Research On Combinatorial Optimization Of Agricultural Material Chain Operation Network Layout And Distribution Center Location

Agricultural material chain operation can set up efficient agricultural material sales channels in the drastically competitive market, which is meaningfully quite. To develop agricultural material chain operation now, the first thing is to optimize and combine resources so that to build agricultural material logistics distribution networks. But the precondition is to optimize operation network and distribution center location, aiming at using minimal resource to meet maximal demand, which is the purpose of this thesis.Agricultural material chain operation network and distribution center are the study object of this thesis. It first summarizes agricultural material chain operation, including concept definition, operation main-body analysis, present situation analysis, feasibility analysis and problem and countermeasure analysis. Then it discusses agricultural material chain operation distribution resource structure in the aspects of network system, distribution system, facility instrument and human resource. Meanwhile influence factors of agricultural material chain operation network and distribution center location are discussed.Basing on describing operation network and distribution center location problem, this thesis considers building optimization model of operation network and distribution center location as a whole. Basing on space reciprocity model, this thesis builds a bi-level programming model to optimize space distributing, scale and scalar of agricultural material chain operation network and distribution center, setting railway station or coach station as agricultural material logistics origin and farmer as terminal point. The upper object function minimizes the sum of transport costs of network to farmer and distribution center to network, land charges and construction cost of network; the lower object function minimizes the sum of transport costs of network to distribution center and railway station or coach station to distribution center, land charges and construction cost of distribution center. Bi-level programming model belongs to NP-Hard problem. The author builds algorithm for the bi-level nonlinear optimization model basing on genetic algorithm. At last, the author applies population distribution data of Hebei province Wuan city to model solution, meanwhile validate validity of model solution.