具有扩散影响的Hopfield型神经网络的全局渐近稳定性

对具有扩散影响的Hopfield型神经网络平衡点的存在唯一性和全局渐近稳定性进行了研究．在激活函数单调非减、可微且关联矩阵和Liapunov对角稳定矩阵有关时,利用拓扑度理论得到了系统平衡点存在的充分条件．通过构造适当的平均Liapunov函数,分析了系统平衡点的全局渐近稳定性．所得结论表明系统的平衡点(如果存在)是全局渐近稳定的而且也蕴含着系统的平衡点的唯一性．     

一类二阶非线性微分方程零解的全局渐近稳定性

本文研究二阶非线性微分方程■零解的全局渐近稳定性,其中各函数是实数上的连续函数．我们得到了零解全局渐近稳定的一些充分必要条件和充分条件．推广和改进了文献中的一些结论．     

具有无穷时滞的细胞神经网络的全局稳定性分析

对具有无穷时滞的细胞神经网络平衡点的存在性、唯一性和全局渐近稳定性进行了分析．在放弃了激活函数的有界性、单调性和可微性假设的情况下,得到了系统的平衡点的存在性条件．利用向量Liapunov函数法的思想,构造适当的含有变时滞和无穷时滞的微分-积分不等式,通过对微分-积分不等式的稳定性分析,得到了神经网络系统的全局渐近稳定的充分条件．     

一类带有一般接触率和常数输入的流行病模型的全局分析

借助极限系统理论和构造适当的Liapunov函数,对带有一般接触率和常数输入的SIR型和SIRS型传染病模型进行讨论．当无染病者输入时,地方病平衡点存在的阈值被找到A·D2对相应的SIR模型,关于无病平衡点和地方病平衡点的全局渐近稳定性均得到充要条件;对相应的SIRS模型,得到无病平衡点和地方病平衡点全局渐近稳定的充分条件．当有染病者输入时,模型不存在无病平衡点．对相应的SIR模型,地方病平衡点是全局渐近稳定的;对相应的SIRS模型,得到地方病平衡点全局渐近稳定的充分条件．     

一类两种群随机生态系统的稳定性

利用构造广义二次三项式作为随机李雅普诺夫函数的方法讨论了两种群随机Volterra生态系统的全局渐近稳定性，并对一类特殊情形给出了全局渐近稳定性的充分判据，推广了常微系统已有结果．     

一类三阶双滞量时滞微分方程的全局渐近稳定性

运用类比法构造Lyapunov函数,讨论了一类三阶双滞量时滞微分方程的全局渐近稳定性,给出了其零解全局渐近稳定的充分性准则.     

基于比率的广义Holling-Tanner系统的全局渐近稳定性

本文对基于比率的广义Holling-Tanner系统进行了定性分析,给出了系统解有界的条件和平衡点局部稳定的条件．通过构造适当的Liapunov函数,得到了正平衡点全局渐近稳定性的充分条件．     

四阶非线性系统的全局渐近稳定性

运用构造李雅普诺夫函数的方法 ,研究了一类四阶非线性系统的全局渐近稳定性 ,给出了该系统零解全局渐近稳定的充分条件     

广义的Lotka—Volterra方程的全局渐近稳定性

通过构造李亚普诺夫函数的方法,研究了广义的Lotka—Volterra时滞模型方程,而且给出了正平衡点的全局渐近稳定性的充分必要条件,同时对前人的结果进行了改进和推广．     

一类四阶非线性系统的全局渐近稳定性

运用Liapunov第二方法讨论了一类四阶非线性系统的全局渐近稳定性,通过构造出较好的Liapunov函数,获得到了其零解全局渐近稳定的充分性准则,去掉了一般要求Liapunov函数具有无穷大这个较强的条件,并推广了部分文献所研究的非线性系统.     

PERSISTENCE AND STABILITY OF A DISCRETE PERIODIC PREDATOR-PREY MODEL

In this paper,we investigate the persistence and global asymptotic stability of a discrete predator-prey system.Based on Lyapunov functions,several crite- ria are established concerning the persistence and globally asymptotic stability of difference systems.     

