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1.
In this paper, we study a class of reaction-diffusion systems with Beddington- DeAngelis function response. The global asymptotic convergence is established by using the comparison principle and the method of monotone iterations, which is via successive improvement of upper-lower solutions function.  相似文献   

2.
研究苍蝇追逐动态行为,针对不同的追逐行为建立了微分方程模型,利用数值模拟的方法分析模型的渐近行为,并结合微分方程的定性理论,讨论了苍蝇个体大小对追逐动态行为的影响.  相似文献   

3.
4.
具有功能性反应和时滞的扩散捕食-食饵系统   总被引:3,自引:0,他引:3  
考虑具有功能性反应和时滞的扩散捕食-食饵系统,其中食饵连两个斑块间具有一定的扩散系数,捕食者可以两个斑块中任意走动,我们讨论了系统的一致持久性和周期解的存在性及全局吸引性.  相似文献   

5.
    
This paper is devoted to studying the dynamical properties of a general intraguild predation model with intraspecific competition. We first investigate the stability of all possible equilibria in relation to the ecological parameters, and then study the long time behavior of the solution. Moreover, we provide a detailed analysis of dynamics of a IGP model with linear functional response and intraspecific competition. Our results show that the impact of the intraspecific competition essentially increases the dynamical complexity of the system.  相似文献   

6.
We obtain some sufficient conditions for the existence of the solutions and the asymptotic behavior of both linear and nonlinear system of differential equations with continuous coefficients and piecewise constant argument.  相似文献   

7.
    
In this study, we address an SIR (susceptible-infected-recovered) model that is given as a system of first order differential equations and propose the SIR model on time scales which unifies and extends continuous and discrete models. More precisely, we derive the exact solution to the SIR model and discuss the asymptotic behavior of the number of susceptibles and infectives. Next, we introduce an SIS (susceptible-infected-susceptible) model on time scales and find the exact solution. We solve the models by using the Bernoulli equation on time scales which provides an alternative method to the existing methods. Having the models on time scales also leads to new discrete models. We illustrate our results with examples where the number of infectives in the population is obtained on different time scales.  相似文献   

8.
We review recent results on the hydrodynamical model for semiconductors. The derivation of the mathematical model from the semi-classical Boltzmann equation in terms of the moment method is performed, and the mathematical analysis of the asymptotic behavior of both classical solutions and entropy weak solutions is given on spatially bounded domain or whole space.Dedicated to Constantine Dafermos on his 60th birthday  相似文献   

9.
This paper deals with a stochastic system which models the population dynamics of a chemostat including species death rate. On the basis of the theory on Markov semigroup, we demonstrate that the probability densities of the distributions for the solutions are absolutely continuous. The densities will convergence in L1 to an invariant density or weakly convergence to a singular measure under appropriate conditions. We also give the sufficient criteria for extinction exponentially of the species. To be specific, when D1>D and the strength of perturbation is relatively small, we derive a precise threshold for the species survival.  相似文献   

10.
For differential equations with piecewise constant arguments of advanced type, numerical stability and oscillations of Runge-Kutta methods are investigated. The necessary and sufficient conditions under which the numerical stability region contains the analytic stability region are given. The conditions of oscillations for the Runge-Kutta methods are obtained also. We prove that the Runge-Kutta methods preserve the oscillations of the analytic solution. Moreover, the relationship between stability and oscillations is discussed. Several numerical examples which confirm the results of our analysis are presented.  相似文献   

11.
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This paper deals with dynamics of a predator-prey model with Allee effect and herd behavior. We first study the stability of non-negative constant solutions for such system. We also establish the existence of Hopf bifurcation solutions for such predator-prey model. The stability and bifurcation direction of Hopf bifurcation solution in the case of spatial homogeneity are further discussed. At the same time, several examples are given by MATLAB. Finally, the numerical simulations of the system are carried out through MATLAB, which intuitively verifies and supplements the theoretical analysis results.  相似文献   

