Research On Inland Port Location Based On Uncertain Demand And Node Failure

With the development of global economic integration,the degree of China's participation in international trade is deepening.As an inland container multimodal transport hub,the development and construction of inland port is not only beneficial to expand inland hinterland,optimize inland container transportation network,but also facilitate the export of goods in inland area and promote the development of inland export-oriented economy.And the rational location of inland port is the key to the effective function of the above inland port.In the decision of location,freight demand is an important factor to be considered,and it is uncertain.In addition,under the influence of natural and man-made disasters,there is a risk of failure in the inland port,which will destroy the existing location network and reduce the operational efficiency of the inland port network once the failure occurs.Therefore,considering the inland port failure and the re-connection after the failure during the site selection will benefit from selecting a more reliable group of nodes and be able to respond quickly after the inland port failure.In summary,this paper makes a comprehensive study on the problem of demand uncertainty and node failure,in order to reduce the influence of uncertain demand and node failure on the inland port network and improve the response ability of the system,and provide a certain basis for the related research of inland port location.In this paper,under the intermodal transport network of inland container,the problem of location under the uncertain demand and the failure of inland port is studied.Aiming at the above two problems,this paper describes the uncertainty of cargo demand by probability scenario and robustness,and describes the failure problem of inland port by failure probability and system reliability parameters.At the same time,considering that the reasonable setting of inland port capacity can reduce the total cost of the system under the condition of ensuring the uniform distribution of cargo flow,this paper constructs different inland port pass capacity level to optimize the inland port pass capacity.Based on this,this paper constructs a robust optimization model aiming at the minimum sum of four costs,including the construction cost of inland port,the transportation cost under conditions,reconnection cost under inland port failure and freight loss cost.The results show that:(1)The demand uncertainty has a great influence on the location of inland port,and a robust model can effectively solve the problem of demand uncertainty in the location of inland port and reduce the maximum regret value when each scenario occurs;(2)Considering the problem of inland port node failure,the system's responsiveness can be quickly restored after the failure occurs,and the inland cargo owners who pass the failed inland port can be assigned to other inland ports for transshipment,effectively reducing the loss caused by the inland port failure;(3)Compared with the site selection model under the single pass capability level,considering the site selection model under the pass level decision can better balance the relationship between construction cost and transportation cost in the system to achieve the optimal total system cost;(4)The railway freight discount factor is directly proportional to the total system cost and has a certain impact on the inland.port location and its passing capacity.A reasonable assessment of the railway freight discount factor during the site selection phase can better attract freight flow and reduce the total cost.