Research On Dynamic Transportation Service Network Design Optimization

With the rapid development of national economy,the total volume of container cargos transportation is rising.The high-level transportation service network design optimization cannot only maximize the economic benefits for enterprises,but also provide high-quality transport services to increase customer resources and market share.Under the premise of the existing transportation resources and considering the transportation demand of the cargos market,it is extremely important to formulate reasonable overall operation plan and strategy in order to provide high-quality transportation services at lower transportation costs.At the same time,due to the time change of supply and demand in transportation market and the complexity of the transportation environment,it is very important to consider the space-time characteristics and the transportation service network under uncertainty.This thesis takes container cargos as the research object,combines the space-time characteristic of transportation service network,studies the dynamic transportation service network design under certain and uncertain,conditions by the theory and method of network optimization,so as to achieve the dual objectives of economic benefits and transportation services.The main works of this thesis are as follows:(1)The optimization design of dynamic transportation service network under deterministic conditions is firstly studied.This thesis mainly constructs a transportation service network within the scope of railway transportation and transshipment of sea-rail intennodal transportation hub.The dynamic transportation service network is described by dividing the planning horizon into several time periods in the transportation service network.The dynamic transportation service network design optimization model is established to solve the problems of service selection and their departure times,service composition,service operation schedule,cargos transportation routes and cargos flow distribution.Besides that,the heuristic algorithm based on "greedy criterion" is designed to solve the problem.(2)The optimization design of dynamic transportation service network under uncertainty conditions is studied.Specifically,the uncertainty of the container cargos transportation service network is analyzed comprehensively in combination with the actual transportation situation.In this thesis,the uncertain factors existing in the transit scope of railway transportation and sea-rail intermodal transportation hub are set as fuzzy variables,to establish a mixed integer optimization model.At the same time,we apply the uncertainty programming theory to the definite transformation of fuzzy programming model.Finally,a case study is implemented to verify the feasibility.