Journal of Combinatorial Optimization最新文献_第9页

Partial inverse min–max spanning tree problem under the weighted bottleneck hamming distance 加权瓶颈汉明距离下的部分逆最小最大生成树问题

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-11-16 DOI: 10.1007/s10878-023-01093-8

Qingzhen Dong, Xianyue Li, Yu Yang

{"title":"Partial inverse min–max spanning tree problem under the weighted bottleneck hamming distance","authors":"Qingzhen Dong, Xianyue Li, Yu Yang","doi":"10.1007/s10878-023-01093-8","DOIUrl":"https://doi.org/10.1007/s10878-023-01093-8","url":null,"abstract":"Min–max spanning tree problem is a classical problem in combinatorial optimization. Its purpose is to find a spanning tree to minimize its maximum edge in a given edge weighted graph. Given a connected graph G, an edge weight vector w and a forest F, the partial inverse min–max spanning tree problem (PIMMST) is to find a new weighted vector (w^*), so that F can be extended into a min–max spanning tree with respect to (w^*) and the gap between w and (w^*) is minimized. In this paper, we research PIMMST under the weighted bottleneck Hamming distance. Firstly, we study PIMMST with value of optimal tree restriction, a variant of PIMMST, and show that this problem can be solved in strongly polynomial time. Then, by characterizing the properties of the value of optimal tree, we present first algorithm for PIMMST under the weighted bottleneck Hamming distance with running time (O(|E|^2log |E|)), where E is the edge set of G. Finally, by giving a necessary and sufficient condition to determine the feasible solution of this problem, we present a better algorithm for this problem with running time (O(|E|log |E|)). Moreover, we show that these algorithms can be generalized to solve these problems with capacitated constraint.\u0000","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138293163","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}

引用次数: 1

On decreasing the orders of $$(k,g)$$ -graphs 关于$$(k,g)$$ -图的降阶问题

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-11-16 DOI: 10.1007/s10878-023-01092-9

Geoffrey Exoo, Robert Jajcay, Tom Raiman

{"title":"On decreasing the orders of $$(k,g)$$ -graphs","authors":"Geoffrey Exoo, Robert Jajcay, Tom Raiman","doi":"10.1007/s10878-023-01092-9","DOIUrl":"https://doi.org/10.1007/s10878-023-01092-9","url":null,"abstract":"A ((k,g))-graph is a k-regular graph of girth (g). Given (kge 2) and (gge 3), ((k,g))-graphs of infinitely many orders are known to exist and the problem of finding a (k, g)-graph of the smallest possible order is known as the Cage Problem. The aim of our paper is to develop systematic (programmable) ways for lowering the orders of existing ((k,g))-graphs, while preserving their regularity and girth. Such methods, in analogy with the previously used excision, may have the potential for constructing smaller (k, g)-graphs from current smallest examples—record holders—some of which have not been improved in years. In addition, we consider constructions that preserve the regularity, the girth and the order of the considered graphs, but alter the graphs enough to possibly make them suitable for the application of our order decreasing methods. We include a detailed discussion of several specific parameter cases for which several non-isomorphic smallest examples are known to exist, and address the question of the distance between these non-isomorphic examples based on the number of changes required to move from one example to another.\u0000","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138293162","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}

引用次数: 0

Dominated coloring in product graphs 产品图形的主导着色

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-11-10 DOI: 10.1007/s10878-023-01094-7

Minhui Li, Shumin Zhang, Chengfu Ye

引用次数: 0

Minmax for facility location game with optional preference under minimum distance requirement 最小距离要求下设施位置游戏的最小值，具有可选偏好

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-11-01 DOI: 10.1007/s10878-023-01087-6

