有限信任是代理仅是在意见相近时才相互影响。通常用ε表示对不同观点的容忍程度,ε>=1时,忽略此限制,反之Bounded confidence存在。DW模型(The Deffuant-Weisbuch model )在Bounded confidence的限制下相近观点相互靠近。HK模型(the Hegselmann-Krause model )个人观点的变化取决于Bounded confidence的限制下所有观点的算术平均(包括自身)。
拓展
1、不均匀的初始条件(nonuniform initial conditions)
几乎所有的研究都是在随机或均匀的初态分布下进行的,不同的初态对结果影响很大,文献29讨论了不均匀的初始条件。
2、多维观点(multidimensional opinions)
a、用第一步去学习 的观点空间,最终群形成
一个规则方形的格子,但中心有干扰,中央群也可能不存在。
(文献26、21、30)
b、有一种对多维连续观点动力学的探讨是研究态度和观点的结构,认为,态度是多维的,但是观点是态度的聚集,动力学是发生在这两个层面上的。(文献32)
c、研究维度参数d的有两种方法。(文献27和文献31)
3、异构的信任范围(heterogeneous bounds of confidence)
取用不同的ε。前面给出了仿真。
4、社会网络和通信政权(social networks and communication regimes)
要研究社会网络对模型的影响。给出了两种方法,小世界网络和无标度特性。
(文献34、35、37、38、39、23、41)
文献36,提到仅有静态网络可以修改动力学,随机选择通信伙伴也是和重要的被叫做通信政权(communication regimes)如果能操控谁和谁在什么时间通信,在大的ε下,强制和阻止统一的观点是可行的。
5、收敛参数、谨慎或质量(convergence parameter,cautiousness or quality)
基于代理的DW模型中收敛参数 是控制代理移向观点的距离,如果代理相互间距小于ε,低的μ,则很快改变观点。
基本模型中,收敛参数影响的只是收敛时间,低μ收敛时间长。
文献42中提到,小的收敛参数,减小了小群的尺寸,还可以影响其他参数,高质量(quality)被看成是低收敛参数,质量(quality)只得是观点不是代理。
6、混杂(miscellaneous)
a、提到两个模型,relative agreement model(相互协议模型)(文献24) 和smooth bounded confidence model(平稳有限信任模型)(文献44):代理间如果距离很大,他们间的相互吸引就小的多,但不是零。
b、代理通信战略(文献36)代理会出于平衡在不同方向找通信伙伴,或出于好奇在相同方向找通信伙伴。有相互影响的收敛参数。
c、Urbig认为态度和观点不同,态度是代理内心的连续的变量;观点是态度被描述或沟通后转变成观点,这一过程就变成离散的了。
Reviewed by
haifg
- 2008-03-11 12:36:21
Models of continuous opinion dynamics under bounded confidence have been presented independently by Krause and Hegselmann and by Deffuant et al in 2000. They have raised a fair amount of attention in the communities of social simulation, sociophysics and complexity science. The researchers working on it come from disciplines as physics, mathematics, computer science, social psychology and philosophy. Agents hold continuous opinions which they can gradually adjust if they hear the opinions of others. The idea of bounded confidence is that agents only interact if they are close in opinion to each other. Usually, the models are analyzed with agent-based simulations in a Monte-Carlo style, but they can also be reformulated on the agent's density in the opinion space in a master-equation style. This paper is to present the agent-based and density-based modeling frameworks including the cases of multidimensional opinions and heterogeneous bounds of confidence; second, to give the bifurcation diagrams of cluster configuration in the homogeneous model with uniformly distributed initial opinions; third to review the several extensions and the evolving phenomena which have been studied so far; and fourth to state some basic open questions.