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Asynchronous cooperative communication systems:A survey on signal designs

Science China(Information Sciences) 2011年第8期54卷 1547-1561页

作者： WANG HuiMing 1,2 & XIA XiangGen 3 1 School of Electronic and Information engineering, Xi’an Jiaotong university, Xi’an 710049,China 2 State Key Laboratory of Integrated Services Networks, Xidian university,Xi’an 710049, China 3 department of electrical and computer engineering,university of delaware,newark,de 19716,usa 1. School of Electronic and Information engineering Xi’an Jiaotong University Xi’an 710049 China2. State Key Laboratory of Integrated Services Networks Xidian University Xi’an 710049 China3. Department of Electrical and Computer Engineering University of Delaware Newark DE 19716 USA

Cooperative communications is a promising technique for future high speed wireless *** systems may be formulated as virtual multi-input multi-output (MIMO) systems where spatial/cooperetive diversity is a key advantage. However,different from MIMO systems,one of the major chal- lenges for cooperative communications systems is that the cooperative transmissions in cooperative systems may be neither time nor frequency synchronized,since the transmissions are from multiple cooperative nodes at different *** existing signal designs for co-located MIMO systems may not be able to collect the cooperative diversity in cooperative communications *** paper gives an overview of recent research efforts on combating the time and frequency asynchronism of the cooperative communication *** focus on the signal designs (or space-time codings/modulations) to achieve full cooperative diversity,and summarize some of the resent distributed space-timing coding and space-frequency coding techniques to combat timing errors and frequency offsets,and in the meantime to achieve full cooperative diversity,in both one-way and two-way cooperative networks.

关键词： cooperative communications time and frequency offsets space-time coding space-frequency codes full cooperative diversity linear receiver

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A wireless secret key generation method based on Chinese remainder theorem in FDD systems

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Science China(Information Sciences) 2012年第7期55卷 1605-1616页

作者： WANG WenJie 1,JIANG HongYan 1 ,XIA XiangGen 2,3 ,MU PengCheng 1 & YIN QinYe 1 1 Ministry of Education Key Lab for Intelligent Networks and Network Security,Xi’an Jiaotong university,Xi’an 710049,China 2 electrical and computer engineering,university of delaware,newark,de 19716,usa 3 Chonbuk National university,Jeonju,South Korea 1. Ministry of Education Key Lab for Intelligent Networks and Network Security Xi’an Jiaotong University Xi’an 710049 China2. Electrical and Computer Engineering University of Delaware Newark DE 19716 USA3. Chonbuk National University Jeonju South Korea

The wireless physical channel parameters are recently used to provide secret ***,the key generation usually suffers from the quantization errors due to the noise,which decreases the key agreement ratio (KAR) between authorized *** existing approaches achieve high KAR by discarding some channel parameters which may lower the key generation efficiency and therefore lower the encryption *** the frequency-division duplex (FDD) systems,the number of reciprocal parameters,such as the multipath angle and delay,is *** how to find a quantization method with high KAR and encryption strength is one of the major problems for secret key generation in FDD *** this paper,a robust quantization scheme based on grouping and shifting is proposed,in which all the available parameters are used for key *** addition,a key mapping method with error correction based on Chinese remainder theorem (CRT) is proposed to further improve the KAR *** demonstrate the effectiveness of the proposed method.

关键词： wireless communication security secret key generation FDD CRT angle and delay estimation

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Explicit classes of permutation polynomials of F33m

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Science China Mathematics 2009年第4期52卷 639-647页

作者： DING CunSheng1, XIANG Qing2, YUAN Jin3 & YUAN PingZhi4 1 department of computer Science and engineering, The Hong Kong university of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China 2 department of Mathematical Sciences, university of delaware, newark, de 19716, usa 3 department of Computing, Macquarie university, NSW 2109, Australia 4 School of Mathematics, South China Normal university, Guangzhou 510631, China department of computer Science and engineering The Hong Kong University of Science and Technology Hong Kong China department of Mathematical Sciences University of Delaware Newark USA department of Computing Macquarie University Sydney Australia School of Mathematics South China Normal University Guangzhou China

Permutation polynomials have been an interesting subject of study for a long time and have applications in many areas of mathematics and engineering. However, only a small number of specific classes of permutation polynomials are known so far. In this paper, six classes of linearized permutation polynomials and six classes of nonlinearized permutation polynomials over F33m are presented. These polynomials have simple shapes, and they are related to planar functions.

