2019

• Record 553 of
  
  Title:Dimensionality reduction based on parallel factor analysis model and independent component analysis method
  
  Author(s):Yan, Ronghua(1,2); Peng, Jinye(1,3); Ma, Dongmei(4)
  Source: Journal of Applied Remote Sensing  Volume: 13  Issue: 1  DOI: 10.1117/1.JRS.13.014532  Published: January 1, 2019  
  Abstract:In hyperspectral image (HSI) analysis, dimensionality reduction is a preprocessing step for HSI classification. Independent component analysis (ICA) reduces the spectral dimension and does not utilize the spatial information of the HSI. To solve it, tensor decompositions have been successfully applied to joint noise reduction in spatial and spectral dimensions of HSIs, such as parallel factor analysis (PARAFAC). However, the PARAFAC method does not reduce the dimension in the spectral dimension. We proposed a method to improve it, which combines ICA and PARAFAC to reduce both the dimension in the spectral dimension and the noise in the spatial and spectral dimensions. The experimental results indicate that this method improves the classification compared with the previous methods. © 2019 Society of Photo-Optical Instrumentation Engineers (SPIE).
  Accession Number: 20191606775115
• Record 554 of
  
  Title:Image Reconstruction of an Emerging Optical Imager
  
  Author(s):Liu, Gang(1,2); Wen, Desheng(1); Song, Zongxi(1); Zhang, Weikang(1,2); Li, Zhixin(1,2); Wei, Xin(1,2); Jiang, Tuochi(1,2)
  Source: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)  Volume: 11902 LNCS  Issue:   DOI: 10.1007/978-3-030-34110-7_30  Published: 2019  
  Abstract:The emerging optical imager can reduce the system weight, size and power consumption by an order of magnitude compared to conventional optical telescopes at the same resolution. It utilizes Fourier-domain interferometry and samples by radial scheme. To date, there is little research on efficient image reconstruction algorithm of it. In this paper, we analyze the sampling properties of the imager and propose a compressive sensing (CS) based image reconstruction method for it. We also discuss the accurate and fast transform from the radial sampling scheme to Cartesian coordinate. The simulations of the proposed method have achieved good performance. © 2019, Springer Nature Switzerland AG.
  Accession Number: 20195207929637
• Record 555 of
  
  Title:Optimal clustering framework for hyperspectral band selection
  
  Author(s):Wang, Qi(1); Zhang, Fahong(2); Li, Xuelong(3,4,5)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: April 29, 2019  
  Abstract:Band selection, by choosing a set of representative bands in hyperspectral image (HSI), is an effective method to reduce the redundant information without compromising the original contents. Recently, various unsupervised band selection methods have been proposed, but most of them are based on approximation algorithms which can only obtain suboptimal solutions toward a specific objective function. This paper focuses on clustering-based band selection, and proposes a new framework to solve the above dilemma, claiming the following contributions: 1) An optimal clustering framework (OCF), which can obtain the optimal clustering result for a particular form of objective function under a reasonable constraint. 2) A rank on clusters strategy (RCS), which provides an effective criterion to select bands on existing clustering structure. 3) An automatic method to determine the number of the required bands, which can better evaluate the distinctive information produced by certain number of bands. In experiments, the proposed algorithm is compared to some state-of-the-art competitors. According to the experimental results, the proposed algorithm is robust and significantly outperform the other methods on various data sets. Copyright © 2019, The Authors. All rights reserved.
  Accession Number: 20200295238
• Record 556 of
  
  Title:Locality and structure regularized low rank representation for hyperspectral image classification
  
  Author(s):Wang, Qi(1); He, Xiang(2); Li, Xuelong(3,4)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: May 7, 2019  
  Abstract:Hyperspectral image (HSI) classification, which aims to assign an accurate label for hyperspectral pixels, has drawn great interest in recent years. Although low rank representation (LRR) has been used to classify HSI, its ability to segment each class from the whole HSI data has not been exploited fully yet. LRR has a good capacity to capture the underlying low-dimensional subspaces embedded in original data. However, there are still two drawbacks for LRR. First, LRR does not consider the local geometric structure within data, which makes the local correlation among neighboring data easily ignored. Second, the representation obtained by solving LRR is not discriminative enough to separate different data. In this paper, a novel locality and structure regularized low rank representation (LSLRR) model is proposed for HSI classification. To overcome the above limitations, we present locality constraint criterion (LCC) and structure preserving strategy (SPS) to improve the classical LRR. Specifically, we introduce a new distance metric, which combines both spatial and spectral features, to explore the local similarity of pixels. Thus, the global and local structures of HSI data can be exploited sufficiently. Besides, we propose a structure constraint to make the representation have a near block-diagonal structure. This helps to determine the final classification labels directly. Extensive experiments have been conducted on three popular HSI datasets. And the experimental results demonstrate that the proposed LSLRR outperforms other state-of-the-art methods. Copyright © 2019, The Authors. All rights reserved.
  Accession Number: 20200295328
• Record 557 of
  
  Title:Research on two-dimensional turntable tracking and aiming system based on BLDC speed regulation system
  
