The refugee crisis is one of the major challenges of modern society. The influxes of refugees are usually sudden and the refugees are in sheer need of services such as health care, education and safety. Planning public services under an imminent humanitarian crisis requires simultaneous strategic and operational decisions. Inspired by a real-world problem that Red Crescent is facing in Southeast Turkey, we study the problem of locating refugee camps and planning transportation of public service providers from their institutions to the located camps. Our modeling approach brings a new facet to the location and routing problem by considering the location of beneficiaries as variables. We develop a branch-price-and-cut algorithm for the problem. To solve the pricing problem, we introduce a cycle-eliminating algorithm using nested recursion to generate elementary hop constrained shortest paths. The best version of our algorithm efficiently solves 244-node real-world instances optimally.

难民危机是现代社会的主要挑战之一。难民的涌入通常是突然的，难民急需诸如保健，教育和安全之类的服务。在迫在眉睫的人道主义危机下规划公共服务需要同时做出战略和运营决策。受红新月会在土耳其东南部面临的现实问题的启发，我们研究了安置难民营的问题，并计划了将公共服务提供者从其机构运送到所设营地的问题。通过将受益人的位置视为变量，我们的建模方法为位置和路由问题带来了新的面貌。我们针对该问题开发了一种分支价格削减算法。为了解决定价问题，我们介绍一种使用嵌套递归的消除周期算法，以生成基本跳约束的最短路径。我们算法的最佳版本可以有效地优化解决244个节点的实际实例。