关键词： permutation polynomials planar functions

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An Improved Fast Recursive Algorithm for V-BLAST With Optimal Ordered detections

An Improved Fast Recursive Algorithm for V-BLAST With Optima...

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2008 IEEE International Conference on Communications(ICC 2008)

作者： Yue Shang and Xiang-Gen Xia department of electrical and computer engineering university of delaware newark de 19716

A fast recursive algorithm for the vertical Bell Laboratories layered space-time （V-BLAST） with the optimal ordered successive interference cancellation （SIC） detection has been proposed by Benesty-Huang-Chen and two improved algorithms have been also recently introduced by Szczeci ński-Massicotte and Zhu-Lei-Chin. In this paper,we first incorporate the existing improvements into the original fast recursive algorithm to give an algorithm that is the fastest known for the optimal SIC detection of V-BLAST. Then,we present a further improvement from which a new algorithm is proposed. Compared with the fastest known algorithm from the existing improvements,this new proposed algorithm has a speedup of 1.3 times in both the number of multiplications and the number of additions.

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Spatial continuity incorporated multi-attribute fuzzy clustering algorithm for blood vessels segmentation

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Science China(Information Sciences) 2010年第4期53卷 752-759页

作者： HAO JuTao1*, ZHAO JingJing2 & LI MingLu3 1School of Optical-electrical and computer engineering, university of Shanghai for Science and Technology, Shanghai 200093, China 2department of electrical engineering, Shanghai university of Electric Power, Shanghai 200090, China 3department of computer Science and engineering, Shanghai Jiaotong university, Shanghai 200240, China 1. School of Optical-electrical and computer engineering University of Shanghai for Science and Technology Shanghai 200093 China2. Department of Electrical Engineering Shanghai University of Electric Power Shanghai 200090 China3. Department of Computer Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

A three-dimensional representation of vasculature can be extremely important in image-guided neurosurgery, pre-surgical planning. In this paper, a spatial continuity incorporated multi-attribute fuzzy clustering algorithm (MAFCM S) is proposed to segment entire blood vessels from TOF MRA images. This clustering method takes both the intensity information and the geometrical information into account, while most of the cur- rent clustering methods only deal with the former. In this method, a new dissimilarity measure, which integrates the intensity and the geometry shape dissimilarity, is introduced. Because of the presence of the geometrical information, the new measure is able to differentiate the pixels with similar intensity values within different geometrical shape structures. Experimental results show that the new algorithm can get better segmentation.

关键词： fuzzy c-means clustering scale space analysis spatial continuity blood vessel segmentation multi-attribute fuzzy clustering

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AN OVERVIEW OF THE deVELOPMENT OF LOW GAIN FEEDBACK AND LOW-AND-HIGH GAIN FEEDBACK

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Journal of Systems Science & Complexity 2009年第4期22卷 697-721页

作者： Zongli LIN department of electrical and computer engineering,university of Virginia,P.O.Box 400473,Ch arlottesville,VA 22904-4743,usa. department of electrical and computer engineering University of Virginia P.O. Box 400473 Charlottesville VA 22904-4743 USA

Low gain feedback refers to certain families of stabilizing state feedback gains that are pararaeterized in a scalar and go to zero as the scalar decreases to zero. Low gain feedback was initially proposed to achieve semi-global stabilization of linear systems subject to input saturation. It was then combined with high gain feedback in different ways for solving various control problems. The resulting feedback laws are referred to as low-and-high gain feedback. Since the introduction of low gain feedback in the context of semi-global stabilization of linear systems subject to input saturation, there has been effort to develop alternative methods for low gain design, to characterize key features of low gain feedback, and to explore new applications of the low gain and low-and-high gain feedback. This paper reviews the developments in low gain and low-and-high gain feedback designs.

关键词： Actuator saturation composite nonlinear feedback input saturation low-and-high gain feedback low gain feedback nonlinear control.

