Optimization Of Agricultural Products Cold Chain Logistics Network Based On Bi-level Programming Model

With driving of increasing consumption needs and expanding city scale,cold chain logistics is developing rapidly all over the country.Agricultural products has the peculiarities of perishability and strong regional characteristics,and it is an important application area of cold chain logistics.Because of the imperfect cold chain logistics network and incomplete facilities and equipment,agricultural products have high damage rate and costs in circulation.Therefore,it is necessary to analyze and optimize the existing cold chain network of agricultural products.If the resources of cold chain logistics are integrated effectively,the damage and circulation cost of agricultural products will be reduced.First of all,this paper elaborates the connotation and characteristics and the logistics network basic theory of agricultural products cold chain,and explains the reason for studying the three-level cold chain logistics network structure of agricultural products that includes agricultural products suppliers,cold chain logistics center and demanding clients.Then,on this basis of analyzing the key nodes,optimization principles and influencing factors in the cold chain logistics network of agricultural products,the paper proposes the main content and objectives of network optimization.Next,combined with the thought and characteristics of the bi-level programming,the paper describes mathematical optimization model of the agricultural product cold chain logistics network.Considering the continuity of the circulation of agricultural products in the network,the paper improves the theory of O.S.to obtain the calculation method of the cost of damage,and ensure that the goods received by customers are intact.Through the analysis and discussion of the three-level damage cost,investment cost,transportation cost and operating costs in the network,considering their own interests between the core logistics company and the clients,the optimization model is built with meeting customer's requirement on quality and time of agricultural products.Due to the non-connectedness of the feasible region and the multi-value of the mapping,the solution of the bi-level programming is very complicated.Therefore,this paper adopts the descending method and artificial intelligence algorithm to solve the model.The underlying model is solved by LINGO11 software,and the upper model uses the MATLAB R2014 a programming to obtain the optimization result by designing the appropriate genetic algorithm.Last of all,the model is applied to the practical case of Y group that has the cold chain network of agricultural products,and the final network optimization plan was determined,which verified the science and effectiveness of the model and algorithm in this paper.