Efficiently Reinforcing Social Networks over User Engagement and Tie Strength

User engagement and tie strength are fundamental and important components in social networks. The model of k-truss not only captures actively engaged users, but also ensures strong tie strength among these users. It motivates us to utilize the model of k-truss in preventing network unraveling, which simultaneously considers both of the basic components. In this paper, we propose and investigate the anchored k-truss problem to reinforce a network by anchoring critical users who can significantly stop the unraveling. We prove the problem is NP-hard for k ≥ 4. A fast edge deletion order based algorithm, named AKT, is proposed with efficient candidate exploration and pruning techniques based on the order. Comprehensive experiments on 10 real-life graphs demonstrate the effectiveness of our model and the efficiency of our methods.