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Communication-Efficient Pilot Estimation for Non-Randomly Distributed Data in Diverging Dimensions J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-06-02
Yue Chao, Xiaochao Xia, Wei Zhong -
Missing Value Imputation in Relational Data using Variational Inference J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-29
Simon Fontaine, Jian Kang, Ji Zhu -
Improved approximation algorithms for multiprocessor indivisible coflow scheduling J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Mingyang Gong, Guangting Chen, Guohui Lin, Bing SuCoflow scheduling is a challenging optimization problem that underlies many data transmission and parallel computing applications. In this paper, we study the indivisible coflow scheduling problem on parallel identical machines with the objective to minimize the makespan, i.e., the completion time of the last flow. In our problem setting, the number of the input/output ports in each machine is a fixed
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The influence of carbon sink trading on carbon emission reduction in agricultural supply chains J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Tingting Meng, Yukun Cheng, Xujin Pu, Rui LiAs global climate change intensifies, the agricultural sector, responsible for over 30% of global greenhouse gas emissions, faces an urgent imperative to mitigate emissions and align with international climate commitments. Carbon sink trading, a market-based mechanism that incentivizes emission reductions through sequestration credits, has emerged as an important tool for accelerating carbon peaking
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Smart health system with deep kronecker network-based key generation for privacy-aware aggregate authentication and access control in IoT J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
M. Sathya, V. Mareeswari, M. Jeyaselvi, A. SolairajThe Internet of Things (IoT) application is an application and service that incorporates both the physical and information world. Similarly, it is difficult for existing health systems to provide privacy-aware aggregate authentication and fine-grained access control. To bridge the concern, a smart health system (SHS) with Deep Kronecker Network_key generation (DKN_keyGen) for privacy-aware aggregate
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Approximating the maximum weight cycle/path partition in graphs with weights one and two J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Xinmeng Guo, Wei Yu, Zhaohui LiuIn this paper, we investigate the maximum weight k-cycle (k-path) partition problem (MaxWkCP/MaxWkPP for short). The input consists of an undirected complete graph \(G=(V,E)\) with \(|V|=kn\), where k, n are positive integers, and a non-negative weight function on E, the objective is to determine n vertex disjoint k-cycles (k-paths), which are cycles (paths) containing exactly k vertices, covering
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ZeSAI: AI vigilant malware detection in email security with zero shot-based hybrid network and threat intelligence integration J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Venkadeshan Ramalingam, R. Gopal, Syed Ziaur Rahman, R. SenthilIn this ever-evolving world of threats, e-mail security is becoming one of the biggest concerns because attackers are constantly searching for new techniques to bypass the existing security measures. Emails containing phishing, malware and other security threats have become far more common place, which is why there is a need to implement new and more efficient adaptive threat detection frameworks.
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On some path-critical Ramsey numbers J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Ye Wang, Yanyan SongFor graphs G and H, the Ramsey number R(G, H) is the smallest r such that any red-blue edge coloring of \(K_r\) contains a red G or a blue H. The path-critical Ramsey number \(R_{\pi }(G,H)\) is the largest n such that any red-blue edge coloring of \(K_r \setminus P_{n}\) contains a red G or a blue H, where \(r=R(G,H)\) and \(P_{n}\) is a path of order n. In this note, we show a general upper bound
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An exponential cone integer programming and piece-wise linear approximation approach for 0-1 fractional programming J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Hoang Giang Pham, Thuy Anh Ta, Tien MaiWe study a class of binary fractional programs commonly encountered in important application domains such as assortment optimization and facility location. These problems are known to be NP-hard to approximate within any constant factor, and existing solution approaches typically rely on mixed-integer linear programming or second-order cone programming reformulations. These methods often utilize linearization
