文章针对软硬时间窗共存装卸一体化车辆路径问题(vehicle routing problem with simultaneous delivery and pickup under coexistence of soft and hard time windows,VRPSDPCSHTW)建立了包含车辆固定出行成本、运输成本和惩罚成本的...文章针对软硬时间窗共存装卸一体化车辆路径问题(vehicle routing problem with simultaneous delivery and pickup under coexistence of soft and hard time windows,VRPSDPCSHTW)建立了包含车辆固定出行成本、运输成本和惩罚成本的数学模型,提出了一种混合离散粒子群优化算法。针对基本离散粒子群算法容易早熟收敛而陷入局部最优等问题,内嵌一种变邻域下降局域搜索方法,并在一定概率下执行以加强种群搜索能力,最后通过3个算例的仿真分析进行了算法验证。展开更多
由于服饰产品是一种时效性很强的商品,而且服饰产品在配送过程中可以外包给快递公司进行配送,对带外包和硬时间窗的服饰运输调度问题(Apparel products Vehicle Routing Problem with Hard Time Windows and Outsourcing,AVRPHTWO)进行...由于服饰产品是一种时效性很强的商品,而且服饰产品在配送过程中可以外包给快递公司进行配送,对带外包和硬时间窗的服饰运输调度问题(Apparel products Vehicle Routing Problem with Hard Time Windows and Outsourcing,AVRPHTWO)进行分析,并构建了AVRPHTWO、一般性VRP(Vehicle Routing Problem)和VRPSTW(Vehicle Routing Problem with Soft Time Windows)的数学模型,通过对基本的人工鱼群算法(artificial fish swarm algorithm,AFSA)进行改进,混沌搜索被引入人工鱼群算法来提高算法的全局收敛性,反馈策略用来指导人工鱼的移动,以此来提高收敛精度。应用混沌人工鱼群算法(chaotic artificial fish swarm algorithm,CAFSA)及遗传算法(genetic algorithm,GA)对所建立的三种模型求解,通过对实验数据进行处理,证明了AVRPHTWO模型和混沌人工鱼群算法求解此类模型的有效性,进一步证明了问题模型的复杂程度影响算法寻优能力,问题模型简单时,遗传算法更优;问题模型复杂时,混沌人工鱼群算法更优。展开更多
Purpose-The purpose of this paper is to explore a real world vehicle routing problem(VRP)that has multi-depot subcontractors with a heterogeneous fleet of vehicles that are available to pickup/deliver jobs with varyin...Purpose-The purpose of this paper is to explore a real world vehicle routing problem(VRP)that has multi-depot subcontractors with a heterogeneous fleet of vehicles that are available to pickup/deliver jobs with varying time windows and locations.Both the overall job completion time and number of drivers utilized are analyzed for the automated job allocations and manual job assignments from transportation field experts.Design/methodology/approach-A nested genetic algorithm(GA)is used to automate the job allocation process and minimize the overall time to deliver all jobs,while utilizing the fewest number of drivers-as a secondary objective.Findings-Three different real world data sets were used to compare the results of the GA vs transportation field experts’manual assignments.The job assignments from the GA improved the overall job completion time in 100 percent(30/30)of the cases and maintained the same or fewer drivers as BS Logistics(BSL)in 47 percent(14/30)of the cases.Originality/value-This paperprovidesa novel approach to solving a real world VRPthathasmultiple variants.While there have been numerous models to capture a select number of these variants,the value of this nested GA lies in its ability to incorporate multiple depots,a heterogeneous fleet of vehicles as well as varying pickup times,pickup locations,delivery times and delivery locations for each job into a single model.Existing research does not provide models to collectively address all of these variants.展开更多
文摘文章针对软硬时间窗共存装卸一体化车辆路径问题(vehicle routing problem with simultaneous delivery and pickup under coexistence of soft and hard time windows,VRPSDPCSHTW)建立了包含车辆固定出行成本、运输成本和惩罚成本的数学模型,提出了一种混合离散粒子群优化算法。针对基本离散粒子群算法容易早熟收敛而陷入局部最优等问题,内嵌一种变邻域下降局域搜索方法,并在一定概率下执行以加强种群搜索能力,最后通过3个算例的仿真分析进行了算法验证。
文摘由于服饰产品是一种时效性很强的商品,而且服饰产品在配送过程中可以外包给快递公司进行配送,对带外包和硬时间窗的服饰运输调度问题(Apparel products Vehicle Routing Problem with Hard Time Windows and Outsourcing,AVRPHTWO)进行分析,并构建了AVRPHTWO、一般性VRP(Vehicle Routing Problem)和VRPSTW(Vehicle Routing Problem with Soft Time Windows)的数学模型,通过对基本的人工鱼群算法(artificial fish swarm algorithm,AFSA)进行改进,混沌搜索被引入人工鱼群算法来提高算法的全局收敛性,反馈策略用来指导人工鱼的移动,以此来提高收敛精度。应用混沌人工鱼群算法(chaotic artificial fish swarm algorithm,CAFSA)及遗传算法(genetic algorithm,GA)对所建立的三种模型求解,通过对实验数据进行处理,证明了AVRPHTWO模型和混沌人工鱼群算法求解此类模型的有效性,进一步证明了问题模型的复杂程度影响算法寻优能力,问题模型简单时,遗传算法更优;问题模型复杂时,混沌人工鱼群算法更优。
文摘Purpose-The purpose of this paper is to explore a real world vehicle routing problem(VRP)that has multi-depot subcontractors with a heterogeneous fleet of vehicles that are available to pickup/deliver jobs with varying time windows and locations.Both the overall job completion time and number of drivers utilized are analyzed for the automated job allocations and manual job assignments from transportation field experts.Design/methodology/approach-A nested genetic algorithm(GA)is used to automate the job allocation process and minimize the overall time to deliver all jobs,while utilizing the fewest number of drivers-as a secondary objective.Findings-Three different real world data sets were used to compare the results of the GA vs transportation field experts’manual assignments.The job assignments from the GA improved the overall job completion time in 100 percent(30/30)of the cases and maintained the same or fewer drivers as BS Logistics(BSL)in 47 percent(14/30)of the cases.Originality/value-This paperprovidesa novel approach to solving a real world VRPthathasmultiple variants.While there have been numerous models to capture a select number of these variants,the value of this nested GA lies in its ability to incorporate multiple depots,a heterogeneous fleet of vehicles as well as varying pickup times,pickup locations,delivery times and delivery locations for each job into a single model.Existing research does not provide models to collectively address all of these variants.