检索结果-南通市图书馆

Sparse microwave imaging:Principles and applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第8期55卷 1722-1754页

作者： ZHANG BingChen1,2,HONG Wen1,2 & WU YiRong1,2 1Science and technology on Microwave Imaging Laboratory,beijing 100190,china {4. of Electronics,Chinese Academy of Sciences,beijing 100190,china 1. Science and technology on Microwave Imaging Laboratory Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China

This paper provides principles and applications of the sparse microwave imaging theory and *** aperture radar(SAR) is an important method of modern remote *** decades microwave imaging technology has achieved remarkable progress in the system performance of microwave imaging technology,and at the same time encountered increasing complexity in system *** sparse microwave imaging introduces the sparse signal processing theory to radar imaging to obtain new theory,new system and new methodology of microwave *** on classical SAR imaging model and fundamental theories of sparse signal processing,we can derive the model of sparse microwave imaging,which is a sparse measurement and recovery problem and can be solved with various *** exist several fundamental points that must be considered in the efforts of applying sparse signal processing to radar imaging,including sparse representation,measurement matrix construction,unambiguity reconstruction and performance *** on these considerations,the sparse signal processing could be successfully applied to radar imaging,and achieve benefits in several aspects,including improvement of image quality,reduction of data amount for sparse scene and enhancement of system *** sparse signal processing has also been applied in several specific radar imaging applications.

关键词： sparse microwave imaging sparse signal processing compressive sensing synthetic aperture radar radar imaging

Scan chain design for shift power reduction in scan-based testing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第4期54卷 767-777页

作者： LI Jia 1,HU Yu 2 & LI XiaoWei 2 1 The School of Software,Tsinghua University,beijing 100084.china 2 The institute of computing {4.,Chinese Academy of Sciences,beijing 100190,china 1. The School of Software Tsinghua University Beijing 100084 China2. The Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Test power of VLSI systems has become a challenging issue *** scan shift power dominates the average test power and restricts clock frequency of the shift phase,leading to excessive thermal accumulation and long test *** paper proposes a scan chain design technique to solve the above *** on weighted transition metric (WTM),the proposed extended WTM (EWTM) that is utilized to guide the scan chain design algorithm can estimate the scan shift power in both the shift-in and shift-out ***,the wire length overhead of the proposed scan chain design can also be reduced by the proposed distance of EWTM (DEWTM) *** results confirm that the proposed approach can significantly reduce scan shift power with low wire length overhead.

关键词： low power DfT scan-based testing test power reduction scan chain design

On the placement of actuators and sensors for flexible structures with closely spaced modes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第7期53卷 1973-1982页

作者： LIU XiaoXiang1,2 & HU Jun1,2 1 beijing institute of Control Engineering, beijing 100190, china 2 State Key Laboratory of Science and {4. on Space Intelligent Control, beijing 100190, china 1. beijing institute of Control Engineering Beijing 100190 China2. State Key Laboratory of Science and Technology on Space Intelligent Control Beijing 100190 China

This paper analyzed the fundamental limitations of previous work and developed a new method to optimally locate actuators and sensors for structures with close modes. Optimization criteria were defined based on the distinguishing modal controllability and observability measures of close modes. An appropriate genetic algorism was adopted as the optimization algorism. Solving the high order Lyapunov functions was avoided by means of the closed-form expressions for controllability and observability Grammians. Since structure with widely separated natural frequencies is approximately balanced, computational efficiency was improved by grouping close modes together and dealing with the resulting subsystems independently. Finally, the effectiveness and optimality of the novel placement scheme were verified on a model structure with close modes.

关键词： close modes controllability/observability sensor/actuator optimization criterion optimization algorithm

维普期刊数据库

Stability analysis of a hypersonic vehicle controlled by the characteristic model based adaptive controller

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第10期55卷 2243-2256页

作者： ZHANG Zhao 1,2 & HU Jun 1 1 beijing institute of Control Engineering,beijing 100190,{4. 2 Science and technology on Space Intelligent Control Laboratory,beijing 100190,{4. 1. beijing institute of Control Engineering Beijing 100190 China2. Science and Technology on Space Intelligent Control Laboratory Beijing 100190 China

