Research On Optimization Of Location-Routing Problem For Emergency Logistics System Under Demands Grading

In recent years,the frequent public emergencies pose a huge threat to the safety of human life and the economic development of society around the world.As one of the countries most affected by disasters(such as the outbreak of Corona Virus Disease 2019,the typhoon Wenbia in 2018,the Wenchuan earthquake in 2008,etc.),it is vital for China to enhance the disaster response and emergency logistics capabilities.Arranging disaster relief at key strategic positions in advance will improve the ability to supply materials in a relatively short period of time,so that disaster relief can be carried out smoothly during golden rescue time and the loss of the entire disaster process can be reduced.The uncertainty of the disaster not only determines the demands needs in the affected area,but also affects the supply of pre-proposed relief and road traffic conditions.This paper describes the uncertainty of disasters based on discrete scenarios,expands the location-routing problem of emergency logistics with consideration of the transportation distance limit,the penalty cost of unmet demand,the uncertainty of demand and supply and resources limitation.The goal is to meet the needs of emergency relief materials while minimizing the total cost of the entire disaster process.Traditional commercial logistics generally only consider efficiency and cost,and this paper adds fairness factors to emergency logistics systems.Demands are graded according to the disaster situation in this paper,analyzing the impact on time,cost and scenarios,focusing on the location-routing optimization model of emergency logistics considering demand grading,making decisions of location and distribution to maximize the overall efficiency of the disaster rescue.In this paper,an accurate algorithm for two-stage integer programming is designed.Based on the proposed basic model and the optimization model considering demand classification,simulation examples are used for solutions.The optimal solution are compared from the aspects of computational complexity,cost improvement,efficiency changes.The simulation explains how the proposed model deals with practical problems.The research results show that the optimization model with demand grading has better performance in reducing costs and promoting disaster relief efficiency.The conclusions of emergency logistics provide reference for decision-maker in disaster management.