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RAZUMIKHIN-TYPE THEOREMS FOR ASYMPTOTIC STABILITY OF IMPULSIVE STOCHASTIC FUNCTIONAL DIFFERENTIAL systems

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Journal of systems science and systems engineering 2010年第1期19卷 72-84页

作者： Pei CHENG~1 Feiqi DENG~2 Xisheng DAI~3 systems engineering institute,South china university of technology,Guangzhou 510640,china systems engineering institute South China University of Technology Guangzhou China

In this paper, we investigate the pth moment uniformly asymptotic stability of impulsive stochastic ftmctional differential systems by extending some Razumikhin-type theorems. Based on the Lyapunov functions and Razumikhin techniques, some criteria are established and their applications to impulsive stochastic delay systems are proposed. An illustrative example shows the effectiveness of our results.

关键词： Stochastic functional differential systems Impulse Razumiltial theorems Asymptotic stability

A new geometric approach to blind source separation of bounded sources

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Progress in Natural science:Materials International 2009年第7期19卷 891-896页

作者： Jinlong Zhang a, Guoxu Zhoua, Zuyuan Yang a, Xiaoxin Liao b a School of Electrics & Information engineering, South china university of technology, Guangzhou 510641, china b Department of Control science and engineering, huazhong university of science and technology, wuhan 430074, china [a]School of Electrics & Information engineering South China University of Technology Guangzhou 510641 China [b]Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Based on the minimum-range approach, a new geometric approach is proposed to deal with blind source separation in this paper. The new approach is the batch mode of the original minimum-range approach. Compared with the original approach, the optimization algorithm of the proposed approach needs no parameters and is more efficient and reliable. In addition, the extension of minimum-rangebased approaches is discussed. The simulations show the efficiency of the proposed approach.

关键词： Blind source separation Independent component analysis Minimum-range approach

Constrained oscillation of a bubble subjected to shock wave in microvessel

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Progress in Natural science:Materials International 2009年第9期19卷 1109-1117页

作者： Farong Gao, Caihua Xiong *, Youlun Xiong institute of Rehabilitation and Medical Robotics, State Key Lab of Digital Manufacturing Equipment and technology, School of Mechanical science and engineering, huazhong university of science and technology, wuhan 430074, china [a]institute of Rehabilitation and Medical Robotics State Key Lab of Digital Manufacturing Equipment and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

A three-phase coupled model of the gasliquid-solid oscillation system is established to analyze the oscillation characteristics of a bubble inside a micro blood vessel with various radii and its shape changes with different interface boundaries. The results show that unlike the spherical symmetric oscillation in an unbounded fluid, the oscillating bubble has significant asymmetric characteristics under the constraint of a fiexible microvessel, especially while its radius reduces to the same order of magnitude as that of the bubble. Moreover, the variation of microbubble motion, whether the geometric shape or oscillation feature, exhibits obvious differences in the micro blood vessel compared with the rigid wall. The reasons behind these phenomena are analyzed in this paper. The conclusions have significant importance in the understanding of the mechanism of microvessel injury in ultrasound therapy.

关键词： Asymmetric oscillation Microbubble Shock wave Micro blood vessel Boundary effects

A global heuristically search algorithm for DNA encoding

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Progress in Natural science:Materials International 2007年第6期17卷 745-749页

作者： Zhang Kai, Pan Linqiang and Xu Jin (The Key Laboratory of Image Processing and Intelligent Control, Department of Control science and engineering, huazhong university of science and technology, wuhan 430074, china) [a]The Key Laboratory of Image Processing and Intelligent Control Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan China

A new efficient algorithm is developed to design DNA words with equal length for DNA computing. The algorithm uses a global heuristic optimizing search approach and converts constraints to a carry number to accelerate the convergence, which can generate a DNA words set satisfying some thermodynamic and combinatorial constraints. Based on the algorithm, a software for DNA words design is developed.

