Enhancing Coupled Networks Robustness via Removing Key Fragile Dependency Links

In coupled networks, a small number of node failures will cause large-scale cascading failures of the whole networks, so coupled networks are more fragile than the general networks. We find that there are some fragile dependency links with high centrality nodes at both ends between coupled sub-networks. Once damaged, it will cause serious cascading failures. Therefore, we propose a method to enhance the robustness of coupled networks by removing key fragile dependency links. First, based on the node centrality, we propose the dependency link centrality product index, analyze the potential destructiveness of fragile dependency links and find the key fragile dependency links. Second, based on removing key fragile dependency links, the risk of cascading collapse after network failures is reduced and the robustness of coupled networks is improved. Compared with the existing removing random dependency links strategy, removing key fragile dependency links strategy proposed in this brief can make coupled networks more robust via removing fewer dependency links, thereby retaining most of the dependency links and better maintaining the network integrity and functionality. The numerical simulation results on three interdependent networks show the effectiveness of this strategy.