Periodic solutions of nonautonomous cellular neural networks with impulses and delays

By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence, uniqueness and global exponential stability of periodic solutions for nonautonomous cellular neural networks with impulses and delays. Further, using the numerical simulation method the influence of the impulsive perturbations on the inherent oscillation is investigated. The numerical simulation shows that our models can occur in many forms of complexities including periodic oscillation and Gui chaotic strange attractor.     

具时滞的Hopfield网络周期解的指数稳定性

The paper is devoted to periodic attractor of delayed Hopfield neural networks with time-varying.By constructing Lyapunov functionals and using inequality techniques,some new sufficient criteria are obtained to guarantee the existence and global exponential stability of periodic attractor.Our results improve and extend some existing ones in[13～14].One example is also worked out to demonstrate the advantages of our results.     

具有粘弹性和热粘弹性方程组的全局周期吸引子

证明了具有粘弹性和热粘弹性方程组在Dirichlet边界条件下,对于任意的非自治时间周期受迫力,均具有唯一的指数吸引任何有界集的周期解,即全局周期吸引子.并且如果受迫力是自治的,则全局周期吸引子恰是系统唯一的指数吸引有界集的平衡解.     

耦合非线性波方程的指数吸引子

在文[1]的基础上，得到了耦合非线性波方程的指数吸引子的存在性．     

Existence and stability of periodic solutions of high-order Hopfield neural networks with impulses and delays

By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, the global exponential stability and periodicity are investigated for a class of delayed high-order Hopfield neural networks (HHNNs) with impulses, which are new and complement previously known results. Finally, an example with numerical simulation is given to show the effectiveness of the proposed method and results. The numerical simulation shows that our models can occur in many forms of complexities including periodic oscillation and the Gui chaotic strange attractor.     

Exponential attractor of the 3D derivative Ginzburg-Landau equation

In this paper, we consider a derivative Ginzburg-Landau-type equation with periodic initial-value condition in three-dimensional spaces. Sufficient conditions for existence and uniqueness of a global solution are obtained by uniform a priori estimates of the solution. Furthermore, the existence of a global attractor and an exponential attractor with finite dimensions are proved.     

Exponential periodic attractor of impulsive BAM networks with finite distributed delays

In this paper, we investigate a class of impulsive bidirectional associative memory (BAM) networks with both periodic coefficients and finite distributed delays. New criteria are established for the existence of an exponential periodic attractor, which generalize and improve the previously known results. Our criteria are less restrictive and can be applied to impulsive or non-impulsive BAM networks with a broad range of activation functions without differentiability and strict monotonicity. Moreover, our results are given in terms of system parameters and finite delay kernels of impulsive BAM networks by employing inequality technique, M-matrix and spectral theory. Finally, an example is given to show the feasibility and effectiveness of our results.     

EXISTENCE AND ATTRACTIVITY OF ALMOST PERIODIC SOLUTION FOR HOPFIELD NEURAL NETWORKS WITH VARIABLE COEFFICIENTS

This paper is to study the existence and attractivity of almost periodic solution for Hopfield-Type delay cellular neural networks(HDCNNs) with variable coefficientsby combining the theory of the exponential dichotomy and Lyapunov functionals method and combine with some analysis techniques. We obtain some sufficient conditions to ensure the networks to have a unique almost periodic solution, and all other solutions converge to this solution.     

具变时滞的细胞神经网络的周期解

本文研究了一类具变时滞细胞神经网络系统,利用重合度理论中的延拓定理、不等式的分析原理、矩阵理论和Lyapunov泛函方法,得到了该系统周期解的存在唯一性及全局指数稳定性的结论,不仅在一些应用领域上是可行的且易检验,而且为神经网络系统周期解的存在性论证,提供了一个新的有效方法.     

Bifurcation structure of a discrete neuronal equation

We present the bifurcations diagram of a threshold automation with memory. This automation has a unique attractor which is periodic if the memory is bounded, periodic or Cantorian if it is unbounded. We show that the associated rotation number is an increasing piecewise constant function of the threshold parameter. If the memory is unbounded, this function is a devil staircase.     

