Center manifolds depending on a parameter

For differential equations u^′=A(t)u+f(t,u,λ) obtained from sufficiently small C¹ perturbations of a nonuniform exponential trichotomy, we establish the C¹ dependence of the center manifolds on the parameter λ. Our proof uses the fiber contraction principle to establish the regularity property. We note that our argument also applies to linear perturbations, without further changes.     

Global attractors in fiber bundles and right invariant systems

This article deals with the notions of Lyapunov stability and attraction of semiflows on fiber bundles. The focus of the studies is the question on the existence of global attractors in bundles associated to principal bundles. Applications to right invariant systems are presented.     

Poisson stability for impulsive semidynamical systems

In this paper, the concept of Poisson stability is investigated for impulsive semidynamical systems. Recursive properties are also investigated.     

Exponential stability of hybrid stochastic functional differential systems with delayed impulsive effects: average impulsive interval approach

In this paper, we aim to investigate the exponential stability of general hybrid stochastic functional differential systems with delayed impulses. By using the average impulsive interval and the Lyapunov function method, we derive some sufficient conditions for exponential stability, which are less conservative than those existing results based on the supremum or infimum of impulsive interval and more convenient to be applied than those Razumikhin‐type conditions in the literature. Meanwhile, we show that unstable hybrid stochastic delay differential systems, both linear and nonlinear, can be stabilized by suitably impulsive sequence. Finally, two examples are discussed to illustrate the effectiveness and advantages of the obtained results. Copyright © 2017 John Wiley & Sons, Ltd.     

Three-dimensional time-varying nonlinear systems containing a Hamilton system

In this paper the following three-dimensional nonlinear system is considered:

     

On attractors and stability for semigroup actions and control systems

The present paper is dedicated to the study of various aspects of attraction and stability for semigroup actions on topological spaces. The main purpose is to present the connections among the distinct notions of attractors and stable sets. The concept of Conley attractor is also investigated and related to the other notions of attractors. All the results are applied to the theory of control systems.     

Razumikhin-type theorems on exponential stability of impulsive delay systems

^** Corresponding author. Email: xzliu{at}math.uwaterloo.ca This paper studies the exponential stability of impulsive delaysystems. By employing the Razumikhin technique and Lyapunovfunctions, several exponential stability criteria are establishedfor both linear and non-linear impulsive delay systems. Someexamples are also worked through to illustrate our results.     

Novel delay-dependent asymptotic stability criteria for neural networks with time-varying delays

The problem of delay-dependent asymptotic stability criteria for neural networks (NNs) with time-varying delays is investigated. An improved linear matrix inequality based on delay-dependent stability test is introduced to ensure a large upper bound for time-delay. A new class of Lyapunov function is constructed to derive a novel delay-dependent stability criteria. Finally, numerical examples are given to indicate significant improvement over some existing results.     

时滞脉冲切换系统的实用稳定性-带Razumikhin条件的Lyapunov函数方法

用带Razumikhin条件的Lyapunov函数方法研究了一般形式的时滞脉冲切换系统的实用稳定性,得到了时滞脉冲切换系统实用稳定、一致实用稳定的充分条件.最后,给出了具体的例子及其数值模拟.     

Stability of an interconnected Schrödinger–heat system in a torus region

In this paper, we study the exponential stability of a two‐dimensional Schrödinger–heat interconnected system in a torus region, where the interface between the Schrödinger equation and the heat equation is of natural transmission conditions. By using a polar coordinate transformation, the two‐dimensional interconnected system can be reformulated as an equivalent one‐dimensional coupled system. It is found that the dissipative damping of the whole system is only produced from the heat part, and hence, the heat equation can be considered as an actuator to stabilize the whole system. By a detailed spectral analysis, we present the asymptotic expressions for both eigenvalues and eigenfunctions of the closed‐loop system, in which the eigenvalues of the system consist of two branches that are asymptotically symmetric to the line Reλ =? Imλ. Finally, we show that the system is exponentially stable and the semigroup, generated by the system operator, is of Gevrey class δ > 2. Copyright © 2016 John Wiley & Sons, Ltd.     

