基于非线性双层规划的货运网络分配模型

采用非线性双层规划理论构建多式联运货运网络分配模型，模型同时考虑了货物运输应该优先保证货主的利益，以及运输时间、成本的改变对货主决策的影响。根据服务对象的不同引入两个相关联的网络概念——运输网络和集计网络，上层为货主在集计网络上确定各种联运方案的货运量，实现集计网络流量的用户均衡，在进行决策时必须考虑下层承运者的路线选择所引起的路网流量的改变；下层为承运者根据上层的决策在其运输子网络中进行路线选择，实现运输子网络流量的系统均衡，并给出其求解算法实例。模型模拟了货主和承运者的实际决策行为及其相互影响关系，解决了货主和承运者决策分离的问题.

A Freight Network Assignment Model Based on Nonlinear Bilevel Programming

The intermodal freight network assignment model is established by using nonlinear bilevel programming theory.The model considers simultaneously that shippers benefit is the most important in freight transportation and the impact of change of travel time and cost on the decisions made by shippers.The upper level denotes that shippers determine the freight flow of each transportation scheme over the aggregate network to obtain an user optimized flow pattern.The decisions can't be taken without considering the change of the freight flow as a result of the routing decision made by carriers.The lower level denotes the decision of carriers,each carrier takes the routing decision within his own subnet of the physical network to achieve a system optimized flow pattern,and an example is given.The model is constructed to describe shippers' and carriers' decision behaviors and the relationship between the decisions made by shippers and those by carriers,which solves the detachment of decisions between shippers and carriers.