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Statistical assessment of H/A target decomposition theorems in radar polarimetry

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science china({2. sciences) 2010年第2期53卷 355-366页

作者： LIU Tao 1,2. , HUANG GaoMing 1 , WANG XueSong 2.& XIAO ShunPing 2.1 School of Electronic engineering, Naval {2. of engineering, Wuhan 430033, china 2.School of Electronic science and engineering, National {2. of Defense Technology, Changsha 410073, china School of Electronic engineering Naval University of Engineering Wuhan China School of Electronic science and {2. National University of Defense Technology Changsha China

Target decomposition (TD) theorems have been widely applied in radar polarimetry, serving as the bridge between radar measurements and the physical parameters of a scatterer. The H/A target decomposition is one of the most suitable tools for performing data interpretation in the study and characterization of natural scatters. In this paper, the statistics of the parameters of eigenvalue, eigenvector and H/A have been analyzed via a novel method, and the probability density functions (PDF) have been obtained. It is pointed out that all these parameters can be seen as asymptotically nonbiased with respect to the number of looks. In order to reduce the biases for a small number of looks, a novel estimator for the parameters has been proposed. We give the basic theorems for accurate estimation of parameters.

关键词： target decomposition theorems H/A characteristic parameters statistical analysis MLE

Numerical simulation of Meiyu front and the diagnosis of moist vorticity vector

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Progress in Natural science:Materials International 2007年第11期17卷 1341-1347页

作者： Ping Fan1,2.and Luo Zhexian2.1. Institute of Atmospheric Physics, Chinese Academy of sciences, Beijing 10002., china 2. Nanjing {2. of information sciences & Technology, Nanjing 2.0044, china) Institute of Atmospheric Physics Chinese Acad. of Sci. Beijing 100029 China Nanjing university of information {2.s and Technology Nanjing 210044 China

Moist vorticity vector is introduced to study the development and evolution of mesoscale convective vortex (MCV) in the Meiyu front precipitation with the Advanced Regional Predication System (ARPS). In this study, the heavy rainfall is simulated to investigate the genesis, development and dissipation of middle scale convective vortex, which occurred from 0000 UTC 3 July to 12.0 UTC 5 July over the Jianghuai River valley. Moist vorticity vector (MVV) has zonal, radial and vertical components in its 3D spatial distribution. The simulation shows that the vertical component of moist vorticity vector well demonstrates the spatial distribution characteristics of middle scale convective vortex, especially in the process of Meiyu front precipitation. Diagnosis upon zonal, radial averaged and mass-integrated quantities of MVV shows that its vertical component and the surface precipitating ratio are in phase with a correlation coefficient of 0.68, indicating that the vertical component of MVV is closely associated with the Meiyu front precipitation. In addition, the tendency of the vertical component of MVV is mainly determined by the interaction between the vorticity and the zonal and radial gradient of condensational or depositional heating.

关键词： moist vorticity vector mesoscale convective vortex Meiyu front precipitation

A novel algorithm of artificial immune system for high-dimensional function numerical optimization

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Progress in Natural science:Materials International 2005年第5期15卷 463-471页

作者： DU Haifeng 1,2.*, GONG Maoguo1, JIAO Licheng1 and LIU Ruochen1(1. Institute of Intelligent information Processing and Key Laboratory of Radar Signal Processing, Xidian university, Xi'an 710071, {2. 2. School of Mechanical engineering, Xi'an Jiaotong university, Xi'an 710049, {2.) Key Lab. of Radar Signal Proc. Inst. of Intelligent Info. Proc. Xidian Univ. Xi'an 710071 China Sch. of Mech. Eng. Xi'an Jiaotong Univ. Xi'an 710049 China

Based on the clonal selection theory and immune memory theory, a novel artificial immune system algorithm, immune memory clonal programming algorithm (IMCPA), is put forward. Using the theorem of Markov chain, it is proved that IMCPA is convergent. Compared with some other evolutionary programming algorithms (like Breeder genetic algorithm), IMCPA is shown to be an evolutionary strategy capable of solving complex machine learning tasks, like high-dimensional function optimization, which maintains the diversity of the population and avoids prematurity to some extent, and has a higher convergence speed.

