Computers & Operations Research最新文献

{"title":"An exact branch-price-and-cut algorithm for the time-dependent cold chain pickup and delivery problem with incompatibility constraints","authors":"Hongyuan Luo ,&nbsp;Tao Ma ,&nbsp;Zhendong Li","doi":"10.1016/j.cor.2025.107007","DOIUrl":"10.1016/j.cor.2025.107007","url":null,"abstract":"<div><div>This paper addresses a cold chain transportation problem derived from a real-life situation, namely a time-dependent pickup and delivery problem with commodity incompatibility constraints (TDPDPI). In TDPDPI, the travel speed of these vehicles varies with the departure time, that is, the time-dependent travel speed. The quality delay cost of the perishable commodity also varies with the departure time, namely the time-dependent quality delay cost. The cost of this problem consists of two components: one is related to the total travel time, and the other is related to the quality delay cost of the perishable commodity. To solve TDPDPI, this paper develops an arc-based (mixed integer programming, MIP) model solved by CPLEX and a route-based (set-partitioning formulation, SPF) model. To address the SPF model, this paper proposes an exact branch-price-and-cut (BPC) algorithm. A specialized bidirectional labeling algorithm is developed to address the pricing problem. Additionally, subset row cuts (SRC) are employed as valid inequalities to enhance the quality of the lower bound in the SPF model. Extensive computational experiments are conducted to evaluate the efficacy of the proposed BPC algorithm. The results demonstrate that the BPC algorithm effectively solves the problem with 50 requests. Finally, this study conducts a sensitivity analysis of the key constraints and parameters of the model, providing valuable managerial insights.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 107007"},"PeriodicalIF":4.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The drone-assisted simultaneous pickup and delivery problem with time windows","authors":"Xia Zhang,&nbsp;Shuang Zeng","doi":"10.1016/j.cor.2025.106996","DOIUrl":"10.1016/j.cor.2025.106996","url":null,"abstract":"<div><div>The explosion of e-commerce has led to a continued increase in CO₂ emissions in logistics. In this article, we explore the role of collaboration between drones and trucks in logistics in mitigating environmental pollution. We propose a mathematical model of drone-assisted truck service that considers customers’ simultaneous pickup and delivery needs within a specific time window. We name it the drone-assisted truck simultaneous pickup and delivery problem considering time windows (DASPDPTW), the objective is to minimize the total CO₂ emissions. The energy consumption of the drone is calculated based on a load-based energy model. We design an improved adaptive large neighborhood search (IALNS) algorithm to solve large instances, which contains some special operators for the DASPDPTW. Numerical experiments have verified the effectiveness of IALNS, and drone-assisted trucks can effectively alleviate environmental pollution. Logistics companies can consider incorporating drones into delivery systems to promote supply chain sustainability.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 106996"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benefit Maximizing Network Design in the public sector","authors":"Robert Aboolian,&nbsp;Majid Karimi","doi":"10.1016/j.cor.2025.107004","DOIUrl":"10.1016/j.cor.2025.107004","url":null,"abstract":"<div><div>This paper introduces the Benefit Maximization Network Design Problem (BNDP), an innovative framework aimed at optimizing public service systems. By integrating consumer choice models with a focus on minimizing consumer disutility, the BNDP strategically maximizes societal welfare by optimizing the net benefits derived from service utilization, carefully weighing the costs of service capacity against the value delivered to the public. An essential aspect of this study is the development of an <span><math><mi>ϵ</mi></math></span>-optimal solution approach, which effectively addresses the intricate optimization challenges inherent in public service system design, including nonlinear equilibrium conditions. This approach efficiently identifies the optimal number, locations, and capacities for service facilities, ensuring practical and effective solutions despite the model’s complexity. A practical application of the BNDP is demonstrated through a detailed case study on preventive healthcare in San Diego, showcasing the model’s ability to refine operational solutions and significantly enhance societal benefits. The results underscore the importance of prioritizing benefit maximization over simplistic capacity thresholds and participation maximization, leading to either higher levels of consumer participation while using optimal levels of resources or comparable levels of customer participation with significantly fewer resources and reasonable utilization rates. Furthermore, the paper explores the model’s applicability in the private sector to maximize corporate profits, highlighting its versatility. The study concludes by advocating for policymakers to prioritize the use of BNDP in establishing optimal budgets for public agencies rather than allocating resources based on exogenous capacities.