Topic-level social network search.

We study the problem of topic-level social network search, which aims to find who are the most influential users in a network on a specific topic and how the influential users connect with each other. We employ a topic model to find topical aspects of each user and a retrieval method to identify influential users by combining the language model and the topic model. An influence maximization algorithm is then presented to find the sub network that closely connects the influential users. Two demonstration systems have been developed and are online available. Empirical analysis based on the user's viewing time and the number of clicks validates the proposed methodologies.