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A lineartime algorithm for weighted paireddomination on block graphs J. Comb. Optim. (IF 1.195) Pub Date : 20211122
Lin, ChingChi, Hsieh, ChengYu, Mu, TaYuIn a graph \(G = (V,E)\), a set \(S\subseteq V(G)\) is said to be a dominating set of G if every vertex not in S is adjacent to a vertex in S. Let G[S] denote the subgraph of G induced by a subset S of V(G). A dominating set S of G is called a paireddominating set of G if the induced subgraph G[S] contains a perfect matching. Suppose that, for each \(v \in V(G)\), we have a weight w(v) specifying

Unfolding Hconvex Manhattan Towers J. Comb. Optim. (IF 1.195) Pub Date : 20211119
Richaume, Lydie, Andres, Eric, LargeteauSkapin, Gaëlle, Zrour, RitaA grid unfolding without refinement method for a new subclass of polycubes, called Manhattan Towers with a Hconvex base, is proposed. Such polycubes can be seen both as a Manhattan Tower and as an orthostack. A direct extension of this algorithm to UpandDown Orthoterrains is also presented.

TLHSA and SACA: two heuristic algorithms for two variant VRP models J. Comb. Optim. (IF 1.195) Pub Date : 20211115
Cai, Xuhong, Jiang, Li, Guo, Songhu, Huang, Hejiao, Du, HongweiVehicle routing problem (VRP) is a classical combinatorial optimization problem. Under this problem, we focus on two variant models which better capture the realworld scenes: multipleorders pickup and delivery problem with timebound window (MOPDPTW) and dynamic vehicle routing problem with time window (DVRPTW). To tackle MOPDPTW, a twolayers heuristic search algorithm is proposed. The inner layer

A novel approach to subgraph selection with multiple weights on arcs J. Comb. Optim. (IF 1.195) Pub Date : 20211113
Raayatpanah, Mohammad Ali, Khodayifar, Salman, Weise, Thomas, Pardalos, PanosIn this paper, an extension of the minimum cost flow problem is considered in which multiple incommensurate weights are associated with each arc. In the minimum cost flow problem, flow is sent over the arcs of a graph from source nodes to sink nodes. The goal is to select a subgraph with minimum associated costs for routing the flow. The problem is tractable when a single weight is given on each arc

Topology preservation on the BCC grid J. Comb. Optim. (IF 1.195) Pub Date : 20211113
Kardos, PéterA frequently investigated problem in various applications of binary image processing is to ensure the topology preservation of image operators. Although the literature primarily focuses on 2D and 3D pictures that are sampled on the conventional square and cubic grids, respectively, some alternate structures such as the bodycentered cubic grid and the facecentered cubic grid have also attracted remarkable

On zeroerror codes produced by greedy algorithms J. Comb. Optim. (IF 1.195) Pub Date : 20211102
Jurkiewicz, MarcinWe present two greedy algorithms that determine zeroerror codes and lower bounds on the zeroerror capacity. These algorithms have many advantages, e.g., they do not store a whole product graph in a computer memory and they use the socalled distributions in all dimensions to get better approximations of the zeroerror capacity. We also show an additional application of our algorithms.

Bicriteria streaming algorithms to balance gain and cost with cardinality constraint J. Comb. Optim. (IF 1.195) Pub Date : 20211102
Wang, Yijing, Xu, Dachuan, Du, Donglei, Jiang, YanjunTeam formation plays an essential role in the labor market. In this paper, we propose two bicriteria algorithms to construct a balance between gain and cost in a team formation problem under the streaming model, subject to a cardinality constraint. We formulate the problem as maximizing the difference of a nonnegative normalized monotone submodular function and a nonnegative linear function. As an

A variable neighborhood search algorithm for human resource selection and optimization problem in the home appliance manufacturing industry J. Comb. Optim. (IF 1.195) Pub Date : 20211030
Ji, Xing, Liao, Baoyu, Yang, ShanlinThe increase in human resource cost puts forward higher requirements for the optimization of home appliance manufacturing processes. This paper studied an integrated human resource optimization problem considering the human resource selection, learning effect, skills degradation effect, and parallel production lines. There are multiple different manufacturing tasks with different normal processing

