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Spotlight SAR sparse sampling and imaging method based on compressive sensing

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science china(Information sciences) 2012年第8期55卷 1816-1829页

作者： XU HuaPing1,YOU YaNan1,LI ChunSheng1&ZHANG LvQian2 1S chool of electronics and Information engineering,Beihang university,beijing 100191,china 2C hinese Academy of engineering,beijing 100088,china school of electronics and Information engineering Beihang University Beijing China Chinese Academy of engineering Beijing China

Spotlight synthetic aperture radar(SAR)emits a chirp signal and the echo bandwidth can be reduced through dechirp processing,where the A/D sampling rate decreases accordingly at the *** sensing allows the compressible signal to be reconstructed with a high probability using only a few samples by solving a linear program *** paper presents a novel signal sampling and imaging method for application to spotlight SAR based on compressive *** signal is randomly sampled after dechirp processing to form a low-dimensional sample set,and the dechirp basis is imported to reconstruct the dechirp *** pursuit(MP)is used as a reconstruction *** reconstructed signal uses polar format algorithm(PFA)for *** our novel mechanism increases the system complexity to an extent,the data storage requirements can be compressed *** simulations verify the feasibility and accuracy of spotlight SAR signal processing via compressive sensing,and the method still obtains acceptable imaging results with 10%of the original echo data.

关键词： spotlight SAR dechirp processing compressive sensing radar signal processing

A GTD model and state space approach based method for extracting the UWB scattering center of moving target

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science china(Information sciences) 2011年第1期54卷 182-196页

作者： WANG Jun,WEI ShaoMing,SUN JinPing & MAO ShiYi school of Electronic and Information engineering,Beihang university,beijing 100191,china school of Electronic and Information engineering Beihang University

Movements of the scattering center on the condition of ultra-wideband(UWB)will impact the extraction of *** paper presents an approach for extracting the moving targets’UWB scattering center parameters based on the geometrical theory of diffraction(GTD)model and the state space approach. Firstly,the UWB GTD scattering model is transformed into state-space equations in order to estimate the range and range rate through the singular value ***,the type parameter in the whole bandwidth is indicated dimension-reducedly by orthonormalized basis and estimated by traversal algorithm and minimumnorm ***,the intensity of scattering center is worked out based on the least square *** paper provides the Cramer-Rao bound(CRB)for parameter *** effectiveness of the approach is verified by computer *** approach can estimate range,range rate,reflection intensity and type parameter simultaneously in order to improve the track of scattering centers and the target identification.

关键词： scattering center extraction GTD model state space approach ultra-wideband Doppler processing

Performance of Digital Pulse Interval Modulation of Atmospheric Optical Wireless Communication System

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Performance of Digital Pulse Interval Modulation of Atmosphe...

On an attack on RSA with small CRT-exponents

Asia-pacific Optical Communications 2004

作者： Zongmin Hu? Junxiong Tang school of electronics engineering and computer science peking university National Key Laboratory for Quantum Information and Measurements beijing 100871 P.R.china

Based on the atmospheric optical irradiance scintillation channel and an avalanche photodiode detector (APD) receiver communication system, this paper analyzes the error probability performance of dig

关键词： Keywords: Optical Wireless Communication DPIM Scintillation Packet Error Rate

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science china(Information sciences) 2010年第8期53卷 1511-1518页

作者： HAN LiDong 1,2 , WANG XiaoYun 3 & XU GuangWu 3,4 1 Key Laboratory of Cryptologic Technology and Information Security, Ministry of Education, Shandong university, Jinan 250100, china 2 school of Mathematics, Shandong university, Jinan 250100, china 3 Institute for Advanced Study, Tsinghua university, beijing 100084, china 4 Department of Electrical engineering and computer science, university of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA Key Laboratory of Cryptologic Technology and Information Security Ministry of Education Shandong University school of Mathematics Shandong University Institute for Advanced Study Tsinghua University Department of Electrical engineering and computer

This paper concerns the RSA system with private CRT-exponents. Since Chinese remainder representation provides efficiency in computation, such system is of some practical significance. In this paper, an existing attack to small private CRT-exponents is analyzed. It is indicated that this attack makes nice use of lattice in RSA analysis, but some argument does not hold in general. Several counterexamples are constructed. Refinements and more precise statements of the attack are given.

关键词： RSA CRT cryptanalysis continued fraction lattice reduction

SWHC-Strict Weak Hybrid Coherence Model for Pthread

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Journal of Systems engineering and electronics 1995年第3期6卷 70-75页

作者： Rong Li Dingxing Wang & Meiming Shen(Department of computer science & TechnologyTsing Hua university, beijing 100084, china) Department of computer science & Technology Tsing Hua university Beijing 100084 China

DSM(SVM) is a memory model which was proposed at the 1980s'. DSM solved the problem thatscalability was contradict with easy programming and merge their merits. The efficiency of DSM is still aproblem. The proposed solutions include prefetching and adopting new coherence model, but neither ofthem is a perfect solution. Prefetch will be less efficient when there are too many false sharing. The weak, relaxed coherence model is quite different from sequential coherence which was assumed by mostprogrammers intuitively, so programming and debugging becomes very difficult. We have proposed StrictWeak Hybrid Coherence (SWHC) model which can eliminate false sharing and provide more temporal andspatial locality, we also provide a scheme to keep sequential coherent. But SWHC model is complicate, asimplified model for Pthread share memory parallel computing model is proposed in the paper.

