Waste collection is an important part of waste management system.Transportation costs and carbon emissions can be greatly reduced by proper vehicle routing.Meanwhile,each vehicle can work again after achieving its cap...Waste collection is an important part of waste management system.Transportation costs and carbon emissions can be greatly reduced by proper vehicle routing.Meanwhile,each vehicle can work again after achieving its capacity limit and unloading the waste.For this,an energy-efficient multi-trip vehicle routing model is established for municipal solid waste collection,which incorporates practical factors like the limited capacity,maximum working hours,and multiple trips of each vehicle.Considering both economy and environment,fixed costs,fuel costs,and carbon emission costs are minimized together.To solve the formulated model effectively,contribution-based adaptive particle swarm optimization is proposed.Four strategies named greedy learning,multi-operator learning,exploring learning,and exploiting learning are specifically designed with their own searching priorities.By assessing the contribution of each learning strategy during the process of evolution,an appropriate one is selected and assigned to each individual adaptively to improve the searching efficiency of the algorithm.Moreover,an improved local search operator is performed on the trips with the largest number of waste sites so that both the exploiting ability and the convergence accuracy of the algorithm are improved.Performance of the proposed algorithm is tested on ten waste collection instances,which include one real-world case derived from the Green Ring Company of Jiangbei New District,Nanjing,China,and nine synthetic instances with increasing scales generated from the commonly-used capacitated vehicle routing problem benchmark datasets.Comparisons with five state-of-the-art algorithms show that the proposed algorithm can obtain a solution with a higher accuracy for the constructed model.展开更多
Disaster relief logistics is a significant element in the management of disaster relief operations.In this paper,the operational decisions of relief logistics are considered in the distribution of resources to the aff...Disaster relief logistics is a significant element in the management of disaster relief operations.In this paper,the operational decisions of relief logistics are considered in the distribution of resources to the affected areas to include scheduling,routing,and allocation decisions.The proposed mathematical model simultaneously captures many aspects relevant to real life to face the challenging situation of disasters.Characteristics such as multiple uses of vehicles and split delivery allow for better use of vehicles as one of the primary resources of disaster response.A multi-period multi-criteria mixed-integer programming model is introduced to evaluate and address these features.The model utilizes a rolling horizon method that provides possibilities to adjust plans as more information becomes available.Three objectives of efficiency,effectiveness,and equity are jointly considered.The augmented epsilon constraint method is applied to solve the model,and a case study is presented to illustrate the potential applicability of our model.Computational results show that the model is capable of generating efficient solutions.展开更多
基金This work was supported by the Guangdong Provincial Key Laboratory(No.2020B121201001)National Natural Science Foundation of China(NSFC)(Nos.61502239 and 62002148)+1 种基金Natural Science Foundation of Jiangsu Province of China(No.BK20150924)Shenzhen Science and Technology Program(No.KQTD2016112514355531).
文摘Waste collection is an important part of waste management system.Transportation costs and carbon emissions can be greatly reduced by proper vehicle routing.Meanwhile,each vehicle can work again after achieving its capacity limit and unloading the waste.For this,an energy-efficient multi-trip vehicle routing model is established for municipal solid waste collection,which incorporates practical factors like the limited capacity,maximum working hours,and multiple trips of each vehicle.Considering both economy and environment,fixed costs,fuel costs,and carbon emission costs are minimized together.To solve the formulated model effectively,contribution-based adaptive particle swarm optimization is proposed.Four strategies named greedy learning,multi-operator learning,exploring learning,and exploiting learning are specifically designed with their own searching priorities.By assessing the contribution of each learning strategy during the process of evolution,an appropriate one is selected and assigned to each individual adaptively to improve the searching efficiency of the algorithm.Moreover,an improved local search operator is performed on the trips with the largest number of waste sites so that both the exploiting ability and the convergence accuracy of the algorithm are improved.Performance of the proposed algorithm is tested on ten waste collection instances,which include one real-world case derived from the Green Ring Company of Jiangbei New District,Nanjing,China,and nine synthetic instances with increasing scales generated from the commonly-used capacitated vehicle routing problem benchmark datasets.Comparisons with five state-of-the-art algorithms show that the proposed algorithm can obtain a solution with a higher accuracy for the constructed model.
文摘Disaster relief logistics is a significant element in the management of disaster relief operations.In this paper,the operational decisions of relief logistics are considered in the distribution of resources to the affected areas to include scheduling,routing,and allocation decisions.The proposed mathematical model simultaneously captures many aspects relevant to real life to face the challenging situation of disasters.Characteristics such as multiple uses of vehicles and split delivery allow for better use of vehicles as one of the primary resources of disaster response.A multi-period multi-criteria mixed-integer programming model is introduced to evaluate and address these features.The model utilizes a rolling horizon method that provides possibilities to adjust plans as more information becomes available.Three objectives of efficiency,effectiveness,and equity are jointly considered.The augmented epsilon constraint method is applied to solve the model,and a case study is presented to illustrate the potential applicability of our model.Computational results show that the model is capable of generating efficient solutions.