Weakly Birkhoff recurrent switching signals, almost sure and partial stability of linear switched dynamical systems

Let {A₁,…,AK}⊂Cd×d be arbitrary K matrices, where K and d both ?2. For any 0<Δ<∞, we denote by the set of all switching sequences u=(λ.,t.):N→{1,…,K}×R₊ satisfying tj−tj−1?Δ and

     

The spectral factorization problem for multivariable distributed parameter systems

This paper studies the solution of the spectral factorization problem for multivariable distributed parameter systems with an impulse response having an infinite number of delayed impulses. A coercivity criterion for the existence of an invertible spectral factor is given for the cases that the delays are a) arbitrary (not necessarily commensurate) and b) equally spaced (commensurate); for the latter case the criterion is applied to a system consisting of two parallel transmission lines without distortion. In all cases, it is essentially shown that, under the given criterion, the spectral density matrix has a spectral factor whenever this is true for its singular atomic part, i.e. its series of delayed impulses (with almost periodic symbol). Finally, a small-gain type sufficient condition is studied for the existence of spectral factors with arbitrary delays. The latter condition is meaningful from the system theoretic point of view, since it guarantees feedback stability robustness with respect to small delays in the feedback loop. Moreover its proof contains constructive elements.     

Dissipativity in impulsive systems via Lyapunov functions

This paper deals with impulsive dissipative semidynamical systems. We present sufficient conditions to obtain dissipativity for autonomous and non‐autonomous systems by using Lyapunov functions. Also, some converse‐type results are presented.     

Stability and boundedness of nonlinear impulsive systems in terms of two measures via perturbing Lyapunov functions

This paper develops the concepts of stability, practical stability and boundedness in terms of two measures for nonlinear impulsive differential systems using the method of perturbing Lyapunov functions. The notion of perturbing Lyapunov functions enables us to discuss stability properties of solutions of nonlinear impulsive differential systems in terms of two measures under much weaker assumptions. The novel results offer a way to unify a variety of stability results found in the relative literature.     

Fundamental systems for linear differential equations smoothly depending on a parameter

Homogeneous linear differential equations in Banach spaces are considered, which depend smoothly on a parameter. A fundamental system of solutions is generated by eigenvalues and eigenvectors of the corresponding operator pencil. The dependence on the parameter of these solutions in canonical form is, in general, not smooth because of branching eigenvalues. This means, the eigenvalues, their number and multiplicities may change in a nonsmooth way with respect to the parameter. We construct a new fundamental system depending smoothly on the parameter, wich can be represented by linear combinations of the solutions in canonical form.     

EVENTUAL STABILITY OF IMPULSIVE DIFFERENTIAL SYSTEMS

In this article, criteria of eventual stability are established for impulsive differential systems using piecewise continuous Lyapunov functions. The sufficient conditions that are obtained significantly depend on the moments of impulses. An example is discussed to illustrate the theorem.     

Stability and boundedness criteria of nonlinear impulsive systems employing perturbing Lyapunov functions

This paper develops a new comparison principle for nonlinear impulsive differential systems, then the stability, practical stability and boundedness of impulsive differential systems are proved by using the method of perturbing Lyapunov functions. The notion of perturbing Lyapunov functions enables us to discuss stability properties of impulsive systems under much weaker assumptions. The reported novel results complement the existing results. It may provide a greater prospect for solving problems which exhibit impulsive effects.     

Exact controllability of infinite dimensional systems persists under small perturbations

This paper studies the concept of controllability for infinite-dimensional linear control systems in Banach spaces. First, we prove that the set of admissible control operators for the semigroup generator is unchanged if we perturb the generator by the Desch–Schappacher perturbations. Second we show that exact controllability is not changed by such perturbations.     

Stability criteria for impulsive systems on time scales

In this paper we study stability of impulsive system on time scales. By using comparison method, Lyapunov function and analysis method, the asymptotic stability criteria for system with impulses at fixed times and impulses at variable times on time scales are obtained, respectively. An example is presented to illustrate the efficiency of proposed result.     

A new criterion for global robust stability of interval delayed neural networks

A novel criterion for the global robust stability of Hopfield-type interval neural networks with delay is presented. An example showing the effectiveness of the present criterion is given.