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Multi-polarimetric SAR image compression based on sparse representation

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science china(information sciences) 2012年第8期55卷 1888-1897页

作者： CHEN Yuan,ZHANG Rong&YIN Dong department of electronic engineering and {3. science,University of science and technology of china,Hefei 23.027,china 1. department of electronic engineering and {3. science University of Science and Technology of China Hefei 230027 China

The use of sparse representation in signal and image processing has gradually increased over the past few *** an over-complete dictionary from a set of signals allows us to represent these signals as a sparse linear combination of dictionary *** considering the relativity among the multi-polarimetric synthetic aperture radar(SAR)images,a new compression scheme for multi-polarimetric SAR image based sparse representation is *** multilevel dictionary is learned iteratively in the 9/7 wavelet domain using a single channel SAR image,and the other channels are compressed by sparse approximation,also in the 9/7 wavelet domain,followed by entropy coding of the sparse *** experimental results are compared with two state-of-the-art compression methods:SPIHT(set partitioning in hierarchical trees)and *** of the efficiency of the coding scheme,our method outperforms both SPIHT and JPEG2000 in terms of peak signal-to-noise ratio(PSNR)and edge preservation index(EPI).

关键词： multi-polarimetric SAR image compression sparse representation multilevel dictionary learning edge preservation index(EPI)

Robust integral sliding mode control for uncertain systems with multiple time delays

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控制理论与应用（英文版） 2010年第2期8卷 211-214页

作者： Xiaoyu ZHANG, Xiangna LI (department of electronic and information {3., North china Institute of science and technology, Beijing 101601, china) department of electronic and information {3. North China Institute of Science and Technology Beijing China

This paper proposes a robust integral sliding mode (RISM) manifold and the corresponding stabilization control law for uncertain systems with multiple time-varying time delays based on the techniques of linear matrix inequalities (LMI). The sufficient condition for the existence of the RISM manifold is given in terms of LMI, and then, the sliding mode control (SMC) law that can keep the system state on the RISM manifold from the initial time moment is developed. The efficiency and feasibility of the results are illustrated by a numerical example.

关键词： Robust control Integral sliding mode Time-delay systems LMI

Research on resolution between multi-component LFM signals in the fractional Fourier domain

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science china(information sciences) 2012年第6期55卷 1301-1312页

作者： LIU Feng 1,XU HuiFa 1,2,TAO Ran 3.& WANG Yue 3.1 department of electronic and information {3.,Naval Aeronautical {3. Institute,Yantai 264001,china 2 The 943.2 th Unit of People's Liberation Army,Qingdao 266111,china 3.School of information science and technology,Beijing Institute of technology,Beijing 100081,china 1. department of electronic and information {3. Naval Aeronautical Engineering Institute Yantai 264001 China2. The 94362th Unit of People’s Liberation Army Qingdao 266111 China3. School of Information Science and Technology Beijing Institute of Technology Beijing 100081 China

When the initial frequencies and chirp rates of multi-component linear frequency modulation (LFM or chirp) signals are close,the signals may not be distinguished in the fractional Fourier domain (FRFD).Consequently,some signals cannot be *** this paper,first,the spectral distribution characteristics of a continuous LFM signal in the FRFD are analyzed,and then the spectral distribution characteristics of a LFM signal in the discrete FRFD are ***,the critical resolution distance between the peaks of two LFM signals in the FRFD is deduced,and the relationship between the dimensional normalization parameter and the distance between two LFM signals in the FRFD is also *** is discovered that selecting a proper dimensional normalization parameter can increase the ***,a method to select the parameter is proposed,which can improve the resolution ability of the fractional Fourier transform (FRFT).Its effectiveness is verified by simulation results.