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"178 ","pages":"Article 107004"},"PeriodicalIF":4.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Routing and driver break scheduling with working and driving regulations: A flexible approach for various general pickup and delivery problem variants","authors":"Ning Xue,&nbsp;Huan Jin,&nbsp;Tianxiang Cui","doi":"10.1016/j.cor.2025.107001","DOIUrl":"10.1016/j.cor.2025.107001","url":null,"abstract":"<div><div>This paper provides a solution to the driver break scheduling problem that can be integrated into current solvers for the generalised pick-up and delivery problem (GPDP) with a negligible increase in development costs. The driver break scheduling problem affects truck drivers who are required to adhere to working time and/or driving time regulations that oblige them to take mandatory breaks. These regulations are in force in many countries across the European Union, Great Britain, Australia, New Zealand, and the United States. We propose a flexible solution strategy that combines routing with driver break scheduling, taking into account both Regulations (EC)561/2006 and 2002/15/EC within a single day of operation. We deliberately incorporate driver breaks into the routes generated, with the aim of minimising route duration. The method proposed in this paper is particularly beneficial for the solvers that have not initially implemented driver break rules but need to introduce this functionality to accommodate customers, given the critical nature of driver break rules for effective scheduling. This is a flexible approach because the method proposed here can be applied directly to any individual route and at any stage of the scheduling process. For instance, it can be used during the constructive heuristic or the improvement heuristic phases. It is also applicable at the column generation stage of an exact method after a route has been constructed. This method is particularly beneficial when a human scheduler wishes to make manual adjustments along a single route, such as adding or removing an order from the route. Experimental analyses, grounded in two benchmark instances, affirm the efficacy of the proposed method. Results indicate that the method yields a 6.1% decrease in distance, a 1.7% reduction in duty time, and a 1.1% decrease in the number of unassigned tasks when contrasted with the standard compliant approach. We also offer guidance on how to tailor this method for driver break scheduling in accordance with the regulatory standards of Australia and New Zealand.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 107001"},"PeriodicalIF":4.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-neighborhood simulated annealing for the oven scheduling problem","authors":"Francesca Da Ros ,&nbsp;Luca Di Gaspero ,&nbsp;Marie-Louise Lackner ,&nbsp;Nysret Musliu ,&nbsp;Felix Winter","doi":"10.1016/j.cor.2025.106999","DOIUrl":"10.1016/j.cor.2025.106999","url":null,"abstract":"<div><div>The Oven Scheduling Problem (OSP) is an NP-hard real-world parallel batch scheduling problem that arises in the semiconductor manufacturing sector. It aims to group compatible jobs in batches and to find an optimal schedule in order to reduce oven runtime, setup costs, and job tardiness. This work proposes a Simulated Annealing (SA) algorithm for the OSP, encompassing a unique combination of four neighborhoods and a construction heuristic as initial solution. An extensive experimental evaluation is performed, benchmarking the proposed SA algorithm against state-of-the-art methods. The results show that this approach consistently finds new upper bounds for large instances, while for smaller instances, it achieves solutions of comparable quality to state-of-the-art methods. These results are delivered in significantly less time than the literature approaches require. Additionally, the SA is extended to tackle a related batch scheduling problem from the literature. Even in this case, the algorithm confirms its effectiveness and robustness across different problem formulations by improving results for many instances.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106999"},"PeriodicalIF":4.