In this study, a two-stage stochastic integer programming model is developed with a centralized planning perspective to simultaneously address mitigation and response decisions in humanitarian logistics, where the mitigation decisions involve both building and transportation infrastructure retrofitting. The objective is to minimize the total cost of retrofitting, relief item transportation and relief item shortage under a limited mitigation budget. Due to the excessive number of binary decision variables, solving the model becomes computationally difficult. Therefore, we propose Lagrangean relaxation to decouple the overall model and solve it by Lagrangean heuristics. Computational results indicate the efficiency of the solution approaches in providing high quality feasible solutions to problem instances of realistic size and complexity.

中文翻译：

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装卸物资运输的综合防灾模型

在这项研究中，开发了一个具有集中计划角度的两阶段随机整数规划模型，以同时解决人道主义物流中的缓解和响应决策，其中缓解决策涉及建筑和运输基础设施的改造。目的是在有限的缓解预算下最大程度地减少翻新，救济物资运输和救济物资短缺的总成本。由于二元决策变量的数量过多，因此求解模型变得计算困难。因此，我们提出拉格朗日松弛法，以使整体模型解耦，并通过拉格朗日启发法求解。计算结果表明，在为实际大小和复杂性的问题实例提供高质量可行的解决方案时，解决方案方法的效率很高。