Research On The Vulnerability Of China Railway Express Freight Network Under Emergencies

With the high-quality development of CHINA RAILWAY Express(CR express),the coverage of CR express is gradually expanding.CR express is playing a more and more important role in ensuring the smooth supply chain of global industrial chain,serving the domestic and international double circulation,helping the implementation of ’six priorities’ and stability in six areas for steady economic momentum,and promoting the development of the global economy.A stable and efficient CHINA RAILWAY Express freight network is of great significance to China-EU freight transportation.However,affected by the internal factors of the railway network and the external environment,the interruption of some lines and the stoppage of stations in the CHINA RAILWAY Express freight network occur from time to time,which have different degrees of impact on the efficiency and service quality of the train transportation.To ensure the smooth and efficient operation of CR express,this thesis uses the complex network theory to study the vulnerability of the CHINA RAILWAY Express freight network.Firstly,this thesis defines the CHINA RAILWAY Express freight network and sorts out the nodes and transportation channels in the network,constructs the topology model of the CHINA RAILWAY Express freight network covering 35 countries,including 272 nodes and390 edges,and calculates and analyzes the topology characteristics of the network.It is found that the CHINA RAILWAY Express freight network has scale-free and small-world characteristics.Secondly,the thesis proposes the definition of the vulnerability of the CHINA RAILWAY Express freight network,selects the relative size of the most connected subgraph and the overall efficiency as the vulnerability measurement and quantitative description,constructs the regional operation stability evaluation system from the political,economic,social and transportation levels,and evaluates 35 countries in CHINA RAILWAY Express freight network by using Entropy TOPSIS method.The Page Rank algorithm is improved by taking the operation stability as the influence factor to identify the important nodes in the network.Finally,this thesis classifies and summarizes the emergencies that CR express suffers in the operation process,designs random attack strategy and deliberate attack strategy,and uses MATLAB software to simulate the vulnerability of CHINA RAILWAY Express freight network under three situations: point failure,edge failure and area failure.The results show that the CHINA RAILWAY Express freight network presents good stability under random attack.However,it shows obvious vulnerability under deliberate attack;compared with edge failure,node failure has a more significant impact on network performance and does more harm to the network;failure in Russia and Kazakhstan will seriously affect the connectivity of the network,and the transport path between China and Europe will be completely interrupted,while failure in Belarus and Ukraine will seriously affect the transportation efficiency of the network.Based on the simulation results,the optimization strategy of the CHINA RAILWAY Express freight network is proposed from three aspects of planning,node line protection and emergency warning.