非自治多种群时滞Kolmogorov系统的持续性和灭绝性

研究非自治多种群时滞Kolmogorov系统,给出了该系统中种群持续和灭绝的充分条件,并把得到的结果应用于非自治时滞Lotka-Volterra系统.把相关文献的有关结果推广到时滞系统.     

一类时滞系统的稳定性分析及控制器设计

研究一类具有状态时滞和输入时滞的时变时滞线性系统.首先,通过选取合适的Lyapunov-Krasovskii泛函,应用LMI方法和Lyapunov-Krasovskill稳定性定理对时滞相关的系统进行稳定性分析,并设计了相应的控制器.改进了时变时滞线性系统方面的一些结果.最后用实例验证所得到结果.     

基于Razumikhin方法研究随机时滞系统的脉冲同步

研究了脉冲信号作用下随机时滞系统的指数稳定性问题,基于Razumikhin方法建立了判断随机时滞脉冲系统指数稳定性判定定理,并给出收敛速度的求法.作为应用,考查了典型随机时滞混沌系统的脉冲同步问题,得到脉冲信号作用下随机时滞混沌系统的收敛速度.数值模拟结果验证了理论结果的正确性.     

具脉冲和时滞影响的非线性抛物系统边值问题的振动结果

研究一类具非线性扩散项的脉冲时滞抛物偏微分系统解的振动性,借助Green公式、垂直相加法和脉冲时滞微分不等式,获得了该类系统在Robin边值条件下振动的充分性条件.所得结果充分反映了脉冲和时滞在系统振动中的影响作用.     

非自治时滞微分系统的周期解

本文将一类非自治时滞微分方程变换为等价的哈密顿系统.这样求解此时滞微分系统可以等价于求解相应的哈密顿系统.运用Floquet变换和辛变换方法,建立了此类微分系统多重周期解的存在性定理,此结果推广了先前文献中的一些结果.     

一类二阶时滞微分方程在控制系统中的应用

基于时滞微分方程稳定性理论,针对一类状态向量中含有时滞的控制系统,研究其时滞相关稳定性问题.通过构造Lyapunov函数,获得了系统稳定、分岔的时滞相关充分条件,所得结论推广和改进了某些已有文献的相应结果.且借助实例及仿真结果解释所得结果的有效性.     

中立型时滞系统的时滞相关鲁棒控制

研究了一类具有时变时滞中立型系统的时滞相关鲁棒控制问题.利用Lyapunov-K rasovsk ii泛函方法,借助于积分不等式,得到了系统经无记忆状态反馈控制后可镇定的时滞相关条件.最后给出数值例子验证了所得结果的有效性.     

具有时滞和间接控制的捕食-被捕食模型的分支分析

研究了一类具有时滞和间接控制的捕食-被捕食模型.选择时滞τ为分支参数,证实了系统在一定的时滞范围内是渐近稳定的.当时滞τ通过一系列的临界值时,Hopf分支产生,即当时滞τ通过某些临界值时,从平衡点处产生一簇周期解.最后,用数值模拟验证了理论分析结果的正确性.     

中立型时滞系统的稳定性改进判据

研究了含有时变时滞的不确定中立系统的时滞相关稳定性问题.假定不确定参数是范数有界的,通过构造新的Lyapunov泛函和使用更一般的时滞分解方法,得到了基于LMI新颖的时滞相关稳定条件,并且用Matlab LMI工具箱很容易地求解.数值实例表明本文方法所得结果优于现有文献中的结果.     

具时滞反馈金融系统的动力学分析与混沌控制

研究了时滞反馈对金融系统的动力学行为的影响.以时滞为分支参数,研究了系统平衡点的局部稳定性,并发现当时滞经过一系列临界值时,系统在平衡点附近经历Hopf分支和Hopf-zero分支.然后,应用规范型方法和中心流形理论得到决定分支周期解性质的详细公式.通过设计合适的反馈增益和时滞,混沌振荡可以控制为稳定的平衡点或周期轨.最后,数值模拟验证了理论结果.     

Stability of interconnected impulsive systems with and without time delays,using Lyapunov methods

In this paper, we consider the input-to-state stability (ISS) of impulsive control systems with and without time delays. We prove that, if the time-delay system possesses an exponential Lyapunov–Razumikhin function or an exponential Lyapunov–Krasovskii functional, then the system is uniformly ISS provided that the average dwell-time condition is satisfied. Then, we consider large-scale networks of impulsive systems with and without time delays and prove that the whole network is uniformly ISS under the small-gain and the average dwell-time condition. Moreover, these theorems provide us with tools to construct a Lyapunov function (for time-delay systems, a Lyapunov–Krasovskii functional or a Lyapunov–Razumikhin function) and the corresponding gains of the whole system, using the Lyapunov functions of the subsystems and the internal gains, which are linear and satisfy the small-gain condition. We illustrate the application of the main results on examples.     

