Journal of Combinatorial Optimization最新文献

{"title":"Approximation algorithms for the W-prize-collecting scheduling problem on a single machine with submodular rejection penalties","authors":"Tianjiao Guo, Wen Liu, Gengsheng Zhang, Bo Hou","doi":"10.1007/s10878-025-01314-2","DOIUrl":"https://doi.org/10.1007/s10878-025-01314-2","url":null,"abstract":"<p>In this paper, we consider the <i>W</i>-prize-collecting scheduling problem on a single machine with submodular rejection penalties. In this problem, we are given one machine, <i>n</i> jobs and a value <i>W</i>. Every job has a processing time and a profit. Each job is either accepted and processed on the machine, or rejected and a rejection penalty is paid. The objective is to minimize the sum of the makespan of the accepted jobs and the rejection penalties of the rejected jobs which is determined by a submodular function, provided that the total profit of the accepted jobs is at least <i>W</i>. Under the assumption that the submodular penalty function is polymatriod, we design a 2-approximation algorithm based on the primal-dual framework.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"35 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism Design with Predictions for Facility Location Games with Candidate Locations","authors":"Jiazhu Fang, Qizhi Fang, Wenjing Liu, Qingqin Nong, Alexandros A. Voudouris","doi":"10.1007/s10878-025-01310-6","DOIUrl":"https://doi.org/10.1007/s10878-025-01310-6","url":null,"abstract":"<p>We study mechanism design with predictions in the single (obnoxious) facility location games with candidate locations on the real line, which complements the existing literature on mechanism design with predictions. We first consider the single facility location games with candidate locations, where each agent prefers the facility (e.g., a school) to be located as close to her as possible. We study two social objectives: minimizing the maximum cost and the social cost, and provide deterministic, anonymous, and group strategy-proof mechanisms with predictions that achieve the best possible trade-offs between consistency and robustness, respectively. Additionally, we represent the approximation ratio as a function of the prediction error, indicating that mechanisms can achieve better performance even when predictions are not fully accurate. We also consider the single obnoxious facility location games with candidate locations, where each agent prefers the facility (e.g., a garbage transfer station) to be located as far away from her as possible. For the objective of maximizing the minimum utility, we prove that any strategy-proof mechanism with predictions is unbounded robust. For the objective of maximizing the social utility, we provide a deterministic, anonymous, and group strategy-proof mechanism with prediction that achieves the best possible trade-off between consistency and robustness.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"135 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of payment schemes on performance in a medical cost-sharing system: bundled payment vs. total prepayment","authors":"Miao Yu, Wang Zhou, Yu Zhao","doi":"10.1007/s10878-025-01301-7","DOIUrl":"https://doi.org/10.1007/s10878-025-01301-7","url":null,"abstract":"<p>Currently, many countries are on the process of reforming their health care payment systems from post-payment to pre-payment. To explore the impact of pre-payment schemes on health system performance we investigate the two payment schemes, bundled payment (BP) and total prepayment (TP), on performance in a medical cost-sharing system. Under the BP scheme, the government compensates hospitals with a lump sum for the entire course of each patient’s care. Under the TP scheme, the government provides the total amount of integrated compensation within a period. A three Stackelberg game with an embedded queueing model is used to explore the interactions among participants: government, hospital, and patients. The government determines the compensation received by hospitals and the copayment paid by patients to maximize social welfare. Next, the hospital determines its service rate for each medical episode to maximize profit. Last, patients make decisions on whether to appeal to the hospital for medical services. We derive the optimal strategy for the participants under the BP and TP schemes, and compare the system performance through numerical analysis. Results show that BP is better than TP in reducing patient expected waiting time, while it outperforms TP in terms of system accessibility and service quality. Our study is the first to consider the total prepayment scheme in the healthcare system decision analysis and the findings offer important insights for policymakers regarding implementing medical insurance reform in practice.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"57 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudo-Shapley value for weak games of threats","authors":"Daniel Li Li, Erfang Shan","doi":"10.1007/s10878-025-01319-x","DOIUrl":"https://doi.org/10.1007/s10878-025-01319-x","url":null,"abstract":"<p>For a real number <span>(omega )</span>, a weak game of threats (<i>N</i>, <i>v</i>) consists of a set <i>N</i> of <i>n</i> players and a function <span>(v:2^Nrightarrow mathbb {R})</span> such that <span>(omega v(emptyset )+(1-omega )v(N)=0)</span>, where <span>(v(emptyset )ne 0)</span> possibly. It is shown that there exists a unique value with respect to <span>(omega )</span> for weak games of threats that satisfies efficiency, linearity, symmetry and the null player property.