关键词： fractional Fourier transform LFM signal signal resolution

A multicast routing algorithm with multiple trees

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Journal of Systems engineering and electronics 2005年第2期16卷 426-432页

作者： Cui Xunxue 1,2 , Gao Wei3.& Fang Hongyu41. New Star Research Institute of Applied technology, Hefei 23.03., P. R. china 2. Jiangsu Key Laboratory of Computer information Processing technology,Soochow University, Suzhou 215006, P. R. china 3. department of electronic engineering and information science,University of science and technology of china, Hefei 23.027, P. R. china 4. School of electronic science and technology, Anhui University, Hefei 23.03., P. R. china New Star Research Institute of Applied technology Hefei 230031 P. R. China 2. Jiangsu Key Laboratory of Computer information Processing technology Soochow University Suzhou 215006 P. R. China department of electronic engineering and {3. science University of Science and Technology of China Hefei 230027 P. R. China School of electronic science and technology Anhui University Hefei 230039 P. R. China

Quality of service (QoS) multicast routing has continued to be a very important research topic in the Internet. A method of multicast routing is proposed to simultaneously optimize several parameters based on multiobjective genetic algorithm, after the related work is reviewed. The contribution lies on that the selection process of such routing is treated with multiobjective optimization. Different quality criterions in IP network are taken into account for multicast communications. A set of routing trees is generated to approximate the Pareto front of multicast problem. Multiple trees can be selected from the final set of nondominated solutions, and applied to obtain a good overall link cost and balance traffic distribution according to some simulation results.

关键词： multicast routing quality of service multiobjective optimization genetic algorithms.

Design of a novel low power 8-transistor 1-bit full adder cell

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Journal of Zhejiang University-science C(Computers and electronics) 2011年第7期12卷 604-607页

作者： Yi WEI,Ji-zhong SHEN (department of information science and {3. engineering,Zhejiang University,Hangzhou 3.0027,china) department of information science and {3. engineering Zhejiang University

An addition is a fundamental arithmetic operation which is used extensively in many very large-scale integration (VLSI) systems such as application-specific digital signal processing (DSP) and *** adder determines the overall performance of the circuits in most of those *** this paper we propose a novel 1-bit full adder cell which uses only eight *** this design,three multiplexers and one inverter are applied tominimize the transistor count and reduce power *** power dissipation,propagation delay,and power-delay produced using the new design are analyzed and com-pared with those of other designs using HSPICE *** results show that the proposed adder has both lower power consumption and a lower power-delay product (PDP) *** low power and low transistor count make the novel 8T full adder cell a candidate for power-efficient applications.

关键词： Full adder design Low power CMOS circuit Very large-scale integration (VLSI)

Building a next generation Internet with source address validation architecture

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science in china(Series F) 2008年第11期51卷 1681-1691页

作者： WU JianPing1,3.REN Gang1,3.& LI Xing2,3.1 department of Computer science,Tsinghua University,Beijing 100084,china 2 department of electronic engineering,Tsinghua University,Beijing 100084,china 3.Tsinghua National Laboratory for information science and technology(TNList) ,Beijing 100084,china department of Computer science Tsinghua University Beijing 100084 China department of electronic engineering Tsinghua University Beijing 100084 China Tsinghua National Laboratory for information science and technology (TNList) Beijing 100084 China

The IP packet forwarding of current Internet is mainly destination based. In the forwarding process, the source IP address is not checked in most *** causes serious security, management and accounting problems. Based on the drastically increased IPv6 address space, a ＂source address validation architecture＂（SAVA） is proposed in this paper, which can guarantee that every packet received and forwarded holds an authenticated source IP address. The design goals of the architecture are lightweight, loose coupling, ＂multi-fence support＂ and incremental deployment. This paper discusses the design and implementation for the architecture, including inter-AS, intra-AS and local subnet. The performance and scalability of SAVA are described. This architecture is deployed into the CNGI-CERNET2 infrastructure a large-scale native IPv6 backbone network of the china Next Generation Internet project. We believe that the SAVA will help the transition to a new, more secure and dependable Internet.

