A singular bioeconomic model with diffusion and time delay

This paper studies a prey-predator singular bioeconomic system with time delay and diffusion, which is described by differential-algebraic equations. For this system without diffusion, there exist three bifurcation phenomena: Transcritical bifurcation, singularity induced bifurcation, and Hopf bifurcation. Compared with other biological systems described by differential equations, singularity induced bifurcation only occurs in singular system and usually links with the expansion of population. When the diffusion is present, it is shown that the positive equilibrium point loses its stability at some critical values of diffusion rate and periodic oscillations occur due to the increase of time delay. Furthermore, numerical simulations illustrate the effectiveness of results and the related biological implications are discussed.     

Exponential stability for cellular neural networks: an LMI approach

A new sufficient conditions for the global exponential stability of the equilibrium point for delayed cellular neural networks （DCNNs） is presented. It is shown that the use of a more general type of Lyapunov-Krasovskii function enables the derivation of new results for an exponential stability of the equilibrium point for DCNNs. The results establish a relation between the delay time and the parameters of the network. The results are also compared with one of the most recent results derived in the literature.     

Exponential estimates for stochastic delay equations with norm-bounded uncertainties

This paper presents the sufficient conditions for the exponential stability of linear or semilinear stochastic delay equations with time-varying norm bounded parameter uncertainties. Exponential estimates for the solutions are also obtained by using a modified Lyapunov-Krasovski functional. These conditions can be tested numerically using interior point algorithms. This work is Supported by the National Natural Science Foundation of China under Grant Nos. 10801056 and 10826095.     

变时滞广义神经网络的指数稳定性

讨论具有可变时滞的Cohen Grossberg广义神经网络平衡态的稳定性问题。以推广的Halanay微分不等式为工具,通过构造合适的Lyapunov函数,结合Dini导数和不等式技巧,对具有可变时滞(适合于任何时滞有界情况)的广义神经网络平衡态的指数稳定性进行分析。在适当的假设条件下,得到了系统渐近指数稳定的几个充分性判据,与此同时也给出了相应的Lyapunov指数。     

GLOBAL STABILITY AND HOPF BIFURCATION OF AN SIS EPIDEMIC MODEL WITH TIME DELAYS

1 IntroductionFor epidemic model with delays, many people have done a lot of work and many valuableresults have been obtained. In SIS ePidemiologic models, susceptibles become infectious aftersufficieot contact with an infective and then become susceptible again after they have recoveredfrom the infection. SIS models with a time delay in the infectious class and a constan poWulation size were analyzed by Cooke and Yorke[1] and Greenberg and Hoppensteadt[2J. TheyfOund that aJl solutions a…     

STUDY ON AN SIS EPIDEMIC MODEL WITH TIME VARIANT DELAY

In this paper, we study an SIS epidemic model with a time variant delay. By means of Liapunov functional, some sufficient conditions of global stability to endemic equilibrium and disease free equilibrium have been obtained. The influence of time delay on the stability of equilibria is displayed.     

多输入离散不确定时滞系统变结构控制设计

研究了多输入离散不确定时滞系统的变结构控制问题。首先对原离散时滞不确定系统进行了化简,将其归结为一个无时滞的不确定离散系统形式;在此基础上提出了一种新的变结构控制设计方法和控制律算法,并给出了动态性能比较。对于不确定性为慢变的情况,该算法能使空间任意点出发的运动,都在有限时间内到达滑动模态的设定邻域,渐近稳定的到达到原点,且抖振以指数速率衰减到零。仿真结果表明了方法的有效性。     

学习效应、有限理性与动态古诺竞争复杂性

引入"学习效应"的思想,构建了一类具有学习效应的有限理性古诺竞争模型,利用非线性动力系统的分支理论研究了该模型均衡点的存在性与稳定性,并进行了对比研究与数值仿真。研究结果表明学习效应对动态古诺竞争复杂性有显著影响:系统稳定域随着企业学习效应的增强而增大;系统到达均衡的速度随着企业学习效应的增强而加快;企业产量调整速度的变化对模型的稳定性有较明显的影响。     

Research on Rumor Spreading Model with Time Delay and Control Effect

Information flow retains a critical role in decision making among investors. In this paper,we employ a diffusion model based on epidemiology theory to study the rumor spreading process within investors. The paper introduce the feedback mechanism of classical control theory into the model, which helps to reflect the interaction between rumor spreaders and information supervision.Further we apply a time delay factor to give investors access to transparent information and change their behavior. Subsequently, the stability of the rumor disappearance equilibrium and the rumor existence equilibrium are analyzed and the condition for the system undergoes a Hopf-bifurcation is given. The mathematical arguments are subjected to numerical simulations to present the ideal case scenarios. The results suggest that, increase the general strength of information supervision and the proportion coefficient associated with the infected population in the short-term delay are conducive to better control.     

Global Dynamics for an HIV Infection Model with Crowley-Martin Functional Response and Two Distributed Delays

In this paper, an HIV dynamics model with two distributed intracellular delays incorporating Crowley-Martin functional response infection rate is investigated. The authors take into account multiple stage disease transmission and the latently infected cells (not yet producing virus) in our system. The authors consider nonnegativity, boundedness of solutions, and global asymptotic stability of the system. By constructing suitable Lyapunov functionals and using the Lyapunov-LaSalle invariance principle, the authors prove the global stability of the infected (endemic) equilibrium and the diseasefree equilibrium for time delays. The authors have proven that if the basic reproduction number R₀ is less than unity, then the disease-free equilibrium is globally asymptotically stable, and if R₀ is greater than unity, then the infected equilibrium is globally asymptotically stable. The results obtained show that the global dynamic behaviors of the model are completely determined by the basic reproduction number R₀ and that the time delay does not affect the global asymptotic properties of the model.     

