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1.
一个具有非线性接触率和种群动力学的传染病模型   总被引:2,自引:0,他引:2  
本文研究了具有非线性接触率和易感类中具有Logistic增长的SI传染病模型的正不变集,平衡位置以及平衡位置的稳定性。  相似文献   

2.
基于非均匀变异的进化算法对高维多峰函数的收敛性分析   总被引:3,自引:0,他引:3  
对基于非均匀变异算子的进化算法的实验和机理分析已经证明了该算法模型的良好特性,最近基于非均匀变异算子的进化算法模型求解一维多峰函数问题的收敛性已经得到证明.基于马尔科夫过程理论,对基于非均匀变异算子的一般性进化算法模型和一般性高维多峰函数的收敛性给出证明,并基于典型算例与同类典型算法进行性能比较,数值试验表明算法模型具有很好的性能表现和应用前景.  相似文献   

3.
This article explores the characteristics of the average abundance function with mutation on the basis of the multi-player snowdrift evolutionary game model by analytical analysis and numerical simulation.The specific field of this research concerns the approximate expressions of the average abundance function with mutation on the basis of different levels of selection intensity and an analysis of the results of numerical simulation on the basis of the intuitive expression of the average abundance function.In addition,the biological background of this research lies in research on the effects of mutation,which is regarded as a biological concept and a disturbance to game behavior on the average abundance function.The mutation will make the evolutionary result get closer to the neutral drift state.It can be deduced that this affection is not only related to mutation,but also related to selection intensity and the gap between payoff and aspiration level.The main research findings contain four aspects.First,we have deduced the concrete expression of the expected payoff function.The asymptotic property and change trend of the expected payoff function has been basically obtained.In addition,the intuitive expression of the average abundance function with mutation has been obtained by taking the detailed balance condition as the point of penetration.It can be deduced that the effect of mutation is to make the average abundance function get close to 1/2.In addition,this affection is related to selection intensity and the gap.Secondly,the first-order Taylor expansion of the average abundance function has been deduced for when selection intensity is sufficiently small.The expression of the average abundance function with mutation can be simplified from a composite function to a linear function because of this Taylor expansion.This finding will play a significant role when analyzing the results of the numerical simulation.Thirdly,we have obtained the approximate expressions of the average abundance function corresponding to small and large selection intensity.The significance of the above approximate analysis lies in that we have grasped the basic characteristics of the effect of mutation.The effect is slight and can be neglected when mutation is very small.In addition,the effect begins to increase when mutation rises,and this effect will become more remarkable with the increase of selection intensity.Fourthly,we have explored the influences of parameters on the average abundance function with mutation through numerical simulation.In addition,the corresponding results have been explained on the basis of the expected payoff function.It can be deduced that the influences of parameters on the average abundance function with mutation will be slim when selection intensity is small.Moreover,the corresponding explanation is related to the first-order Taylor expansion.Furthermore,the influences will become notable when selection intensity is large.  相似文献   

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梁小林  刘梅 《经济数学》2009,26(2):91-97
研究了具有不同失效率和修理率的,2中连续取k的可修系统.在假设失效部件的修理规则为后到先修,且修复如新的条件下,得到了具有不同失效率和修理率的n中连续取k的可修系统各状态的概率,并进一步获得了这类可修系统的一些重要的可靠性指标或者其Laplace变换.  相似文献   

6.
左截断右删失数据下半参数模型风险率函数估计   总被引:3,自引:0,他引:3  
文章给出了右删失左截断数据半参数模型下的风险率函数估计,讨论了风险率函数估计的渐近性质,获得了这些估计的渐近正态性,对数律和重对数律.由于假定删失机制服从半参数模型下,从而知道模型的更多信息,因此对于给出参数的极大似然估计,可以改进风险率函数估计的渐近性质.也就是说,删失数据模型具有半参数的辅助信息下, 风险率函数估计的渐近方差比通常的完全非参数的估计的渐近方差更小.这说明加入了额外的信息提高了风险率函数估计的效率.  相似文献   

