The Power-law Of Directed Network

In recent years, network data has been emerging quickly in the social science, such as in online communication, protein interactions, disease transmission, scientific literature collaboration and citation, and so on. The degrees of the network vertices have preliminarily summarized the basic characteristic of the network. A lot of network data have presented the so called power-law phenomena, which have been revealed in undirected network. The effective study in directed network, however, it has still been lacking. This thesis aims to reveal the mechanism of the power law in directed network through studying the probability distribution of the in-degree and out-degree.