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Robust static and dynamic maximum flows J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-25
Christian Biefel, Martina Kuchlbauer, Frauke Liers, Lisa WaldmüllerWe study the robust maximum flow problem and the robust maximum flow over time problem where a given number of arcs \(\Gamma \) may fail or may be delayed. Two prominent models have been introduced for these problems: either one assigns flow to arcs fulfilling weak flow conservation in any scenario, or one assigns flow to paths where an arc failure or delay affects a whole path. We provide a unifying
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Impact of payment schemes on performance in a medical cost-sharing system: bundled payment vs. total prepayment J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Miao Yu, Wang Zhou, Yu ZhaoCurrently, 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
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The independent quadratic assignment problem: complexity and polynomially solvable special cases J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Ante Ćustić, Wei Yang, Yang Wang, Abraham P. PunnenIn 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
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Approximating combinatorial contracts with a cardinality constraint J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Qinqin Gong, Ling Gai, Yanjun Jiang, Yang Lv, Ruiqi YangWe explore the problem of combinatorial contract design, a subject introduced and studied by Dütting et al. (2023). Previous research has focused on the challenge of selecting an unconstrained subset of agents, particularly when the principal’s utility function exhibits XOS or submodular characteristics related to the subset of agents that exert effort. Our study extends this existing line of research
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Approximation algorithms for the W-prize-collecting scheduling problem on a single machine with submodular rejection penalties J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Tianjiao Guo, Wen Liu, Gengsheng Zhang, Bo HouIn this paper, we consider the W-prize-collecting scheduling problem on a single machine with submodular rejection penalties. In this problem, we are given one machine, n jobs and a value W. 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
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On combinatorial network flows algorithms and circuit augmentation for pseudoflows J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Steffen Borgwardt, Angela MorrisonThere 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,
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Mechanism Design with Predictions for Facility Location Games with Candidate Locations J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Jiazhu Fang, Qizhi Fang, Wenjing Liu, Qingqin Nong, Alexandros A. VoudourisWe 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
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Pseudo-Shapley value for weak games of threats J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Daniel Li Li, Erfang ShanFor a real number \(\omega \), a weak game of threats (N, v) consists of a set N of n players and a function \(v:2^N\rightarrow \mathbb {R}\) such that \(\omega v(\emptyset )+(1-\omega )v(N)=0\), where \(v(\emptyset )\ne 0\) possibly. It is shown that there exists a unique value with respect to \(\omega \) for weak games of threats that satisfies efficiency, linearity, symmetry and the null player
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Approximation algorithms for the partition set cover problem with penalties J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Qi Wang, Bo Hou, Gengsheng Zhang, Yisheng Zhou, Wen LiuIn this paper, we consider the partition set cover problem with penalties. In this problem, we have a universe U, a partition \(\mathscr {P}=\{P_{1},\ldots ,P_{r}\}\) of U, and a collection \(\mathscr {S}=\{S_{1},\ldots ,S_{m}\}\) of nonempty subsets of U satisfying \(\bigcup _{S_i\in \mathscr {S}} S_i=U\). In addition, each \(P_t\) \((t\in [r])\) is associated with a covering requirement \(k_t\) as
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Further combinatorial analysis of substar reliability in star networks J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-21
Hao Li, Eminjan SabirSubstar reliability defined as the probability that a fault-free substar of a certain scale is still available in the star network \(S_n\) 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
