相比于海洋运输,内河运输中集装箱船舶较小,船舶装载能力受到一定的限制.本文研究能力限制条件下内河集装箱枢纽港选址问题,建立一个混合整数非线性规划模型.不同于传统的枢纽选址问题的研究大多是基于枢纽之间的运输折扣因子的假设,本文采用基于流量的非线性费用函数来表示规模经济,从而使得所研究的问题是一个凹函数优化问题.为简化本文的问题,将目标函数分段线性化.基于线性化后的模型,根据能力限制的条件,提出一个启发式求解算法,以及一个加速技巧.最后,通过以长江为例,进行算例分析,来说明模型和算法的效果.
As compared with sea/ocean shipping, small ships are deployed in river shipping, and ship capacities are limited. This paper investigates a capacitated hub port location problem in river shipping, and a mixed-integer nonlinear programming model is proposed. Different from the transportation discount used in the conventional hub location problems, this paper adopts the flow-based nonlinear cost functions to describe scale economies, leading to a concave optimization problem. In order to simplify our problem, we utilize a piecewise linear function to linearize the objective function. Based on the linearized problem and capacity constraints, a heuristic algorithm with an accelerating technique is proposed to solve our problem. Finally, a case study of the Yangtze River is presented to account for the effectiveness of our model and algorithm.