
Source: Journal of Quantitative Spectroscopy and Radiative Transfer Volume: 225 Issue: DOI: 10.1016/j.jqsrt.2018.12.020 Published: March 2019
Abstract:The Mueller matrix is an important parameter in the field of polarization optics, and how to measure it efficiently and accurately becomes considerably significant for its practical applications. In this paper, for the first time to our knowledge, we propose a new method for Mueller matrix acquisition based on a division-of-aperture simultaneous polarimetric imaging technique. Different from the traditional method where, for obtaining the 16 elements of the Mueller matrix, a 16-times-measurement must be conducted by jointly changing the states of polarization (SOPs) of the input and output lights, while in our method it is enough by just changing the SOPs of the input light 4 times. This time-saving and easy-calculating feature is owing to our specific polarimetric camera, where a full-Stokes vector is obtained easily since 3 linear SOPs (0°, 45°, 90°) and 1 circular SOP can be recorded simultaneously by spatially sharing the same detector. To simply verify the effectiveness of our method, a specific polarization device patched by 8 sub-polarizers is chosen as the sample to be measured. Experimental results show that they are consistent with the theoretical results, both in the Mueller matrix and the corresponding images. We predict that this method for Mueller matrix acquisition can get wide potential applications for rapid identifications in biomedicine and material science. ? 2018 Elsevier Ltd
Accession Number: 20185206297305
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Record 285 of
Title:A Fast Lossless Data Compression Method for the Wedge Filter Spectral Imager
Author(s):Li, Hong-Bo(1,2); Hu, Bing-Liang(1); Yu, Lu(1,2); Wei, Rui-Yi(1); Yu, Tao(1)
Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 39 Issue: 1 DOI: 10.3964/j.issn.1000-0593(2019)01-0297-06 Published: January 1, 2019
Abstract:Wedge filter spectral imager, with no moving components and low complexity, has become an important development direction of low cost miniature imaging spectrometer. Based on the state of the art hyperspectral lossless compression standard CCSDS123, we propose a lossless data compression method for the wedge filter spectral imager. The proposed method redefines the local difference vector in CCSDS123, taking fully advantage of the spatial-spectral co-modulation characteristics of the wedge filter spectral imager. To compress the raw data from a wedge filter spectral imager, the compression encoder firstly predicts the sample value using its local sum and local difference vector, then computes a prediction residual and the corresponding mapped prediction residual, finally encodes the mapped prediction residual via a sample-adaptive entropy coding approach. The proposed method can effectively compress the raw data from a wedge filter spectral imager by using the local correlation in the spatial-spectral space. To verify the compression performance of the proposed method, experiments are taken on 6 raw datasets containing different scenes. The results show that the proposed method surpasses the original CCSDS123 method by about 21.62% higher compression ratio on the test datasets with almost the same computational time. ? 2019, Peking University Press. All right reserved.
Accession Number: 20191506772849
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Record 286 of
Title:Photochromic effect of transparent lead-free ferroelectric KSr2Nb5O15 ceramics
Author(s):Cao, Shuyao(1); Gao, Feng(1); Xu, Jie(1); Zhu, Jihong(2); Chen, Qian(1); Guo, Yiting(1); Li, Leilei(1); Liu, Junting(1); Gao, Tong(2); Pawlikowska, Emilia(3); Szafran, Mikolaj(3); Cheng, Guanghua(4,5)
Source: Journal of the European Ceramic Society Volume: 39 Issue: 16 DOI: 10.1016/j.jeurceramsoc.2019.08.009 Published: December 2019
Abstract:Transparent KSr2Nb5O15 (KSN) lead-free ferroelectric ceramics have been synthesized via modified pressureless sintering method. A significant photochromic effect was observed for the transparent KSN ceramics prepared without rare-earth dopant modification. The piezoelectric properties depend on the grain orientations were investigated. The optical transmittance of the KSN ceramics is greater than 40% in the wavelength range of 530–800 nm. After NUV irradiation, the absorbance was enhanced by more than 40% in a broad visible range (more than 79%). The absorbance returned to the initial value after a thermal bleaching process. The results of the cycling tests and response experiments showed the stability and saturation of the photochromic effect. In addition, the possible photochromic mechanism of the KSN ceramics is discussed and the photochromic centers are identified. This transparent KSN ceramics exhibits an obvious photochromic effect and is a potential candidate materials for optical data storage and information recording applications. ? 2019 Elsevier Ltd
Accession Number: 20193507361409
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Record 287 of
Title:Influence of two-photon absorption and free-carrier effects on all-optical logic gates in silicon waveguides
Author(s):Wu, Wei(1,2); Sun, Qibing(1,3); Wang, Leiran(1,2); Wang, Guoxi(1,2); Zeng, Chao(1,3); Zhang, Zhaodong(4); Zhang, Lingxuan(1,3); Zhang, Qihao(1,3); Zheng, Aihu(1,3); Cheng, Dong(1,2); Zhao, Wei(1,2); Zhang, Wenfu(1,2)
Source: Applied Physics Express Volume: 12 Issue: 4 DOI: 10.7567/1882-0786/ab066f Published: April 1, 2019
Abstract:We investigate the impact of two-photon absorption (TPA) and free-carrier effects on all-optical logic gates in silicon waveguides, in which the conversion efficiency is greatly reduced and the waveform is seriously distorted. A silicon-organic hybrid dual-slot waveguide without TPA is proposed for all-optical logic gates and could offer an extremely large nonlinear parameter higher than 1.4 × 107 W-1 km-1. The all-optical logic AND, OR, and XOR gates based on four-wave mixing in this waveguide are realized for 100 Gb s-1 data signals in the C-band. These results provide potential applications for all-optical signal processing in integrated optics, optical communications, and optical computation. ? 2019 The Japan Society of Applied Physics.
Accession Number: 20192006937527
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Record 288 of
Title:Performance of high-power diode lasers operated at cryogenic temperature
Author(s):Zhang, Pu(1); Wang, Mingpei(1,2); Nie, Zhiqiang(1); Yang, Wuhao(1,2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11182 Issue: DOI: 10.1117/12.2536712 Published: 2019
Abstract:High power diode lasers (HPDLs) have been applied in more and more fields, such as material processing, pumping of solid-state lasers and fiber lasers, medical therapy. With the improvement of output power, efficiency and reliability, thermal management has been one of most critical issue for HPDLs. The junction temperature of a diode laser package has critical effects on laser characteristics, affecting wavelength, output power, threshold current, slope efficiency, and operating lifetime. Lower junction temperature is an effective means to achieve high output power and high electrooptical conversion efficiency of diode lasers. In recent years, high-power diode lasers operated at cryogenic temperature have attracted academic interests. Herein, high power diode lasers suitable at cryogenic temperature and a measurement setup at cryogenic temperature have been developed. The optical-electrical performance of microchannel cooled high power diode lasers from 0～ -60 have been studied theoretically and experimentally. The output power increases 18% and the conversion efficiency increases 6.3% from 0° to -60°C. The high diode laser bars operated at cryogenic will be applied in pumping high energy lasers in the future. ? 2019 SPIE.
Accession Number: 20200308054714
