考虑情感的三策略囚徒困境博弈模型与合作演化

基于社会比较情境下强者和弱者之间产生的同情、欺凌、漠然、尊敬、嫉妒和畏惧等6种情感,建立个体情感特征的定量表达方法。考虑情感驱动的三策略囚徒困境博弈模型,设计了6种情感与合作、背叛及孤独3个博弈策略之间的对应关系和定量表达机制。采用二维格子网络、随机网络和无标度网络等三种网络模型进行演化博弈仿真分析。结果显示:较大的背叛成功诱惑促进了采取背叛策略的情感类型发展演化和繁荣稳定,系统的最终演化状态都体现出程度不同的负性情感特征;空间网络结构对情感类型和合作行为的演化存在重要影响,无标度网络结构能够导致具有一定良性特征的情感类型演化稳定,并带来较高的合作水平;从社会比较及由此产生的对比效应和同化效应的角度,对三种网络下不同的情感演化状态进行了相应阐释。     

一个创新网络动态性的仿真模型

提出了一个关于创新网络动态性研究的仿真模型,模型较为全面地考察了网络的形成过程和不同的角色在创新和网络中的作用,研究结论指出:网络的形成是由于创新主体为适应创新的复杂性而寻求资源互补效应的动态相互作用的结果,中小型企业的个体在网络演化的早期和中期起了重要的作用,合作体的作用主要发挥在中后期.     

供应链网络道德风险演化与仿真研究

针对目前供应链网络存在的越来越严重的道德风险问题,利用演化博弈和系统动力学理论,从供应链网络结构入手,对其演化过程进行了研究。首先基于供应商之间合作过程中的诚信和败德行为,建立供应链网络同级企业间道德风险的演化博弈模型,并分析了其演化路径。其次通过对制造商和供应商之间博弈的动态性分析,建立供应链网络上下游企业间道德风险演化的SD模型,并对其演化过程进行了仿真分析。研究结果表明:供应链网络道德风险的演化结果取决于网络内败德企业获得的超额收益、收益调整程度、惩罚力度和惩罚机制。另外,罚款力度大小与供应链网络道德风险演化的动态性密切相关;动态惩罚机制在其演化的波动性控制方面,具有明显效果。     

高校网络舆情危机演化GERT模型及其应对机制和策略

首先分析了高校网络舆情危机演化过程,构建了高校网络舆情危机的GERT演化模型,设计了"分级应对"机制,通过百度指数和阶段活动持续时间两个主要指标进行危机等级判断,为管理者提供了有效的决策依据.建议管理者建立事前预防、事中控制、事后反思和监测的应对机制,来防止危机的扩大和再次发生.最后,用案例验证模型、应对机制和策略的有效性.     

基于组织进入、退出和合作的技术创新网络演化模型

技术创新网络是企业、大学、研究机构等相关组织基于共同的技术创新目标而建立起来的一种网络组织形式,像其他生命体一样存在着萌芽、成长、成熟和衰退的生命周期.网络的演化与网络成员的行为密切相关,在分析组织进入网络、增加合作和退出网络机制的基础上构建了技术创新网络演化模型,研究不同演化阶段的特征.理论推导和仿真结果表明:技术创新网络整个生命周期中保持着无标度特性;组织进入网络、增加合作和退出网络的速度决定了技术创新网络的生命周期以及其所处生命周期的阶段.     

考虑随机扰动的群体决策理性演化模型

在群体决策过程中,随机噪音对个体理性和群体理性的变化具有不可忽视的影响.针对存在随机扰动条件下群体决策理性的演化行为,在假设个体和群体理性之间存在作用叠加效果的基础上,建立了刻画个体和群体理性受随机噪声影响的个体和群体理性演化动力学模型,利用随机微分方程理论,论证了模型解的存在性和唯一性,在给定群体决策的随机扰动为白噪声的假设条件下得到了模型的解析解,讨论了群体决策中两个重要参数:理性作用强度和随机干扰作用强度对于群体理性演化的影响.理论分析结果表明:群体决策理性的演化行为取决于这两个参数的相对大小,存在着三条不同的演化路径,数值算例验证了模型的合理性和有效性,并对群体理性的演化行为进行了直观说明,对于深入认识群体决策规律和提高决策质量具有积极的理论和实际意义.     

