On Port Supply Chain Supernetwork Equilibrium Model With Random Demand

With the increasing development of globalization, ports have played a more prominent role in the international trade and logistics. Meanwhile, their functions have been gradually improved. Ports have become the core links in the integrated transportation network, and they have been the centers of the flow of goods, funds or information. Against this backdrop, the port supply chain finally comes into being.In recent years, some hot and difficult problems on port supply chain have been studied, such as how to coordinate all links reasonably or how to optimize the supply chain. So far, a large number of researchers have paid attention to supply chain and the majority of them have basically centered on manufacturing. In contrast, researches on port supply chain are few and even no integrated theory system has been formed.In the paper, we apply the equilibrium theory and variational inequality to modeling the competition behavior and equilibrium conditions at the tiers of suppliers, port agents and the demand market. Meanwhile economic explanation is given. Then through integrating models of each tier, we develop a multi-commodity flow port supply chain super-network equilibrium model with random demand, and we derive the equilibrium conditions. The existence and uniqueness of model solution can be demonstrated by means of qualitative analysis. Then the solution of equilibrium price and quantity is figured out with the improved projective algorithm which also guarantees convergence of the result. Finally, numerical examples illustrate the rationality of the model.In this paper, the study has three innovation points. Firstly, we develop a port supply chain super-network equilibrium model by integrating the theories such as super-network model, equilibrium model framework and variational inequality. Secondly, demand equilibrium conditions are reflected by random demand functions at the tier of port agents and we finally achieve the equilibrium state of port supply chain super-network model. Thirdly, the port supply chain super-network equilibrium model is established on the basis of multi-commodity flow instead of one-commodity.