12.
Chang  Woojin  Down  Douglas G. 《Queueing Systems》2002,42(4):401-419
In this paper we find exact asymptotic expressions for the event that the total queue length is large for a k i -limited exponential polling model with equal service rates and two classes of customer. It is found that this behaviour divides into two very different regimes, depending on the arrival rates to the system. Using these exact asymptotic expressions, we provide heuristics for choosing the k i values to provide a given level of quality of service to one class while giving best effort to the other class.  相似文献   

13.
Our aim in this paper is to investigate the global asymptotic stability of all positive solutions of the higher order nonlinear difference equation
where B, C and α, β, γ are positive, k {1, 2, 3, … }, and the initial conditions x−2k+1, … , x−1, x0 are positive real numbers. We show that the unique positive equilibrium of the equation is globally asymptotically stable and has some basins that depend on certain conditions posed on the coefficients. Our concentration is on invariant intervals, the character of semicycles, and the boundedness of the above mentioned equation. Our final comments are about informative examples.  相似文献   

14.
This paper deals with the dynamics of a predator-prey model with Hassell-Varley-Holling functional response. First, we show that the predator coexists with prey if and only if predator's growth ability is greater than its death rate. Second, using a blow-up technique, we prove that the origin equilibrium point is repelling and extinction of both predator and prey populations is impossible. Third, the local and global stability of the positive steady state coincide when the predator interference is large. Finally, for a typical biological case, we show instability of the positive equilibrium implies global stability of the limit cycle. Numerical simulations are carried out for a hypothetical set of parameter values to substantiate our analytical findings.  相似文献   

15.
具有时滞的生态流行病模型的稳定性和Hopf分支   总被引:10,自引:0,他引:10       下载免费PDF全文
该文考虑一类食饵染病的时滞捕食被捕食模型. 作者分析了系统的非负不变性, 边界平衡点的性质和全局稳定性. 证明了当时滞τ=τ-1+τ-2适当小时, 正平衡点是局部渐近稳定的,随着时滞的增加, 正平衡点由稳定变为不稳定, 系统在正平衡点附近发生Hopf分支.  相似文献   

16.
    
We present and analyze a nonlinear size-structured juvenile-adult model with a fixed sex-ratio, in which juveniles are structured by size, while adults by age. Global or local stability results are investigated by the method of characteristics and prior estimations, which show that, if the net reproduction rate is less than one, the population will be extinct for any initial distributions; On the other hand, the population may be extinct or increase in a manner faster than exponential style if the net reproduction rate is greater than one. By using Laplace transform methods, asymptotic behavior of solutions is analyzed too.  相似文献   

17.
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We investigate the asymptotic profile to the Cauchy problem for a non‐linear dissipative evolution system with conservational form (1) provided that the initial data are small, where constants α, ν are positive satisfying ν2<4α(1 ? α), α<1. In (J. Phys. A 2005; 38 :10955–10969), the global existence and optimal decay rates of the solution to this problem have been obtained. The aim of this paper is to apply the heat kernel to examine more precise behaviour of the solution by finding out the asymptotic profile. Precisely speaking, we show that, when time t → ∞ the solution and solution in the Lp sense, where G(t, x) denotes the heat kernel and is determined by the initial data and the solution to a reformulated problem obtained in Section 3, β is related to ?+ and ?? which are determined by (41) in Section 4. The numerical simulation is presented in the end. The motivation of this work thanks to Nishihara (Asymptotic profile of solutions to nonlinear dissipative evolution system with ellipticity. Z. Angew Math Phys 2006; 57 : 604–614). Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

19.
本文讨论一类燃烧波模型.在较弱的条件下证明该问题解的存在唯一性,并给出了解的渐近行为.  相似文献   

20.
    
In this paper, we study a class of second order difference equations with three paremeters. With positive initial values, the asymptotic behavior of positive solutions are investigated.  相似文献   

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