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Bayesian Adaptive Tucker Decompositions for Tensor Factorization J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-22
Federica Stolf, Antonio Canale -
Semiparametric Weighted Spline Regression (SWSR) in Confirmatory Clinical Trials with Time-Varying Placebo Effects J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-20
Tianyu Zhan, Yihua Gu -
Efficient Approximation of Leverage Scores in Two-dimensional Autoregressive Models with Application to Image Anomaly Detection J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-19
Junlie Huang, Xinlai Kang, Qiannan Huang, Mengyu Li, Cheng Meng, Jingyi Zhang -
Community Detection with Heterogeneous Block Covariance Model J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-19
Xiang Li, Yunpeng Zhao, Qing Pan, Ning Hao -
Mode and Ridge Estimation in Euclidean and Directional Product Spaces: A Mean Shift Approach J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-19
Yikun Zhang, Yen-Chi Chen -
Gaussian Variational Approximation for Ordinal Data with Crossed Random Effects J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-16
Manja Grønberg, John T. Ormerod, Line K. H. Clemmensen -
Linear-time algorithm for generating L-shaped floorplans using canonical ordering technique J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-15
Shiksha, Krishnendra Shekhawat, Ritu Chandna, Akshaj GuptaL-shaped floorplans are defined by rectangular modules enclosed within a rectilinear outer boundary, forming an L-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
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Better approximating SONET k-edge partition for small capacity k J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-15
Junhui Ye, Huihuang Jiang, Guangting Chen, Yong Chen, Guohui Lin, An ZhangWe 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 k and the sum of the orders of these subgraphs is minimized. The problem is NP-hard when \(k \ge 3\) and admits an \(O(\log k)\)-approximation algorithm. For small capacity
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Big data-driven optimal weighted fused features-based ensemble learning classifier for thyroid prediction with heuristic algorithm J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-15
K. Hema Priya, K. ValarmathiDiagnosis 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
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Neighbor sum distinguishable $$k$$ -edge colorings of joint graphs J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-15
Xiangzhi Tu, Peng Li, Yangjing Long, Aifa WangIn a graph G, the normal k-edge coloring \(\sigma \) is defined as the conventional edge coloring of G using the color set \(\left[ k \right] =\left\{ 1,2,\cdots ,k \right\} \). If the condition \(S\left( u \right) \ne S\left( v \right) \) holds for any edge \(uv\in E\left( G \right) \), where \(S\left( u \right) =\sum \nolimits _{uv\in E\left( G \right) }{\sigma \left( uv \right) }\), then \(\sigma
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Randomized approximation algorithms for monotone k-submodular function maximization with constraints J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-12
Yuying Li, Min Li, Yang Zhou, Shuxian Niu, Qian LiuIn recent years, k-submodular functions have garnered significant attention due to their natural extension of submodular functions and their practical applications, such as influence maximization and sensor placement. Influence maximization involves selecting a set of nodes in a network to maximize the spread of information, while sensor placement focuses on optimizing the locations of sensors to maximize
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Faster parameterized algorithms for variants of 3-Hitting Set J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-07
Dekel TsurIn the A-Multi3-Hitting Set problem (A-M3HS), where \(A \subseteq \{1,2,3\}\), the input is a hypergraph G in which the hyperedges have sizes at most 3 and an integer k, and the goal is to decide if there is a set S of at most k vertices such that \(|S \cap e| \in A\) for every hyperedge e. In this paper we give \(O^*(2.027^k)\)-time algorithms for \(\{1\}\)-M3HS and \(\{1,3\}\)-M3HS, and an \(O^*(1
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A review on the versions of artificial bee colony algorithm for scheduling problems J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-07
Beyza Gorkemli, Ebubekir Kaya, Dervis Karaboga, Bahriye AkayToday, artificial bee colony (ABC) algorithm is one of the most popular swarm intelligence based optimization techniques. Although it was originally introduced to work on continuous space for numerical optimization problems, several researchers also successfully use the ABC for other problem types. In this study, variants of the ABC for scheduling problems are surveyed. Since the scheduling problems
