The Research On Emergency Material Dispatch Problem Based On Hub-and-Spoke Network

The emergency logistics system is a special logistics action in order to provide the emergency material to deal with incidents, in pursuit of maximize efficiency of time and minimize disaster losses as the objective. At present, though the China Emergency Logistics Research has some results, the results are far from being able to meet the needs of emergencies. In order to minimizing the loss caused by the natural disasters and the unexpected events, it is necessary to make more researches on the dispatch system of the emergency logistics and on its optimization.Based on the research results of the emergency logistics and the hub-and-spoke network, in this paper, the large-scale emergency material dispatch model based on the hub-and-spoke network is proposed. Main work of this dissertation is described as the following:1. The large-scale emergency material dispatch system is divided into three subsystems which either connect each other or are independent—the emergency material dispatch system in the region of supply, of transportation, and of requirement.2. In the region of emergency material supply, a bi-level optimization mathematical model based on both the earliest start time for materials outside-transports and the lowest cost is established. According to the different conditions of outside-transports, the model is respectively given algorithm and example in the one-time outside-transports system and in the continuous outside-transports system.3. In the region of emergency material transportation, in the shortest time transporting the emergency materials from the hub in the region of emergency material supply to the hub in the region of emergency material requirement is the key. The emergency material dispatch in this region is regarded as the Shortest Path Problem. And then two kinds of algorithms seeking the Shortest Path Problem (which are Dijkstra algorithm and Floyd algorithm) are introduced. Finally, their programs with MATLAB are respectively written, and an example is given.4. In the region of emergency material requirement, firstly, a mathematical model of single-depot, multi-point of emergency continuous consumption system, in pursuit of the minimum of the total time of each emergency point as the objective, is established; and then the model is analyzed and simplified; finally, the tabu search algorithm for this model and example is given.