Study On Some Problem About Optimizing Logistics Delivery System Of Railway Baggage & Parcel

Combing parcel express operation and development of UPS, FedEx, DHL and TNT in china, author analyses the position of railway baggage & parcel transportation based on its reform and operation at present. It is pressing and necessary for the enterprise of railway baggage & parcel transportation to develop modern logistics.The thesis resolves logistics delivery problem applying the location theory and VRP theory in modern logistics. The author reviews in detail the means, models and algorithms of node location, and analyses VRP by partitioning it into three parts: generic VRP, VRPTW, VRPB and VRPSD. The author also summarizes model and algorithms of this problem combining VRPTW which is studied frequently, and analyzes emphatically the research results of all kinds of heuristic algorithms.Location plan for logistics base and delivery sites of railway baggage & parcel is multilayer location problem. The author sets up mathematical model of the generic problem, and resolves this problem by local search algorithm based on sweep algorithm and iteration arithmetic. The practical example indicates that the model and algorithm are valid. Combing uncertain demand of railway baggage & parcel, probability model and dynamic model of node location, the author sets up probability model and dynamic model of location plan of railway baggage & parcel delivery sites. At the same time, aiming at the shortage of the two models, the author sets up mathematical model for location planning problem on railway baggage & parcel logistics base and distribution sites with uncertain demand, and puts forward simple and suitable to the practice method of seeking distribution function, curve fitting, and finding demand of clients according to integrating distribution function.VRP is NP-hard problem, and it is also a research hotspot in the logistics. Emphatically considering delivery and collecting simultaneously during the course of delivery of railway baggage & parcel, the thesis studies the instances existing preferential client and thinking over a-large-amount of clients, and sets up models of the two problems. Aiming at the mathematical model of generic...