广义加权网络演化模型

在复杂网络BBV演化模型的基础上,采用新的赋权方式构建广义加权网络FBBV动态演化模型,给出FBBV模型的演化算法,然后对FBBV模型的性质进行理论推导,给出点权、边权的演化公式和点权、度和边权的分布规律.最后对FBBV模型进行了数值模拟,模拟的结果和理论推导结果一致.     

基于复杂网络上的演化博弈

论述了基于复杂网络的演化博弈.通过介绍相应的演化博弈模型-囚徒困境模型以及一些复杂网络,鉴于复杂网络的优点以及博弈演化的特性,将两者巧妙的结合起来,介绍了研究这类问题的一些方法.     

基于参与主体异质性条件下囚徒困境合作演化博弈模型研究

利用演化博弈理论,对参与主体异质性条件下的囚徒困境模型进行了探讨,求出了满足不同条件下的演化稳定策略,并对种群中个体异质性对演化稳定策略的影响进行了分析,得出种群中选择相同策略的个体异质性差异越大,参与个体选择合作行为作为演化稳定策略的可能性就越大.极端地,当个体的异质性趋向于无穷大时,合作成为唯一的演化稳定占优策略,为现实大多数合作系统中能保持长期的一种合作稳定状态提供了合理地解释.     

随机增长网络的度分布

增长和择优机制是无标度网络中的两种重要的演化机制,在分析BA模型的基础上,提出了一种新的节点增长方式,即考虑了新增节点的连边数是随机变量的情况,从而建立了随机增长网络模型,并利用随机过程理论得到了在这种增长方式下网络的度分布,结果表明这个网络是无标度网络。     

Application of three controls optimally in a vector-borne disease – a mathematical study

We have proposed and analyzed a vector-borne disease model with three types of controls for the eradication of the disease. Four different classes for the human population namely susceptible, infected, recovered and vaccinated and two different classes for the vector populations namely susceptible and infected are considered. In the first part of our analysis the disease dynamics are described for fixed controls and some inferences have been drawn regarding the spread of the disease. Next the optimal control problem is formulated and solved considering control parameters as time dependent. Different possible combination of controls are used and their effectiveness are compared by numerical simulation.     

Dynamics of infection with nonlinear incidence in a simple vaccination model

We develop and analyze a simple SIV epidemic model including susceptible, infected and imperfectly vaccinated classes, with a nonlinear incidence rate. We investigate the interaction of the nonlinear incidence and partial immunity. Our main results show that nonlinear incidence rate could induce the forward bifurcation with hysteresis except for the backward bifurcation. The plausible effects of vaccination program have been demonstrated by two models with nonlinear incidence rate. Vaccination program may contribute to disease spread, depending on which transmission term involves nonlinear incidence rate.     

Imprecise parameters for near-optimal control of stochastic SIV epidemic model

The change of parameters may influence the dynamic behaviors of epidemic diseases. Biological system parameters can also be changed due to diverse uncertainties such as lack of data and errors in the statistical approach. The problem of how to define and decide the optimal-control strategies of epidemic diseases with imprecise parameters deserves further researches. The paper presents a stochastic susceptible, infected, and vaccinated (SIV) system that includes imprecise parameters. Firstly, we give the method of parameter estimates of the SIV model. Then, by using Ekeland's principle and Hamiltonian function, we obtain the sufficient conditions and necessary conditions of near-optimal control of the SIV epidemic model with imprecise parameters. At last, numerical examples prove our theoretical results.     