关键词： clonal selection immune memory artificial immune system evolutionary algorithms Markov chain.

Theory and techniques of data mining in CGF behavior modeling

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science china({2. sciences) 2011年第4期54卷 717-731页

作者： YIN YunFei 1,2.GONG GuangHong 2.& HAN Liang 2.1 College of Computer science,Chongqing university,Chongqing 400044,{2. 2.School of Automation science and Electrical engineering,Beijing university of Aeronautics and Astronautics,Beijing 100083,{2. College of Computer science Chongqing University Chongqing China School of Automation science and Electrical {2. Beijing University of Aeronautics and Astronautics Beijing China

For the large quantity of data,rules and models generated in the course of computer generated forces (CGFs) behavior modeling,the common analytical methods are statistical methods based on the tactical rules,tactical doctrine and empirical ***,from the viewpoint of data mining,we can find many of these analytical methods are also each-and-every different data mining *** this paper,we survey the data mining theory and techniques that have appeared in the course of CGF behavior modeling from the viewpoint of data ***,we redefine and reclassify these theories and techniques according to the research requirements of data mining (the knowledge structure of data mining).We aim to help the CGF investigators to learn the key points and the research methods of the data intelligent processing in the CGF behavior modeling,and thus we can provide the references for the colleagues who are engaged in the research and practice of the CGF behavior modeling by this *** also introduce our ongoing work on the CGF behavior modeling based on data mining.

关键词： CGF CGF behavior modeling data mining theory and techniques

Effect of Asymmetry in a Bistable System Subject to Multiplicative Colored Noise

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Communications in Theoretical Physics 2007年第12期48卷 1059-1062页

作者： ZHOU Yu-Rong~(1,2.GUO Feng~3 and PANG Xiao-Feng~1~1 School of Life science and Technology,{2. of Electronic science and Technology of china,Chengdu 610054,china~2.School of information and Electric engineering,Panzhihua {2.,Panzhihua 617000,china~3 School of Automation engineering,{2. of Electronic science and Technology of china,Chengdu 610054,china School of Life science and Technology University of Electronic Science and Technology of China Chengdu 610054 China School of information and Electric {2. Panzhihua University Panzhihua 617000 China School of Automation engineering University of Electronic Science and Technology of China Chengdu 610054 China

By the method of the stochastic energetics,we investigate the stochastic resonance (SR) phenomenon of anoverdamped Brown particle in an asymmetric bistable potential,driven by external periodical signal and *** expressions have been obtained for the quasi-steady-state probability distribution *** is found thatthe input energy (IE) pumped into the system by the external driving shows an SR-like behavior as a function of thenoise strength,whereas the IE turns to be a monotonic function of the correlation time of the *** effect ofpotential asymmetry is also studied on SR and IE.

关键词： asymmetric bistable system stochastic resonance stochastic energetics

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Formation control for networked spacecraft in deep space:with or without communication delays and with switching topology

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science china({2. sciences) 2011年第3期54卷 469-481页

作者： WANG Nan 1,2. ZHANG TianWu 2.& XU JieQiong 1 1 School of Aeronautic science and {2., Beijing university of Aeronautics and Astronautics, Beijing 100191, china 2.Department of Computer science and {2., Henan Institute of {2., Zhengzhou 451191, china School of Aeronautic science and {2. Beijing University of Aeronautics and Astronautics Beijing China Department of Computer science and engineering Henan Institute of Engineering Zhengzhou China

In this paper, several formation controllers are developed with constant and variable connected communication topology for six-degree-of-freedom (6-DOF) networked spacecraft flying in deep space with constant and time-varying communication delays considered. In the control algorithm, any explicit leader does not exist in the formation team and it is required that each spacecraft communicate only with its neighbors and therefore the required communication loads of the whole formation is greatly reduced. The proposed control strategies allow that each spacecraft can track its desired position and attitude and simultaneously the whole group moves to the desired formation and obtain its desired relative attitudes with its neighbors. Simulation results demonstrate the effectiveness of the proposed controllers.

