The Research On Vehicle Routing Problem For Emergency Logistics Distribution

In recent years,China occurred a lot of large-scale public emergency frequently,such as the Tangshan earthquake in 1976,the worst flooding of Yangzi River in 1998,the crises of SARS in 2003,the poison gas leaked of Chongqing and the water serious pollutioned of Songhua River in 2005,the Avian Influernza,the south snow disaster in the beginning of 2008, the Wenchuan Earthquake,the influenza A virus subtype H1Nl,the recent 7.1 magnitude earthquake occurred in Qinghai Yushu on April 14,2010 and so on,which not only resulted in gigantic loses,but also left a deeply grieved memory in people's mind. Due to the high-speed development of modern society,the social problems about population,resource, environment public sanitation and so on become more incisively,and kinds of public emergencies occur more frequently,more dangerous and the influencing scope becomes much wider than before.The emergency logistics system is a special logistic action in order to provide the emergency materials to deal with incidents,There are two aims that emergency logistics systems want to reach.The first is to dealing with incidents at the best early start-time,the second is to reduce the total cost of dealing with these sudden public incidents as it can. So when public emergency broke out,the emergency logistic must be established in order to supply abundant lash-up materials to resolve or deal with satisfying the essential demand of the residents, burying the death, rescuing the sound,sanitary engineering, the reestablishment after the bale, resuming production and getting back the order and so on; or else, the area of calamities and loss of live and assets would be expanded continuously. So that the establishment of emergency logistic when the emergency broke out could render the bailout materials be delivered to the spots where need them, which would have an effect upon the outcomes of the whole succor.This article studies the vehicle routing problem for emergency logistics distribution, which is based on satisfied the time limitied of emeregency materials distribution,the arrangement of vehicles'routing is more reasonable to ultimately reduce the cost of transportation,which is very meaningful for improving the efficiency of emergency logistic.Firstly, this article proposed and analyzed the concept of emergency logistics and the characteristics,the research content and the operation flow of logistics system.Meanwhile, the article analyzed the related problems of vehicle routing problem,including the introduction,the classification,the mathematical model of typical problems and the basic solution methods. Based on the discussion of Vehicle Routing Problem (VRP) and emergency logistics,this article proposed the vehicle routing problem for emergency logistics distribution.And then,it analyzed the differences between this problem and VRP problem,and established the typical mathematical model of the VRP of unfully loaded emergency logistics distribution,simultane-ously chose Ant Colony Optimization(ACO) to solve this article solved the problem by ACO, it analyzed ACO's principle,characteristic,and established its mathematical model and then analyzed the executive steps of the algorithm's.Based on the analyses before and the defects of ACO in this article,through the inspiration of the initial solution,it updated the pheromone on the choice of strategy and pobability of transfer to mend ACO.At the end of this paper, object-oriented C++ language was applied to compile the computational procedure to improved ACO to carry the example. The result confirmed this algorithm is feasible and valid for solving this kind of problem.