Dynamic model of worms with vertical transmission in computer network

An e-epidemic SEIRS model for the transmission of worms in computer network through vertical transmission is formulated. It has been observed that if the basic reproduction number is less than or equal to one, the infected part of the nodes disappear and the worm dies out, but if the basic reproduction number is greater than one, the infected nodes exists and the worms persist at an endemic equilibrium state. Numerical methods are employed to solve and simulate the system of equations developed. We have analyzed the behavior of the susceptible, exposed, infected and recovered nodes in the computer network with real parametric values.     

Stability and bifurcation of an SIVS epidemic model with treatment and age of vaccination

In this paper, we consider a two-dimensional SIS model with vaccination. It is assumed that vaccinated individuals become susceptible again when vaccine loses its protective properties with time. Here the rate at which vaccinated individual move to susceptible class again, depends upon vaccine age and hence it is assumed to be a variable. This SIVS model with treatment exhibits backward bifurcation under certain conditions on treatment which complicate the criteria for the success of the treatment by making it possible to have stable endemic states. We also show how the infectivity and the recovery function affect the existence of backward bifurcation.     

一类带有感染年龄SIR模型最优化免疫策略的存在性

对于一个免疫策略来讲,付出(单位时间内接种疫苗的数量)和效果(再生数的大小)是两个重要概念.在给定的费用下找到带有最小再生数的策略和在给定的再生数下找到最小费用的策略是两个最优问题.对一个确定的免疫策略来说,人群中的易感群体和染病群体会趋于相对稳定的状态.当一种疾病侵袭已免疫人群时,用带有感染年龄的SIR模型去描述这类疾病的传播更为准确.因此,本文研究了一类带有感染年龄的SIR模型,得到了最优化策略的存在性.     

考虑个体保护意识的关联信用风险传染机理研究

针对关联信用风险及其传染这一热点和难点问题,本文基于复杂网络异质平均场理论,运用风险传播动力学SIR经典模型,探讨风险信息促成的个体保护意识对关联信用风险传染的影响机理,并在BA无标度网络中进行数值仿真分析。研究结果表明:被感染个体数量、个体反应强度、有保护意识的易感个体比例与关联信用风险传染阈值正相关;考虑个体保护意识、增强易感个体反应强度以及提高有保护意识的易感个体比例能够有效抑制关联信用风险的传染速度和传染规模,并且能够延缓关联信用风险高峰期的到来。     

A network modelling approach for assessing the efficiency of prevention strategies

Survey data and a simulation model based on a stochastic pair formation process are used to construct networks of sexual contacts. We model heterosexual partnerships which can be steady or casual depending on their average duration. Transmission of an infectious disease can take place in pairs of a susceptible and an infected individual. We study networks of sexual contacts accumulated during 1 year for different types of mixing patterns. The networks are constructed on the basis of data from a survey in The Netherlands. We analyze the network structure for different mixing patterns and investigate the relationship between network structure and disease spread; furthermore we study the effect of prevention measures on the structure of the network.     

Vaccination strategies based on feedback control techniques for a general SEIR-epidemic model

This paper presents several simple linear vaccination-based control strategies for a SEIR (susceptible plus infected plus infectious plus removed populations) propagation disease model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes more difficult contacts among susceptible and infected. The vaccination control objective is the asymptotically tracking of the removed-by-immunity population to the total population while achieving simultaneously that the remaining populations (i.e. susceptible plus infected plus infectious) tend asymptotically to zero.     

On vaccination controls for the SEIR epidemic model

This paper presents a simple continuous-time linear vaccination-based control strategy for a SEIR (susceptible plus infected plus infectious plus removed populations) disease propagation model. The model takes into account the total population amounts as a refrain for the illness transmission since its increase makes more difficult contacts among susceptible and infected. The control objective is the asymptotically tracking of the removed-by-immunity population to the total population while achieving simultaneously the remaining population (i.e. susceptible plus infected plus infectious) to asymptotically tend to zero.