so far, few of researches have focused on the theory and application of directed networks, and most of them treated directed networks as a na?ve extension of undirected networks .
迄今为止,在复杂网络的研究中,对有向网络的系统的研究还很少,许多学者认为有向网络只是无向网络的自然扩充,他们把本属于有向网络的问题都简化抽象为无向网络问题。