Research On Invulnerability Of Urban Transit Network Based On Theory Of Complex Network

The urban transit is the most effective way to solve the problem of urban transportation because of its large capacity,reliablity,comfortablity and so on.With the increasing networking and the proportion of urban transit in urban transportation system, the conventional disaster accident and terrorist attack aimed at urban transit have brought people huge losses of life and property in recent years,so it posed higher demand to the reliability and security of urban transit.It has theoretical and practical significance to research on invulnerability of urban transit network based on the theory of complex network.It can identify the hub point and key track interval of urban transit network,and can prevent attack and damage to urban transit network through the reasonable distribution of defense resources.The reasearch can also help the decision maker formulate effective emergency measures and has an important impact on expanding,planning and exploring the potential,and on improving the reliability,service,attra ctive of urban transit network.After analyzing the feature of structrue and function of urban transit network,this paper first defines the task of the network composed of three subnetworks is passenger transportation.Furthermore, the invulnerability of urban transit network is defined.This paper based on common measures of invulnerability of complex network choses respectively three measures of invulnerability for the three subnetworks,then uses attack strategies based on different layered subnetwork to attack the urban transit network with simulation.For the aim of function of the urban transit network, it establishes the measure and performance of invulnerability which reflect the whole invulnerability of the network from the relationship among the three subnetworks.Above all, taking the example of Guangzhou subway,a directed and layered network model of urban transit which contains three subnetworks called respectively physical network,logical network and demand network can be built,and the relationship of three subnetworks are analyzed. The conclusion reflecting the variation of the overall and part of invulnerability can be got and compared by programming.The importance of station and track considered as the weak are calculated and arranged, some improvments are provided for the optimization of invulnerability of network according to the results.