Parallelmachine scheduling of jobs with mixed job, machine and positiondependent processing times J. Comb. Optim. (IF 1.195) Pub Date : 20211016
Przybylski, BartłomiejWe consider a number of parallelmachine scheduling problems in which jobs have variable processing times. The actual processing time of each job is described by an arbitrary positive function of the position it holds on a machine. However, the function itself may additionally depend on the job or a machine this job was assigned to. Our aim is to find a schedule that minimizes the objectives of maximum

Maximum properly colored trees in edgecolored graphs J. Comb. Optim. (IF 1.195) Pub Date : 20211015
Hu, Jie, Li, Hao, Maezawa, ShunichiAn edgecolored graph G is a graph with an edge coloring. We say G is properly colored if any two adjacent edges of G have distinct colors, and G is rainbow if any two edges of G have distinct colors. For a vertex \(v \in V(G)\), the color degree \(d_G^{col}(v)\) of v is the number of distinct colors appearing on edges incident with v. The minimum color degree \(\delta ^{col}(G)\) of G is the minimum

A speciationbased bilevel niching method for multimodal truss design problems J. Comb. Optim. (IF 1.195) Pub Date : 20211015
Islam, Md. Jakirul, Li, Xiaodong, Deb, KalyanmoyTruss design is a wellknown structural optimization problem that has important practical applications in various fields. Truss design problems are typically multimodal by nature, meaning that it offers multiple optimal solutions concerning the topology (combinatorial optimization problem) and/or sizes (continuous optimization problem) of the members, but they are evaluated to have similar or equally

Measuring the influence and amplification of users on social network with unsupervised behaviors learning and efficient interactionbased knowledge graph J. Comb. Optim. (IF 1.195) Pub Date : 20211011
Tran, Quan M., Nguyen, Hien D., Huynh, Tai, Nguyen, Kha V., Hoang, Suong N., Pham, Vuong T.This study introduces a metric to measure the influence of users and communities on Social Media Networks. The proposed method is a combination of Knowledge Graph and Deep Learning approaches. Particularly, an effective Knowledge Graph is built to represent the interaction activities of users. Besides, an unsupervised deep learning model based on Variational Graph Autoencoder is also constructed to

Monochromatic disconnection: ErdősGallaitype problems and product graphs J. Comb. Optim. (IF 1.195) Pub Date : 20211011
Li, Ping, Li, XueliangFor an edgecolored graph G, we call an edgecut M of G monochromatic if the edges of M are colored with a same color. The graph G is called monochromatically disconnected if any two distinct vertices of G are separated by a monochromatic edgecut. The monochromatic disconnection number, denoted by md(G), of a connected graph G is the maximum number of colors that are allowed to make G monochromatically

On total and edge coloring some Kneser graphs J. Comb. Optim. (IF 1.195) Pub Date : 20211010
de Figueiredo, C. M. H., Patrão, C. S. R., Sasaki, D., ValenciaPabon, M.In this work, we investigate the total and edge colorings of the Kneser graphs K(n, s). We prove that the sparse case of Kneser graphs, the odd graphs \(O_k=K(2k1,k1)\), have total chromatic number equal to \(\Delta (O_k) + 1\). We prove that Kneser graphs K(n, 2) verify the Total Coloring Conjecture when n is even, or when n is odd not divisible by 3. For the remaining cases when n is odd and divisible

The sum of rootleaf distance interdiction problem by upgrading edges/nodes on trees J. Comb. Optim. (IF 1.195) Pub Date : 20211009
Zhang, Qiao, Guan, Xiucui, Jia, Junhua, Qian, XinqiangNetwork interdiction problems by upgading critical edges/nodes have important applications to reduce the infectivity of the COVID19. A network of confirmed cases can be described as a rooted tree that has a weight of infectious intensity for each edge. Upgrading edges (nodes) can reduce the infectious intensity with contacts by taking prevention measures such as disinfection (treating the confirmed