延迟多重休假MX/G/1排队系统的队长分布

考虑延迟多重休假的M^x／G／1排队，在假定延迟时间、休假时间和服务时间都是一般概率分布函数下，研究了队长的瞬态和稳态性质、通过引进“服务员忙期”，导出了在任意时刻t瞬态队长分布的L变换的递推表达式和稳态队长分布的递推表达式，以及平稳队长的随机分解．     

Stability for the mix-delayed Cohen-Grossberg neural networks with nonlinear impulse

<正> In this paper,the authors are concerned with the stability of the mix-delayed Cohen-Grossbergneural networks with nonlinear impulse by the nonsmooth analysis.Some novel sufficientconditions are obtained for the existence and the globally asymptotic stability of the unique equilibriumpoint,which include the well-known results on some impulsive systems and non-impulsive systems asits particular cases.The authores also analyze the globally exponential stability of the equilibriumpoint.Two examples are exploited to illustrate the feasibility and effectiveness of our results.     

THE EQUILIBRIA OF THE SIZE STRUCTURED POPULATION MODEL

In this paper the existence and stability of the positive equilibrium of the size-structured population model are proved by Rabinowitz‘s theorem and the local linearization method.The result here shows that near the bifurcation point where a branch of positive equilibria appears,the stability of the positive equilibrium on the branch is dcpendent on the direction of the bifurcation.The argument for the model of age-structured population is generalized in this paper.     

单滑块变质心再入飞行器分岔特性

基于非线性动力学模型,给出了单滑块变质心再入飞行器的平衡点及其稳定性随滑块偏移距离的变化规律,得到了系统分岔图,并在此基础上求解了典型条件下各吸引子的吸引域。结果表明滑块偏移距离对再入飞行器的平衡点数量及稳定性具有明显的影响,同时初始飞行条件对飞行器的最终收敛状态也具有重要的影响,不合适的初始条件有可能导致飞行器被锁定在不期望的平衡点或极限环中,从而引起失速或失控等问题。此外,通过分析不同系统参数下的分岔图变化规律,总结了再入飞行器结构及气动参数对系统分岔特性的影响,进而为系统参数的设计提供了参考。     

Exact Controllability and Stabilization of Networkswith an Interior Point Mass

1IntroductionInrecentyears,therehavebeenmanyinterestingtopicsoncontrolandstabilizationofsocalled"hybridsystems"illwhichthedynamicsystemsandpossiblyrigidstructuresarerelatedthroughsomeformsofcouplillg.Forexample,seeII],[2]fornetworksofstringswithillteriorpointmasses,15],I6]forseriallyconnectedbeams,17],[slforbeamswitllelldmasses.Thereisseriouserrorinwork[l]becausesystem(l.l)illif]isnotm-dissipativeaccordillgtotheenergynormal(l.3)ll].Inthisarticle,wecorrectthemodelof[l]alldgiveanewenergynormal…     

连续型联想细胞神经网络局部指数稳定性研究

由于细胞神经网络的潜在应用前景 ,它现已成为神经网络研究的新热点。首先给出连续型联想细胞神经网络的数学模型 ,得到了连续型细胞神经网络平衡点局部指数稳定的充要条件及平衡点指数吸引域的估计 ,研究表明对平衡点的指数吸引域的估计 ,只要计算平衡点处的导算子矩阵的对数范数即可。该研究对连续型联想细胞神经网络的设计和应用均有重要的作用。     

THE GLOBAL STABILITY OF A COMPETINGCHEMOSTAT MODEL WITH DELAYED NUTRIENT RECYCLING

In this paper, by applying the method of Liapunov functionals we study the global stability of the positive equilibrium of a competing chemostat model with delayed nutrient recycling. The sufficient conditions of the global stability (involved in average time delay or not) are obtained.     

具有无界时变时滞的线性系统的稳定性

讨论了一类无界时变时滞线性系统的稳定性，给出了无界时变时滞线性系统稳定性的充分条件，这些条件也适用于常时滞系统。同时讨论了具有多个无界时变时滞系统的稳定性，并且改进了一些已有的关于常时滞系统稳定性的结论。最后给出了本文结论的两个示例。     

捕食者具有传染病的时滞捕食系统模型分析

提出了一类捕食者具有传染病的时滞生态-流行病模型.该模型中,捕食者和食饵均具有密度制约,并引入时滞对模型加以讨论.利用特征根法、函数分析法及线性化方法对模型动力学特性进行分析.证明了模型平衡点的存在性并分析其渐近稳定性,得出系统平衡点的渐近稳定性和Hopf分支存在的充分条件.     

End-to-end rate-based congestion control with random loss: convergence and stability

The convergence and stability analysis for two end-to-end rate-based congestion control algorithms with unavoidable random loss in packets are presented, which can be caused by, for example, errors on wireless links. The convergence rates of these two algorithms are analyzed by linearizing them around their equilibrium points, since they are globally stable and can converge to their unique equilibrium points. Some sufficient conditions for local stability in the presence of round-trip delay are obtained based on the general Nyquist criterion of stability. The stability conditions can be considered to be more general. If random loss in the first congestion control algorithm is not considered, they reduce to the local stability conditions which have been obtained in some literatures. Furthermore, sufficient conditions for local stability of a new congestion control algorithm have also been obtained if random loss is not considered in the second congestion control algorithm.