Existence of asymptotically almost periodic solutions and stability properties for functional difference equations

For functional difference equations with unbounded delay,we characterized the existence of totally stable and asymptotically almost periodic solution by using stability properties of a bounded solution in a certain limiting equation.

EXISTENCE AND STABILITY OF PERIODIC AND ALMOST PERIODIC SOLUTIONS TO THE BOUSSINESQ SYSTEM IN UNBOUNDED DOMAINS

In this paper we investigate the existence and stability of periodic solutions(on a half-line R_(+))and almost periodic solutions on the whole line time-axis R to the Boussinesq system on several classes of unbounded domains of R^(n) in the framework of interpolation spaces.For the linear Boussinesq system we combine the L^(p)—L^(q)-smoothing estimates and interpolation functors to prove the existence of bounded mild solutions.Then,we prove the existence of periodic solutions by invoking Massera’s principle.We also prove the existence of almost periodic solutions.Then we use the results of the linear Boussinesq system to establish the existence,uniqueness and stability of the small periodic and almost periodic solutions to the Boussinesq system using fixed point arguments and interpolation spaces.Our results cover and extend the previous ones obtained in[13,34,38].

Existence and Uniqueness of Almost Periodic Solutions for Some Infinite Delay Integral Equations

In this paper, the existence and uniqueness of almost periodic solutions for some infinite delay integral equations are discussed. By using Krasnoselskii fixed point theorem,some new results are obtained.

The Existence of Periodic and Almost Periodic Solutions of Logistic Type Equation

In this paper, we study the Logistic type equation x= a（t）x -b（t）x^2＋ e（t）. Under the assumptions that e（t） is small enough and a（t）, b（t） are contained in some positive intervals, we prove that this equation has a positive bounded solution which is stable. Moreover, this solution is a periodic solution if a（t）, b（t） and e（t） are periodic functions, and this solution is an almost periodic solution if a（t）, b（t） and e（t） are almost periodic functions.

PERIODIC AND ALMOST PERIODIC SOLUTIONS FOR A NON-AUTONOMOUS RESPIRATORY DISEASE MODEL WITH A LAG EFFECT

This paper studies a kind of non-autonomous respiratory disease model with a lag effect.First of all,the permanence and extinction of the system are discussed by using the comparison principle and some differential inequality techniques.Second,it assumes that all coefficients of the system are periodic.The existence of positive periodic solutions of the system is proven,based on the continuation theorem in coincidence with the degree theory of Mawhin and Gaines.In the meantime,the global attractivity of positive periodic solutions of the system is obtained by constructing an appropriate Lyapunov functional and using the Razumikin theorem.In addition,the existence and uniform asymptotic stability of almost periodic solutions of the system are analyzed by assuming that all parameters in the model are almost periodic in time.Finally,the theoretical derivation is verified by a numerical simulation.

Almost periodic solutions of memristive multidirectional associative memory neural networks with mixed time delays

Traditional biological neural networks cannot simulate the real situation of the abrupt synaptic connections between neurons while modeling associative memory of human brains.In this paper,the memristive multidirectional associative memory neural networks(MAMNNs)with mixed time-varying delays are investigated in the sense of Filippov solution.First,three steps are given to prove the existence of the almost periodic solution.Two new lemmas are proposed to prove the boundness of the solution and the asymptotical almost periodicity of the solution by constructing Lyapunov function.Second,the uniqueness and global exponential stability of the almost periodic solution of memristive MAMNNs are investigated by a new Lyapunov function.The sufficient conditions guaranteeing the properties of almost periodic solution are derived based on the relevant definitions,Halanay inequality and Lyapunov function.The investigation is an extension of the research on the periodic solution and almost periodic solution of bidirectional associative memory neural networks.Finally,numerical examples with simulations are presented to show the validity of the main results.

Almost Periodic Solutions for Nonlinear Duffing Equations

The main purpose of this paper is to investigate the existence of almost periodic solutions for the Duffing differential equation.By combining the theory of exponential dichotomies with Liapunov functions,we obtain an intersting result on the existence of almost periodic solutions.

EXISTENCE OF ALMOST PERIODIC SOLUTIONS FOR DIFFERENCE SYSTEMS

In this work, we first define the notions of almost periodic sequences, asymptotically almost periodic sequences, as well as uniformly almost periodic sequences,and reveal their basic properties. Then for the almost periodic difference systems of general form we establish the criteria of existence for almost periodic solutions.Especially, several existence theorems are proved in terms of discrete Liapunov functions.

PERIODIC AND ALMOST PERIODIC SOLUTIONS OF A CERTAIN INFINITE DELAY INTEGRAL EQUATION

In this paper, hy using successive approximation method and fixed-point theorem, we discuss a class of infinite delay integral equation and obtain some sufficient conditions which guarantee the existence and uniqueness of the periodic and almost periodic solutions of the system.

