Modeling And Empirical Analysis Of Bus And Subway Weighted Composite Network In Nanjing

Urban public transport network is an significant part of urban transportation system and plays an important role in daily life.Along with urban development and increasing population,the contradiction between the growing travel demand of urban residents and the congested public transport is becoming increasingly prominent.In order to promote the normal and efficient operation of public transport,the study of urban public transport network with bus and subway as the core has received extensive attention.Based on the theory of complex network,we constructs a model of bus subway weighted composite network after deeply analyzing the topology and function of urban public transport network,and makes a further analysis of this model.The main work and achievements of this paper are as follows:First of all,on the basis of the double-layer network of bus and subway,by adding edges of the subway station and its surrounding area within a cetain range d,we put forward a bus and subway composite network model.Considering the influence of bus and subway capacity,driving speed,number of running lines,distance of stations and congestion,three weights of capacity,time and capacity efficiency are defined,and the composite network is weighted.The result show that the increase of model parameter d makes the connection between nodes and lines more closely.At the same time,the efficient edges of bus station and subway station will lead more people in the bus and subway transfer,a variety of travle arrangements with the efficient convergence to meet peopele's travel needs.Secondly,due to the large difference between the regular and the peak travel time,we define the weights of capacity,time and capacity efficiency under the time varying conditions.In order to increase the network capacity on the peak period,the departure time interval of each line will be reduced,and at the same time,as the traffic on load increases,the risk of road congestion increases.The result show that the capacity of edge will increase significantly,but the capacity efficiency will be small increase.Adding the number of shared bicycle around the bus station and subway staion,can effectively enhance the travel efficiency of the entire network.At last,throught the local and global evaluation index,we analyze the importance of node.According to the edge weights of capacity,time and capacity efficiency,the importance of edge is analyzed.The result show that under the node attack strategy,the node-weight attack based on capacity efficiency has a greate influence on the giant connected component and global efficiency of the network.Under the edge attack strategy,the attack mode based on time and capacity efficiency will influent the global and giant connected component relatively large.