Traditional Hungarian method can only solve standard assignment problems, while can not solve competition assignment problems. This article emphatically discussed the difference between standard assignment problems an...Traditional Hungarian method can only solve standard assignment problems, while can not solve competition assignment problems. This article emphatically discussed the difference between standard assignment problems and competition assignment problems. The kinds of competition assignment problem algorithms based on Hungarian method and the solutions of them were studied.展开更多
In order to overcome the shortcoming of the classical Hungarian algorithm that it can only solve the problems where the total cost is the sum of that of each job, an improved Hungarian algorithm is proposed and used t...In order to overcome the shortcoming of the classical Hungarian algorithm that it can only solve the problems where the total cost is the sum of that of each job, an improved Hungarian algorithm is proposed and used to solve the assignment problem of serial-parallel systems. First of all, by replacing parallel jobs with virtual jobs, the proposed algorithm converts the serial-parallel system into a pure serial system, where the classical Hungarian algorithm can be used to generate a temporal assignment plan via optimization. Afterwards, the assignment plan is validated by checking whether the virtual jobs can be realized by real jobs through local searching. If the assignment plan is not valid, the converted system will be adapted by adjusting the parameters of virtual jobs, and then be optimized again. Through iterative searching, the valid optimal assignment plan can eventually be obtained.To evaluate the proposed algorithm, the valid optimal assignment plan is applied to labor allocation of a manufacturing system which is a typical serial-parallel system.展开更多
载重约束的电动车辆路径问题(capacitated electric vehicle routing problem,CEVRP)是物流配送中的一种NP困难的组合优化问题,要求满足车辆的载重和电量约束条件,最小化总配送距离。提出一种混合遗传搜索算法来解决CEVRP,将其分解为两...载重约束的电动车辆路径问题(capacitated electric vehicle routing problem,CEVRP)是物流配送中的一种NP困难的组合优化问题,要求满足车辆的载重和电量约束条件,最小化总配送距离。提出一种混合遗传搜索算法来解决CEVRP,将其分解为两个子问题:载重约束的车辆路径问题和固定路径车辆充电问题。设计了双层染色体结构的编码方案,表示两个子问题的决策变量。采用Split操作生成满足载重约束的车辆路径,使用Relocate、2-Opt、2-Opt^(*)、SWAP和SWAP^(*)邻域搜索算子对其进行局部优化;提出一种基于回溯的充电策略,将合适的充电站编号插入车辆路径,以满足电量约束。本文算法与五种方法实验比较的结果表明,本文算法在多数CEVRP测试问题上能找到比其它方法更好的解,尤其适合于求解大规模的CEVRP。展开更多
物流作为现代经济的重要组成部分,在国民经济和社会发展中发挥着重要作用.物流中的三维装箱问题(Three-dimensional bin packing problem,3D-BPP)是提高物流运作效率必须解决的关键难题之一.深度强化学习(Deep rein-forcement learning,...物流作为现代经济的重要组成部分,在国民经济和社会发展中发挥着重要作用.物流中的三维装箱问题(Three-dimensional bin packing problem,3D-BPP)是提高物流运作效率必须解决的关键难题之一.深度强化学习(Deep rein-forcement learning,DRL)具有强大的学习与决策能力,基于DRL的三维装箱方法(Three-dimensional bin packing method based on DRL,DRL-3DBP)已成为智能物流领域的研究热点之一.现有DRL-3DBP面对大尺寸容器3D-BPP时难以达成动作空间、计算复杂性与探索能力之间的平衡.为此,提出一种四向协同装箱(Four directional cooperative packing,FDCP)方法:两阶段策略网络接收旋转后的容器状态,生成4个方向的装箱策略;根据由4个策略采样而得的动作更新对应的4个状态,选取其中价值最大的对应动作为装箱动作.FDCP在压缩动作空间、减小计算复杂性的同时,鼓励智能体对4个方向合理装箱位置的探索.实验结果表明,FDCP在100×100大尺寸容器以及20、30、50箱子数量的装箱问题上实现了1.2%~2.9%的空间利用率提升.展开更多
文摘Traditional Hungarian method can only solve standard assignment problems, while can not solve competition assignment problems. This article emphatically discussed the difference between standard assignment problems and competition assignment problems. The kinds of competition assignment problem algorithms based on Hungarian method and the solutions of them were studied.
文摘In order to overcome the shortcoming of the classical Hungarian algorithm that it can only solve the problems where the total cost is the sum of that of each job, an improved Hungarian algorithm is proposed and used to solve the assignment problem of serial-parallel systems. First of all, by replacing parallel jobs with virtual jobs, the proposed algorithm converts the serial-parallel system into a pure serial system, where the classical Hungarian algorithm can be used to generate a temporal assignment plan via optimization. Afterwards, the assignment plan is validated by checking whether the virtual jobs can be realized by real jobs through local searching. If the assignment plan is not valid, the converted system will be adapted by adjusting the parameters of virtual jobs, and then be optimized again. Through iterative searching, the valid optimal assignment plan can eventually be obtained.To evaluate the proposed algorithm, the valid optimal assignment plan is applied to labor allocation of a manufacturing system which is a typical serial-parallel system.
文摘载重约束的电动车辆路径问题(capacitated electric vehicle routing problem,CEVRP)是物流配送中的一种NP困难的组合优化问题,要求满足车辆的载重和电量约束条件,最小化总配送距离。提出一种混合遗传搜索算法来解决CEVRP,将其分解为两个子问题:载重约束的车辆路径问题和固定路径车辆充电问题。设计了双层染色体结构的编码方案,表示两个子问题的决策变量。采用Split操作生成满足载重约束的车辆路径,使用Relocate、2-Opt、2-Opt^(*)、SWAP和SWAP^(*)邻域搜索算子对其进行局部优化;提出一种基于回溯的充电策略,将合适的充电站编号插入车辆路径,以满足电量约束。本文算法与五种方法实验比较的结果表明,本文算法在多数CEVRP测试问题上能找到比其它方法更好的解,尤其适合于求解大规模的CEVRP。
文摘物流作为现代经济的重要组成部分,在国民经济和社会发展中发挥着重要作用.物流中的三维装箱问题(Three-dimensional bin packing problem,3D-BPP)是提高物流运作效率必须解决的关键难题之一.深度强化学习(Deep rein-forcement learning,DRL)具有强大的学习与决策能力,基于DRL的三维装箱方法(Three-dimensional bin packing method based on DRL,DRL-3DBP)已成为智能物流领域的研究热点之一.现有DRL-3DBP面对大尺寸容器3D-BPP时难以达成动作空间、计算复杂性与探索能力之间的平衡.为此,提出一种四向协同装箱(Four directional cooperative packing,FDCP)方法:两阶段策略网络接收旋转后的容器状态,生成4个方向的装箱策略;根据由4个策略采样而得的动作更新对应的4个状态,选取其中价值最大的对应动作为装箱动作.FDCP在压缩动作空间、减小计算复杂性的同时,鼓励智能体对4个方向合理装箱位置的探索.实验结果表明,FDCP在100×100大尺寸容器以及20、30、50箱子数量的装箱问题上实现了1.2%~2.9%的空间利用率提升.