EXISTENCE AND UNIQUENESS OF ALMOST PERIODIC SOLUTIONS FOR FORCED RAYLEIGH EQUATIONS

The aim of this paper is to investigate the existence and uniqueness of almost periodic solutions for the forced Rayleigh equation. By combining the theory of exponential dichotomies with Liapunov functions, we obtain an interesting result on the existence of almost periodic solutions.

ON ALMOST PERIODIC SOLUTIONS TO THIRD-ORDER NEUTRAL DELAY-DIFFERENTIAL EQUATIONS WITH PIECEWISE CONSTANT ARGUMENT

We present some conditions for the existence and uniqueness of almost periodic solutions to third order neutral delay-differential equations with piecewise constant.

ON ALMOST PERIODIC SOLUTIONS OF AHIGHER ORDER ALMOST PERIODIC SYSTEM

This paper deals with the problems on the existence and uniqueness and stability of almost periodic solutions of a higher almost periodic system. We establish the sufficient conditions which guarantee the existence and uniqueness and stability of almost periodic solutions of this system.

STABILITY AND ALMOST PERIODIC SOLUTIONS OF NEUTRAL FUNCTIONAL DIFFERENTIAL EQUATIONS WITH INFINITE DELAY

For the operator D(t), we prove the inherence theorem, Theorem 2. Basing on it, we study the stability with respect to the hull for neutral functional differential equations with infinite delay. We prove that if periodic Eq.(1) possesses the solution ξ(t) that is uniformly asymptotically stable with respect to then Eq.(1) has an mω-periodic solution p(t), for some integer m≥1. Furthermore, we prove that if the almost periodic Eq.(1) possesses the solution ξ(t) that is stable under disturbance from H+ (ξ,D,f), then Eq.(1) has an almost periodic solution.

THE EXISTENCE AND UNIQUENESS AND STABILITY OF ALMOST PERIODIC SOLUTIONS FOR FUNCTIONAL DIFFERENTIAL EQUATIONS WITH INFINITE DELAYS

This paper deals with the problems on the existence and uniqueness and stability of almost periodic solutions for functional differential equations with infinite delays.The author obtains some sufficient conditions which ganrantee the existence and uniqueness and stability of almost periodic solutions with module containment.The results extend all the results of the paper and solve the two open problems proposed in under much weaker conditions than that proposed in.

Weighted Pseudo Almost Periodic Solutions of N-th Order Neutral Differential Equations with Piecewise Constant Arguments

In this work, we present some existence theorems of weighted pseudo almost periodic solutions for N-th order neutral differential equations with piecewise constant argument by means of weighted pseudo almost periodic solutions of relevant difference equations.

PERIODIC SOLUTIONS AND ALMOST PERIODIC SOLUTIONS OF A NONAUTONOMOUS PREDATOR-PREY SYSTEM WITH STAGE-STRUCTURE AND DELAY

In this paper, by using the comparing theorem, Razumikhin-type theorem and V-function method, we consider a nonautonomous predator-prey system with stage-structure and time-delay. We get the sufficient conditions for the uniform persistence and the solutions global attractivity of this system. For a periodic system, we obtain the existence and uniqueness of a positive periodic solution of this system. For an almost periodic system, we prove the existence and the uniform asymptotic stability of the almost periodic solutions of this system.

ALMOST PERIODIC SOLUTIONS OF NONLINEAR DUFFING'S EQUATIONS WITH DELAY

We consider the delay Duffing equation wilers g uniformly almost periodic in t. We provide existence, uniqueness results for almost periodic soltltion of eq.(1), the method of approach uses sub and supersolutions and degree theory.

Almost Periodic Solutions by the Harmonic Balance Method

We consider non-autonomous ordinary differential equations in two cases.One is the one-dimensional case that admits a condition of hyperbolicity,and the other one is the higher-dimensional case that admits an exponential dichotomy.For differential equations of this kind,we give a rigorous treatment of the Harmonic Balance Method to look for almost periodic solutions.

PERMANENCE,PERIODIC AND ALMOST PERIODIC SOLUTIONS OF NONAUTONOMOUS STAGE STRUCTURED POPULATION DYNAMICS WITH TIME DELAY AND DIFFUSION

A nonautonomous stage-structured two species model with time delay and diffusion is considered. It is shown that the system is uniformly persistent under some conditions. By discussing the independent subsystem, more brief sufficient conditions are drawn for a unique positive periodic solution which is globally attractive and the existence of the positive almost periodic solution which is uniformly asymptotically stable by the Razumikhin function method.

ON THE EXISTENCE AND UNIQUENESS OF ALMOST PERIODIC SOLUTIONS TO DISCRETE TWO-SPECIES COMPETITIVE SYSTEMS

In this paper, we consider almost periodic discrete two-species competitive sys-tems. By using Lyapunov functional, the existence conditions and uniqueness of almost periodic solutions for the this type of systems are obtained.