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我国自然资源分布不平衡，受地区经济发展和城市布局等因素的影响，全国集装箱货源分布和流向存在着很大差异，导致铁路集装箱供需矛盾十分突出，空箱调运较为频繁.以往空箱调运优化模型都是以调运费用最小为目标，没有考虑重箱运输的收益.综合考虑空重集装箱运输，以铁路运输利润最大为目标，在完成局间排空箱任务基础上，将适箱货物按重要程度分为不同的等级，对高等级货物优先运输，并按所需集装箱类型不同建立空箱调运非线性混合整数规划模型.其中，运输利润为重箱运输收益与空箱调运成本之差.算例分析结果验证了模型的正确性和可行性.

Empty and Loaded Container Transportation Optimization Based on Cargo Rank

The distribution and flow direction of container freight are significantly different from place to place in China due to the affecting of many factors such as unbalanced distribution of natural resources,the region economy development,city layout and other factors.And this leads to the prominent contradiction between supply and demand of railway container.Therefore,the empty container allocation has become increasingly important.The former optimization models on empty container allocation mostly minimize allocation costs without regarding to loaded container transportation income.The paper addresses the two concerns and formulates a nonlinear integer programming model based on demanding rank of cargo suitable for container and container type.The objective function is maximizing the transportation profit by freight charges subtracting empty container allocation cost.After the empty allocation between different railway bureaus,the empty container demand of the higher rank cargo is more priority than that of the lower rank cargo for the same container type in every container demand station.The model is proved to be validity and feasibility by an example.