European Journal of Operational Research最新文献_第9页

Decision-focused neural adaptive search and diving for optimizing mining complexes 优化采矿综合体的决策神经自适应搜索和潜水

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-27 DOI: 10.1016/j.ejor.2024.07.024

{"title":"Decision-focused neural adaptive search and diving for optimizing mining complexes","authors":"","doi":"10.1016/j.ejor.2024.07.024","DOIUrl":"10.1016/j.ejor.2024.07.024","url":null,"abstract":"<div><div>Optimizing industrial mining complexes, from extraction to end-product delivery, presents a significant challenge due to non-linear aspects and uncertainties inherent in mining operations. The two-stage stochastic integer program for optimizing mining complexes under joint supply and demand uncertainties leads to a formulation with tens of millions of variables and non-linear constraints, thereby challenging the computational limits of state-of-the-art solvers. To address this complexity, a novel solution methodology is proposed, integrating context-aware machine learning and optimization for decision-making under uncertainty. This methodology comprises three components: (i) a hyper-heuristic that optimizes the dynamics of mining complexes, modeled as a graph structure, (ii) a neural diving policy that efficiently performs dives into the primal heuristic selection tree, and (iii) a neural adaptive search policy that learns a block sampling function to guide low-level heuristics and restrict the search space. The proposed neural adaptive search policy introduces the first soft (heuristic) branching strategy in mining literature, adapting the learning-to-branch framework to an industrial context. Deployed in an online fashion, the proposed hybrid methodology is shown to optimize some of the most complex case studies, accounting for varying degrees of uncertainty modeling complexity. Theoretical analyses and computational experiments validate the components’ efficacy, adaptability, and robustness, showing substantial reductions in primal suboptimality and decreased execution times, with improved and more robust solutions that yield higher net present values of up to 40%. While primarily grounded in mining, the methodology shows potential for enabling smart, robust decision-making under uncertainty.</div></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A machine learning approach to rank pricing problems in branch-and-price 用机器学习方法解决分行定价问题

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-26 DOI: 10.1016/j.ejor.2024.07.029

{"title":"A machine learning approach to rank pricing problems in branch-and-price","authors":"","doi":"10.1016/j.ejor.2024.07.029","DOIUrl":"10.1016/j.ejor.2024.07.029","url":null,"abstract":"<div><p>This paper presents a novel approach exploiting machine learning to enhance the efficiency of the branch-and-price algorithm. The focus is, specifically, on problems characterized by multiple pricing problems. Pricing problems often constitute a substantial portion of CPU time due to their repetitive nature. The primary contribution of this work includes the introduction of a machine learning-based ranker that strategically guides the search for new columns in the column generation process. The master problem solution is analyzed by the ranker, which then suggests an order for solving the pricing problems to prioritize those with the potential to improve the master problem the most. This prioritization mechanism is essential in speeding up the column generation since, by identifying new columns early in the process, we can terminate the search procedure sooner. Furthermore, our technique exhibits applicability across all nodes of the branching tree, making it a valuable tool for solving a wide range of optimization problems. We demonstrate the usefulness of this approach in the challenging domain of operating room scheduling, an area that has seen limited exploration in the context of machine learning. Extensive experimental evaluations underline the effectiveness of the developed algorithm, consistently outperforming traditional search strategies in terms of time, number of solved pricing problems, searched nodes in the branching tree, and performed column generation iterations.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Local stability in kidney exchange programs 换肾计划在当地的稳定性

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-26 DOI: 10.1016/j.ejor.2024.07.031

{"title":"Local stability in kidney exchange programs","authors":"","doi":"10.1016/j.ejor.2024.07.031","DOIUrl":"10.1016/j.ejor.2024.07.031","url":null,"abstract":"<div><p>When each patient of a kidney exchange program has a preference ranking over its set of compatible donors, questions naturally arise surrounding the stability of the proposed exchanges. We extend recent work on stable exchanges by introducing and underlining the relevance of a new concept of locally stable, or L-stable, exchanges. We show that locally stable exchanges in a compatibility digraph are exactly the so-called local kernels (L-kernels) of an associated blocking digraph (whereas the stable exchanges are the kernels of the blocking digraph), and we prove that finding a nonempty L-kernel in an arbitrary digraph is NP-complete. Based on these insights, we propose several integer programming formulations for computing an L-stable exchange of maximum size. We conduct numerical experiments to assess the quality of our formulations and to compare the size of maximum L-stable exchanges with the size of maximum stable exchanges. It turns out that nonempty L-stable exchanges frequently exist in digraphs which do not have any stable exchange. All the above results and observations carry over when the concept of (locally) stable exchanges is extended to the concept of (locally) strongly stable exchanges.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of encoding and neighborhood in landscape analysis and tabu search performance for job shop scheduling problem 编码和邻域对工作车间调度问题的景观分析和塔布搜索性能的影响

