Université de Fribourg

Reducing the heterogeneity of payoffs: an effective way to promote cooperation in the prisoner's dilemma game

Jiang, Luo-Luo ; Zhao, Ming ; Yang, Han-Xin ; Wakeling, Joseph Rushton ; Wang, Bing-Hong ; Zhou, Tao

In: Physical Review E, 2009, vol. 80, p. 031144

In this paper, the accumulated payoff of each agent is regulated so as to reduce the heterogeneity of the distribution of all such payoffs. It is found that there exists an optimal regulation strength at which cooperation in the prisoner's dilemma game is optimally promoted. If the heterogeneity is regulated to be either too weak or too strong, the promotive effect disappears and the evolution of...

Université de Fribourg

Effects of social diversity on the emergence of global consensus in opinion dynamics

Yang, Han-Xin ; Wu, Zhi-Xi ; Zhou, Changsong ; Zhou, Tao ; Wang, Bing-Hong

In: Physical Review E, 2009, vol. 80, no. 4, p. 046108

We propose a variant of the voter model by introducing the social diversity in the evolution process. Each individual is assigned a weight that is proportional to the power of its degree, where the power exponent α is an adjustable parameter that controls the level of diversity among individuals in the network. At each time step, a pair of connected individuals, say i and j, are...

Université de Fribourg

Optimal view angle in collective dynamics of self-propelled agents

Tian, Bao-Mei ; Yang, Han-Xin ; Li, Wei ; Wang, Wen-Xu ; Wang, Bing-Hong ; Zhou, Tao

In: Physical Review E, 2009, vol. 79, no. 5, p. 052102

We study a system of self-propelled agents with the restricted vision. The field of vision of each agent is only a sector of disk bounded by two radii and the included arc. The inclination of these two radii is characterized by the view angle. The consideration of restricted vision is closer to the reality because natural swarms usually do not have a panoramic view. Interestingly, we find that...

Université de Fribourg

Local preferential attachment model for hierarchical networks

Wang, Li-Na ; Guo, Jin-Li ; Yang, Han-Xin ; Zhou, Tao

In: Physica A: Statistical Mechanics and its Applications, 2009, vol. 388, no. 8, p. 1713-1720

A railway transportation system can be represented by a bipartite network consisting of trains and stations, where a train is connected to all stations where it stops. In this paper, motivated by the resource-allocation process taking place on networks, we design a method to project a Chinese train-station bipartite network into a weighted station network. A new metric is proposed to quantify the...