Global dynamics of an age-structured cholera model with both human-to-human and environment-to-human transmissions and saturation incidence

In this paper, an age-structured cholera model with both human-to-human and environment-to-human transmissions and saturation incidence is proposed. In the model, we consider the infection age of infectious individuals and the biological age of pathogen in the environment. It is verified that the global dynamics of the model is completely determined by the basic reproduction number. Asymptotic smoothness is verified as a necessary argument. By analyzing corresponding characteristic equations, we discuss the local stability of each of feasible steady states. Uniform persistence is shown by using the persistence theory for infinite dimensional dynamical system. The global stability of each of feasible steady states is established by using suitable Lyapunov functionals and LaSalle’s invariance principle. Numerical simulations are carried out to illustrate the theoretical results.     

A bioeconomic model of a ratio-dependent predator-prey system and optimal harvesting

This paper deals with the problem of a ratio-dependent prey-predator model with combined harvesting. The existence of steady states and their stability are studied using eigenvalue analysis. Boundedness of the exploited system is examined. We derive conditions for persistence and global stability of the system. The possibility of existence of bionomic equilibria has been considered. The problem of optimal harvest policy is then solved by using Pontryagin’s maximal principle.     

一类阶段结构捕食系统的持久性和全局稳定性

研究了一类具有阶段结构的捕食-食饵系统,通过对模型进行定性分析,给出了系统的持久性、全局渐近稳定性的充分条件.     

一类具有饱和传染力的Schoner竞争系统的概周期解

对一类具有饱和传染力的Schoner竞争系统进行了研究,得到了系统持久生存和任一正解全局渐近稳定的充分条件;同时当系统是概周期系统时,通过构造适当的Liapunov函数,建立了相应系统存在唯一、全局渐近稳定的概周期正解的充分判据.     

On Persistence and Stability of Some Spatially Inhomogeneous Systems

Local and global stability and persistence of some coupled map lattices (CMLs) and partial differential equations are studied. A logistic CML with noninteger time step and delay is introduced. The persistence results for reaction-diffusion equations are extendable to the telegraph reaction-diffusion equation for a sufficiently small delay parameter. The stability and persistence results are applied to ecology, physics, economics, and immunology.     

Delay model of glucose-insulin systems: Global stability and oscillated solutions conditional on delays

Recently P. Palumbo, S. Panunzi and A. De Gaetano analyzed a delay model of the glucose-insulin system. They proved its persistence, the existence of a unique positive equilibrium point, as well as the local stability of this point. In this paper we consider further the uniform persistence of such equilibrium solutions and their global stability. Using the omega limit set of a persistent solution and constructing a full time solution, we also investigate the effect of delays in connection with the behavior of oscillating solutions to the system. The model is shown to admit global stability under certain conditions of the parameters. It is also shown that the model admits slowly oscillating behavior, which demonstrates that the model is physiologically consistent and actually applicable to diabetological research.     

Global Qualitative Analysis for a Ratio-Dependent Predator-Prey Model with Delay

A ratio-dependent predator-prey model with time lag for predator is proposed and analyzed. Mathematical analyses of the model equations with regard to boundedness of solutions, nature of equilibria, permanence, and stability are analyzed. We note that for a ratio-dependent system local asymptotic stability of the positive steady state does not even guarantee the so-called persistence of the system and, therefore, does not imply global asymptotic stability. It is found that an orbitally asymptotically stable periodic orbit exists in that model. Some sufficient conditions which guarantee the global stability of positive equilibrium are given.     

具有Holling Ⅱ类功能反应且周期系数的非自治捕食扩散系统的持久与全局渐近稳定性

研究了一类具有扩散系数和 Holling 类功能反应的一捕两食三种群非自治捕食系统 ,得到了系统持久生存和周期系统存在唯一全局渐近稳定的周期解的条件 .     

THE EFFECT OF A PREDATOR RESOURCE ON A DIFFUSIVE PREDATOR PREY SYSTEM

A model of a predator-prey system with diffusion and predator resource is studied. Both constant and variable resources are considered. In the absence of diffusion, criteria for local stability, instability, and global stability of equilibria, as well as persistence and extinction, are obtained. It is shown that an otherwise unstable uniform equilibrium state may be stabilized by diffusion.