Research On Defense Resource Allocation Of Dangerous Goods Transportation Network Based On Mean Variance Model

Since the reform and opening up,China's economic system has continued to develop and innovate,and has rapidly become the world's second largest economy.The scale of the chemical industry is also rapidly expanding.A large number of dangerous goods transport vehicles carrying flammable explosions,radiation and poisons are transported on the transport network to form a mobile “time bomb”.At the same time,the existing industry norms and requirements for the transportation of various dangerous goods in China are relatively weak,and the dangerous goods are characterized by strong destructiveness and wide spread,and are prone to secondary hazards.Once an accident occurs in the transportation process of dangerous goods,It poses a great threat to the lives and property of the people.Based on this,the defense resources can reduce the serious consequences caused by accidents,thereby ensuring the safety of people's lives and property,and improving the management level of the road management department.The problem of how to allocate limited defense resources to the various destinations of the transportation network is The purpose of the research is to use complex network theory,community partitioning theory and mean variance combination model to study.First of all,in order to demonstrate the complex network characteristics of dangerous goods transportation network,through theoretical study and literature research,taking the concept of dangerous goods transportation and complex network as the starting point,in-depth study of the characteristics of the complex parameters of dangerous goods transportation complex network,based on this separately from physics The cyberspace and service cyberspace constructs the overall framework of the dangerous goods transportation network.By introducing the original method and the adjacent node theory,the physical network model and service network model of the dangerous goods transportation network are constructed,and the network topology of the two is proposed.Basic qualifications,assumptions,and research processes.Secondly,in order to solve the cumbersome problem caused by the excessive data volume,the applicability of the GN algorithm is determined by in-depth exploration of the commonly used community partitioning theory,and the main problems of the calculation speed and accuracy of the GN algorithm are proposed.Improvements have led to the establishment of a community partitioning model for complex networks of dangerous goods transport.Thirdly,the mean variance model of economics is introduced,and its feasibility in the complex network model of dangerous goods transportation is demonstrated.The basic definitions and assumptions of the mean variance model,the optimal solution and the problems of the model itself are discussed in depth.A mean variance model suitable for complex networks of dangerous goods transport.Based on the above three models,this paper proposes a model of dangerous goods transportation network defense resource allocation based on mean variance model;based on the spatial coordinates of each node in the physical network model of the dangerous goods transport complex network model,using the community partition model to complex The network performs block processing to lay the foundation for improving the calculation efficiency and accuracy in the mean variance model.Based on the annual traffic data of each node in the service network model of the dangerous goods transportation complex network,the block processing is constructed.The covariance matrix between the communities and the nodes within each community,and discusses the singularity of the covariance matrix ?,and then solves the defense resource allocation of each node through the mean variance model.Finally,based on the Dalian dangerous goods transportation network,the science and accuracy of the model were confirmed.The analysis results show that the node with the highest allocation of defense resources has the highest node importance in the physical network model of dangerous goods transportation complex network,and the highest annual traffic volume in the service network model,which proves the physical network model and service network of the community where the node is located.The model has a good degree of fit;in the physical network model of the complex network of dangerous goods transportation in the community,the node is not the most important and the traffic volume is the highest in the service network model,but the highest defense resources are allocated,which proves the traffic volume.Excessive size difference has a great impact on the allocation of defense resources.There are two nodes in the community.In the physical network model of dangerous goods transportation complex network,the node has the highest degree of importance and the highest volume in the service network model.The higher defense resources prove that the size of the physical network space covered by the community and the spatial coordinates of the internal nodes have a greater impact on the allocation of defense resources.