Research On Vehicle Routing Of Emergency Materials With Different Corruption Rate Before And After Delivery

The research on vehicle routing problem of perishable emergency materials distribution after sudden disasters has important theoretical significance and practical application value.At present,the research on vehicle route selection of perishable emergency materials under single distribution center and m(m>1)distribution centers only considers the corruption of emergency materials before they reach the disaster site,in practice,however,the perishable emergency materials can not be consumed immediately after they reach the disaster site,and the perishable emergency materials will continue to be corrupted due to the influence of the time consuming in each disaster site,and the rate of corruption varies before and after they reach the disaster site.at the same time,the objective of the problem is mostly to minimize the cost of corruption incurred prior to reaching the disaster site,which may result in the complete spoilage of materials when they reach some of the disaster sites,making it difficult to meet the needs of the disaster sites.In this paper,the objective of the problem is to minimize the maximum corruption cost of a single disaster site,considering that corruption will occur before and after the delivery of perishable emergency materials and the corruption rate is different before and after the delivery,the vehicle routing problem for perishable emergency materials distribution in a single distribution center and m(m>1)distribution centers is studied.The main work and innovative achievements of this paper are as follows.Construction and algorithm design of vehicle routing problem model for perishable emergency materials under a single distribution center with corruption and different corruption rates before and after delivery to the disaster site.With the objective of minimizing the maximum cost of corruption in a single disaster site,and taking into account the corruption of emergency supplies in the distribution centre before and after they reach the affected sites,resulting in the unavailability of emergency supplies to meet the needs of all affected sites,the problem is divided into two cases:sufficient vehicles and insufficient vehicles in the distribution center.When the number of distribution vehicles is sufficient,the accurate algorithm A^*with the complexity of design time is O(un~2)to solve the distribution volume of materials and the distribution route of vehicles at each disaster site,where u and n are the number of vehicles and the number of disaster points respectively;The approximate algorithm GA^*with design time complexity O(n~2)is used to calculate the distribution quantity of goods and the distribution route of vehicles,n is the number of disaster sites.Finally,a case study of the local road network in the earthquake stricken area of Aba prefecture is carried out to verify the effectiveness of the model and algorithm.Construction and algorithm design of vehicle routing problem model for perishable emergency materials under m(m>1)distribution centers with different corruption rates before and after delivery.With the goal of minimizing the maximum cost of corruption in a single disaster site,and taking into account the corruption of emergency supplies in each distribution centre before and after they reach the affected sites,resulting in the unavailability of emergency supplies to meet the needs of all affected sites,the problem is divided into two cases:the number of vehicles in each distribution center is enough and the number is not enough.When the number of vehicles in each distribution center is sufficient,the accurate algorithmMA^*with the complexity of design time is O(u(m+n)~2)to solve the distribution volume and the vehicle distribution path of each disaster point,where m,n and u are the number of distribution center,the number of disaster points and the number of vehicles respectively;when the number of vehicles in each distribution center is not enough,the approximate algorithmMGA^*with the complexity of O((m+n)~2)is used to calculate the distribution volume and the distribution path,among which m,n are the number of distribution center,the number of disaster points.Finally,the effectiveness of the model and algorithm is verified by a case study of local road network in Aba earthquake stricken area.