Optimal logistic systems of natural resources and energy based on the computer simulation

为了保证日本的自然资源和能源安全，我们开发了离散化模型和时间进步法的物流模拟器。该模拟器的仿真模型包括从生产国港口通过水路将铁矿石运输到日本炼钢厂的矿车、容量受限的海港、炼钢厂的堆场等。该模拟器不仅可以计算运输成本，还可以根据各炼铁厂的库存评估耗尽风险，从而估计出最优的运输路线和船队。使用该模拟器，我们发现最优路线由30%的日本？澳大利亚?南美洲吗?欧盟组合路线和70%的直达穿梭运输路线。

In order to secure the natural resources and energies for Japan, we developed the logistics simulator with discretized models and time marching method. The simulator has some simulation models such as an ore carrier that transports iron ore by water from the port in a producing country to Japan's iron mills, a sea port with some capacity constraints, a stock yard of the iron mill and so on. The simulator can calculate not only shipping cost but also depleted risk evaluated from the stockpiles of each iron mill, so we can estimate the optimal shipping routes and fleet. Using this simulator, we found that the optimum routes was consisted of 30 % of the Japan?Australia?South America?EU combination route and 70% of the direct shuttle transportations routes.