Université de Fribourg

Accurate and diverse recommendations via eliminating redundant correlations

Zhou, Tao ; Su, Ri-Qi ; Liu, Run-Ran ; Jiang, Luo-Luo ; Wang, Bing-Hong ; Zhang, Yi-Cheng

In: New Journal of Physics, 2009, vol. 11, p. 123008

In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different...

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

Emergence of target waves in paced populations of cyclically competing species

Jiang, Luo-Luo ; Zhou, Tao ; Perc, Matjaž ; Huang, Xin ; Wang, Bing-Hong

In: New Journal of Physics, 2009, vol. 11, p. 103001

We investigate the emergence of target waves in a cyclic predator–prey model incorporating a periodic current of the three competing species in a small area situated at the center of a square lattice. The periodic current acts as a pacemaker, trying to impose its rhythm on the overall spatiotemporal evolution of the three species. We show that the pacemaker is able to nucleate target waves that...