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"42 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On combinatorial network flows algorithms and circuit augmentation for pseudoflows","authors":"Steffen Borgwardt, Angela Morrison","doi":"10.1007/s10878-025-01313-3","DOIUrl":"https://doi.org/10.1007/s10878-025-01313-3","url":null,"abstract":"<p>There are numerous combinatorial algorithms for classical min-cost flow problems and their simpler variants like max flow or shortest path problems. It is well-known that many of these algorithms are related to the Simplex method and the more general circuit augmentation schemes: prime examples are the network Simplex method, a refinement of the primal Simplex method, and min-mean cycle canceling, which corresponds to a steepest-descent circuit augmentation scheme. We are interested in a deeper understanding of the relationship between circuit augmentation and combinatorial network flows algorithms. To this end, we generalize from primal flows to so-called pseudoflows, which adhere to arc capacities but allow for a violation of flow balance. We introduce ‘pseudoflow polyhedra,’ wherein slack variables are used to quantify this violation, and characterize their circuits. This enables the study of combinatorial network flows algorithms in view of the walks they trace in these polyhedra, and the pivot rules for the steps. In doing so, we provide an ‘umbrella,’ a general framework, that captures several algorithms. We show that the Successive Shortest Path Algorithm for min-cost flow problems, the Shortest Augmenting Path Algorithm for max flow problems, and the Preflow-Push algorithm for max flow problems lead to (non-edge) circuit walks in these polyhedra. The former two are replicated by circuit augmentation schemes for simple pivot rules. Further, we show that the Hungarian Method leads to an edge walk and is replicated, equivalently, as a circuit augmentation scheme or a primal Simplex run for a simple pivot rule.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"136 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The independent quadratic assignment problem: complexity and polynomially solvable special cases","authors":"Ante Ćustić, Wei Yang, Yang Wang, Abraham P. Punnen","doi":"10.1007/s10878-025-01302-6","DOIUrl":"https://doi.org/10.1007/s10878-025-01302-6","url":null,"abstract":"<p>In this paper, we study the independent quadratic assignment problem which is a variation of the well-known Koopmans–Beckman quadratic assignment problem. The problem is strongly NP-hard and is also hard to approximate. Some polynomially solvable special cases are identified along with a complete characterization of linearizable instances of the problem, the validity of which is shown to be verifiable in linear time. This improves the existing quadratic bound for this problem. Additional complexity results are also presented.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"19 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Further combinatorial analysis of substar reliability in star networks","authors":"Hao Li, Eminjan Sabir","doi":"10.1007/s10878-025-01315-1","DOIUrl":"https://doi.org/10.1007/s10878-025-01315-1","url":null,"abstract":"<p>Substar reliability defined as the probability that a fault-free substar of a certain scale is still available in the star network <span>(S_n)</span> when the occurrence of faults. The substar reliability is one of the most practical reliability measures because a user in the current star multiprocessors is given a certain substar for the execution of his/her program. Wu and Latifi(Inf. Sci. 178 (2008)) derived upper-bound on the substar reliability of <span>(S_n)</span> by analysing the intersection of no more than three substars. Later, Li et al.(IEEE. Trans. Rel. 65 (2016)) derived lower-bound on the substar reliability of <span>(S_n)</span> by considering the intersection of no more than four substars. In the paper, we further derive the upper- and lower bounds on the substar reliability of <span>(S_n)</span> by taking into account the intersection of no more than five or four substars, respectively. At a result, we obtain more accurate value of the upper-bound on substar reliability of <span>(S_n)</span>. The experimental study indicates that both the upper- and lower bounds are very close to approximate results especially for the low value of the node reliability.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"56 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Better approximating SONET k-edge partition for small capacity k","authors":"Junhui Ye, Huihuang Jiang, Guangting Chen, Yong Chen, Guohui Lin, An Zhang","doi":"10.1007/s10878-025-01308-0","DOIUrl":"https://doi.org/10.1007/s10878-025-01308-0","url":null,"abstract":"<p>We study the SONET edge partition problem that models telecommunication network design to partition the edge set of a given graph into several edge-disjoint subgraphs, such that each subgraph has size no greater than a given capacity <i>k</i> and the sum of the orders of these subgraphs is minimized. The problem is NP-hard when <span>(k ge 3)</span> and admits an <span>(O(log k))</span>-approximation algorithm. For small capacity <span>(k = 3, 4, 5)</span>, by observing that some subgraph structures are more favorable than the others, we propose modifications to existing algorithms and design novel amortization schemes to prove their improved performance. Our algorithmic results include a <span>(frac{4}{3})</span>-approximation for <span>(k = 3)</span>, improving the previous best <span>(frac{13}{9})</span>-approximation, a <span>(frac{4}{3})</span>-approximation for <span>(k = 4)</span>, improving the previous best <span>((frac{4}{3} + epsilon ))</span>-approximation, and a <span>(frac{3}{2})</span>-approximation for <span>(k = 5)</span>, improving the previous best <span>(frac{5}{3})</span>-approximation. Besides these improved algorithms, our main contribution is the amortization scheme design, which can be helpful for similar algorithms and problems.