Greedy algorithms for the profitaware social team formation problem J. Comb. Optim. (IF 1.195) Pub Date : 20211009
Liu, Shengxin, Poon, Chung KeungMotivated by applications in online labor markets, we study the problem of forming multiple teams of experts in a social network to accomplish multiple tasks that require different combinations of skills. Our goal is to maximize the total profit of tasks that are completed by these teams subject to the capacity constraints of the experts. We study both the offline and online settings of the problem

Network construction/restoration problems: cycles and complexity J. Comb. Optim. (IF 1.195) Pub Date : 20211007
Wang, Tianyu, Averbakh, IgorIn network construction/restoration problems introduced in Averbakh and Pereira (IIE Trans 44(8):681–694, 2012; Eur J Oper Res 244:715–729, 2015), a server (construction crew) builds edges of a given network starting from a given vertex (the depot), with a constant construction speed. The server can travel within the already constructed part of the network with a speed that is incomparably faster than

A general greedy approximation algorithm for finding minimum positive influence dominating sets in social networks J. Comb. Optim. (IF 1.195) Pub Date : 20211006
Chen, Weidong, Zhong, Hao, Wu, Lidong, Du, DingZhuIn social networks, the minimum positive influence dominating set (MPIDS) problem is NPhard, which means it is unlikely to be solved precisely in polynomial time. For the purpose of efficiently solving this problem, greedy approximation algorithms seem appealing because they are fast and can provide guaranteed solutions. In this paper, based on the classic greedy algorithm for cardinality submodular

Modeling and optimizing an agrosupply chain considering different quality grades and storage systems for fresh products: a Benders decomposition solution approach J. Comb. Optim. (IF 1.195) Pub Date : 20211004
KeshavarzGhorbani, Fatemeh, Pasandideh, Seyed Hamid RezaThis paper proposes a mathematical model in the context of agrosupply chain management, considering specific characteristics of agroproducts to assist purchase, storage, and transportation decisions. In addition, a new method for determining the required quality score of different types of products is proposed based on their loss factors and purchasing costs. The model aims to minimize total cost

Equilibrium customer and socially optimal balking strategies in a constant retrial queue with multiple vacations and Npolicy J. Comb. Optim. (IF 1.195) Pub Date : 20210929
Wang, Zhen, Liu, Liwei, Zhao, Yiqiang Q.In this paper, equilibrium strategies and optimal balking strategies of customers in a constant retrial queue with multiple vacations and the Npolicy under two information levels, respectively, are investigated. We assume that there is no waiting area in front of the server and an arriving customer is served immediately if the server is idle; otherwise (the server is either busy or on a vacation)

Allocation rules for cooperative games with restricted communication and a priori unions based on the Myerson value and the average tree solution J. Comb. Optim. (IF 1.195) Pub Date : 20210927
Béal, Sylvain, Rémila, Eric, Solal, PhilippeWe consider cooperatives games (TUgames) enriched by a system of a priori unions and a communication forest graph which are independent from each other. These two structures reflect the limitations of cooperation possibilities. In this framework, we introduce four Owentype allocation rules, which are defined by a twostep application of an allocation rule à la Owen (in: Henn R, Moeschlin O (eds)

Spanning tree of a multiple graph J. Comb. Optim. (IF 1.195) Pub Date : 20210927
Smirnov, Alexander V.We study undirected multiple graphs of any natural multiplicity \(k>1\). There are edges of three types: ordinary edges, multiple edges and multiedges. Each edge of the last two types is a union of k linked edges, which connect 2 or \((k+1)\) vertices, correspondingly. The linked edges should be used simultaneously. The multiple tree is a multiple graph with no multiple cycles. The number of edges

