Combinatorial Optimization Of Transportation Service Purchase In Containner Multi-modal Transport

Multi-modal transportation service connects the transportation modal of sea, road, rail, air and others as one system, by the medium of containers, which provides "whole course, one document" transport logistics services to the shippers. Multi-modal transportation service purchase is definited as the process of obtaining the service requirements from the multi-modal transportation market services to containers transport, for the purpose of implementing production or extending the transportation network,. Multi-modal transportation service purchase optimization is definited from the perspective of the shippers and the principal of the shippers'maximum benefit, to choose the best carrier combination. The ultimate target of transportation service purchase is to pursue the opimum freight, efficiency and quality of transportation services.During the process of multi-modal transportation service purchase, in order to achieve the coherent transportation of the container cargos, the shppers usually select the sectional transport services through the multimodal transport operators. In this paper, there are three kinds of participants during the course of container transport service purchase:the real shppers, the multi-modal transport operator(MTO) and the section al transport carrier. The participants must be the purchase party(the shipper) or the supply party(the carrier). In the multi-modal transportation sum services purchase process, the shipper party is the real shipper of containers, and the carrier party is the multi-modal transport operator who provides sum transportation service. In the multi-modal transport segmental service purchase process, the shpper party is the multi-modal transport operator, and the carrier party is the sectional transport carrier.In this paper, the research fo multi-modal transport services purchase is discussed from the perspective of the shipper party, which explores the use of combinatorial optimization methods for oriented multi-modal transport services and its improvement. The optimum combinational state is analyzed, which involves both service purchase of sum transport(from the perspective of the container owner) and segmental transport (from the perspective of the multimodal transport operator).Regarding to the research, the following three aspects are studied in this paper:(1) For the sum transport service purchase study, a series of multi-attribute combinatorial optimization models are established, regarding to the freight, service quality, carriers' reputation, and their transport network capacity. Firstly, the evaluation index for multi-mode transportation operator is established, and the weight coefficients of the main attribute are given through balance idea. Secondly, the combination process of multi-modal transportation services purchase with combinatorial auction and bidding competition is analyzed and simulated. Also, the multi-objective mixed integer programming model for combinatorial optimization is established. Finally, the concept of Euclidean distance formula of state vector is introduced in the study and the multi-objective mixed integer programming problem can be turned into a single objective programming problem to discuss combinatorial optimization problems in multi-modal container transportation services purchase.(2) For the section transport service purchase study, the combinatorial optimization model is established, aiming at the minimum sum freight and the jointless connection for the transportation links. This paper studied the combinatorial optimization method for the multimodal transport operators to select the sectional transport services as shippers.First of all, analyze all the elements in the actual sectional transport service, and determine the variable parameters in the service purchase. Secondly, analyze the data structures of variable parameters, and introduce the value structure of the time variable and non-numerical structure of the site variables. Then the nonlinear mixed integer programming model is established based on convergence of transport modes before and after.(3) To achieve the above optimization purposes of purchase of both sum transport services and sectional transport services of multi-modal transoportation, the algorithm are designed for the above problems of nonlinear mixed integer programming models, involving both the multimodal transport operators and the real container shippers. Through the cooperate reasoning of set reasoning, logical reasoning, ane heuristic search, the optimization model for sum transporat service and segtional transport service of the multi-modal transportation services purchase optimization problems could be solved and realized at last.