Research On Risk Spread And Control Strategy Of Multimodal Transportation Network

Multimodal transportation is an advanced form of transport organization.It can make an organic integration of a variety of single mode transportation capacity and scattered resources.With the transport services advantages such as high efficiency,safety,economy,multimodal transportation has gradually gradually developed into an important way of the international trade in goods and the inevitable trend in the development of modern transportation system.Under the background of economic and trade globalization,the multimodal transportation network structure and the relationships between various business entities are becoming more and more complex inevitably affected by internal and external various risk factors.Gradually increasing the types of risk source and constantly changing operation mechanism will lead to multimodal transportation accidents which also become the important bottleneck restricting the fast and efficient development of multimodal transportation.Multimodal transportation network is a complex freight network which is composed of multiple nodes,connection edges and external environment with interaction function.Each network node has its own operation mode and will cooperate together with other nodes in terms of physical communication and information interaction of collaborative process.Due to internal or external interference factors,risk produced from a certain node is spreaded through the business relationship with each other,and impact on other associated nodes and cause serious damage to the multimodal transportation networks.Therefore,identification of the risk factors,inquiry of the risk factors relationship,establishment of the risk spread model and effective risk control measures are of great significance in preventing the happening of the operation accidents,reducing the risk influence degree,reducing the personnel and property losses caused by accident and improving the efficiency and service level of multimodal transportation network.Based on above,multimodal transportation network is the research object in this paper.The theory and method about complex network and risk spread are applied to the risk spread problem.The main content is as follows:(1)Analysis on the formation mechanism.Based on complex network theory,multimodal transportation network elements,complexity and formation mechanism are analyzed qualitatively.Evolution model applied to multimodal transportation complex network is designed based on the nodes' function differences.Research results validate that the multimodal transportation complex network has the scale-free characteristic.This part of the study will lay the theory foundation for subsequent research.(2)Identification of risk factors.Clarifying the principles and methods of risk identification,the internal and external risk factors influencing the multimodal transportation network are recognized and refined based on operations characteristic analysis.Relationship model of risk factors is established based on the Interpretative Structural Modeling Method.The configurative hierarchy relationship between the main risk factors is clarified which affecting the safety of multimodal transportation network(3)Analysis on the path of risk spread.In this paper,the deep causes and risk spread process are analyzed.Based on risk spread theory,the chain,radiant and centralized risk spread path are proposed.Risk spread process is deducted by introducing time variable which will contribute to more scientific understanding of process and the characteristics of the risk spread.Based on the operation risk factors,a combined optimization mathematical model is proposed.The PSACO solution algorithm is used to solve the problem which provides the basis for the decision of the actual path selection of multimodal transportation network.(4)Modeling and simulation of risk spread.Clarifying the the theoretical and practical basis,the dynamic theory of complex networks is introduced into the study of the risk spread of multimodal transportation complex network.Based on the disaster spreading dynamic model,the risk spread dynamics model is built.Finally,the risk spread model is simulated from three aspects,such as node type,initial risk value and node risk threshold in order to reveal the inherent law of risk spread.(5)Research on the risk control strategy.Three traditional complex network immune strategies are introduced.The risk spread rate equation of cargo transportation volume is established.The application effect of traditional immunization strategies is compared which are used in multimodal transportation network risk control.A kind of improved acquaintance immunization strategy is proposed.Finally,the concrete implementation methods of the risk spread are put forward from the perspective of node immune.