Models And Algorithms Of Interval Planning For Uncertain Logistics Network Design

Logistics network design is a basic problem for the scientific rational and sustainable development of modern logistics. With the stable development of national economy, during the powerful support of national macroscopical policy to the revitalization of logistics industry, marketing of logistics industry is deepening and demand potential, the complexity of logistics system and the uncertainty of demand becomes more and more prominent. The research of idea and method of uncertain logistics network design has important theoretical value and practical significance.In this dissertation, the author applies thought and concept of interval planning to research on the problem of logistics network design under uncertain demand, by analyzing the uncertain demand characteristic about the structure of logistics network, measured uncertain variables and parameters by the form of interval numbers, established interval planning model for logistics network design, and designed interval optimal algorithm. The main research work is as follows:(1) Superiority demonstration on interval uncertain logistics network designThe uncertain influence factors of logistics demand are analyzed, and the uncertainty of demand characteristics are pointed out which mainly including three aspects:risk of logistics facilities location (node decision); uncertainty of the logistics network structure and uncertainty of distribution route optimization. Currently, stochastic planning and fuzzy planning is the main method to solve the problem of uncertain logistics network design, interval planning is used relatively less, but it has an advantage that it can obtain interval solution, and has superiority of scenario decision. In practice it can give a feasible decision space for final decision.(2) Present of the interval logistics network planning and the general model By analyzing the uncertainty of demand, the interval logistics network planning is defined that to the given logistics, constrainted uncertain variables by interval variables or interval parameters to construct planning model adaped the logistics network structure, and combined interval algorithm and optimization algorithm to design the solving model, and with computer program design to solve the problem. Also the general model structure of interval logistics network planning is established.(3) Model and algorithm for interval continuous logistics network designBased on the gravity method, the interval planning model of continuous logistics network under multiple commodities and multiple decision nodes and the interval planning model based on regional obstacle constraints are established. A solving model by interval iterative genetic algorithm is designed. It is showed by a tested example that the solving result of the model and algorithm has superiority of interval coordinates, it can meet decision under uncertain demand with anyone viable coordinate in a "limited area".(4) Model and algorithm of interval0-1mixed integer programming and bi-level programmingThe uncertain demand characteristic of discrete logistics network are analyzed, and interval0-1mixed integer programming model and interval bi-level programming model are established. Combined with the actual characteristics of the logistics network, to construct interval arithmetic and interval number comparison adapted the two class logistics network demand structure. By defining the risk coefficient and maximum decision-making deviation to transform the model to certainty, and a hierarchica interval optimization genetic algorithm is designed to solve. The results of examples show that the method and algorithm has the interval optimal solution and the superiority of scenario decision.(5) Proposed interval levels-nodes hierarchical triangular OD demand model of uncertain complex logistics networkThe demand characteristics of uncertain complex logistics network structure are analyzed, as belows:1) uncertainty of network rate function, distributed volumes and fees of nodes;2) demand uncertainty of nodes in each level. The demand structure is an interval levels-nodes hierarchical triangular OD, it also can show that nodes in each level maybe exist demand with any nodes in any level of its downstream in the logistics chain.(6) Model and algorithm for interval complex logistics network planning with multi-levels, multi-nodes and multi-commodityUnder the analysis of interval levels-nodes hierarchical triangular OD demand structure of complex uncertain logistics network, with two interval decision variables, combined with the corresponding interval parameter constraint to establish the interval complex logistics network planning model with multi-levels, multi-nodes and multi-commodity, an interval hierarchical optimal genetic algorithm is designed to solve the problem. It shows its superiority by a tested example simulation and algorithm comparison.This dissertation mainly researches on how to establish model and design algorithm for the problem of uncertain logistics network design. The author intends to expant a new idea for the uncertain logistics network planning, and provides a reasonable decision-making service for the application of logistics system.