The closed loop attitude stability of a hypersonic vehicle controlled by the characteristic model-based all-coefficient adaptive controller is studied in this paper,and an algorithm based on the computation of induced matrix 1-norm or ∞-norm is *** of all,the Taylor series expansion is applied to discretize the inputoutput description of the attitude dynamics of the *** obtained difference equations have the same structure as characteristic model;thus the intervals which contain all possible values of certain characteristic model parameters are *** the linear feedback controller is used in the feedback loop,with some conservation,the closed loop system is viewed as a class of interval time-varying systems defined by a number of free time-varying *** free parameters take values from predefined *** sufficient and necessary condition for the stability of this class of system is ***,a sufficient condition for the stability of hypersonic vehicle attitude control loop is proposed and demonstration example is *** method proposed checks up the stability of the closed loop system by evaluating a finite number of matrix norms,and overcomes the difficulties brought by the time-varying nature of the characteristic model and parameter estimation.

关键词： characteristic model hypersonic vehicle interval time-varying system stability test attitude control

A direct product decomposition of QMV algebras

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Mathematics 2012年第4期55卷 841-850页

作者： LU Xian 1 ,SHANG Yun 1,& LU RuQian 1,2 1 institute of Mathematics,Academy of Mathematics and Systems Science,beijing 100190,china 2 Key Laboratory of Intelligent Information Processing,institute of computing technology,Chinese Academy of Sciences,beijing 100190,china 1. institute of Mathematics Academy of Mathematics and Systems Science Beijing 100190 China2. Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

We study the direct product decomposition of quantum many-valued algebras (QMV algebras) which generalizes the decomposition theorem of ortholattices (orthomodular lattices).In detail,for an idempo- tent element of a given QMV algebra,if it commutes with every element of the QMV algebra,it can induce a direct product decomposition of the QMV *** the same time,we introduce the commutant C(S) of a set S in a QMV algebra,and prove that when S consists of idempotent elements,C(S) is a subalgebra of the QMV *** also generalizes the cases of orthomodular lattices.

关键词： QMV algebra commutativity idempotent decomposition theorem

维普期刊数据库

Prediction-based guidance algorithm for high-lift reentry vehicles

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第3期54卷 498-510页

作者： ZHANG Zhao 1,2 & HU Jun 1 1 beijing institute of Control Engineering, beijing 100190, china 2 Science and {4. on Space Intelligent Control Laboratory, beijing 100190, china 1. beijing institute of Control Engineering Beijing 100190 China2. Science and Technology on Space Intelligent Control Laboratory Beijing 100190 China

In this work, we propose a pseudo four-degrees-of-freedom (DOF) prediction based guidance algo- rithm specifically for high-lift reentry vehicles. The algorithm is composed mainly of three parts. First, at the beginning of each guidance cycle, the 4.DOF predictor is called upon to predict the final downrange, crossrange, and heading errors. Then, the magnitude of the bank angle is determined from the downrange error, using the proportional-integral (PI) control method. Finally, two bank angle reversal time points are determined to minimize the crossrange and heading errors. Compared with traditional predictor-corrector guidance, the algorithm proposed does not require iterative procedures which significantly decreases the computational burden for the on-board computer and makes the implementation practical. Simulation results for dispersion tests demonstrated that our algorithm is computationally efficient and robust against uncertainties and disturbances.

关键词： pseudo 4.DOF prediction-based guidance high-lift reentry vehicle

Giant complete automaton for uncertain multiple string matching and its high speed construction algorithm

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第8期54卷 1562-1571页

作者： HU Yue 1,2, GAO QingShi 1,2 ,GUO Li 2 & WANG PeiFeng 1 1 School of Information Engineering,University of Science and technology beijing,beijing 100083,china 2 {4. of computing technology,Chinese Academy of Sciences,beijing 100190,china 1. School of Information Engineering University of Science and Technology Beijing Beijing 100083 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Multiple string matching is often completed under the presence of U- or V-uncertain-strings,or combinations *** large numbers of strings with U-, V-,and U-V-uncertain-strings,including the interleaving of two or more uncertain strings,is important to thoroughly gathering useful information and detecting harmful *** paper proposes a complete automaton and its high-speed construction algorithm for large-scale U-, V-,and U-V-uncertain multiple strings,including two or more uncertain strings interlaced with one *** maximum number of parallel complete automation of the V-uncertain string is also *** paper reveals that there are two kinds of pretermissions,i.e.,similarly-connected and interlaced-string pretermissions,and that mistake may appear in the matching of the regular expressions,or states in the automaton may increase in number,if the intersection of the U-uncertain strings sets and the homologous subsequent special point in the U-uncertain strings sets are not eliminated from the whole system.