  Author(s):Cao, Yu(1,2,3); Wang, Haitao(1); Jing, Feng(1,2); Han, Junfeng(1); Xie, Meilin(1,2)
  Source: Proceedings of 2019 IEEE 8th Joint International Information Technology and Artificial Intelligence Conference, ITAIC 2019  Volume:   Issue:   DOI: 10.1109/ITAIC.2019.8785734  Published: May 2019  
  Abstract:This paper analyzes the commutation process of brushless dc motor, the control structure, control chip, control technology and control strategy of the system are also determined. In order to improve the system speed performance, the three closed-loop structure of position, speed and current is adopted in the control structure. Most functions of the system are realized by more reasonable software, therefore system reliability will be improved. In view of the problems of classical PID algorithm in brushless dc motor speed, the integral separation PID control algorithm is adoptedand successfully applied to this design. Aiming at BLDC turntable PWM mode is used, the hardware and software design with DSP+FPGA as the control core is completed. The performance of the whole design is validated by relying on the indoor experimental platform. The sketchy tracking accuracy of the system reaches 41 μrad, which meets the system requirements. The debugging results show that the system has good dynamic and static function[1]. © 2019 IEEE.
  Accession Number: 20193507360286
• Record 558 of
  
  Title:Self-trapped spatially localized states in combined linear-nonlinear periodic potentials
  
  Author(s):Shi, Jincheng(1,2,3); Zeng, Jianhua(1,4)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: September 21, 2019  
  Abstract:We analyze the existence and stability of two kinds of self-trapped spatially localized gap modes, gap solitons and truncated nonlinear Bloch waves, in one-and two-dimensional optical or matter-wave media with self-focusing nonlinearity, supported by a combination of linear and nonlinear periodic lattice potentials. The former is found to be stable once placed inside a single well of the nonlinear lattice, it is unstable otherwise. Contrary to the case with constant self-focusing nonlinearity, where the latter solution is always unstable, here, we demonstrate that it nevertheless can be stabilized by the nonlinear lattice since the model under consideration combines the unique properties of both the linear and nonlinear lattices. The practical possibilities for experimental realization of the predicted solutions are also discussed. Copyright © 2019, The Authors. All rights reserved.
  Accession Number: 20200170516
• Record 559 of
  
  Title:Asymmetric localized states in periodic potentials with a domain-wall-like Kerr nonlinearity
  
  Author(s):Shi, Jincheng(1,2,3); Zeng, Jianhua(1,2)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: September 21, 2019  
  Abstract:We study the existence of one-dimensional localized states supported by linear periodic potentials and a domain-wall-like Kerr nonlinearity. The model gives rise to several new types of asymmetric localized states, including single- and double-hump soliton profiles, and multihump structures. Exploiting the linear stability analysis and direct simulations, we prove that these localized states are exceptional stable in the respective finite band gaps. The model applies to Bose–Einstein condensates loaded onto optical lattices, and in optics with period potentials, e.g., the photonic crystals and optical waveguide arrays, thereby the predicted solutions can be implemented in the state-of-the-art experiments. Copyright © 2019, The Authors. All rights reserved.
  Accession Number: 20200241625
• Record 560 of
  
  Title:Study on the spectral imaging technology of adaptive classification
  
  Author(s):Xin, Wu(1,2); Li, Libo(2); Gao, Xiaohui(2); Wu, Yinhua(2); Wu, Chenyu(1,3)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 11337  Issue:   DOI: 10.1117/12.2547063  Published: 2019  
  Abstract:The spectral imaging technology of adaptive classification is a new spectral technology based on traditional spectral imaging technology. Based on the traditional imaging spectrometer, the following research is carried out in this paper: Firstly, this paper introduces the development and theory of the spectral imaging technology of adaptive classification, then designs the optical system of the adaptive feature-specific spectral imaging classifier, and finally verifies the performance of the system through classifying experiment. The experimental results show that the classifying accuracy and speed of the information processing of the adaptive feature-specific spectral imaging classifier are better than those of the traditional imaging spectrometers. © 2019 SPIE.
  Accession Number: 20200408062483
• Record 561 of
  
  Title:Calibration Mechanism Design and Stiffness Analysis
  
  Author(s):Xia, Siyu(1); Shi, Jinfeng(1); Ren, Guorui(1); Li, Chuang(1)
  Source: IOP Conference Series: Materials Science and Engineering  Volume: 520  Issue: 1  DOI: 10.1088/1757-899X/520/1/012014  Published: April 17, 2019  
  Abstract:According to the optical requirements of a space camera, a calibration mechanism in the form of a worm gear driven cantilever beam is designed, and a stop is added at the cantilever beam's end for limiting its amplitude. A detailed finite element model considering the clearance between moving parts in the mechanism and the preload of bearing is established using MSC.Patran & Nastran. By comparing the vibration test and analysis results, the stiffness and the dynamic environment adaptability of the mechanism is investigated and the first-order resonant frequency of the calibration mechanism is much larger than 100Hz which is high enough for the telescope's structure. Finally, the result shows that the error between the analysis result and the test data is within 10%, and it is verified that the calibration mechanism scheme has higher stiffness. © 2019 Published under licence by IOP Publishing Ltd.
  Accession Number: 20192006932472
• Record 562 of
  
