基于江海直达运输模式和投资约束的长江干散货运优化模型

引入了江海直达运输模式和投资约束的概念,对已有的长江干散货运输网络进行优化,并比较了江海直达与江海联运2种运输模式的特点。根据中国内河航运成熟性市场的特质和航运企业滚动规划的经营特征,以最小运营成本与最小船舶投资成本为目标函数,建立了集成处理运输模式选择、航线配船和船型更新的模型。简化了模型的时间维度,设计了基于背包问题的拉格朗日松弛算法,并应用A集团数据求解模型。分析结果表明:当以现行模式的航运总成本为基准点,在引入江海联运模式后,航运总成本可下降2%左右;在引入江海直达运输模式后,航运总成本的最大下降幅度超过8%,但财务风险会增大;当资金成本率为7%且不考虑投资约束时,成本节约效应可提高16.2%,但投资净预算将会上升60.1%。从最优航线配置可以看出,在不同航线上,江海直达与江海联运2种运输模式应协同使用。

Optimization model of dry bulk feright in Yangtze River based on river-sea transportation mode and investment constraint

The concepts of river-sea transportation mode and investment constraint were introduced,the existed transportation network of dry bulk freight in Yangtze River was optimized,and the characteristics of river-sea transportation mode and river-sea combined transportation mode were compared.According to the characteristic of mature market for inland shipping and the management feature of rolling planning for shipping enterprise in China,the minimum operation cost and the minimum ship investment cost were taken as objective functions,and the model that integrated transportation mode selection,ship assignment and ship type update was set up.The time dimension of the model was simplified,the Lagrangian relaxation algorithm based on knapsack problem was designed,and the data of group A were used to solve the model.Analysis result shows that while the total shipping cost of current mode is taken as a reference point,the total shipping cost can decrease by about 2% after using river-sea combined transportation mode.After using river-sea transportation mode,the maximum descent range is more than 8%,but the financial risk will increase.While the fund cost rate is 7% and the investment constraint is not considered,cost-reduction effect increases by 16.2%,but net investment budget will raise by 60.1%.From the configuration of optimal route,the river-sea transportation mode and river-sea combined transportation mode must be used together on different routes.3 tabs,2 figs,16 refs.