An ant colony optimization approach for the proportionate multiprocessor open shop J. Comb. Optim. (IF 1.195) Pub Date : 20210923
Adak, Zeynep, Arıoğlu, Mahmure Övül, Bulkan, SerolMultiprocessor open shop makes a generalization to classical open shop by allowing parallel machines for the same task. Scheduling of this shop environment to minimize the makespan is a strongly NPHard problem. Despite its wide application areas in industry, the research in the field is still limited. In this paper, the proportionate case is considered where a task requires a fixed processing time

On the restricted kSteiner tree problem J. Comb. Optim. (IF 1.195) Pub Date : 20210921
Bose, Prosenjit, D’Angelo, Anthony, Durocher, StephaneGiven a set P of n points in \(\mathbb {R}^2\) and an input line \(\gamma \) in \(\mathbb {R}^2\), we present an algorithm that runs in optimal \(\varTheta (n\log n)\) time and \(\varTheta (n)\) space to solve a restricted version of the 1Steiner tree problem. Our algorithm returns a minimumweight tree interconnecting P using at most one Steiner point \(s \in \gamma \), where edges are weighted by

Metaheuristic algorithms for the bandwidth reduction of largescale matrices J. Comb. Optim. (IF 1.195) Pub Date : 20210917
Gonzaga de Oliveira, S. L., Carvalho, C.This paper considers the bandwidth reduction problem for largescale sparse matrices in serial computations. A heuristic for bandwidth reduction reorders the rows and columns of a given sparse matrix. Thus, the method places entries with a nonzero value as close to the main diagonal as possible. Bandwidth optimization is a critical issue for many scientific and engineering applications. This manuscript

Adjacent vertex distinguishing edge coloring of ICplanar graphs J. Comb. Optim. (IF 1.195) Pub Date : 20210915
Liu, Zhuoya, Xu, ChangqingThe adjacent vertex distinguishing edge coloring of a graph G is a proper edge coloring in which each pair of adjacent vertices is assigned different color sets. The smallest number of colors for which G has such a coloring is denoted by \(\chi '_a(G)\). An important conjecture due to Zhang et al. (Appl Math Lett 15:623–626, 2002) asserts that \(\chi '_a(G)\le \Delta (G)+2\) for any connected graph

Population monotonicity in matching games J. Comb. Optim. (IF 1.195) Pub Date : 20210909
Xiao, Han, Fang, QizhiThe matching game is a cooperative profit game defined on an edgeweighted graph, where the players are the vertices and the profit of a coalition is the maximum weight of matchings in the subgraph induced by the coalition. A population monotonic allocation scheme is a collection of rules defining how to share the profit among players in each coalition such that every player is better off when the

Adaptive online portfolio strategy based on exponential gradient updates J. Comb. Optim. (IF 1.195) Pub Date : 20210909
Zhang, Yong, Lin, Hong, Zheng, Lina, Yang, XingyuBased on the momentum principle and adaptive learning mechanism, we design online portfolio selection strategies, which are suitable for nonstationary financial market. Firstly, we propose a Movingwindowbased Adaptive Exponential Gradient (MAEG) strategy, which updates the learning rate of the EG algorithm by maximizing the recent cumulative return using the price data in a fixed length moving window

Correction To: Solving $$(k1)$$ ( k  1 ) stable instances of kterminal cut with isolating cuts J. Comb. Optim. (IF 1.195) Pub Date : 20210909
Velednitsky, MarkA Correction to this paper has been published: 10.1007/s10878021007693

A value for cooperative games with coalition and probabilistic graph structures J. Comb. Optim. (IF 1.195) Pub Date : 20210907
Shi, Jilei, Cai, Lei, Shan, Erfang, Lyu, WenrongIn this paper we generalize TUgames with coalition and graph structures to TUgames with coalition and probabilistic graph structures. We introduce the probabilistic graphpartition value and we show that the value is uniquely determined by the axioms of probabilistic graph efficiency, probabilistic balanced contributions and probabilistic collective balanced contributions and the axioms of probabilistic

