Research On Optimization Modeling And Method For Railway Specialized Logistics Network

Logistics network is a collection of organizations and facilities that are interconnected and play an important role in logistics operation,which determines logistics efficiency and reflects the market competitiveness of one enterprise.As the main facilities used in logistics operation,logistics network has received more attention in recent years.Nowadays,China railway is expanding the logistics market,while the lagging logistics network has severely restricted its development.It is necessary to optimize the existing freight yard to form an efficient logistics network.Combining with China railway's actual development,this thesis takes commodity vehicles,express and fresh goods as research objects.Combining different logistics operation modes,cargo properties and market competition,different mathematical models for optimizing logistics network are constructed,which can deepen the existing research results and guide the development of railway specialized logistics network.Based on the research of related scientific research projects from China Railway Corporation,this thesis makes a systematic research and in-depth exploration of railway logistics network optimization modeling method,which can be summarized as follows.(1)The evolution mechanism of railway logistics network is proposed.The influencing factors in the formation and development of railway logistics network are analyzed.An idea that the factors including the customers' number and distribution,the logistics operation mode play an important role in the process of logistics network's evolution is proposed.Therefore,the logistics operation mode of commodity vehicles,express and fresh goods,the network structure,the cargo flow in the network and the evolution route of logistics network are raised in this thesis.(2)Evaluation for the development status of the existing railway logistics network nodes is designed.The evaluation index system including four major categories of traffic location,construction and development,market supply and demand,policy support with a total of 29 detailed items is proposed.Extensions evaluation method is used to evaluate and analyze the existing more than 2500 railway freight yards.(3)Optimization model for railway commodity vehicles logistics network is designed.The logistics operation mode of railway commodity vehicles named "Forward Stocking" is proposed and the characteristic of the network is raised.Then,a dynamic mathematical model for optimizing railway commodity vehicles logistics network is designed,which can meet the development requirements of different period.This model can solve not only the quantity,location,construction scale of different grades logistics bases,but also the service assignment scheme between different nodes in the logistics network.Combining with the existing and potential customers of commodity vehicles,amulti-period optimization scheme for railway commodity vehicles logistics network is designed,which including 23 first-grade logistics bases,9 second-grade logistics bases with the function of dispatching and 276 second-grade logistics bases with the function of arriving.Also the service assignment scheme and the plans of railway commodity vehicles freight trains between different nodes are proposed.These results show that the method is effective and universal.(4)Optimization model for high-speed railway express logistics network is designed.The logistics operation mode in accordance with high-speed railway express and the logistics network structure are proposed.Based on the model above,a multi-period dynamic and competitive location-distribution logistics network optimization model combining with market competitiveness model and its solving algorithm are designed,which obtain the results of the quantity,location and construction scale of different bases in the high-speed railway express logistics network,and the optimal pricing strategy for the high-speed railway express business.In the end,an optimization scheme including 100 high-speed railway express logistics bases and 100 high-speed railway express service stations,and the service assignment scheme between different nodes are designed,which verify the reliability and economy of the model.(5)Optimization model for railway cold chain logistics network is designed.On the basis of the characteristic of cold chain logistics operation and fresh goods'inventory changes,an optimization model for railway cold chain logistics network and its solving algorithm are designed.Combining with the actual data,a layout scheme with 20 first-grade logistics bases and 79 second-grade logistics bases,and the service assignment scheme between different nodes are designed,which prove the effectiveness of the model.