... email network is expressed as a directed graph. Given the network, we find a maximal complete sub-graph as a clique which becomes a target of following network analysis. B. Email network analysis ... email network analysis. As well as informal community analysis, we compare before and after leader characteristics with network centralities and communication patterns. The informal networks ... B. Wellman, “Studying online social networks,” Journal of Computer-Mediated Communication, Vol. 3, No. 1, 1997. [8] B. Wellman, “Computer Networks As Social Networks,” Science Vol. 293, No....