Dynamical bifurcation of the damped Kuramoto–Sivashinsky equation

In this paper, we study the primary instability of the damped Kuramoto–Sivashinsky equation under a periodic boundary condition. We prove that it bifurcates from the trivial solution to an attractor which determines the long time dynamics of the system. Using the attractor bifurcation theorem and the center manifold theory, we describe the bifurcated attractor in detail.     

Finite dimensional global and exponential attractors for a class of coupled time-dependent Ginzburg-Landau equations

We study a coupled nonlinear evolution system arising from the Ginzburg-Landau theory for atomic Fermi gases near the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover.First,we prove that the initial boundary value problem generates a strongly continuous semigroup on a suitable phase-space which possesses a global attractor.Then we establish the existence of an exponential attractor.As a consequence,we show that the global attractor is of finite fractal dimension.     

Periodic solutions of nonautonomous cellular neural networks with impulses

Sufficient conditions are obtained for the existence and global exponential stability of a unique periodic solution of a class of neural networks with impulses by using Mawhin’s continuation theorem of coincidence degree theory and constructing Lyapunov functions. An illustrative example is given to demonstrate the effectiveness of the obtained results.     

Existence and global exponential stability of periodic solution of a class of neural networks with impulses

Sufficient conditions are obtained for the existence and global exponential stability of a unique periodic solution of a class of neural networks with variable and unbounded delays and impulses by using Mawhin’s continuation theorem of coincidence degree theory and by constructing Lyapunov functions.     

Stability of solutions to a destabilized hopf equation

The Hopf, or inviscid Burgers equation, destabilized by a linear source term is studied for periodic data. It is shown that for mean-zero initial data whose integral has a unique minimum in each period, the stationary solution is a global attractor.     

Global dynamics of the periodic logistic system with periodic impulsive perturbations

This paper studies the global behaviors of the periodic logistic system with periodic impulsive perturbations. The results of D.D. Bainov and P.S. Simeonov (1993) are extended and dynamics different from the corresponding continuous system are found. It is shown that the system may have a unique positive periodic solution which is globally asymptotically stable, or go extinct when the two periods are rational dependent. When they are rational independent, the system has no periodic solutions, however, still has a global attractor or go extinct under some conditions.     

Existence of the generalized exponential attractor for coupled suspension bridge equations with double nonlocal terms

We investigate the long-time dynamical behavior of coupled suspension bridge equations with double nonlocal terms by using the quasi-stable methods. We first establish the well-posedness of the solutions by means of the monotone operator theory. Secondly, the dissipation of solution semigroup is obtained, and then, the asymptotic smoothness of solution semigroup is verified by the energy reconstruction method; ultimately, we prove the existence of global attractor. Finally, we show the existence of the generalized exponential attractor.     

有阻尼受迫sine-Gordon方程的全局周期吸引子

本文证明了当阻尼与扩散系数在一定的参数范围内时,有阻尼的受迫sineGordon方程的狄氏问题对于任意非自治时间周期受迫力均具有唯一的指数吸引有界集的周期解．并且,如果受迫力是自治的,则全局吸引子恰是系统唯一的指数吸引有界集的平衡解．     

Invariant set and attractor of nonautonomous functional differential systems

The paper is devoted to the invariant set and periodic attractor for nonautonomous functional differential systems. Some sufficient criteria of the invariant set and periodic attractor are derived. Particularly, we have provided an estimate on existence range of periodic attractor by using the properties of nonnegative matrices and differential inequality technique.     

BAM-type impulsive neural networks with time-varying delays

By using the continuation theorem of coincidence degree theory and constructing a suitable Lyapunov functional, we derive some sufficient conditions for the existence and global exponential stability of a unique periodic solution of BAM neural networks, which assumes neither the monotony nor the boundedness of the activation functions. It is believed that these results are significant and useful for the design and applications of BAM neural networks.