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Knowledge graph based question-answering model with subgraph retrieval optimization","authors":"Rui Zhu ,&nbsp;Bo Liu ,&nbsp;Qiuyu Tian ,&nbsp;Ruwen Zhang ,&nbsp;Shengxiang Zhang ,&nbsp;Yanna Hu ,&nbsp;Jiuxin Cao","doi":"10.1016/j.cor.2025.106995","DOIUrl":"10.1016/j.cor.2025.106995","url":null,"abstract":"<div><div>Knowledge graph-based question answering (QA) is a critical domain within natural language processing, aimed at delivering precise and efficient responses to user queries. Current research predominantly focuses on minimizing subgraph sizes to enhance the efficiency and compactness of the search space. However, natural language queries often exhibit ambiguities, and merely reducing subgraph sizes may overlook relevant answer entities. Additionally, redundant relationships among entities in the knowledge graph can adversely affect QA model performance. To address these limitations, this paper introduces a novel QA model that optimizes subgraph retrieval. The proposed model enhances entity linking and subgraph retrieval by leveraging contextual features from both questions and entities. It disambiguates entities using relevant contextual features and refines the search process through entity relation merging and entity ranking strategies. This methodology improves entity recognition and linking, reduces subgraph dimensions, and broadens answer coverage, resulting in substantial improvements in QA performance. Experimental results on the CCKS2019-CKBQA dataset demonstrate the modelś effectiveness, showing an average F1 score improvement of 2.99% over the leading baseline model. Furthermore, the model’s application in the field of ocean engineering underscores its practical utility and significance.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106995"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143132610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved A* algorithm incorporating RRT* thought: A path planning algorithm for AGV in digitalised workshops","authors":"Na Liu,&nbsp;Zihang Hu,&nbsp;Min Wei,&nbsp;Pengfei Guo,&nbsp;Shuhan Zhang,&nbsp;Aodi Zhang","doi":"10.1016/j.cor.2025.106993","DOIUrl":"10.1016/j.cor.2025.106993","url":null,"abstract":"<div><div>The implementation of efficient path planning algorithms can facilitate enhanced transport efficiency in AGVs (Automated Guided Vehicles). However, the current path planning algorithms used in the workshop can determine the shortest path, but there are problems such as low search efficiency, long search time, and many path inflection points. Such issues have the potential to negatively impact the transport efficiency of the AGV, rendering them unsuitable for actual workshop conditions. This paper proposes a new algorithm, named IA-RRT* (Improved A* Algorithm Integrating RRT* Thought), for path planning of AGV in digitalised workshops. The algorithm modifies the cost evaluation function of the A* algorithm to provide a less strong direction for the search, narrowing the search scope and preventing the algorithm from converging too quickly and getting stuck in a local optimal path. Meanwhile, the IA-RRT* algorithm combines the randomness concept of the RRT* algorithm with an inflection point penalty term. The objective is to find a path with fewer inflection points, making it more practical for production. Simulation experiments have shown that the IA-RRT* algorithm outperforms several other path planning algorithms in terms of path length cost, algorithm calculation time, and number of inflection points. The paths generated by the IA-RRT* algorithm are applicable to the working situation of AGV and have practical significance.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106993"},"PeriodicalIF":4.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A branch-and-cut-and-price algorithm for shared mobility considering customer satisfaction","authors":"Min Xu","doi":"10.1016/j.cor.2025.106998","DOIUrl":"10.1016/j.cor.2025.106998","url":null,"abstract":"<div><div>This study determines the exact optimal fleet size, ride-matching patterns, and vehicle routes for shared mobility services (SMS) that maximize the profit of service operators considering ride-pooling and customer satisfaction. We make the first attempt to consider a nonlinear multivariate customer satisfaction function with respect to the features of the riders and the system under a ‘two riders-single vehicle’ ride-pooling scenario in a special case of dial-a-ride problem (DARP). A set packing model and a tailored branch-and-cut-and-price (BCP) approach are proposed to find the exact optimal solution of the problem. Unlike existing exact solution methods for DARP, we exploit the characteristic of the ride-pooling