On the enumeration of minimal nonpairwise compatibility graphs J. Comb. Optim. (IF 1.195) Pub Date : 20210901
Azam, Naveed Ahmed, Shurbevski, Aleksandar, Nagamochi, HiroshiA graph is said to be a pairwise compatibility graph (PCG) if there exists an edgeweighted tree whose leaf set is the graph’s vertex set, and there exists an edge between two vertices in the graph if and only if the distance between them in the tree lies within a given interval. It is a challenging task to enumerate all nonPCGs that are minimal in the sense that each of their induced subgraphs is

HMEIICT: Fairnessaware link prediction in complex networks using community information J. Comb. Optim. (IF 1.195) Pub Date : 20210827
Saxena, Akrati, Fletcher, George, Pechenizkiy, MykolaThe evolution of online social networks is highly dependent on the recommended links. Most of the existing works focus on predicting intracommunity links efficiently. However, it is equally important to predict intercommunity links with high accuracy for diversifying a network. In this work, we propose a link prediction method, called HMEIICT, that considers both the similarity of nodes and their

Rescheduling problems with allowing for the unexpected new jobs arrival J. Comb. Optim. (IF 1.195) Pub Date : 20210827
Zhang, Xingong, Lin, WinChin, Wu, ChinChiaIn modern manufacturing and services, rescheduling frequently happens in manufacturing practice, which a disruption may happen. In this paper, the rescheduling problem with the unexpected new jobs arrival is studied, and the effect of time disruptions is taken into account on a previously planned optimal schedule. Rescheduling means that a set of original jobs has already given jobs sequence by minimizing

1line minimum rectilinear steiner trees and related problems J. Comb. Optim. (IF 1.195) Pub Date : 20210826
Li, Jianping, Lichen, Junran, Wang, Wencheng, Yeh, Jean, Yeh, YeongNan, Yu, Xingxing, Zheng, YujieIn this paper, motivated by many practical applications, we address the 1line minimum rectilinear Steiner tree (1LMRStT) problem, which is a variation of the Euclidean minimum rectilinear Steiner tree problem. More specifically, given n points in the Euclidean plane \({\mathbb {R}}^2\), it is asked to find the location of a line l and a Steiner tree T(l), consisting only of vertical and horizontal

A new metric to compare local community detection algorithms in social networks using geodesic distance J. Comb. Optim. (IF 1.195) Pub Date : 20210824
Bakhtar, Sahar, Harutyunyan, Hovhannes A.Community detection problem is a wellstudied problem in social networks. One major question to this problem is how to evaluate different community detection algorithms. This issue is even more challenging in the problem of local community detection where only local information of communities is available. Normally, two community detection algorithms are compared by evaluating their resulted communities

Lower bounds for batched bin packing J. Comb. Optim. (IF 1.195) Pub Date : 20210823
Balogh, János, Békési, József, Dósa, György, Epstein, Leah, Levin, AsafWe consider batched bin packing. Items are presented in a constant number of batches, and each batch should be packed before the next batch is presented. The cases of two, three, and four batches are studied. We prove improved lower bounds for the standard and parametric variants in some of the cases, and shorten the proofs for all other cases. To achieve this, we apply a new technique in our analysis

An integrated method for hybrid distribution with estimation of demand matching degree J. Comb. Optim. (IF 1.195) Pub Date : 20210820
Gai, Ling, Jin, Ying, Zhang, BinyuanTimely and effective distribution of relief materials is one of the most important aspects when fighting with a natural or a manmade disaster. Due to the sudden and urgent nature of most disasters, it is hard to make the exact prediction on the demand information. Meanwhile, timely delivery is also a problem. In this paper, taking the COVID19 epidemic as an example, we propose an integrated method

Advancing local search approximations for multiobjective combinatorial optimization problems J. Comb. Optim. (IF 1.195) Pub Date : 20210818
Weerasena, LakmaliThis study proposes a theoretical framework for defining approximations of the Pareto sets of multiobjective combinatorial optimization (MOCO) problems. The concept of trepresentation is proposed for modeling the approximation quality and describes a local search algorithm to produce a trepresentation. Unlike the current local search algorithms found in the literature, the proposed algorithm yields