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"57 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear-time algorithm for generating L-shaped floorplans using canonical ordering technique","authors":"Shiksha, Krishnendra Shekhawat, Ritu Chandna, Akshaj Gupta","doi":"10.1007/s10878-025-01287-2","DOIUrl":"https://doi.org/10.1007/s10878-025-01287-2","url":null,"abstract":"<p><i>L</i>-shaped floorplans are defined by rectangular modules enclosed within a rectilinear outer boundary, forming an <i>L</i>-shape that can not be altered through simple extension or contraction of a boundary wall. The boundary of such floorplans comprises five convex corners and one concave corner. The concave corner on the boundary of the plan can not be converted into a convex corner without altering the horizontal and vertical adjacency among the modules. This paper introduces a linear-time algorithm based on canonical ordering to generate <i>L</i>-shaped floorplans from properly triangulated plane graphs (PTPGs). Here, modules in the floorplan correspond to the nodes of the given graph, while edges in the graph represent wall adjacency between modules. The proposed algorithm assigns a unique labeling to the given graph, ensuring the presence of a concave corner on the resulting floorplan’s boundary. Simple boundary wall extensions or contractions cannot eliminate this concave corner. It also produces multiple <i>L</i>-shaped floorplans corresponding to the given PTPG, with variations mainly on their concave corners, highlighting the unique configurations possible within the same boundary constraints. Our algorithm offers simplicity over existing methods and is easy to implement. Additionally, we have implemented the algorithm in Python, enabling easy integration for generating <i>L</i>-shaped floorplans in various architectural and VLSI circuit design applications.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"13 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143980081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Big data-driven optimal weighted fused features-based ensemble learning classifier for thyroid prediction with heuristic algorithm","authors":"K. Hema Priya, K. Valarmathi","doi":"10.1007/s10878-025-01304-4","DOIUrl":"https://doi.org/10.1007/s10878-025-01304-4","url":null,"abstract":"<p>Diagnosis of thyroid disease is a most important cause in the field of medicinal research and it is a complex onset axiom. Secretion of Thyroid hormone plays a major role in the regulation of metabolism. Hence, it is very significant to predict thyroid disease in the initial stage, which is helpful for preventing more serious health complications due to thyroid cancer. The diagnostic accuracy of machine leaning-based approaches is greater but these techniques require large amounts of data for the diagnosis process. In the conventional approaches, the time needed for the prediction process is also high. Feature engineering is less investigated in conventional models and hence error produced during the prediction process is high. Hence, in this research work, a machine learning-aided thyroid disease prediction technique is designed to provide higher prediction accuracy and reliability. Initially, the thyroid data is gathered from the standard benchmark resources. Next, the data transformation process is carried out to make the data usable for analysis and visualization. After, the features are extracted using Principal Component Analysis (PCA), “One-Dimensional Convolutional Neural Network Model (1DCNN). Moreover, the statistical features are also extracted for getting more relevant information from the data. The three sets of features such as PCA-based, 1DCNN-based and statistical are concatenated and fed to the “optimal weighted feature selection” process, where the optimal features and weights are tuned by an Improved Archimedes Optimization Algorithm (IAOA). Next, the selected optimally fused features are given to the Ensemble Learning (EL) for predicting the thyroid diseases, where the EL with be suggested by incorporating stacking classifier, XGboost, and Multivariate regression classifier. Ensembling of three different classifiers provides higher thyroid disease prediction accuracy and it makes the decision about normal and abnormal classes. Here, the same IAOA is used for optimizing the parameters of every classifier. The investigational outcomes demonstrate that the proposed ensemble classifier provides higher performance than others. Experimental results prove that the thyroid prediction accuracy of the developed EL approach is 96.30%, precision is 99.67% and F1-score is 97.93%, which is more extensive than the state-of-the-art approaches.</p>","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":"17 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143979910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}