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Scheduling problems with rejection in green manufacturing industry J. Comb. Optim. (IF 0.9) Pub Date : 2025-05-07
Fanyu Kong, Jiaxin Song, Cuixia Miao, Yuzhong ZhangGreen manufacturing is used to describe an environmentally friendly manufacturing approach, which explicitly considers the impact of production on the environment and resources. Therefore, the production scheduling of solving energy conscious is in line with the focus of green manufacturing. In this paper, we consider the scheduling problems with rejection in the green manufacturing industry. The objective
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Order Determination for Tensor-valued Observations Using Data Augmentation J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-08
Una Radojičić, Niko Lietzén, Klaus Nordhausen, Joni Virta -
Spatially Clustered Compositional Regression: A Nonparametric Bayesian Approach J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-07
Jingcheng Meng, Yimeng Ren, Xuening Zhu, Guanyu Hu -
Studying the divisibility of power LCM matrices by power GCD matrices on gcd-closed sets J. Comb. Theory A (IF 0.9) Pub Date : 2025-05-02
Jianrong Zhao, Chenxu Wang, Yu FuLet S={x1,…,xn} be a gcd-closed set (i.e. (xi,xj)∈S for all 1≤i,j≤n). In 2002, Hong proposed the divisibility problem of characterizing all gcd-closed sets S with |S|≥4 such that the GCD matrix (S) divides the LCM matrix [S] in the ring Mn(Z). For x∈S, let GS(x):={z∈S:z
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Spatial Adaptive Selection using Binary Conditional Autoregressive Model with Application to Brain-Computer Interface J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-05-01
Zikai Lin, Junsouk Choi, Ruoxuan Mao, Bangyao Zhao, Jian Kang -
Characterization of polystochastic matrices of order 4 with zero permanent J. Comb. Theory A (IF 0.9) Pub Date : 2025-04-30
Aleksei L. Perezhogin, Vladimir N. Potapov, Anna A. Taranenko, Sergey Yu. VladimirovA multidimensional nonnegative matrix is called polystochastic if the sum of its entries over each line is equal to 1. The permanent of a multidimensional matrix is the sum of products of entries over all diagonals. We prove that if d is even, then the permanent of a d-dimensional polystochastic matrix of order 4 is positive, and for odd d, we give a complete characterization of d-dimensional polystochastic
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Analyzing the 3-path vertex cover problem in selected graph classes J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-28
Sangram K. Jena, K. SubramaniIn this paper, we focus on analyzing the 3-path vertex cover (3PVC) problem in a number of graph classes. Let \(G=(V,E)\) be a simple graph. A set \(C \subseteq V\) is called a k-path vertex cover of G, if each path of order k in G, contains at least one vertex from C. In the k-path vertex cover problem, we are given a graph G, and asked to find a k-path vertex cover of minimum size. For \(k=3\), the
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Semi-online scheduling with non-increasing job sizes and a buffer J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-28
Leah Epstein, Hanan Zebedat-HaiderThis work considers a semi-online version of scheduling on m identical machines, where the objective is to minimize the makespan. In the variant studied here, jobs are presented sorted by non-increasing sizes, and a buffer of size k is available for storing at most k jobs. Every arriving job has to be either placed into the buffer until its assignment, or else it has to be assigned immediately to a
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A 3-space dynamic programming heuristic for the cubic knapsack problem J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-28
Ibrahim Dan Dije, Franklin Djeumou Fomeni, Leandro C. CoelhoThe cubic knapsack problem (CKP) is a combinatorial optimization problem, which can be seen both as a generalization of the quadratic knapsack problem (QKP) and of the linear Knapsack problem (KP). This problem consists of maximizing a cubic function of binary decision variables subject to one linear knapsack constraint. It has many applications in biology, project selection, capital budgeting problem
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A multi-objective perspective on the cable-trench problem J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-26
Lara Löhken, Michael StiglmayrThe cable-trench problem is defined as a linear combination of the shortest path and the minimum spanning tree problem. In particular, the goal is to find a spanning tree that simultaneously minimizes its total length and the total path length from a pre-defined root to all other vertices. Both, the minimum spanning tree and the shortest path problem are known to be efficiently solvable. However, a