Path cover with minimum nontrivial paths and its application in twomachine flowshop scheduling with a conflict graph J. Comb. Optim. (IF 1.195) Pub Date : 20210816
Chen, Yong, Cai, Yinhui, Liu, Longcheng, Chen, Guangting, Goebel, Randy, Lin, Guohui, Su, Bing, Zhang, AnPath cover is a wellknown intractable problem that finds a minimum number of vertex disjoint paths in a given graph to cover all the vertices. We show that a variant, in which the objective is to minimize the number of length0 paths, is polynomialtime solvable. We further show that another variant, to minimize the total number of length0 and length1 paths, is also polynomialtime solvable. Both

The maximum average connectivity among all orientations of a graph J. Comb. Optim. (IF 1.195) Pub Date : 20210812
Casablanca, Rocío M., Dankelmann, Peter, Goddard, Wayne, Mol, Lucas, Oellermann, OrtrudFor distinct vertices u and v in a graph G, the connectivity between u and v, denoted \(\kappa _G(u,v)\), is the maximum number of internally disjoint u–v paths in G. The average connectivity of G, denoted \({\overline{\kappa }}(G),\) is the average of \(\kappa _G(u,v)\) taken over all unordered pairs of distinct vertices u, v of G. Analogously, for a directed graph D, the connectivity from u to v

Optimal frequency assignment and planar list L(2, 1)labeling J. Comb. Optim. (IF 1.195) Pub Date : 20210811
Zhu, Haiyang, Zhu, Junlei, Liu, Ying, Wang, Shuling, Huang, Danjun, Miao, LianyingG has a list kL(2, 1)labeling if for any klist assignment L, there exists a coloring \(c:V(G)\rightarrow \bigcup \limits _{v\in V} L(v)\) of G such that \(c(v)\in L(v)\) for \(\forall v\in V(G)\) and for \(\forall u,v\in V(G)\), \(c(u)c(v)\ge 2\) if \(d(u,v)=1\), \(c(u)c(v)\ge 1\) if \(d(u,v)=2\). \(\lambda _{2,1}^{l}(G)=\min \{kG\) has a list kL(2, 1)labeling\(\}\) is called the list L(2

Linearsize universal discretization of geometric centerbased problems in fixed dimensions J. Comb. Optim. (IF 1.195) Pub Date : 20210806
Shenmaier, VladimirMany geometric optimization problems can be reduced to finding points in space (centers) minimizing an objective function which continuously depends on the distances from the centers to given input points. Examples are kMeans, Geometric kMedian/Center, Continuous Facility Location, mVariance, etc. We prove that, for any fixed \(\varepsilon >0\), every set of n input points in fixeddimensional space

Surface polygonization of 3D objects using norm similarity J. Comb. Optim. (IF 1.195) Pub Date : 20210806
Saha, Somrita, Biswas, ArindamThis work presents an algorithm to polygonize the surface of triangulated 3D digital objects by unifying the edgeadjacent face triangles having similar norms. If the cosine of the dihedral angle between two faces is above a predefined threshold, then the faces are considered to be similar with respect to their norms. By applying the Least Square Method on the boundary vertices of the set of the merged

Robust twostage combinatorial optimization problems under convex secondstage cost uncertainty J. Comb. Optim. (IF 1.195) Pub Date : 20210805
Goerigk, Marc, Kasperski, Adam, Zieliński, PawełIn this paper a class of robust twostage combinatorial optimization problems is discussed. It is assumed that the uncertain secondstage costs are specified in the form of a convex uncertainty set, in particular polyhedral or ellipsoidal ones. It is shown that the robust twostage versions of basic network optimization and selection problems are NPhard, even in a very restrictive cases. Some exact