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Carbon Nanotubes:from Nanoscale Building Blocks to Macrostructures

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复旦学报（自然科学版） 2007年第5期46卷 700-页

作者： Bingqing Wei(department of Mechanical engineering, university of delaware, newark, de 19716, usa) department of Mechanical engineering university of delaware Newark DE19716

1 Results Carbon nanotubes (CNTs) have fascinating *** order to use these novel one-dimensional structures for applications such as in nano-electronic,nano-mechanical and electrochemical energy storage device and as structural elements in various composites,the structure of nanotubes needs to be tailored and various architectures and macroscale assembles have to be configured using nanotube building *** macrostructures are macroscopically organized groups of CNTs,which are expecte...

关键词： carbon nanotubes macrostructures building blocks energy storage synthesis

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INFORMATION AND COMPLEXITY IN CONTROL SYSTEMS: A TUTORIAL

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Journal of Systems Science & Complexity 2001年第1期14卷 1-16页

作者： WANG Leyi (department of electrical and computer engineering, Wayne State university, detroit, Michigan 48202, usa) Wayne State university 美国 48202

This is a tutorial paper which presents schematically the concepts of information, uncertainty, and complexity, and their relationships in their applications to control systems. By focusing on exact or lower bounds on achievable performance in the presence of uncertainties, studies of complexity in a control system can potentially reveal fundamentally limiting factors of the system, suggest beneficial modifications to system structures and hardware configurations to remove these limitations, provide benchmark values for evaluating a design and for quantifying rooms for performance improvement, and demonstrate intrinsic tradeoffs. Compared to its counterparts in communications (Shannon’s information theory), computations (computational complexity and information-based complexity), and approxima- tions (n-widths and Kolmogorov entropy), studies of information and complexity in control systems encounter further challenges, such as characterization of feedback robustness, interaction between identification and control, and co-existence of deterministic and stochastic uncertainties. Some of these issues are outlined and discussed.

关键词： Information uncertainty complexity control identification.

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Two optimization algorithms for solving robotics inverse kinematics with redundancy

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控制理论与应用（英文版） 2010年第2期8卷 166-175页

作者： Jianxin XU, Wei WANG, Yuanguang SUN (department of electrical and computer engineering, National university of Singapore, Singapore 117576) department of electrical and computer engineering National University of Singapore Singapore Singapore

The kinematic redundancy in a robot leads to an infinite number of solutions for inverse kinematics, which implies the possibility to select a 'best' solution according to an optimization criterion. In this paper, two optimization objective functions are proposed, aiming at either minimizing extra degrees of freedom (DOFs) or minimizing the total potential energy of a multilink redundant robot. Physical constraints of either equality or inequality types are taken into consideration in the objective functions. Since the closed-form solutions do not exist in general for highly nonlinear and constrained optimization problems, we adopt and develop two numerical methods, which are verified to be effective and precise in solving the two optimization problems associated with the redundant inverse kinematics. We first verify that the well established trajectory following method can precisely solve the two optimization problems, but is computation intensive. To reduce the computation time, a sequential approach that combines the sequential quadratic programming and iterative Newton-Raphson algorithm is developed. A 4-DOF Fujitsu Hoap-1 humanoid robot arm is used as a prototype to validate the effectiveness of the proposed optimization solutions.

关键词： Inverse kinematics Redundant robot Objective function Optimization Numerical approach

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RELAXED CONDITIONS FOR CONSENSUS IN MULTI-AGENT COORDINATION

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Journal of Systems Science & Complexity 2008年第3期21卷 347-361页

作者： Qin LI Zhongping JIANG department of electrical and computer engineering Polytechnic University Six Metrotech Center Brooklyn NY 11201 USA

This paper proposes relaxed sufficient conditions for the consensus of multi-agent systems by the averaging protocols with time-varying system topology. Bidirectional information exchange between neighboring agents is considered and both the discrete-time and continuous-time consensus protocols are studied. It is shown that the consensus is reached if there exists an unbounded time sequence such that two agents who own the maximum and minimum states at each time instant in the sequence will be jointly connected at some future time. Further, this result is applied to the original nonlinear Vicsek model, and a sufficient condition for the heading consensus of the group with restricted initial conditions is obtained.

关键词： Averaging protocol consensus multi-agent systems Vicsek's model

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