  Title:Probability analysis and control of river runoff-sediment characteristics based on pair-copula functions: The case of the Weihe River and Jinghe River
  
  Author(s):You, Qiying(1,2,3,4); Jiang, Hao(5); Liu, Yan(1,3,4); Liu, Zhao(1,3,4); Guan, Zilong(1,3,4)
  Source: Water (Switzerland)  Volume: 11  Issue: 3  DOI: 10.3390/w11030510  Published: 2019  
  Abstract:Analyzing the encounter frequency of high-low runoff and sediment yield is important for the appropriate dispatching of runoff-sediment resources, as well as river regulation. However, there have been no reports on the utilization of the pair-copula function in analyzing the runoff-sediment characteristics from a probabilistic perspective and conducting probability control on the runoff-sediment yields of different hydrologic stations. This paper builds marginal distribution functions on the basis of kernel distribution theory. In addition, this paper builds the joint distribution functions through pair-copula functions in order to analyze the encounter probability and the compensation characteristics of high-low runoff and sediment at different stations on the Weihe River in China, as well as the origins of runoff-sediment, to conduct probability control of river runoff-sediment resource allocation. The results show that, in different periods, the synchronous probability of high-low runoff of theWeihe River's Xianyang and Huaxian Stations, and the Jinghe River's Zhangjiashan Station differ, while that of high-low sediment at the three stations changes little-remaining at around 54%. Therefore, the sediment and runoff of theWeihe River apparently have different origins. In years of high and low runoff, if the runoffs of the Xianyang and Zhangjiashan Stations can be kept within a certain range, then the runoff of the Huaxian Station will be in a particular range, at a certain probability. Sediment at the Huaxian Station can be controlled, in a similar way. These results are of great significance for the water and sediment management department of the Weihe river, in order to reasonably allocate water and sediment resources. © 2019 by the authors.
  Accession Number: 20191506763910
• Record 563 of
  
  Title:A purely Kerr nonlinear model admitting flat-top solitons
  
  Author(s):Zeng, Liangwei(1,2,3,4,5); Zeng, Jianhua(1,2,3,4,5); Kartashov, Yaroslav V.(6,7,8); Malomed, Boris A.(1,2,3,9,10,11,12,13,14,15)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: February 25, 2019  
  Abstract:We elaborate one- and two-dimensional (1D and 2D) models of media with self-repulsive cubic nonlinearity, whose local strength is subject to spatial modulation that admits the existence of flat-top solitons of various types, including fundamental ones, 1D multipoles, and 2D vortices. Previously, solitons of this type were only produced by models with competing nonlinearities. The present setting may be implemented in optics and Bose-Einstein condensates. The 1D version gives rise to an exact analytical solution for stable flat-top solitons, and generic families may be predicted by means of the Thomas-Fermi approximation. Stability of the obtained flat-top solitons is analyzed by means of linear-stability analysis and direct simulations. Fundamental solitons and 1D multipoles with k = 1 and 2 nodes, as well as vortices with winding number m = 1, are completely stable. For multipoles with k ≥ 3 and vortices with m ≥ 2, alternating stripes of stability and instability are identified in their parameter spaces. Copyright © 2019, The Authors. All rights reserved.
  Accession Number: 20200257837
• Record 564 of
  
  Title:Mirror module design of x-ray telescopes of eXTP mission
  
  Author(s):Basso, S.(1); Civitani, M.(1); Pareschi, G.(1); Sironi, G.(1); Spiga, D.(1); Tagliaferri, G.(1); Wang, J.(2); Yang, Y.(2); Xu, Y.(2); Chen, Y.(2); Sheng, L.(3); Yan, Y.(3); Qiang, P.(3); Zhao, B.(3)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 11119  Issue:   DOI: 10.1117/12.2530807  Published: 2019  
  Abstract:The eXTP (enhanced X-Ray Timing and Polarimetry) mission is a Chinese science space mission developed in collaboration with many international countries. Devoted to observations in the X-ray band, with imaging, spectroscopic, timing and polarimetry capabilities, is now entering phase B. The payload includes 9 Spectroscopic Focusing Array (SFA) and 4 Polarimetry Focusing Array (PFA) telescopes. The SFA telescopes, equipped with SDDs, have a spatial resolution of 1 arcmin, while the PFA telescopes, equipped with imaging gas pixel photoelectric polarimeters, have a spatial resolution of 30 arcsec. Both optics work in the 0.5-10 keV range with a focal length of 5.25 m and a field of view of 12 arcmin. The technology used for the optics production is Nickel electroforming from super-polished mandrels, like many previous successful X-ray missions. The reflecting coating is a double layer Au+C, which ensures optimal response at high and low energies. The PFA and SFA have the same optical design, in order to minimize the number of mandrels to be produced. In this paper, we present the optical design of these telescopes assisted with raytracing and a preliminary concept for the mechanical design supported by FEM simulation. © 2019 SPIE.
  Accession Number: 20195207928748