The Research On Connectivity Vulnerability Of Metro Complex Networks

With the development and progress of science and technology, urban rail transit systems (metro systems) are paid more and more attentions all over the world. Urban rail transit systems not only provide the impetus for the development of the city, but also give support for the development of modern metropolis. Therefore, the reliability and robustness of urban transit systems become more and more important. However, there are few researchers investigating the reliability and robustness of urban rail transport systems until now. In this paper, urban rail transit systems will be converted into networked systems to investigate the safety and reliability of them, as followsFirst, we study the individuality and commonality of urban rail transit complex network (metro complex network). We introduce urban rail transit complex networks all over the world and investigate their characteristics and universal properties of them. We discover that average degree of nodes lies in the interval [2,2.45] and most of the average shortest paths belong to [10,16], meanwhile the average betweennesses of the nodes and edges have linear relationships with the number of nodes. Furthermore, the hub network of urban rail transit network possesses the small-world property and scale-free property.Second, we give three attack rules in this paper, and we investigate the vulnerability of urban rail transit networks from two aspects. Moreover, we assess the vunerability of urban rail transit network according to topological vunerability and functionality vulnerability. Based on the discussions, we find that the highest betweenness node-based attack is the most effective method to destroy the network. Meanwhile, we compare the vulnerabilities of different urban rail transit networks.Third, we investigate the vulnerability of interdependent urban rail transit networks subject to external attacks. According to analyze the properties of them, we give the interdependent networked model and study the vulnerability of rail network based on the failures to the power network and communication network. We discuss the dependent intensity and discover that the rail network has a large dependency on the power network but has a weak dependency on the communication network. Furthermore, we obtain the top 10 critical nodes of power and communication networks. Finally, we investigate the network recovery of urban rail transit network subject to failures. We know that network optimization in the basis of the network recovery, so this paper analyzes the network optimization and investigate connectivity recovery of network subject to failures to nodes and edges. Although the recovery strategies are based on urban rail transit networks, these recovery strategies have universality and they can be applied into other networks.