关键词: 重叠社区, 社区结构, 社会网络, 边界节点, 启发式算法

Abstract: A heuristic algorithm is proposed to detect overlapping communities in this paper.The algorithm is based on the local modularity and the vertex with greatest degree is considered as the initial community.Then expanding the community by putting the adjacent vertex which has maximal contribution into it.Furthermore，the algorithm takes into account the overlapping property of community.If there are border vertices which contribute greatly to more than one community，adding them to these communities.Finally，In order to make the result more reasonable，the detected communities is adjusted according to overlapping coefficient.Two typical social networks，Zachary and American College Football，are applied to the algorithm.The results show that it can detect overlapping communities rapidly and correctly and also mine the border vertices.

Key words: overlapping communities, community structure, social network, border vertex, heuristic algorithm