LMI conditions for stability of impulsive stochastic Cohen–Grossberg neural networks with mixed delays

In this paper, the global asymptotic stability of impulsive stochastic Cohen–Grossberg neural networks with mixed delays is investigated by using Lyapunov–Krasovskii functional method and the linear matrix inequality (LMI) technique. The mixed time delays comprise both the multiple time-varying and continuously distributed delays. Some new sufficient conditions are obtained to guarantee the global asymptotic stability of the addressed model in the stochastic sense using the powerful MATLAB LMI toolbox. The results extend and improve the earlier publications. Two numerical examples are given to illustrate the effectiveness of our results.     

Global asymptotic stability of BAM fuzzy cellular neural networks with time delay in the leakage term,discrete and unbounded distributed delays

In this article, a class of bidirectional associative memory (BAM) fuzzy cellular neural networks (FCNNs) with time delay in the leakage term, discrete and unbounded distributed delays is formulated to study the global asymptotic stability. This approach is based on the Lyapunov–Krasovskii functional with free-weighting matrices. Using linear matrix inequality (LMI), a new set of stability criteria for BAM FCNNs with time delay in the leakage term, discrete and unbounded distributed delays is obtained. Also, the stability behavior of BAM FCNNs is very sensitive to the time delay in the leakage term. In the absence of a leakage term, a new stability criteria is also derived by employing a Lyapunov–Krasovskii functional and using the LMI approach. Our results establish a new set of stability criteria for BAM FCNNs with discrete and unbounded distributed delays. Numerical examples are provided to illustrate the effectiveness of the developed techniques.     

On the exponential stability of solutions of periodic systems of the neutral type with several delays

We obtain conditions for the exponential stability of the zero solution of linear periodic systems of differential equations of the neutral type with several constant delays, which are stated in terms of a Lyapunov–Krasovskii functional of a special form. We derive estimates that specify the decay rate of solutions at infinity.     

Stability analysis for networked control systems with sampling,transmission protocols and input delays

In this paper, the stability problem is investigated for networked control systems. Input delays and multiple communication imperfections containing time-varying transmission intervals and transmission protocols are considered. A unified framework based on the hybrid systems with memory is proposed to model the whole networked control system. Hybrid systems with memory are used to model hybrid systems affected by delays and permit multiple jumps at a jumping instant. The stability analysis depends on the Lyapunov–Krasovskii functional approaches for hybrid systems with memory and the proposed stability theorem does not need strict decrease of the Lyapunov–Krasovskii functional during jumps. Based on the developed stability theorems, stability conditions for networked control systems are established. An explicit formula is given to compute the maximal allowable transmission interval. In the special case that the networked control system contains linear dynamics, an explicit Lyapunov functional is constructed and stability conditions in terms of linear matrix inequalities (LMI) are proposed. Finally, an example of a chemical batch reactor is given to illustrate the effectiveness of the proposed results.     

一类非线性时滞系统的时滞相关镇定及跟踪控制问题

本文讨论了一类满足Lipschitz条件的非线性时滞系统的镇定与跟踪控制问题.基于非线性状态反馈控制器,利用Lyapunov-Krasovskii泛函和矩阵理论,得到了系统时滞相关全局渐近镇定的新判据,并且保证了输出和状态跟踪控制的误差全局渐近收敛于零.本文推广了文献[9]所得到的结论.因此,本文所研究的模型及所给出的判定条件更具有一般性和实用性.     

Improved stability criteria for neutral type Lur’e systems with time-varying delays

In this letter, the problem of stability analysis for neutral type Lur’e systems with interval time-varying delays is considered. By introducing a novel Lyapunov–Krasovskii (L–K) functional and utilizing second order reciprocal convex combination technique and Finsler lemma, an improved delay-dependent stability criteria is derived in terms of linear matrix inequalities (LMIs). The information about the time-varying delays and their upper bounds are fully used in the L–K functional. Finally, a numerical example is provided to illustrate the effectiveness of the proposed method.     

Exponential stability criterion for chaos synchronization in modulated time-delayed systems

In this paper, we consider two unidirectionally coupled time delayed systems with periodic delay time modulation. A new stability condition for synchronization is derived analytically with the help of the Krasovskii–Lyapunov approach for single and two time delays. The numerical calculations greatly support our analytical results.