Xinping Xu, Jingwen Zhang, Lihua Xie

{"title":"Minmax for facility location game with optional preference under minimum distance requirement","authors":"Xinping Xu, Jingwen Zhang, Lihua Xie","doi":"10.1007/s10878-023-01087-6","DOIUrl":"https://doi.org/10.1007/s10878-023-01087-6","url":null,"abstract":"In this paper, we study the optional preference model for the facility location game with two heterogeneous facilities on a line interval [0, 1], by further enforcing the requirement of a minimum distance (0le dle 1) between the two facilities. Each agent has one of three favorable preferences towards the two facilities, i.e., facility 1, facility 2, or optional preference. Here, we consider two variants of the optional preference model: Min (caring for the closer one) and Max (caring for the further one). In both variants, each agent wishes to get close to his preferred facilities, and thus his cost is his distance to his preferred facility. In this game, we consider agents’ locations as public information and agents’ preferences as private information which needs to be reported by agents. The objective is to design a mechanism for the two facilities’ locations such as to minimize the maximum cost of agents (MinMax) and achieve truthful report of agents’ preferences. Given any value of d, for both variants, we propose a strategyproof mechanism with an approximation ratio of 2. We also establish lower bounds of any deterministic strategyproof mechanism for both variants and show that the gaps between the lower bounds and the upper bounds are relatively small.","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509767","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}

引用次数: 0

On the chromatic number of $$P_5$$ -free graphs with no large intersecting cliques 关于没有大相交群的$$P_5$$-自由图的色数

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-10-15 DOI: 10.1007/s10878-023-01088-5

Weilun Xu, Xia Zhang

引用次数: 0

Semi-online early work maximization problems on two hierarchical uniform machines with partial information of processing time 具有部分处理时间信息的两个层次均匀机器上的半在线早期工作最大化问题

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-10-15 DOI: 10.1007/s10878-023-01086-7

Man Xiao, Xiaoqiao Liu, Weidong Li

{"title":"Semi-online early work maximization problems on two hierarchical uniform machines with partial information of processing time","authors":"Man Xiao, Xiaoqiao Liu, Weidong Li","doi":"10.1007/s10878-023-01086-7","DOIUrl":"https://doi.org/10.1007/s10878-023-01086-7","url":null,"abstract":"In this paper, we consider four semi-online early work maximization problems on two hierarchical uniform machines (M_1) and (M_2), where machine (M_1) with speed (s>0) is available for all jobs and machine (M_2) with speed 1 is only available for high-hierarchy jobs. When the total size of all jobs is known, we design an optimal online algorithm with a competitive ratio of (min {1+s,frac{2+2s}{1+2s}}). When the total size of low-hierarchy jobs is known, we design an optimal online algorithm with a competitive ratio of (min {{1+s, frac{sqrt{9,s^2+10,s+1}-s-1}{2,s}}}). When the total size of high-hierarchy jobs is known, we design an optimal online algorithm with a competitive ratio of (min {sqrt{s+1}, sqrt{s^2+2,s+2}-s}). When both the total sizes of low-hierarchy and high-hierarchy jobs are known, we give a lower bound (frac{2s+2}{s+2}) for the case (sle frac{2}{3}), and an optimal online algorithm with a competitive ratio of (frac{3s+3}{3s+2}) for the case (s>frac{2}{3}).","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509759","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}

引用次数: 0

Research on sensitive text classification detection and classification based on improved artificial neural network 基于改进人工神经网络的敏感文本分类检测与分类研究

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-09-28 DOI: 10.1007/s10878-023-01085-8

Haisheng Gu, Qing Li, Duanming Shen

{"title":"Research on sensitive text classification detection and classification based on improved artificial neural network","authors":"Haisheng Gu, Qing Li, Duanming Shen","doi":"10.1007/s10878-023-01085-8","DOIUrl":"https://doi.org/10.1007/s10878-023-01085-8","url":null,"abstract":"With the rapid development of information technology, a large number of sensitive words have appeared, which has brought great harm to network security and social stability. Therefore, how to identify and classify these sensitive information accurately has become an important issue. Combined with the improved artificial network algorithm, an adaptive classification algorithm is proposed in the experiment, which can provide local intelligent classification service according to the classification results. At the same time, the algorithm transforms the clustering model structure of the traditional network algorithm, introduces the classification information, so that it can be applied to the classification problem, and expands the application field of the data field theory. The experimental results show that: (1) From the experimental results of different text quantities, the SOM algorithm assigns the classification task to different levels of nodes, and realizes the modularization of detection. (2) The overall mean results show that the highest recall rate is 87%, which has met the basic grading criteria, and the detection accuracy of sensitive words will also be improved. (3) The experimental results show that the algorithm can accurately classify the sensitive and speed up the parameter optimization, and is superior to the comparison algorithm in many indicators. (4) From the simulation results, compared with the traditional neural network algorithm, the precision and recall of the algorithm are maintained at more than 90% and the loss is less than 0.11.","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509510","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}