关键词： deep space graph theory formation control communication topology delays

Color image enhancement based on HVS and PCNN

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science china({2. sciences) 2010年第10期53卷 1963-1976页

作者： ZHANG YuDong, WU LeNan , WANG ShuiHua & WEI Geng School of information {2. & engineering, southeast university, Nanjing 2.0096, china School of information {2. & engineering Southeast University Nanjing China

To enhance color images more effectively, a novel strategy is presented in this paper. We firstly translate the image to be enhanced from RGB space into HIS space, secondly keep its H component unchanged, and thirdly stretch its S component exponentially, and at last process its I component in the following manner: couple both the gray value and the spatial information into an inner activity item of corresponding neuron, integrate the human visual system into a dynamic component of corresponding neuron, and compare the inner activity item with dynamic component to obtain the enhanced image. Experiments demonstrate the effectiveness and validity of our strategy.

关键词： image enhancement human visual system (HVS) pulse coupled neural network (PCNN) color image

Terahertz radiation sources based on free electron lasers and their applications

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science china({2. sciences) 2012年第1期55卷 1-15页

作者： TAN Ping1,HUANG Jiang2.LIU KaiFeng2.XIONG YongQian2.FAN MingWu1,2.1Department of Electronic and information engineering,Huazhong {2. of science and Technology,Wuhan 430074,china 2.ollege of Electrical and Electronic engineering,State Key Laboratory of Advanced Electromagnetic engineering and Technology,Huazhong {2. of science and Technology,Wuhan 430074,china Department of Electronic and information engineering Huazhong University of Science and Technology Wuhan China College of Electrical and Electronic engineering State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

The tunability,high power and flexible picoseconds-pulse time structure of terahertz(THz)radiation make the THz free-electron laser(FEL)a very attractive THz source of coherent *** paper focuses on the development and perspectives of THz radiation sources based on the *** principles of the low gain THz FEL oscillator,the SASE THz FEL amplifier and the supperradiant THz FEL are reviewed briefly,and the key technologies of THz FEL,such as injector,accelerator,undulator and optical cavity,are discussed,*** current status of and future prospects for THz radiation sources based on the FEL are emphasized in this *** research and development have shown bright future in free-electron laser(FEL)THz radiation *** potential applications can be carried out in the field of imaging,material research,biology medicine,communication,diagnostics and many others.

关键词： terahertz source terahertz applications free electron laser

Theoretical analysis and experiment of micromechanics and mechanics-optics coupling of distributed optic-fiber crack sensing

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中国科学：技术科学英文版 2011年第S1期54卷 185-191页

作者： LIU HaoWu 1,2.CHEN Jiang 2.SUN Man 3 & DING Rui 2.1 State Key Laboratory of Hydraulics and Mountain River engineering,Sichuan university,Chengdu 610065,{2. 2.School of Water Resource Hydropower,Sichuan university,Chengdu 610065,{2. 3 School Electrical engineering and information,Sichuan university,Chengdu 610065,{2. State Key Laboratory of Hydraulics and Mountain River engineering Sichuan University Chengdu China School of Water Resource Hydropower Sichuan University Chengdu China School Electrical engineering and {2. Sichuan University Chengdu China

The micromechanical behaviors and mechanics-optics coupling effects of optic-fiber-concrete complex in the distributed optic-fiber sensing concrete-crack technology,which was used in health monitoring of Wu Gorge Bridge on Yangtze River and a large dam successfully,have been investigated.A micromechanical theoretical analysis method and micromechanical frictional contact bi-interface model,as well as a modified optical theoretical analysis method of the mechanics-optics coupling effects are presented.A series of verification experiments,including mechanical experiments and mechanics-optics coupling experiments,have been *** results of micromechanical theoretical analysis and the analysis of the modified theory of mechanics-optics coupling along with mechanical and optical experimental data are shown to be in close *** the micromechanical theory and the modified theory of mechanics-optics coupling with their analysis methods can not only enhance credibility of this novel distributed sensing technology but also provide a way to understand its sensing mechanism and optimize its technical details and system.

关键词： optic-fiber sensing mechanics-optics coupling micromechanics health monitoring concrete structure crack detection

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