Université de Fribourg

Role of activity in human dynamics

Zhou, Tao ; Kiet, H. A. T. ; Kim, B. J. ; Wang, B.-H. ; Holme, P.

In: Europhysics Letters, 2008, vol. 82, no. 2, p. 28002

The human society is a very complex system; still, there are several non-trivial, general features. One type of them is the presence of power-law–distributed quantities in temporal statistics. In this letter, we focus on the origin of power laws in rating of movies. We present a systematic empirical exploration of the time between two consecutive ratings of movies (the interevent time). At an...

Université de Fribourg

Recommendation model based on opinion diffusion

Zhang, Yi-Cheng ; Medo, Matúš ; Ren, Jie ; Zhou, Tao ; Li, T. ; Yang, F.

In: Europhysics Letters, 2007, vol. 80, no. 6, p. 68003

Information overload in the modern society calls for highly efficient recommendation algorithms. In this letter we present a novel diffusion-based recommendation model, with users' ratings built into a transition matrix. To speed up computation we introduce a Green function method. The numerical tests on a benchmark database show that our prediction is superior to the standard recommendation...