Cascading Failures In Coupled Networks Based On Different Coupled Modes

Infrastructure network systems are becoming increasingly perfect and complete in modern society along with human progress and science development, today’s networks which are becoming more and more interdependent will take great convenience to people’s lives. However, with the increasing complexity of networks owing to the interdependence among them, the situation could happen beyond people’s control eventually, therefore, the catastrophic failures are more likely to occur in coupled networks. Related research has shown that, compared with single networks, coupled networks are more easily lead to cascading failures, which will result in some more serious catastrophic consequences, so the problems about cascading failures phenomenon in coupled networks are needed to be solved. Currently, the studies on cascading failures in coupled networks are becoming the focus of attention in domestic and overseas, but still exists some shortcomings on the aspect about the influence of coupled modes in coupled networks on cascading failures, which need us to do a future research. This article intends to study on the cascading failures in a variety of topological coupled networks further, based on different coupled modes. The main contents are as follows:(1) Cascade models of local coupled networks are proposed. The majority of research results related to coupled networks have concentrated on interdependent networks, which to function each node in a network depends on one and only one node in another network, vice versa, but overlooked the facts that many real-world networks interact with other networks by only several links, in addition, compared with interdependent networks, the process of cascading propagation is distinct in coupled networks. We put forward a local coupled cascade mode, and study the cascading phenomenon triggered by dynamic behavior of load in coupled networks from a new point of view.(2) Protection strategies of local coupled networks are proposed. Different from interdependent networks entirely, the "bridges" among local coupled networks exist load flow and they play a significant role in cascading failures’process. The study found that increasing the capability of edges to handle extra load among local coupled networks could improve the whole network robustness against cascading failures to a great extent, moreover, we present two effective protection methods which includes adjusting the capacities of edges and immunization strategy, and investigate the efficiency by numerical simulations.(3) The robustness of interdependent networks with different link patterns against cascading failures is studied. Taking dynamic properties of complex network into consideration, such as load redistribution, capacity, etc., we proposed a cascading mode with tunable parameters in two interdependent networks. We investigate the robustness of interdependent networks against cascade spreading that are constructed by three kinds of link patterns and two artificial networks, the numerical simulations have shown that both the link patterns and the value of parameters in cascade mode have important influence on the robustness against failures. Through the analysis and comparison, we obtain the better link pattern and the appropriate interdependent network structure in order to prevent and control the cascading propagation effectively.Through investigating the effect of different coupled modes on the ability against catastrophic failures in coupled networks, efficient control and protection strategies have proposed to avoid cascading propagation, and we numerically try to find the better coupled mode, which could provide scientific evidence and reliable guidance for maintaining and developing interdependent network systems.