Growing topic network model based on BBS

Based on the statistic data of some BBS forum, the general properties of topic diffusion is analyzed from growing and scale-free in internet virtual community. Furthermore, considering the accelerating and attenuating of user joining in growing of topic network, a network growing model of virtual community is given. The simulation results show that the topic network growing from our model has power-law distribution, and the process of growing has the same characteristics as the real BBS virtual community networks.