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Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

science china(physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3 & JIA Ya 2 1 department of physics, Lanzhou university of technology, Lanzhou 730050, china 2.department of physics, Central china Normal university, wuhan 430079, china 3 College of Electrical and Information Engineering, Lanzhou university of technology, Lanzhou 730050, china 1. department of physics Lanzhou University of Technology Lanzhou 730050 China2. Department of Physics Central China Normal University Wuhan 430079 China3. College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou 730050 China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness

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COMPETITIVE INVESTMENT STRATEGIES IN NEW technology ADOPTION WITH A FURTHER NEW technology ANTICIPATED

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Journal of Systems science & Complexity 2007年第3期20卷 444-453页

作者： Baojian YIN . Shigeng HU department of Mathematics Huazhong University of Science and Technology Wuhan 430074 China.

This paper studies a general dynamic duopoly in which two firms compete in the adoption of current technology with a further new technology anticipated. Three kinds of equilibria may occur in technology adoption, namely the preemptive, sequential, and simultaneous equilibrium, depending on the level of operating costs and the first-move advantage. It shows that the faster technological innovation encourages the leader to invest earlier, while induces the follower to invest later. Furthermore, like the investment costs, with the increase of the operating costs, the follower tends to invest later, while the leader tends to invest earlier. However, the investment thresholds are more sensitive to the change of the operating costs than that of the investment costs.

关键词： Operating costs preemption real options technological uncertainty.

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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.

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THE NUMERICAL SIMULATION OF FLOW IN ALUMINUM REDUCTION CELLS

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Journal of Hydrodynamics 1991年第1期3卷 11-15页

作者： Zhuang Ye-gao Zhang Qi-de, department of Mechanics, huazhong university of Scieuce and technology, wuhan 430074, P. R. china huazhong Univ of science and Technology Wuhan China

The electromagnetic force causes a circulation of both cryolite and the metal in the aluminum reduction cells. This motion has the effect of reducing the current efficiency of the cell, and increases the distance between the an- ode and the cathode. Using the time-averaged Navier-Stokes equations and the K-e model of turbulence this paper numerically calculated the distributions of velocities, pressure, turbulent kinetic energy in the cells and deforma- tion of the interface of cryolite and metal. These results may be used to control the process of production and to improve the design of the cells.

关键词： Pr Flow THE NUMERICAL SIMULATION OF FLOW IN ALUMINUM REDUCTION CELLS

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A toy model for magnetized neutrino-dominated accretion flows

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science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 98-101页

作者： LEI WeiHua,WANG DingXiong,ZHANG Lei,GAN ZhaoMing & ZOU YuanChuan School of physics,huazhong university of science and technology,wuhan 430074,china 1. School of physics Huazhong University of Science and Technology Wuhan 430074 China

In this paper,we present a simplified model for a magnetized neutrino-dominated accretion flow(NDAF) in which the effect of black hole(BH) spin is taken into account by adopting a set of relativistic correction factors,and the magnetic field is parameterized as β,the ratio of the magnetic pressure to the total *** is found that the disc properties are sensitive to the values of the BH spin and β,and more energy can be extracted from NDAFs by using a faster spin and lower β.

关键词： black hole gamma-ray bursts accretion disc magnetic field

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A Note on the Graph of Class One

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应用数学 1991年第4期 128-129页

作者： Wan Honghui Cheng Zaishu (department of Mathematics huazhong university of science and technology wuhan 430074, P. R. china)

1 Introduction Let G be a simple graph. An edge colouring ∏ of G is a map ∏: E(G)→{1,2,…} such that no two adjacent edges have the same image. The chromatic index X’ (G) of G is the minimum cardinality of all pos... 详细信息

关键词： A Note on the Graph of Class One Graph

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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.

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Search　Algorithm　for　Determining　the　Range　of　the　Possible　Collision　of　Conver　Polygons

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Journal of Systems Engineering and Electronics 1996年第3期7卷 31-42页

作者： Li Qinghua(department of Computer science and Engineeringhuazhong university of science technology, wuhan, 430074, P. R. china) department of Computer science and Engineering huazhong university of science technology Wuhan 430074 P. R. China

Let P=(po, p1,..., pn-1 ) and Q=(qo,q1..., qm-1) be two arbitrary convex polygonsin plane. In this paper, the author studies the problems of how to quickly determine their possiblecollision range and movable range. In the paper, a new sufficient and necessary condition for decidingpossible collision is proposed,and the basic characters of the oblique supporting lines are investigated,and on these grounds the problem to determine the possible collision range is transformed into thatof searching the supporting points on the sets of convex polygon vertexs. Using the strategy ofsearching simultaneously the sets of vertexes of P and Q, the author constructs the fast algorithmfor finding the supporting points, the time-complexity of which is O(log2(m + n)). Based on theseresults, the algorithms to quickly determine the range are given, which possess the time-complexityof O(log2(m+n)).

关键词： Possible collision Ranges of possible and impossible collision Oblique supporting line,Supporting points.

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Stability of neutral stochastic differential equations

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Chinese science Bulletin 1997年第13期42卷 1143-1144页

作者： LIAO Xiaoxi and MAO Xuerong1 department of Automatic Control, huazhong university of science and technology, wuhan 430074, china 2.department of Statistics and Modelling science, university of Strathclyde GL LXH, U K.

Let ω（t） = （ω1（t）,…, ωm（t））T be a Brownian motion defined on a complete probabili-ty space （Ω, F, P）. τ>0, A, B, C are n×n matrices. σ: R+×Rn×Rn→Rn×n, whichis locally Lipschitz continuous and satisfies the linear growth condition. Theorem 1. Assume that there exists a symmetric nonnegative n×n matrix D such thatthe symmetric

关键词： root

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Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

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science china(physics,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1, 3 & PAN Liuzhan1, 2 1. Institute of Laser physics and Chemistry, Sichuan university, Chengdu 610064, china 2. department of physics, Luoyang Normal College, Luoyang 471022, china 3. State Key Laboratory of Laser technology, huazhong university of science and technology, wuhan 430074, china Correspondence should be addressed to L Baida (email: badalu@***) Received July 10, 2003 1. Institute of Laser physics and Chemistry Sichuan University 610064 Chengdu China 2. State Key Laboratory of Laser technology Huazhong University of Science and Technology 430074 Wuhan China 3. department of physics Luoyang Normal College 471022 Luoyang China

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1 and included in our theory.

关键词： spectral anomaly spectral switch partially coherent and polychromatic light far field aperture diffraction

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