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Adaptive detection for distributed targets in Gaussian noise with Rao and Wald tests

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Science china(Information Sciences) 2012年第6期55卷 1290-1300页

作者： SHUAI XiaoFei,KONG LingJiang & YANG JianYu school of electronic engineering,{3. of electronic Science and technology of china,chengdu 610054,china 1. school of electronic engineering University of Electronic Science and Technology of China Chengdu 610054 China

The problem of adaptively detecting a range distributed target or targets in Gaussian interference is considered in this *** is assumed that a set of secondary data is ***,we derive the adaptive Rao and Wald tests with one-step detection algorithm,and find that both of them are of the same asymptotic performance as the GLRT ***,the Rao and Wald tests are derived by resorting to the two-step design *** our surprise,our derivations show that all the Rao,Wald and GLR tests in the two-step design strategy are ***,the property assessments are *** is shown that these new detectors guarantee CFAR property with respect to the Gaussian ***,simulation results show that these results are accurate.

关键词： Rao and Wald tests adaptive detection distributed targets maximum likelihood estimator

The analyticity of solutions to a class of degenerate elliptic equations

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Science china Mathematics 2010年第8期53卷 2061-2068页

作者： LI ChunHe school of Mathematical Science,university of electronic Science and {3. of china,chengdu 610054,china 1. school of Mathematical Science University of Electronic Science and Technology of China Chengdu 610054 China

In the present paper,the analyticity of solutions to a class of degenerate elliptic equations is obtained.A kind of weighted norms are introduced and under such norms some degenerate elliptic operators are of weak coe... 详细信息

关键词： analyticity degenerate elliptic equations weighted norm weak coerciveness

Single-channel blind separation of overlapped multicomponents based on energy operator

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Science china(Information Sciences) 2010年第1期53卷 147-157页

作者： CAI QuanWei, WEI Ping & XIAO XianCi College of electronic engineering, university of electronic Science and technology of china, chengdu 610054, china 1. College of electronic engineering University of Electronic Science and Technology of China Chengdu 610054 China

A method utilizing single channel recordings to blind separate the multicomponents overlapped in both time and frequency domains is proposed in this paper. The main idea of the method is based on using the energy operator and differential energy operator to estimate instantaneous frequencies and amplitudes of each component and then to reconstruct these components. This method, due to the good time resolution of the energy operator and differential energy operator, as well as the very low computational complexity, is very useful in real time processing and practical applications. Simulation results demonstrated the effciency of this method.

关键词： single channel time frequency overlap multicomponents separation energy operator differential energy operator

An improved model of Robinson equivalent circuit analytical model

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Science china(Technological Sciences) 2010年第7期53卷 1993-1999页

作者： MAO XiangYu & DU PingAn school of Mechatronics engineering, university of {3. Science and technology of china, chengdu 61173., china 1. school of Mechatronics engineering University of Electronic Science and Technology of China Chengdu 611731 China

The Robinson equivalent circuit analytical model can be used only in calculating shielding effectiveness of enclosure with the same multi-holes in one wall, but cannot be used in different multi-holes in two walls. According to the practical requirement, this article uses Konefal's and Farhana's characteristic impedance of apertures to improve the equivalent circuit analytical model in different multi-holes in two walls. The improved equivalent circuit analytical model is more useful than Robinson equivalent circuit analytical model. In the article, all kinds of enclosures are simulated by TLM (Transmission-Line Matrix method) to prove that this improved model is feasible in multimode.

关键词： equivalent circuit improved model apertures shielding effectiveness TLM (Transmission-Line Matrix method)

Effects of pH on the peripheral light-harvesting antenna complex for Rhodopseudomonas palustris

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Science china(Life Sciences) 2008年第8期51卷 760-766页

作者： FENG Juan, LI XueFeng & LIU Yan school of Life Science and technology, university of {3. Science and technology of china, chengdu 610054, china 1. school of Life Science and technology University of Electronic Science and Technology of China Chengdu 610054 China

In this work steady-state absorption spectroscopy, circular dichroism spectroscopy and sub-micro-second time-resolved absorption spectroscopy were used to investigate the effect of pH on the struc-tures and functions of LH2 complex for Rhodopseudomonas palustris. The results revealed that: (1) B800 Bchla was gradually transformed to free pigments absorbing around 760 nm on the minutes timescale upon the induction of strong acidic pH, and subsequently there disappeared the CD signal for Qy band of B800 in the absence of B800. In addition, Carotenoids changed with the similar tendency to B850 BChl. (2) The introduction of strong basic pH gave rise to no significant changes for B800 Bchla, while B850 BChla experienced remarkable spectral blue-shift from 852 to 83. nm. Similar phe-nomenon was seen for the CD signal for Qy band of B850. Carotenoids displayed strong and pH-independent CD signals in the visible range. (3. In the case of both physiological and basic pH, broad and asymmetrical positive Tn←T1 transient absorption appeared following the pulsed photo-excitation of Car at 53. nm. By contrast, the featureless and weak positive signal was observed on the sub-microsecond timescale in the acidic pH environment. The aforementioned experimental results indicated that acidic pH-induced removal of B800 Bchla prevented the generation of the caro-tenoid triplet state (3.ar*), which is known to be essential for the photo-protection function. Neverthe-less, carotenoids can still perform this important physiological role under the basic pH condition, where the spectral blue shift of B850 exerts little effect on the overall structure of the cyclic aggregate, therefore favoring the formation of carotenoid triplet state.

