Complexity Modeling And Stability Analysis Of Urban Subway Network

In recent years, with the development of cities, there are more and more vehicles inall cities, which causes problems such as traffic congestion, pollution and traffic safety.Constructing public transportation which is mainly based on the subway system is the onlysolution to the traffic problems of modern cities. Comparing with other traffic means,subway has advantages such as high speed, environment friendless, large volume and highefficiency. Meanwhile, subway also has disadvantages as huge investment, longconstruction cycle and its construction will bring huge influence to the city. At the time ofsubway construction, we must do planning and researches to make sure the subwaysystem can serve the urban traffic system in the best mode and play the most importantrole in the urban traffic. So far, as a new research method, complex network theory hasbeen applied in different fields of science. Using complex network theory to study thecharacteristic of urban subway network has great meaning in planning, construction andoperation of subway network.Urban subway network can be seen as complex network which consists of routes andstations. This thesis introduces the basic theory and method of complex network theoryfirstly, and then proves subway networks belong to complex network through Empiricaldata of some urban subway networks.Secondly, this thesis does some researches on the complexity of subway network, andthen finds the main determinant factors of importance of nodes in the network based onthe former researches. This thesis puts forward a new method and parameter to evaluatethe important nodes in subway network, overcoming the disadvantages of previousmethods, which has great meaning in planning, constructing and operating urban subwaynetwork.Finally, this thesis studies the stability of subway network when it is under differentmodes of attack and finds the determinant factors of stability. Through simulation, we findout subway network shows great robustness under random failure and high frailty underattack. According to the complexity of subway network, along with the research method inthe thesis, we take subway network of Wuhan city as an example, build complex networkmodel, do further researches about the function of the new method put forward in thisthesis through empirical data.