Research Of The Optimization Express Freight Service Network Based On The Delay Analysis

The economic development of every country can't live without transportation industry.By the progress of society and the extraordinary change of the economic structure,the demand of express freight transportation increases year by year,and the market also puts forward higher requirements for timeliness,safety,convenience and reliability of the freight service network.Although the development of freight transportion of our country came later than the western developed countries,the tendency of development of the express freight transportion of our country was gone up.According to the different modes of every transportion,haved launched different express freight transportion service.However,by the passage of time,the development of express freight transport had exposed many problems.Especially in recent years,the delay problem of express freight transport is getting worse,it brought a varity of negative influences.The express freight is highly sensitive to transportation time.Therefore,it is necessary to make sure that the timeliness for the freight enterprises.If there is a serious bottleneck and obstruct of the delay of express freight service network,then have no way of taking about express freight transportation.For whole social economic,the delay of express freight transportation shows hindering effect on the inceasing of economic benefits.For freight enterprises,the delay will have an adverse influence on the development of transport enterprises.The delay problem will not only cause the economic efficiency of enterprises can not be improved,but also lose the confidence of customer,reducing the credibility of enterprises.Therefore,considering the uncertain conditions that effect to express freight service network,not only improve the whole efficiency of express freight transportation,improving service levels and the service quality,but also provide reference and guidance for the dynamic express freight service network.The paper dynamically optimize the express freight service network based on the delay anylsis.Specific studies are as follows:(1)Based on a large number of literatures,some basic theories on express freight transport service network are introduced.Proposed the concept and the construction of express freight transport service network.Then,illuminated the target and content of the optimization of express freight service network.(2)Firstly,the paper analyses the uncertain influence for express freight service network.Secondly,based on the summary of the research of applicable delay function,put forward the applicable delay function that basis of the node split into different clusters,Next,in order to facilitate the follow-up modeling,the paper unified applicable delay functions.Based on the summary of the research on the reliability of transportation time,the paper proposes the delays of transportation time of express freight service network.Finally,the paper builds up a mathematical model considering the the delays of transportation time of express freight transport service network design under the uncertain influence.(3)Firstly,to solve k shortest paths,Double-Sweep algorithm satisifying precedence relations was designed.Secondly,using monte carlo method and the harmony search algorithm to solve the model.In order to verify the accuracy of the result,the Lingo algorithm is also given.Finally,in the example,the thesis verifies the effectiveness of the model and the algorithm.