Optimization Research Of Express Delivery Network Based On Complex Network Theory

In recent years,with the rapid development of Internet technology and information technology,China’s e-commerce has been rapid development.However,the current express service can not meet the needs of online shopping logistics,in a short period of time express companies have not fully adapted to the development of online shopping model from business processes,management models,network infrastructure,which has become a major obstacle to the development of online shopping.Express network is the basis of express enterprise service.Scientific and reasonable express delivery network can be flexible to adapt to the personalized needs of customers.It can be flexible to deliver more varieties and smaller batch of goods.And it can reduce the overall cost and improve the overall efficiency of goods in circulation.According to complex network theory,based on analysis structural features of the express network,this paper focus on the express network optimization which is about considering delivery timeliness and connection cost,considering transmission capacity and connection costs,and constraint-based express delivery time and node traffic.Also this paper researches the two-phase express delivery based on critical nodes.(1)Optimization research of express network considering delivery timeliness and connection costAccording to the operation characteristics of express enterprises "prompt delivery",it put forward network optimization method which based on the distribution of time and cost.Delivery timeliness and connection cost are related to the structure of express delivery network.Changing the structure of express network will affect delivery timeliness and delivery costs.This paper first analyzes the shortest path of express network which edges distance weighted,computing delivery timeliness between any two nodes according to the distance weighted shortest path and node delay,computing the connection cost of all network edge length summation.Next,taking the minimum connection cost as the optimization goal,it constructs an optimization model of express delivery network with the constraint of delivery timeliness.Then,it designs an algorithm to seek the network with the minimum connection cost by gradually deleting the minimum marginal benefits edge for two times and add the highest marginal benefit edge for one times from the fully connected network.Finally,it takes the example of the backbone network of an express delivery company in Guangxi province to verify the effectiveness of the model and algorithm.(2)Optimization research considering transmission capacity and connection costThrough the analysis of the characteristics of the network traffic flow and the study on the effect of the structure of express network on the network transmission capability,balancing the relationship between the network transmission capability and the connection cost.First of all,introduce the concept of betweenness,considering the relationship between the betweenness and cargo flow,modify the betweenness definition,and design the calculation method of betweenness.Next,according to the betweenness calculation formula derived the relationship of express network transmission capacity and node betweenness and node capacity.It pointed out that the transmission capacity of express network is related with handling ability and betweenness of the bottleneck node.Then,taking the minimum connection cost as the optimization goal,it constructs an optimization model of express delivery network with the constraint of expect transmission capacity,and it designs an algorithm to seek the network with the optimal structure by gradually adding edge,reconnecting edge and deleting edge.Finally,it takes the example of the backbone network of an express delivery company in Guangxi province to verify the effectiveness of the model and algorithm.(3)Optimization research based on the constraint of delivery timeliness and node flowOptimization of the express network with the constraints of maximum delivery time and node flow.First,it analyzes the transportation costs,the cost of sorting and storage cost of the express network,and it calculates goods flow pass through the edge and node adopting the Dijkstra algorithm.Then,taking the minimum delivery cost as the optimization goal,it constructs an optimization model of express delivery network with the constraint of delivery timeliness and node flow,and it designs a greedy iterative algorithm to seek the network with the optimal structure.Finally,it takes the example of the backbone network of an express delivery company in Guangxi province to verify the effectiveness of the model and algorithm.(4)Research on two-stage express delivery based on critical nodesMultiple batches,small batches,large service radius and demand uncertainty is the main reason for high express delivery costs.Firstly,this paper introduces the concept and characteristics of critical node.Next,it designs two-stage structure and delivery process of express network based on critical nodes.Then,it makes a comparative analysis on delivery time and cost between the two-stage express delivery and the current express delivery model.At last,it use Tabu search algorithm to solve the problem of critical node location selection taking the example in China.It makes process reengineering of the whole delivery base on cloud storages-the critical nodes.Changing the current characteristics of multiple batches,small batches,large service radius and demand uncertainty.The two-stage express delivery based on critical nodes is not only greatly reduces the delivery time,but also can reduce the delivery cost.