关键词： Parallel processing DSM Strict Weak Hybrid Coherence

A Data-Centric Trust Evaluation Mechanism in Wireless Sensor Networks

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A Data-Centric Trust Evaluation Mechanism in Wireless Sensor...

Crawling gait realization of the mini-modular climbing caterpillar robot

The Ninth International Symposium on Distributed Computing and Applications to Business,engineering and science

作者： Mingming Li,Jianbin Hu,Jiang Du school of computer science,Chongqing university of Posts and Telecommunications Chongqing,china school of electronics engineering and computer science,peking university beijing,china

New generation wireless sensor networks are demanding in in-time *** trust evaluation is based entities and needs lengthy time to *** data security would be neglected in entity-based sensor networks. False data is another problem because it is hard to be filtered in these entity-based trust *** propagation of false data and redundant information wastes a lot of system *** paper proposes a new notion to address these challenges:data-centric trust evaluation mechanism(DTSN) and a new method:Proof-of-Reputation-Relevance(PoRR)to realize *** trust evaluation mechanism protects both entities and data via authentic consensus on event reports and aggregate related reports’trust via *** DTSN decision logic makes a decision according to the output of DST. Performance evaluation and security analysis confirm the efficiency and security of the proposed mechanism.

关键词： DTSN PoRR WSN Trust Evaluation DST

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Progress in Natural science:Materials International 2009年第12期19卷 1821-1829页

作者： Wei Wang~(a,*),Kun Wang~a,Houxiang Zhang~b a Robotics Institute,school of Mechanical engineering and Automation,Beihang university,beijing 100083,china b TAMS,Department of computer science,university of Hamburg,Vogt-Koelln-Strasse 30,Hamburg 22527,Germany Robotics Institute School of Mechanical Engineering and Automation Beihang University Beijing 100083 China TAMS Department of Computer Science University of Hamburg Vogt-Koelln-Strasse 30 Hamburg 22527 Germany

The concept of a modular climbing caterpillar robot is inspired by the kinematics of real *** typical kinematics models and gaits are investigated based on the crawling motion of the inchworm and the tobacco *** to the fixed constraints between the suckers and the wall,the gait of a caterpillar robot engages a changing kinematic chain which is from an open chain to a closed chain,and then to an open chain in *** the open chain periods,an unsymmetrical phase method(UPM) is used to ensure the reliable attachment of the passive suckers to the *** the closed-chain state,a four-link kinematics model is adopted to fulfill the fixed *** combining the two methods together,the complete joint control trajectories are acquired for a modular caterpillar robot with seven *** last,on-site tests confirm the proposed principles and the validity of the climbing gait.

关键词： Climbing robot Modular Biologically inspired Gait

Guest Editorial for Special Issue on Human-centered Intelligent Robots:Issues and Challenges

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 599-601页

作者： Zhijun Li C.L.Philip Chen Wei He IEEE College of Automation science and engineering South China University of Technology Department of computer and Information science Faculty of Science and Technology University of Macao school of Automation and Electrical engineering University of Science and Technology Beijing

The special issue aims to address a broad spectrum of topics ranging from human-centered intelligent robots acting as a servant,secretary,or companion to intelligent robotic *** special issue publishes original papers of innovative ideas and concepts,new discoveries,and novel applications and business models relevant to the field of human-centered intelligent *** this special issue,modeling,intelligent control,

关键词： In Guest Editorial for Special Issue on Human-centered Intelligent Robots:Issues and Challenges

One-Branch Zero-IF Wireless Receiver Topology with Multiphase Local Oscillator

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Transactions of Tianjin university 2010年第2期16卷 109-113页

作者：李金城仇玉林 school of electronics and Information engineering Beijing Jiaotong University Institute of Microelectronics Chinese Academy of Sciences

This paper proposes a one-branch zero-IF receiver topology, which samples the I and Q signals of the modulated RF carrier with one signal path by means of a multiphase local oscillator. The suggested one-branch re- ceiver works without matching problem, and it is also capable of cancelling out the flicker noise and DC-offset when the local oscillator is configured to the four-phase mode. The one-branch receiver saves much area and power com- pared with the traditional two-branch ones. All of the advantages above make the one-branch receiver topology a promising architectural candidate for low-power and low-cost RF CMOS receiver designs. Keywords： RF CMOS; zero-IF; flicker noise; image rejection; low-power; IQ matching

关键词： RF CMOS zero-IF flicker noise image rejection low-power IQ matching