Analysis Of Evolution On Urban Rail Transit Network Invulnerability

Due to the rapid development of social economy in recent years,traffic congestion has become a difficult problem faced by major cities in China.The development of urban rail transit is an effective way to alleviate urban traffic congestion,which has received more and more attention in China,and scientific and reasonable planning is an important premise.In order to make the development of urban rail transit more stable and efficient,it is of great practical significance to use complex network theory to analyze the invulnerability evolution of urban rail transit network.Firstly,the invulnerability of urban rail transit network was analyzed from the perspective of multi-node failure and single-node failure.Based on the attack strategy,the invulnerability of urban rail transit network under multi-node failure is analyzed,and a deliberate attack strategy based on the influence of node failure was proposed.Compared with the existing attack strategy,the example shows that the new attack strategy can destroy the efficiency of network connection to the greatest extent.Considering the low probability of simultaneous failure of multiple nodes in the urban rail transit network,the influence of single node failure on network was analyzed comprehensively,a new measure index of urban rail transit network's invulnerability--invulnerability intensity was proposed based on the global efficiency of the network,and the algorithm of network invulnerability intensity was designed,this can realize the quantitative analysis of the invulnerability of urban rail transit network.Then,based on the invulnerability intensity of the network,evaluation methods of the importance of urban rail transit network lines and nodes were proposed.Considering the overall network efficiency and the changes of the network invulnerability intensity after the failure of the line,the calculation method of the line importance was established.A node importance index system including 5 indexes was established from the aspects of node structure attribute and node failure effect,and a comprehensive evaluation method of node importance based on entropy weight-TOPSIS was proposed.Taking Shanghai rail transit network as an example,the rationality of the above two evaluation methods was verified.Finally,based on the invulnerability intensity,the invulnerability evolution rules of urban rail transit network were analyzed.Firstly,the evolution rules of the statistical characteristics of urban rail transit network were analyzed.Then the evolution results of the invulnerability of Shanghai rail transit network and shenzhen rail transit network were analyzed as a whole.The results show that: overall,the larger the network size,the stronger the invulnerability,with the continuous expansion of the network scale,the network structure is becoming more and more perfect,and the invulnerability changes tend to be stable.At the same time,the results of invulnerability evolution were analyzed locally,by defining the inner and outer parts of the network,the growth patterns of the urban rail transit network were divided,and the invulnerability evolution rules of Shanghai rail transit network under the five growth patterns were analyzed in detail.Finally,on the basis of previous studies,the gray correlation analysis of statistical characteristics the invulnerability and of urban rail transit network was finished.The results show that the complexity of urban rail transit network is the key factor of its invulnerability.The research results can provide some references for the planning and management of urban rail transit network.