Global attractivity in a discrete delay logistic model

1.IntroductionIntherecentworks[l--31,theauthorsconsideredthediscretedelaylogisticmodelIn[3],itwasshownthateverypositivesolutionof(l)oscillatesaboutitspositiveequilibriumx~(a--1)/0ifandonlyifIn[if(seealso[2]),itwasprovedthatiftheneverypositivesolutionof(1)tendstox~(or--1)/pasn-- co.Thepurposeofthispaperistoobtainanothersufficieatconditionforthepositiveequilibriumxof(1)tobeaglobalattractorbyusingamethodverydmerelltfromthatusedin[1,21.Themainresultofthispaperisthefollowingtheorem.*Thisworkispart…     

GLOBAL ATTRACTIVITY IN AGENERALIZED DELAY LOGISTIC EQUATION

Abstract.Based on the literature     

一类时滞Logistic差分方程的全局吸引性

§ 1　ＩｎｔｒｏｄｕｃｔｉｏｎＣｏｎｓｉｄｅｒｔｈｅｎｏｎａｕｔｏｎｏｍｏｕｓｄｅｌａｙｌｏｇｉｓｔｉｃｄｉｆｆｅｒｅｎｃｅｅｑｕａｔｉｏｎΔｙｎ =ｐｎｙｎ( 1 - ｙτ(ｎ) )　 ,ｎ =0 ,1 ,2 ,...,( 1 1 )ｗｈｅｒｅｐｎ ∞ｎ =0 ｉｓａｓｅｑｕｅｎｃｅｏｆｐｏｓｉｔｉｖｅｒｅａｌｎｕｍｂｅｒｓ ,τ(ｎ) ∞ｎ =0 ｉｓａｎｏｎｄｅｃｒｅａｓｉｎｇｓｅｑｕｅｎｃｅｏｆｉｎｔｅｇｅｒｓ,τ(ｎ) <ｎａｎｄｌｉｍｎ→∞τ(ｎ) =∞ ,Δｙｎ=ｙｎ +1- ｙｎ.Ｍｏｔｉｖａｔｅｄｂｙｐｌａｕｓｉｂｌｅａｐｐｌｉｃａｔｉｏｎｓ…     

Global attractivity for scalar differential equations with small delay

For scalar functional differential equations , we refine the method of Yorke and 3/2-type conditions to prove the global attractivity of the trivial solution. The results are applied to establish sufficient conditions for the global attractivity of the positive equilibrium of scalar delayed population models of the form , and illustrated with the study of two food-limited population models with delay, for which several criteria for their global attractivity are given.     

一类广义时滞 Logistic 方程的全局吸引性

本文研究了一类广义时滞Logistic方程的全局吸引性,获得了该方程的正平衡点全局吸引的一个充分条件,对已有的结果进行了改进和推广.     

Global attractivity of a family of nonautonomous max-type difference equations

This paper studies a family of nonautonomous max-type difference equations with several delays. Using some transformations we prove global attractivity of positive solutions to these equations under some conditions. Some of our results considerably extend related ones in the literature. Two examples are given to illustrate the main results.     

具有可变时滞的非线性非自治差分方程的线性化全局渐近稳定性及其应用

证明了在一定条件下,具有可变时滞的非线性非自治差分方程的全局渐近稳定性可由某种线性差分方程的渐近稳定性确定,给出了这类差分方程全局渐近稳定的充分条件.作为实例,获得了具有可变时滞的离散型非自治广义Log istic方程的全局吸收性判别准则.     

Global attractivity and positive almost periodic solution for delay logistic differential equation

In this paper, we establish some sufficient conditions for the global attractivity of positive solutions and the unique existence of positive almost periodic solutions for delay logistic differential equations of the form

x^′(t)=r(t)x(t)(a(t)−b(t)x(t)−L(_xt)).$x^{\prime }\left(t\right)=r\left(t\right)x\left(t\right)(a\left(t\right)-b\left(t\right)x\left(t\right)-L\left(x_t\right))\text{.}$

Global attractivity of the almost periodic solution of a delay logistic population model with impulses

In this paper, we study the existence of almost periodic solutions of a delay logistic model with fixed moments of impulsive perturbations. By using a comparison theorem and constructing a suitable Lyapunov functional, a set of sufficient conditions for the existence and global attractivity of a unique positive almost periodic solution is obtained. As applications, some special models are studied; our new results improve and generalize former results.     

Global attractivity of nonautonomous stage-structured population models with dispersal and harvest

The nonautonomous stage-structured single-species dispersal model with harvesting of mature individuals in an N-patch environment is considered, in which the individual members of the population have a life history that takes them through two stages, immature and mature. By using the theory of monotone and concave operators to functional differential equations, we establish conditions under which this population dynamical system admits a positive periodic solution which attracts all positive solutions.     

Global attractivity of a positive periodic solution for a nonautonomous stage structured population dynamics with time delay and diffusion

By employing the continuation theorem of coincidence degree theory, the existence of a positive periodic solution for a nonautonomous stage structured population dynamics with time delay and diffusion is established. Further, by constructing a Lyapunov functional and using the result of the existence of positive periodic solution, the attractivity of a positive periodic solution for above system is obtained.     

Global attractivity for impulsive population dynamics with delay arguments

This article investigates the global attractivity for impulsive population dynamics with delay arguments. Several sufficient conditions are obtained to ensure the global attractivity of the zero solution. These conditions do not require the boundedness of delay arguments, nor do they require some strict conditions on impulsive functions.     

Pseudo-almost periodicity of some nonautonomous evolution equations with delay

This paper is concerned with pseudo-almost periodicity of the solutions to the nonautonomous evolution equation with delay u^′(t)=A(t)u(t)+f(t,u(t−h))$u^{\prime }\left(t\right)=A\left(t\right)u\left(t\right)+f(t,u(t-h))$. Some sufficient conditions which ensure the existence and uniqueness of pseudo-almost periodic mild solutions to the evolution equation with delay are given. An example is shown to illustrate our results.