7.
在常利率环境下,研究当索赔时间间隔为Erlang(2)分布且保费收取为两步保费的风险模型,推导出该模型Gerber-Shiu罚金折现期望函数所满足的微积分方程.  相似文献   

8.
Vaccination is a very important strategy for the elimination of infectious diseaVaccination is a very important strategy for the elimination of infectious diseases. A SIVS epidemic model with infection age and nonlinear vaccination has been formulated in this paper. Using the theory of differential and integral equation, we show the local asymptotic stability of the infection-free equilibrium and the endemic equilibrium under some assumptions.  相似文献   

9.
具有非线性接触率和时滞的SIRS流行病模型   总被引:12,自引:0,他引:12  
本文研究了具有非线性接触率βI^ps/1+αI^q和恢复类中具有分布时滞的SIRS流行病模型的解的存在性和连续性,正不变集,平衡位置以及平衡位置的稳定性。  相似文献   

10.
This paper considers the asymptotic behavior of solutions to the system of one-dimensional viscoelastic model with damping and prove that the corresponding solutions time-asymptotically behave like nonlinear diffusion wave as in [4,11]. In addition, It is also shown that the system of one-dimensional viscoelastic model with damping is a viscosity approximation of a hyperbolic conservation laws with damping.  相似文献   

11.
This paper considers the asymptotic behavior of solutions to the system of onedimensional viscoelastic model with damping and prove that the corresponding solutions time-asymptotically behave like nonlinear diffusion wave as in [4,11]. In addition, It is also shown that the system of one-dimensional viscoelastic model with damping is a viscosity approximation of a hyperbolic conservation laws with damping.  相似文献   

12.
《代数通讯》2013,41(4):1669-1676
It has been previously shown by Lindner and Rodger that quasigroups associated with 2-perfect extended m-cycle systems can be equationally defined if and only if m ∈ {3, 5, 7}. In this paper we present a single identity for each such m which is equivalent to the identities given for these varieties.

  相似文献   

13.
This paper consider a nonautonomous schoner model with feedback control and diffusion. It is shown that the system can be made persistence. Then the existence and the uniqueness of the positive solutions and positive almost periodic solutions for corresponding periodic system and almost periodic system are also discussed.  相似文献   

14.
本文研究了一个非自治的具有阶段结构和时滞的捕食-食饵模型.利用比较原理获得了系统持久性的条件,在假设系统为周期系统的条件下通过构造Liapunov函数证明了正周期解的存在唯一性和全局渐近稳定性.  相似文献   

15.
In this paper, we study a predator-prey model with prey refuge and disease. We study the local asymptotic stability of the equilibriums of the system. Further, we show that the equilibria are globally asymptotically stable if the equilibria are locally asymptotically stable. Some examples are presented to verify our main results. Finally, we give a brief discussion.  相似文献   

16.
We consider a discrete time risk model in which the net payout (insurance risk) {Xk,k=1,2,···} are assumed to take real values and belong to the heavy-tailed class L ∩ D and the discount factors (financial risk) {Yk,k=1,2,···} concentrate on [θ,L],where 0 θ 1,L∞,{Xk,k=1,2,···},and {Yk, k=1,2,···} are assumed to be mutually independent. We investigate the asymptotic behavior of the ruin probability within a finite time horizon as the initial capital tends to infinity, and figure out that the convergence holds uniformly for all n ≥ 1, which is different from Tang Q H and Tsitsiashvili G (Adv Appl Prob, 2004, 36: 1278–1299).  相似文献   

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分析了期权的定价,研究了借款利率大于债券利率同时投资策略受限制情况下期权的定价.  相似文献   

19.
一个具有时滞和非线性接触率的传染病模型   总被引:10,自引:1,他引:9  
本文研究了具有非线性接触率和在恢复类中具有分布时滞的SIRS传染病模型的解的存在性、连续性和平衡位置以及平凡平衡位置的稳定性。  相似文献   

20.
本文研究了一类索赔时间间隔与索赔量相关且分两段收取保费的风险模型.利用微分的方法得到了罚金折现期望满足的积分-微分方程,并给出了此方程解的一个表达式.  相似文献   

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