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-25 DOI: 10.1016/j.ejor.2024.07.028

引用次数: 0

Protecting labor rights: Contract design and coordination between brand firms and suppliers 保护劳工权利：品牌企业与供应商之间的合同设计与协调

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-25 DOI: 10.1016/j.ejor.2024.07.025

{"title":"Protecting labor rights: Contract design and coordination between brand firms and suppliers","authors":"","doi":"10.1016/j.ejor.2024.07.025","DOIUrl":"10.1016/j.ejor.2024.07.025","url":null,"abstract":"<div><p>This paper explores the design of a contract aimed at coordinating brand firms and their suppliers to collectively protect the suppliers’ labor rights. It finds that a unilateral cost-sharing contract can incentivize suppliers to protect labor rights, while improving the profits of both brand firms and their suppliers. However, such a contract fails to coordinate the supply chain because of an insufficient incentive for both involved parties. Two improved contracts of this contract can coordinate brands firms and their suppliers to improve their efforts to protect labor rights under certain conditions while failing to achieve coordination. Accordingly, this research proposes a bilateral cost- and revenue-sharing contract. The results indicate that with an appropriate revenue-sharing proportion, this contract effectively encourages brand firms and their suppliers to participate in protecting labor rights and coordinate the supply chain. In addition, an increase in the proportion of prosocial consumers incentivizes brand firms and their suppliers to improve labor rights. Nonetheless, consumers’ excessive reliance on brand goodwill to evaluate the total supply chain efforts to protect labor rights will reduce their efforts. Finally, as the impact of labor rights protection efforts on reference prices increases, it can stimulate brand companies and suppliers to increase investment in improving labor rights. At this high impact level, the reference price in the centralized model may surpass that in the unilateral cost-sharing contract. However, if supply chain members invest little effort to protect labor rights, the increase in this impact could reduce consumers’ reference price.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Centrally-chosen versus user-selected swaps: How the selection of swapping stations impacts standby battery inventories 集中选择与用户选择交换：交换站的选择如何影响备用电池库存

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-24 DOI: 10.1016/j.ejor.2024.07.022

{"title":"Centrally-chosen versus user-selected swaps: How the selection of swapping stations impacts standby battery inventories","authors":"","doi":"10.1016/j.ejor.2024.07.022","DOIUrl":"10.1016/j.ejor.2024.07.022","url":null,"abstract":"<div><p>Swapping depleted batteries of electric vehicles promises much better driving-to-total-travel-time ratios than plug-in charging. Nonetheless, large-scale battery swapping systems have not successfully established yet. One obstacle, on top of the high infrastructure cost, is certainly the additional invest into extra standby batteries that await their swaps at stations. Existing research is focused on systems in which users decide individually where they want to swap batteries. This system requires significant standby battery inventories to protect against uncertain swapping demand. This paper evaluates another system where users must register their trips on a central platform, so that battery swaps can be coordinated based on central optimization results. To benchmark central optimization and user choice regarding their impact on standby battery inventories, we formulate the min-battery swapping problem: For a given set of vehicle trips, this optimization problem minimizes the number of standby batteries, distributes them in a given station network, and derives detailed swapping plans to feasibly power all trips. First, we present a thorough analysis of computational complexity. Then, we provide an efficient mixed-integer programming formulation that is adaptable to different swapping policies and (when fed into a default solver) solves instances with up to 200 trips to proven optimality in just a few seconds. Our computational study reveals that central optimization promises a significant reduction of standby battery inventories. This potential is shown to increase if swaps of not yet fully-charged batteries are allowed and swaps are pooled at a reduced number of swapping stations.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377221724005630/pdfft?md5=e1997316fac5d314beac1d9715a3b51b&pid=1-s2.0-S0377221724005630-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sales strategy selection for liner companies under shipping e-commerce considering canvassing ability competition 考虑拉票能力竞争的航运电子商务下班轮公司的销售策略选择

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-24 DOI: 10.1016/j.ejor.2024.07.027