关键词： DNA computing encoding heuristic optimizing search

A low frequency piezoelectric power harvester using a spiral-shaped bimorph

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science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 649-659页

作者： HU Yuantai1,2,HU Hongping2 & YANG Jiashi3 1. institute of Mechanics and Sensing technology,Central South university,Changsha 410083,china 2. Department of Mechanics,huazhong university of science and technology,wuhan 430074,china 3. Department of engineering Mechanics,university of Nebraska,Lincoln,NE 68588-0526,USA 1. institute of Mechanics and Sensing technology Central South University Changsha 410083 China 2. Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China 3. Department of engineering Mechanics University of Nebraska Lincoln NE 68588-0526 USA

We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.

关键词： spiral-shaped bimorph,piezoelectric harvester,power density.

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

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Journal of Iron and Steel Research International 2012年第10期19卷 13-19页

作者： XIAO Xiao-feng1,2, YE Sheng-ping2, YIN Wei-xin3, XUE Qiong4 (1. School of Mechanical engineering and Automation, wuhan Textile university, wuhan 430073, Hubei, china 2. State Key Laboratory of Material Processing and Die and Mould technology, huazhong university of science and technology, wuhan 430074, Hubei, china 3. wuhan Zhike Abrasive-Resistant Material science and technology Development Co Ltd, wuhan 430073, Hubei, china 4. College of science, wuhan university of technology, wuhan 430079, Hubei, china) [a] School of Mechanical engineering and Automation Wuhan Textile University Wuhan 430073 Hubei China [b] State Key Laboratory of Material Processing and Die and Mould technology Huazhong University of Science and Technology Wuhan 430074 Hubei China [c] wuhan Zhike Abrasive-Resistant Material science and technology Development Co Ltd Wuhan 430073 Hubei China [d] College of science Wuhan University of Technology Wuhan 430079 Hubei China

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2 and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

关键词： composite liner bimetal liquid-liquid compound composite interface lost foam casting high Cr white cast iron

The optimization of DNA encodings based on GA/SA algorithms

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Progress in Natural science:Materials International 2007年第6期17卷 739-744页

作者： Wang Wei1, Zheng Xuedong2, Zhang Qiang1 and Xu Jin2(1. Liaoning Key Laboratory of Intelligent Information Processing, Dalian university, Dalian 116622, china 2. Department of Control science and engineering, huazhong university of science and technology, wuhan 430074, china) [a]Liaoning Key Laboratory of Intelligent Information Processing Dalian University Dalian China [b]Department of Control science and engineering Huazhong Univerisity of Science and Technology Wuhn China

The design of DNA sequence plays an important role in improving the reliability of DNA computation. Proper constrained terms that DNA sequence should satisfy are selected, and then the evaluation formulas of each DNA individual corresponding to the selected constrained terms are proposed. The heuristic improved genetic algorithm (GA)/simulated annealing (SA) algorithm is presented to solve the multi-objective optimize problem, and the DNA sequence design system is developed. Furthermore, an example is illustrated to show the efficiency of our method given here.

关键词： DNA encoding multi-objective optimize GA/SA algorithms

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 430074, china 2. School of Automation, wuhan university of science & technology, wuhan 430070, china 3. School of Information, Central South university of Economy, Politics and Law, wuhan 430064, 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.

Multi-objective carrier chaotic evolutionary algorithm for DNA sequences design

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Progress in Natural science:Materials International 2007年第12期17卷 1515-1520页

作者： Xiao Jianhua, Xu Jin, Geng Xiutang and Pan Linqiang(Key Laboratory of Image Processing and Intelligent Control, Department of Control science and engineering, huazhong university of science and technology, wuhan 430074, china) Key Laboratory of Image Processing and Intelligent Control Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

DNA computing is a new vista of computation, which is of biochemical type. Since each piece of information is encoded in biological sequences, their design is crucial for successful DNA computation. DNA sequence design is involved with a number of design criteria, which is difficult to be solved by the traditional optimization methods. In this paper, the multi-objective carrier chaotic evolution algorithm (MCCEA) is introduced to solve the DNA sequence design problem. By merging the chaotic search base on power function carrier, a set of good DNA sequences are generated. Furthermore, the simulation results show the efficiency of our method.

关键词： DNA computing carrier chaotic search multi-objective evolutionary algorithm DNA sequences design.