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Chaotic guided local search algorithm for solving global optimization and engineering problems J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-26
Anis NaanaaChaos optimization algorithm (COA) is an interesting alternative in a global optimization problem. Due to the non-repetition and ergodicity of chaos, it can explore the global search space at higher speeds than stochastic searches that depend on probabilities. To adjust the solution obtained by COA, guided local search algorithm (GLS) is integrated with COA to form a hybrid algorithm. GLS is a metaheuristic
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Path survival reliabilities as measures of reliability for lifeline utility networks J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-26
Brian Godwin Lim, Renzo Roel Tan, Richard de Jesus, Lessandro Estelito Garciano, Agnes Garciano, Kazushi IkedaLifeline utility networks have been studied extensively within the domain of network reliability due to the prevalence of natural hazards. The reliability of these networks is typically investigated through graphs that retain their structural characteristics. This paper introduces novel connectivity-based reliability measures tailored for stochastic graphs with designated source vertices and failu
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Induced C4-free subgraphs with large average degree J. Comb. Theory B (IF 1.2) Pub Date : 2025-04-23
Xiying Du, António Girão, Zach Hunter, Rose McCarty, Alex ScottWe prove that there exists a constant C so that, for all s,k∈N, if G has average degree at least kCs3 and does not contain Ks,s as a subgraph then it contains an induced subgraph which is C4-free and has average degree at least k. It was known that some function of s and k suffices, but this is the first explicit bound. We give several applications of this result, including short and streamlined proofs
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The two-center problem of uncertain points on cactus graphs J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-21
Haitao Xu, Jingru ZhangWe study the two-center problem on cactus graphs in facility locations, which aims to place two facilities on the graph network to serve customers in order to minimize the maximum transportation cost. In our problem, the location of each customer is uncertain and may appear at O(m) points on the network with probabilities. More specifically, given are a cactus graph G and a set \(\mathcal {P}\) of
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Finite Mixtures of Multivariate Contaminated Normal Censored Regression Models J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-04-22
Tsung-I Lin, Wan-Lun Wang -
A Stability Framework for Parameter Selection in the Minimum Covariance Determinant Problem J. Comput. Graph. Stat. (IF 1.4) Pub Date : 2025-04-22
Qiang Heng, Hui Shen, Kenneth Lange -
Pivot-minors and the Erdős-Hajnal conjecture J. Comb. Theory B (IF 1.2) Pub Date : 2025-04-16
James DaviesWe prove a conjecture of Kim and Oum that every proper pivot-minor-closed class of graphs has the strong Erdős-Hajnal property. More precisely, for every graph H, there exists ϵ>0 such that every n-vertex graph with no pivot-minor isomorphic to H contains two sets A,B of vertices such that |A|,|B|⩾ϵn and A is complete or anticomplete to B.
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Optimal bounds for zero-sum cycles. I. Odd order J. Comb. Theory B (IF 1.2) Pub Date : 2025-04-16
Rutger Campbell, J. Pascal Gollin, Kevin Hendrey, Raphael SteinerFor a finite (not necessarily abelian) group (Γ,⋅), let n(Γ) denote the smallest positive integer n such that for each labelling of the arcs of the complete digraph of order n using elements from Γ, there exists a directed cycle such that the arc-labels along the cycle multiply to the identity. Alon and Krivelevich [2] initiated the study of the parameter n(⋅) on cyclic groups and proved n(Zq)=O(qlogq)
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Haar graphical representations of finite groups and an application to poset representations J. Comb. Theory B (IF 1.2) Pub Date : 2025-04-16
Joy Morris, Pablo SpigaLet R be a group and let S be a subset of R. The Haar graph Haar(R,S) of R with connection set S is the graph having vertex set R×{−1,1}, where two distinct vertices (x,−1) and (y,1) are declared to be adjacent if and only if yx−1∈S. The name Haar graph was coined by Tomaž Pisanski in one of the first investigations on this class of graphs.