scenario and decompose the ride matching and vehicle routing in an effective two-phase method to solve the pricing problem of the BCP approach. Particularly, in Phase 1, feasible matching patterns subject to practical constraints are identified. In Phase 2, a heuristic and an exact label-correcting method with a bounded bi-directional search are sequentially employed to solve a new variant of elementary shortest path problem with time window (ESPPTW) in a network constructed upon rides and feasible ride matching patterns identified in Phase 1. The labeling methods are further accelerated by a strengthened dominance test, the aggregate extension to other depots, and the decremental search space. Valid inequalities are also incorporated to further improve the upper bound. The proposed solution method is evaluated in randomly generated instances and the instances created from the real mobility data of Didi. Managerial insights are generated through impact analysis.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106998"},"PeriodicalIF":4.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143132609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benders decomposition for the large-scale probabilistic set covering problem","authors":"Jie Liang ,&nbsp;Cheng-Yang Yu ,&nbsp;Wei Lv ,&nbsp;Wei-Kun Chen ,&nbsp;Yu-Hong Dai","doi":"10.1016/j.cor.2025.106994","DOIUrl":"10.1016/j.cor.2025.106994","url":null,"abstract":"<div><div>In this paper, we consider a probabilistic set covering problem (PSCP) in which each 0-1 row of the constraint matrix is random with a finite discrete distribution, and the objective is to minimize the total cost of the selected columns such that each row is covered with a prespecified probability. We develop an effective decomposition algorithm for the PSCP based on the Benders reformulation of a standard mixed integer programming (MIP) formulation. The proposed Benders decomposition (BD) algorithm enjoys two key advantages: (i) the number of variables in the underlying Benders reformulation is equal to the number of columns but independent of the number of scenarios of the random data; and (ii) the Benders feasibility cuts can be separated by an efficient polynomial-time algorithm, which makes it particularly suitable for solving large-scale PSCPs. We enhance the BD algorithm by using initial cuts to strengthen the relaxed master problem, implementing an effective heuristic procedure to find high-quality feasible solutions, and adding mixed integer rounding enhanced Benders feasibility cuts to tighten the problem formulation. Numerical results demonstrate the efficiency of the proposed BD algorithm over a state-of-the-art MIP solver. Moreover, the proposed BD algorithm can efficiently identify optimal solutions for instances with up to 500 rows, 5000 columns, and 2000 scenarios of the random rows.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106994"},"PeriodicalIF":4.1,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143228653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The vehicle routing problem with transfers","authors":"Maichel M. Aguayo ,&nbsp;Francisco N. Avilés ,&nbsp;Subhash C. Sarin ,&nbsp;Claudia Archetti","doi":"10.1016/j.cor.2025.106980","DOIUrl":"10.1016/j.cor.2025.106980","url":null,"abstract":"<div><div>In the vehicle routing problem (VRP), a fleet of capacitated vehicles serves a set of customers with known demands at minimum cost. The Split Delivery VRP (SDVRP), a variant of VRP, permits customer demands to be served by different vehicles, and thereby results in a significant cost reduction. In this paper, we study the VRP with transfers (VRP-T), where, as in the SDVRP, customers can be visited by multiple vehicles. However, differently from the SDVRP, customer locations can be used as transfer locations to exchange load among vehicles. We find that the routing costs can potentially be reduced by at most 50% by allowing such transfers in the VRP. We develop a two-index mixed-integer programming (MIP) model and heuristic algorithm based on <span><math><mi>Multi − start local search (MSLS)</mi></math></span>. The solutions obtained by the <span><math><mi>MSLS</mi></math></span> are used as warm-start for the MIP and the corresponding approach is tested. Computational results indicate substantial savings in the costs incurred and the number of vehicles required when transfers are allowed. Results also suggest that transfers are at least as effective in reducing the cost as split delivery.</div></div>","PeriodicalId":10542,"journal":{"name":"Computers & Operations Research","volume":"177 ","pages":"Article 106980"},"PeriodicalIF":4.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143228652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}