基于迭代框架的主动链接选择半监督社区发现算法

Semi-supervised community detection algorithm using active link selection based on iterative framework

针对非负矩阵分解(NMF)半监督社区发现方法随机选择先验约束,导致提升相同性能需要更多约束信息的问题,提出一种基于迭代框架的主动链接选择半监督社区发现算法——ALS_GNMF。在迭代框架下,首先,主动选择不确定性高且对社区划分指导性强的链接对作为先验信息;其次,为主动选择的链接对增加must-link约束,增强社区间连接,生成先验矩阵;同时,增加cannot-link约束,减弱社区间连接,修改邻接矩阵;最后,将先验矩阵作为正则项,加入基于NMF的最优化目标函数,并融合网络拓扑结构信息,以期用较少的先验信息,达到较高的社区发现准确性和鲁棒性。实验结果表明,ALS_GNMF算法在真实网络及人工网络上,相同的先验比例下,性能比未采用迭代框架和主动策略的NMF半监督社区发现方法有更大的提升,且在结构不清晰的网络中表现稳定。

In order to solve the problem that large amounts of supervised information was needed to achieve satisfactory performance, owing to the implementation of the semi-supervised community detection methods based on Non-negative Matrix Factorization （NMF） which selected prior information randomly, an Active Link Selection algorithm for semi-supervised community detection based on Graph regularization NMF （ALS_GNMF） was proposed. Firstly, in the iteration framework, the most uncertain and informative links were selected actively as prior information links. Secondly, the must-link constraints of these links, which generated the prior matrix, were added to enhance the connections in a certain community. At the same time, the cannot-link constraints were added, which modified the adjacency matrix, to weaken the connections between communities. Finally, the prior matrix was used as a graph regularization term to incorporate into the optimization objective function of NMF. And combining with network topology information, higher community discovery accuracy and robustness were achieved with less prior information. At the same prior ratio on both synthetic and real networks, experimental results demonstrate that the ALS_GNMF algorithm significantly outperformes the existing semi-supervised NMF algorithms in terms of efficiency, and it is stable especially on networks with unclear structure.