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On the parenthesisations of matrix chains: All are useful, few are essential J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-14
Francisco López, Lars Karlsson, Paolo BientinesiThe product of a matrix chain consisting of n matrices can be computed in \(C_{n-1}\) (Catalan’s number) different ways, each identified by a distinct parenthesisation of the chain. The best algorithm to select a parenthesisation that minimises the cost runs in \(O(n \log n)\) time. Approximate algorithms run in O(n) time and find solutions that are guaranteed to be within a certain factor from optimal;
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Maximizing utilitarian and Egalitarian welfare of fractional hedonic games on tree-like graphs J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-14
Tesshu Hanaka, Airi Ikeyama, Hirotaka OnoFractional hedonic games are coalition formation games where a player’s utility is determined by the average value they assign to the members of their coalition. These games are a variation of graph hedonic games, which are a class of coalition formation games that can be succinctly represented. Due to their applicability in network clustering and their relationship to graph hedonic games, fractional
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Testing Higher-order Clusterability on Graphs J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-13
Yifei Li, Donghua Yang, Jianzhong LiAnalysis of higher-order organizations, represented as small connected subgraphs, is a fundamental task on complex networks. This paper studies a new problem of testing higher-order clusterability: given neighbor query access to an undirected graph, can we judge whether this graph can be partitioned into a few clusters of highly-connected cliques? This problem is an extension of the former work proposed
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Uav trajectory optimization for maximizing the ToI-based data utility in wireless sensor networks J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-11
Qing Zhao, Zhen Li, Jianqiang Li, Jianxiong Guo, Xingjian Ding, Deying LiIt’s a promising way to use Unmanned Aerial Vehicles (UAVs) as mobile base stations to collect data from sensor nodes, especially for large-scale wireless sensor networks. There are a lot of works that focus on improving the freshness of the collected data or the data collection efficiency by scheduling UAVs. Given that sensing data in certain applications is time-sensitive, with its value diminishing
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A sharp upper bound for the edge dominating number of hypergraphs with minimum degree J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-11
Zhongzheng Tang, Zhuo DiaoIn a hypergraph H(V, E), a subset of edges \(A\subseteq E\) forms an edge dominating set if each edge \(e\in E\setminus A\) is adjacent to at least one edge in A. The edge dominating number \(\gamma '(H)\) represents the smallest size of an edge dominating set in H. In this paper, we establish upper bounds on the edge dominating number for hypergraphs with minimum degree \(\delta \): (1) For \(\delta
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Approximation algorithms for solving the heterogeneous rooted tree/path cover problems J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-11
Pengxiang Pan, Junran Lichen, Ping Yang, Jianping LiIn this paper, we consider the heterogeneous rooted tree cover (HRTC) problem, which further generalizes the rooted tree cover problem. Specifically, given a complete graph \(G=(V,E; w,f; r)\) and k construction teams, having nonuniform construction speeds \(\lambda _{1}\), \(\lambda _{2}\), \(\ldots \), \(\lambda _{k}\), where \(r\in V\) is a fixed common root, \(w:E\rightarrow {\mathbb {R}}^{+}\)
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Approximation algorithm for dynamic facility location problem J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-11
Li Zhang, Qiaoliang LiIn this paper, we consider dynamic facility location problem with unit demand (DFLPUD). We propose a 1.52-approximation algorithm that skillfully integrates dual-fitting and greedy augmentation schemes. Our algorithmic framework begins by formulating DFLPUD as a set covering linear integer programming problem. Then we scale the opening cost of all facilities and use the solution of dual-fitting algorithm
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An improved approximation algorithm for covering vertices by $$4^+$$ -paths J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-11
Mingyang Gong, Zhi-Zhong Chen, Guohui Lin, Lusheng WangPath cover is one of the well-known NP-hard problems that has received much attention. In this paper, we study a variant of path cover, denoted by \(\hbox {MPC}^{{4}+}_v\), to cover as many vertices in a given graph \(G = (V, E)\) as possible by a collection of vertex-disjoint paths each of order four or above. The problem admits an existing \(O(|V|^8)\)-time 2-approximation algorithm by applying several
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Link fault tolerability of the Cartesian product power graph $$(K_{9}-C_{9})^{n}$$ : conditional edge-connectivities under six link fault patterns J. Comb. Optim. (IF 0.9) Pub Date : 2025-04-11
Zhaoman Huang, Yayu Yang, Mingzu Zhang, Weihua YangHigh-performance computing extensively depends on parallel and distributed systems, necessitating the establishment of quantitative parameters to evaluate the fault tolerability of interconnection networks. The topological structures of interconnection networks in some parallel and distributed systems are designed as n-dimensional \((K_{9}-C_{9})^{n}\), obtained through the repeatedly application of