Uniform Voronoi tessellation of digital manifolds: a GPUbased algorithm with applications to remeshing J. Comb. Optim. (IF 1.195) Pub Date : 20210804
Soni, Ashutosh, Bhowmick, ParthaWe present here a GPUfriendly algorithm for uniform Voronoi tessellation (UVT) of a digital manifold, which, in particular, may be conceived as the voxelized representation of a 2manifold surface. Its pipeline integrates several novel ideas, such as local directional field, which is used to estimate field energy, and when combined with Voronoi energy, provides an estimate of the uniformity of tessellation

Constructing tree decompositions of graphs with bounded gonality J. Comb. Optim. (IF 1.195) Pub Date : 20210802
Bodlaender, Hans L., van Dobben de Bruyn, Josse, Gijswijt, Dion, Smit, HarryIn this paper, we give a constructive proof of the fact that the treewidth of a graph is at most its divisorial gonality. The proof gives a polynomial time algorithm to construct a tree decomposition of width at most k, when an effective divisor of degree k that reaches all vertices is given. We also give a similar result for two related notions: stable divisorial gonality and stable gonality.

Determining the edge metric dimension of the generalized Petersen graph P(n, 3) J. Comb. Optim. (IF 1.195) Pub Date : 20210731
Wang, David G. L., Wang, Monica M. Y., Zhang, ShiqiangIt is known that the problem of computing the edge dimension of a graph is NPhard, and that the edge dimension of any generalized Petersen graph P(n, k) is at least 3. We prove that the graph P(n, 3) has edge dimension 4 for \(n\ge 11\), by showing semicombinatorially the nonexistence of an edge resolving set of order 3 and by constructing explicitly an edge resolving set of order 4.

Sublinear search spaces for shortest path planning in grid and road networks J. Comb. Optim. (IF 1.195) Pub Date : 20210729
Blum, Johannes, Funke, Stefan, Storandt, SabineShortest path planning is a fundamental building block in many applications. Hence developing efficient methods for computing shortest paths in, e.g., road or grid networks is an important challenge. The most successful techniques for fast query answering rely on preprocessing. However, for many of these techniques it is not fully understood why they perform so remarkably well, and theoretical justification

Discouraging pool block withholding attacks in Bitcoin J. Comb. Optim. (IF 1.195) Pub Date : 20210729
Chen, Zhihuai, Li, Bo, Shan, Xiaohan, Sun, Xiaoming, Zhang, JialinThe existence of mining pools in Bitcoin enables the miners to gain more stable reward. However, it is proved that the pools are vulnerable for security attacks. A strategic pool manager has strong incentive to launch pool block withholding attack by sending some of her miners to infiltrate the other pools. The infiltrating miners try to find (partial) proofofwork solutions but discard the solution

Computing directed Steiner path covers J. Comb. Optim. (IF 1.195) Pub Date : 20210727
Frank Gurski, Dominique Komander, Carolin Rehs, Jochen Rethmann, Egon WankeIn this article we consider the Directed Steiner Path Cover problem on directed cographs. Given a directed graph \(G=(V,E)\) and a set \(T \subseteq V\) of socalled terminal vertices, the problem is to find a minimum number of vertexdisjoint simple directed paths, which contain all terminal vertices and a minimum number of nonterminal vertices (Steiner vertices). The primary minimization criteria

Approximation algorithms for simple assembly line balancing problems J. Comb. Optim. (IF 1.195) Pub Date : 20210727
Santiago Valdés RaveloThis work considers the three main optimization variants of the Simple Assembly Line Balancing problem (SALBP): SALBP1, SALBP2 and SALBPE. These problems have origin in typical industrial production processes, where, to obtain a final product, partially ordered operations must be processed in workstations connected by a transportation equipment. Each version determines a different objective to be

Characterizing slope regions J. Comb. Optim. (IF 1.195) Pub Date : 20210727
Rocio GonzalezDiaz, Darshan Batavia, Rocio M. Casablanca, Walter G. KropatschThis paper provides a theoretical characterization of monotonically connected image surface regions, called slope regions. The characterization is given by several topological properties described in terms of critical points relative to the region. We formally prove the necessary and sufficient conditions that a region needs to satisfy to be a slope region. We also provide a prototype of slope regions

