| With the rapid development of China’s economy and society and the continuous popularity of e-commerce,the domestic courier market continues to develop at a rapid pace,high value-added,small volume,personalized goods gradually become the object of express services,customers on the timeliness of express cargo delivery and security requirements are increasingly high.Courier enterprises use air cargo to increase speed,and also consider how to optimize the design of air cargo networks to reduce the cost of air cargo transportation.The continuous growth of air cargo volume has put forward higher requirements for the development of air cargo,and all parties should put more effort into developing air logistics.Therefore,this thesis takes the optimized design of air cargo networks for express delivery enterprises as the research object.Based on the analysis of the current status of domestic and international research,this thesis outlines the basic knowledge of air cargo,the characteristics and advantages of multimodal transport,and describes the basic model of hub-spoke network as well as the prediction methods and intelligent optimization algorithms used in the thesis,so as to carry out the following research.Firstly,the air cargo volume forecasting index system is constructed from three aspects: economic development factors,transportation supply factors and demand factors,and the correlation between each index and air cargo volume is determined by using grey correlation analysis,and the optimal weighted combination forecasting model based on Holt-Winters and PSO-SVR for air cargo volume is established and forecasted for 2021-2025.After comparing three different air cargo network types,a hub-spoke air cargo network is selected as the basic network structure,and a hybrid hub-spoke air cargo network allowing direct flights and a hub-spoke air cargo network oriented to air-rail intermodal transport are described.Secondly,we study the multiple assignment hybrid hub-spoke network structure,allowing direct flights between non-hub points on the basis of a strict hub-spoke air cargo network,establishing a hub location model with the objective of minimizing the transportation cost of the air cargo network,and solving the model using genetic algorithm.In the solution process,the initial hub is determined using systematic cluster analysis,and SF Airlines is used as an example analysis to determine the location of air cargo hub nodes and the specific transportation path between each node.Finally,under the condition that the hub nodes in the air cargo network are determined,the path optimization is carried out by considering the transport mode of freighter-high-speed rail intermodal transport,and an air-rail intermodal transport path optimization model is established with the objective of minimizing the transport cost of the air cargo network,and the model is solved by using ant colony algorithm,and SF Airlines is used as an example analysis to determine the best path of air-rail intermodal transport.This thesis studies the optimal design of air cargo networks,which not only enriches and improves the research theory about air cargo networks of express enterprises,but also helps express enterprises to save air freight transportation costs and improve transportation efficiency,which has certain practical significance. |