关键词： multiple string matching U-uncertain-strings V-uncertain-strings U-V-uncertain-strings complete automaton

Information content security on the Internet:the control model and its evaluation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2010年第1期53卷 30-49页

作者： FANG BinXing1, GUO YunChuan2,3 & ZHOU Yuan4.1School of Computer, beijing University of Posts and Telecommunications, beijing 100029, china 2institute of computing technology, Chinese Academy of Sciences,{4., china 3Graduate University of Chinese Academy of Sciences, beijing 10004., china 4.ational Computer Network Emergency Response Technical Team/Coordination Center of china, beijing 100029, china 1. School of Computer Beijing University of Posts and Telecommunications Beijing 100029 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China4. National Computer Network Emergency Response Technical Team/Coordination Center of China Beijing 100029 China

Flooding of harmful information on the Internet seriously endangers the physiological and mental health of teenagers. Due to the user-friendliness of the Internet as well as the difficulty in the authentication for the access of specific categories of information, curbing the transmission of harmful information, i.e., assuring the information content security (ICS), has become a reasonable yet challenging alternative. At present, there is an urgent need to develop a systematic model that can effectively carry out the curbing. In fact, curbing the transmission of harmful information by way of filtering can be modeled by access control. In the paper, based on the three core-elements of communication, namely, "Who communicates with whom", "How do they communicate" and "What is the content of communication", we propose a control model, called ICCON. Unlike the existing access control, the reference monitor (RM) of our model is placed in the transmission channel, and moreover, an evaluation frame is proposed, through which the effectiveness of the RM in controlling information transmission on the Internet can be quantitatively evaluated.

关键词： content security access control quantitative evaluation

N-glycosylation proteome of endoplasmic reticulum in mouse liver by ConA affinity chromatography coupled with LTQ-FT mass spectrometry

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Chemistry 2010年第4期53卷 768-777页

作者： SONG LiNa1, WANG JingLan1, LIU JinFeng1, LU Zhuang1,3, SUI ShaoHui1, JIA Wei1 , YANG Bing1, CHI Hao2, WANG LeHeng2, HE SiMin2, YU WenFeng1, MENG LingYan1, CHEN Shuo1, PENG Xu1, LIANG YiMin1, CAI Yun1 & QIAN XiaoHong1 1State Key Laboratory of Proteomics, beijing Proteome Research Center, beijing institute of Radiation Medicine, beijing 102206,{4. 2institute of computing technology, Chinese Academy of Sciences, beijing 100190,{4. 3beijing institute of Biotechnology, beijing 100081,{4. 1. State Key Laboratory of Proteomics Beijing Proteome Research Center Beijing Institute of Radiation Medicine Beijing 102206 China3. Beijing Institute of Biotechnology Beijing 100081 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Glycosylation is the most versatile and one of the most significant protein post-translational modifications. It is generally classified into three categories according to the amino acid to which the glycan is attached: N-glycosylation, O-glycosylation and C-glycosylation. Synthesis of N-glycoproteins occurs in the rough endoplasmic reticulum (rER), and all N-glycoproteins synthesized in rER have uniform glycan endings with mannose (Man) and glucose (Glc). A systematic strategy was developed to comprehensively profile N-glycoproteins in complex biological samples. The lectin Concanvalin A (ConA), which has a high affinity for glycans ending with Man, was used to extract the N-glycoproteins synthesized or located in the rER, and identified the N-glycoproteins and their glycosylation sites by LTQ-FT MS. The analysis was repeated three times at both the biological sample and mass spectrometry levels. In total, 323 glycosylation sites on 212 N-glycoproteins were identified in the mouse liver. Of these, 131 were known N-glycoproteins in the Swissprot database. The identified N-glycoproteins were classified according to their cell location by the Swissprot database and GO software. The identified N-glycoproteins in this study would serve as a good complement to the N-glycoprotein database for the mouse liver.

关键词： glycosylation rER lectin affinity chromatography ConA LTQ-FT MS

维普期刊数据库