Decomposability of a class of kcutwidth critical graphs J. Comb. Optim. (IF 1.195) Pub Date : 20210724
ZhenKun Zhang, Zhong Zhao, LiuYong PangThe cutwidth minimization problem consists of finding an arrangement of the vertices of a graph G on a line \(P_n\) with \(n=V(G)\) vertices, in such a way that the maximum number of overlapping edges (i.e., the congestion) is minimized. A graph G with cutwidth k is kcutwidth critical if every proper subgraph of G has cutwidth less than k and G is homeomorphically minimal. In this paper, we mainly

Local routing in a tree metric 1spanner J. Comb. Optim. (IF 1.195) Pub Date : 20210723
Milutin Brankovic, Joachim Gudmundsson, André van RenssenSolomon and Elkin (SIAM J Discret Math 28(3):1173–1198, 2014) constructed a shortcutting scheme for weighted trees which results in a 1spanner for the tree metric induced by the input tree. The spanner has logarithmic lightness, logarithmic diameter, a linear number of edges and bounded degree (provided the input tree has bounded degree). This spanner has been applied in a series of papers devoted

On the complexity of minimum qdomination partization problems J. Comb. Optim. (IF 1.195) Pub Date : 20210723
Sayani Das, Sounaka MishraA domination coloring of a graph G is a proper vertex coloring with an additional condition that each vertex dominates a color class and each color class is dominated by a vertex. The minimum number of colors used in a domination coloring of G is denoted as \(\chi _{dd}(G)\) and it is called domination chromatic number of G. In this paper, we give a polynomialtime characterization of graphs with domination

Approximation algorithms for stochastic set cover and single sink rentorbuy with submodular penalty J. Comb. Optim. (IF 1.195) Pub Date : 20210721
Jian Sun, Haiyun Sheng, Yuefang Sun, Donglei Du, Xiaoyan ZhangStochastic combinatorial optimization problems are usually defined as planning problems, which involve purchasing and allocating resources in order to meet uncertain needs. For example, network designers need to make their best guess about the future needs of the network and purchase capabilities accordingly. Facing uncertain in the future, we either “wait and see” changes, or postpone decisions about

Theory and applications in combinatorial optimization. J. Comb. Optim. (IF 1.195) Pub Date : 20210722
John Baptist Gauci,Silvano Martello 
Nonsubmodular constrained profit maximization from increment perspective J. Comb. Optim. (IF 1.195) Pub Date : 20210705
Liman Du, Shengminjie Chen, Suixiang Gao, Wenguo YangThe growing importance of online social networks where people share information with others leads to the emergence of viral marketing, a new way to promote the sales of products. A derivation of classical Influence Maximization (IM) problem is the Profit Maximization (PM) problem that we focus on in this paper. We propose the PM problem with a cardinality constraint in order to make it closer to the

Optimized thresholdbased convolutional neural network for plant leaf classification: a challenge towards untrained data J. Comb. Optim. (IF 1.195) Pub Date : 20210702
Bhanuprakash Dudi, V. RajeshThe problem of identifying the plant type seems to be tough due to the altering leaf color, and the variations in leaf shape overage. The plant leaf classification is very challenging and important issue to solve. The main idea of this paper is to introduce a novel deep learningbased plant leaf classification model. Initially, the preprocessing is done by RGB to gray scale conversion, histogram equalization

A PTAS for nonresumable open shop scheduling with an availability constraint J. Comb. Optim. (IF 1.195) Pub Date : 20210702
Yuan Yuan, Yan Lan, Ning Ding, Xin HanShop scheduling problem is one of the most classical problems in combinatorial optimization. In this paper, we study twomachine open shop scheduling problem, provided that one machine is subject to maintenance period which has to be performed in a fixed time interval. The target is to minimize the makespan. This paper considers nonresumable scenario, i.e., if a job which starts before the maintenance