{"title":"Sales strategy selection for liner companies under shipping e-commerce considering canvassing ability competition","authors":"","doi":"10.1016/j.ejor.2024.07.027","DOIUrl":"10.1016/j.ejor.2024.07.027","url":null,"abstract":"<div><p>The rapid growth of e-commerce applications has promoted the establishment of shipping e-commerce channels by many liner companies in addition to their existing traditional Non-vessel operating common carrier (NVOCC) channel. Unlike NVOCC channels, shipping e-commerce channels guarantee shippers the availability of contracted container slots. However, some problems arise, including the competition with NVOCC channels, shipping slot sales’ risk, and the increasing liner companies’ costs. Therefore, this paper addresses optimal sales strategy selection in the liner transportation industry, including a single traditional NVOCC channel (TN) strategy, and a dual channel with both e-commerce and NVOCC channels (EN) strategy. Two contract scheme models are constructed considering the channel competition on canvassing ability, overselling behavior, demand fluctuation, and the limited liner vessel capacity. Findings show that the impact of overselling behavior on the profit under the EN and TN is not always negative, which is related to the shipping capacity and probability of the high canvassing ability. Comparative analyses reveal that the EN is dominant if the unit overselling compensation cost varies small. Meanwhile, the TN is profitable if the unit overselling compensation cost increases and the canvassing cost of e-commerce channel exceeds a certain value. Otherwise, the selection of sales strategy relies on the arrival rate, the canvassing cost of the e-commerce channel and shipping capacity. The results offer new insights to both theoretical research on container slot sales and the practical selection of sales strategy since shipping e-commerce has changed the slot selling mode in the container shipping industry, which could also enhance the competitiveness of liner companies in the container shipping industry.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377221724005824/pdfft?md5=456be79cc548a518d6a48b98e962e730&pid=1-s2.0-S0377221724005824-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Robust ordinal regression for subsets comparisons with interactions 用于有交互作用的子集比较的稳健序数回归

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-23 DOI: 10.1016/j.ejor.2024.07.021

{"title":"Robust ordinal regression for subsets comparisons with interactions","authors":"","doi":"10.1016/j.ejor.2024.07.021","DOIUrl":"10.1016/j.ejor.2024.07.021","url":null,"abstract":"<div><p>This paper is devoted to a robust ordinal method for learning the preferences of a decision maker between subsets. The decision model, derived from Fishburn and LaValle (1996) and whose parameters we learn, is general enough to be compatible with any strict weak order on subsets, thanks to the consideration of possible interactions between elements. Moreover, we accept not to predict some preferences if the available preference data are not compatible with a reliable prediction. A predicted preference is considered reliable if all the simplest models (Occam’s razor) explaining the preference data agree on it. Following the robust ordinal regression methodology, our predictions are based on an uncertainty set encompassing the possible values of the model parameters. We define a new ordinal dominance relation between subsets and design a procedure to determine whether this dominance relation holds. Numerical tests are provided on synthetic and real-world data to evaluate the richness and reliability of the preference predictions made.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377221724005629/pdfft?md5=4ba6c81c7300adfc9f6ebbc61b982ef7&pid=1-s2.0-S0377221724005629-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Robust optimal design of a tree-based water distribution network with intermittent demand 具有间歇性需求的树状配水管网的稳健优化设计

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-23 DOI: 10.1016/j.ejor.2024.07.020

引用次数: 0

An effective subgradient algorithm via Mifflin’s line search for nonsmooth nonconvex multiobjective optimization 针对非平滑非凸多目标优化的米夫林线搜索子梯度有效算法

IF 6 2区管理学

European Journal of Operational Research Pub Date : 2024-07-22 DOI: 10.1016/j.ejor.2024.07.019

{"title":"An effective subgradient algorithm via Mifflin’s line search for nonsmooth nonconvex multiobjective optimization","authors":"","doi":"10.1016/j.ejor.2024.07.019","DOIUrl":"10.1016/j.ejor.2024.07.019","url":null,"abstract":"<div><p>We propose a descent subgradient algorithm for unconstrained nonsmooth nonconvex multiobjective optimization problems. To find a descent direction, we present an iterative process that efficiently approximates the <span><math><mi>ɛ</mi></math></span>-subdifferential of each objective function. To this end, we develop a new variant of Mifflin’s line search in which the subgradients are arbitrary and its finite convergence is proved under a semismooth assumption. To reduce the number of subgradient evaluations, we employ a backtracking line search that identifies the objectives requiring an improvement in the current approximation of the <span><math><mi>ɛ</mi></math></span>-subdifferential. Meanwhile, for the remaining objectives, new subgradients are not computed. Unlike bundle-type methods, the proposed approach can handle nonconvexity without the need for algorithmic adjustments. Moreover, the quadratic subproblems have a simple structure, and hence the method is easy to implement. We analyze the global convergence of the proposed method and prove that any accumulation point of the generated sequence satisfies a necessary Pareto optimality condition. Furthermore, our convergence analysis addresses a theoretical challenge in a recently developed subgradient method. Through numerical experiments, we observe the practical capability of the proposed method and evaluate its efficiency when applied to a diverse range of nonsmooth test problems.</p></div>","PeriodicalId":55161,"journal":{"name":"European Journal of Operational Research","volume":null,"pages":null},"PeriodicalIF":6.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0