大规模外贸物流系统规划计算方法研究

求解大规模外贸物流系统规划时，常常会遇到系统变量过多，从而导致计算速度慢，计算精度低有时甚至完全不能求解的问题。解决这类问题的重要途径之一,就是先用动态规划方法求出系统中各起运点到各运到点之间的所有最短线路和各线路的对应费率；然后将各最短线路的费率作为线性规划方法的计算参数，从而使系统的变量数大大减少，再用线性规划方法求得满足各种约束条件限制及品质要求的系统总体最优解。

On the Plan Calculation Method of Larger Foreign Trade Logistical System

The problem that the variables are too many always is met when people calculate the plan of larger foreign trade logistical system. It led to the calculation being too slow and crude, even getting no result. One of the important methods to solve the problem is finding out each shortest roads and their cost rates between every start ports and end ports by means of dynamic programming and then using these rates as calculation parameters of the liner programming. It reducing the number of the variables greatly. The optimum solution which satisfies various limited conditions and quality requirement is evaluated with liner programming at last.