关键词： IP source address validation network architecture network security

On the new results of global attractive set and positive invariant set of the Lorenz chaotic system and the applications to chaos control and synchronization

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science in china(Series F) 2005年第3期48卷 304-321页

作者： LIAO Xiaoxin 1, 2, 3., FU Yuli 4 & XIE Shengli 4 1. department of Control science & Control engineering, Huazhong University of science & technology, Wuhan 43.074, china 2. School of Automation, Wuhan University of science & technology, Wuhan 43.070, china 3. School of information, Central South University of Economy, Politics and Law, Wuhan 43.064, china 4. School of electronics & information engineering, South china University of technology, Guangzhou 510640, china Correspondence should be addressed to Liao Xiaoxin (email: xiaoxin_liao@***) 1. department of Control science & Control engineering Huazhong University of Science & Technology 430074 Wuhan China 2. School of Automation Wuhan University of Science & Technology 430070 Wuhan China 3. School of information Central South University of Economy Politics and Law 430064 Wuhan China 4. School of electronics & information engineering South China University of Technology 510640 Guangzhou China

Constructing a family of generalized Lyapunov functions, a new method is proposed to obtain new global attractive set and positive invariant set of the Lorenz chaotic system. The method we proposed greatly simplifies the complex proofs of the two famous estimations presented by the Russian scholar Leonov. Our uniform formula can derive a series of the new estimations. Employing the idea of intersection in set theory, we extract a new Leonov formula-like estimation from the family of the estimations. With our method and the new estimation, one can confirm that there are no equilibrium, periodic solutions, almost periodic motions, wandering motions or other chaotic attractors outside the global attractive set. The Lorenz butterfly-like singular attractors are located in the global attractive set only. This result is applied to the chaos control and chaos synchronization. Some feedback control laws are obtained to guarantee that all the trajectories of the Lorenz systems track a periodic solution, or globally stabilize an unstable (or locally stable but not globally asymptotically stable) equilibrium. Further, some new global exponential chaos synchronization results are presented. Our new method and the new results are expected to be applied in real secure communication systems.

关键词： Lorenz chaotic system global attractive set positive invariant set globally exponential tracking globally exponential synchronization.

A new method for adaptive color image filtering

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Chinese science Bulletin 2000年第13期45卷 1230-1235页

作者： JIANG Gangyi, YU Mei & YU Bokang1. department, of information & electronic {3., Hang/hou University of Commerce, Hangzhou 3.003., china 2. department, of electronic {3., Hangzhou institute of electronics {3., Hangzhou 3.003., china 3. State Key Laboratory on Machine Perception, Peking University, Beijing 100871, china Correspondence should be addressed to Yu Mei department of information & electronic {3. Hangzhou University of Commerce Hangzhou China State Key Laboratory on Machine Perception Peking University Beijing China department of electronic engineering Hangzhou Institute of Electronics Engineering Hangzhou China

An adaptive color image filter (ACIF) is proposed in this note. Through analyzing noise corruption of color image, efficient locally adaptive filters are chosen for image enhancement. The proposed adaptive color image filter combines advantages of both nonlinear vector filters and linear filters, it attenuates noise and preserves edges and details very well. Experimental results show that the proposed filter performs better than vector median filter, directional-distance filter, directional-magnitude vector filter, adaptive nearest-neighbor filter, and α-trimmed mean filter.

关键词： color image noise analysis locally adaptive filters adaptive color image filter (ACIF).

The Detection of Defects in Optical Fibers Using a Hybrid Opto-electronic Correlator

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Chinese Journal of Lasers 2000年第3期9卷 15-21页

作者： LIU Yange LIU Wei ZHANG Yimo ZHOU Ge (College of Precision Instrument and Opto-electronics engineering, Tianjin University Opto-electronic {3. science and technology Lab., Tianjin 3.0072, china) 天津大学光电信息技术科学开放实验室天津

A hybrid opto-electronic correlator for detecting defects i n optical fibers is proposed. After the light from a He-Ne laser being expanded and filtered it is not collimated but directly passes a Fourier transform lens and illuminates a reference fiber and a test fiber at the same input plane. The Fourier transform spectrum of the two fibers is therefore obtained at the rear focal plane of the lens, where it is sampled via a CCD array connected with a computer through a frame grabber. The computer performs filter, inverse Fourier transform and setting threshold operation on classification. The system is an equivalent of joint transform correlator with a Fourier lens of long focal length. The experiment results for optical fibers having incoordinate defects are presented. The results indicate that the system can be used for fiber defect detection, and has the advantages of high identification, compact configuration, easy adjustment and flexible manipulation.

关键词： joint transform correlation Fourier transform optical fiber defect detection