关键词： pH-induced B800-removal triplet state photo-protection function

On the maximum likelihood method for target localization using MIMO radars

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Science china(Information Sciences) 2010年第10期53卷 2127-2137页

作者： XIA Wei , HE ZiShu & LIAO YuYu school of electronic engineering, {3. of electronic Science and technology of china, chengdu 61173., china 1. school of electronic engineering University of Electronic Science and Technology of China Chengdu 611731 China

A multiple-input multiple-output (MIMO) radar uses multiple antennas to simultaneously transmit multiple independent probing signals, and uses multiple antennas to receive the backscattered signals. The modeling of MIMO radar with transmit spatial diversity and coherent reception is addressed herein. The maximum likelihood (ML) method for parameter estimation using MIMO radars is considered, and two approximate ML algorithms are proposed. In the uniform noise scenario, one of the proposed algorithms performs similarly to the delay-and-sum beamformer which is optimal in the ML sense in single target case, while it outperforms the other proposed approximate ML algorithm at the cost of more computational load. In the non-uniform noise scenario, the proposed approximate ML algorithms both outperform the delay-and-sum beamformer. The efficiency of the proposed methods is validated by the simulation results.

关键词： maximum-likelihood multiple-input multiple-output (MIMO) radars parameter estimation

Construction of a multidimensional plane network-on-chip architecture based on the hypercube structure

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Progress in Natural Science:Materials International 2009年第5期19卷 635-641页

作者： Chang Wu, Yubai Li, Qicong Peng, Song Chai, Zhongming Yang DSP Lab, school of Communication and Information engineering, university of {3. Science and technology of china, chengdu 610054, china [a]DSP Lab School of Communication and Information Engineering University of Electronic Science and Technology of China Chengdu 610054 China

In current network-on-chip (NOC) studies and in practical applications, the mesh structure is the most widely used and deeply researched structure. However, the hypercube structure is more symmetrical and regular than the mesh or torus structures. This paper compares the network characteristics of these three direct topologies and proposes a method to compress the hypercube into a plane structure. This structure, which has the multidimensional property based on the hypercube, is called the multidimensional plane (MDP) NOC. The compression process is divided into two steps: the transformation of router denotations and the connection of channels. Then, SystemC is used to implement the MDP NOC and it is compared with the mesh and torus NOCs in terms of four aspects of performance, including average latency time, normalization throughput, energy consumption and area cost.

关键词： NOC Hypercube Dimension SystemC Simulation

Analysis of forest backscattering characteristics based on polarization coherence tomography

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Science china(Technological Sciences) 2010年第S1期53卷 166-175页

作者： LUO HuanMin 1,LI XiaoWen 1,2,CHEN ErXue 3.CHENG Jian 4 & CAO ChunXiang 21 Institute of Geo-Spatial Information Science and technology,university of electronic Science and technology of china,chengdu 610054,china 2 State Key Laboratory of Remote Sensing Science,Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal university,Beijing 100101,china 3.nstitute of Forest Resources Information Technique of Chinese Academy of Forestry,Beijing 100091,china 4 school of electronic engineering,university of electronic Science and technology of china,chengdu 610054,china State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China Beijing Normal Univ Beijing 100101 Peoples R China Univ Elect Sci & Technol china Inst Geospatial Informat Sci & Technol Chengdu 610054 Peoples R China Chinese Acad Forestry Inst Forest Resources Informat Tech Beijing 100091 Peoples R China Univ Elect Sci & Technol china Sch Elect Engn Chengdu 610054 Peoples R China

It is difficult to make an inventory of vertical profiles of forest structure parameters in field ***,analysis and understanding of forest backscattering characteristics contribute to estimation and detection of forest vertical structure because of the close relationships between backscattering characteristics and structure *** vertical structure function in the complex interferometric coherence definition,which represents the vertical variation of microwave scattering with the penetration depth at a point in the 2-D radar image and can be used to analyze the forest backscattering characteristics,can be reconstructed from polarization coherence tomography(PCT).Based on PCT,the paper analyzes the forest backscattering characteristics and explores the inherent relationship between the result of PCT and the forest structure parameters from numerical simulation of Random Volume over Ground model(RVoG),Polarimetric SAR interferometry(PolInSAR)simulation of forest scene and PolInSAR data at L-band of the test site ***,the effects of the extinction coefficient and surface-to-volume scattering ratio in RVoG model on vertical backscattering characteristics are analyzed by means of numerical ***,by applying PCT to L-band POLInSAR simulations of forest scene,different variations of vertical backscattering due to different extinction coefficients and the ratios of surface-to-volume scattering resulting from different polarizations,forest types and densities are displayed and *** a concept of relative average backscattering intensity is presented,and the factors which affect its vertical distribution are also *** results show that there is high sensitivity of the vertical distribution of forest relative average backscattering intensity to the polarization,forest type and ***,based on repeat pass DLR E-SAR L-band airborne POLInSAR data,the capability of PCT technology for detection

关键词： backscattering characteristic POLInSAR PCT vertical structure function

THE TRANSIENT SOLUTION FOR M/G/1 QUEUEWITH SERVER VACATIONS

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Acta Mathematica Scientia 1997年第3期17卷 276-282页

作者：唐应辉 UNIV ELECT SCI & TECHNOL china DEPT MATH APPLCHENGDU 610054PEOPLES R CHINA

In this paper, the transient solutions for M/G/1 queues with single server vacation and multiple server vacations are firstly studied, and the recursion expressions of their Laplace transform are given. Further the distribution and stochastic decomposition result of the queue length at a random point in equilibrium are directly obtained from the transient solution. As will be seen this paper provides a intuitive and elegant method for studying transient solutions for M/G/1 queues with single server.

关键词： server-vacation queue length transient solution stochastic decomposition