引用次数: 1

Derivations of large classes of facet defining inequalities of the weak order polytope using ranking structures 利用排序结构导出弱阶多面体的大类分面定义不等式

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-09-27 DOI: 10.1007/s10878-023-01075-w

Adolfo R. Escobedo, Romena Yasmin

{"title":"Derivations of large classes of facet defining inequalities of the weak order polytope using ranking structures","authors":"Adolfo R. Escobedo, Romena Yasmin","doi":"10.1007/s10878-023-01075-w","DOIUrl":"https://doi.org/10.1007/s10878-023-01075-w","url":null,"abstract":"Ordering polytopes have been instrumental to the study of combinatorial optimization problems arising in a variety of fields including comparative probability, computational social choice, and group decision-making. The weak order polytope is defined as the convex hull of the characteristic vectors of all binary orders on n alternatives that are reflexive, transitive, and total. By and large, facet defining inequalities (FDIs) of this polytope have been obtained through simple enumeration and through connections with other combinatorial polytopes. This paper derives five new large classes of FDIs by utilizing the equivalent representations of a weak order as a ranking of n alternatives that allows ties; this connection simplifies the construction of valid inequalities, and it enables groupings of characteristic vectors into useful structures. We demonstrate that a number of FDIs previously obtained through enumeration are actually special cases of the large classes. This work also introduces novel construction procedures for generating affinely independent members of the identified ranking structures. Additionally, it states two conjectures on how to derive many more large classes of FDIs using the featured techniques.","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509511","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}

引用次数: 0

Area, perimeter, height, and width of rectangle visibility graphs 矩形可见性图的面积、周长、高度和宽度

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-09-20 DOI: 10.1007/s10878-023-01084-9

John S. Caughman, Charles L. Dunn, Joshua D. Laison, Nancy Ann Neudauer, Colin L. Starr

{"title":"Area, perimeter, height, and width of rectangle visibility graphs","authors":"John S. Caughman, Charles L. Dunn, Joshua D. Laison, Nancy Ann Neudauer, Colin L. Starr","doi":"10.1007/s10878-023-01084-9","DOIUrl":"https://doi.org/10.1007/s10878-023-01084-9","url":null,"abstract":"A rectangle visibility graph (RVG) is represented by assigning to each vertex a rectangle in the plane with horizontal and vertical sides in such a way that edges in the graph correspond to unobstructed horizontal and vertical lines of sight between their corresponding rectangles. To discretize, we consider only rectangles whose corners have integer coordinates. For any given RVG, we seek a representation with smallest bounding box as measured by its area, perimeter, height, or width (height is assumed not to exceed width). We derive a number of results regarding these parameters. Using these results, we show that these four measures are distinct, in the sense that there exist graphs (G_1) and (G_2) with ({{,textrm{area},}}(G_1) < {{,textrm{area},}}(G_2)) but ({{,textrm{perim},}}(G_2) < {{,textrm{perim},}}(G_1)), and analogously for all other pairs of these parameters. We further show that there exists a graph (G_3) with representations (S_1) and (S_2) such that ({{,textrm{area},}}(G_3)={{,textrm{area},}}(S_1)<{{,textrm{area},}}(S_2)) but ({{,textrm{perim},}}(G_3)={{,textrm{perim},}}(S_2)<{{,textrm{perim},}}(S_1)). In other words, (G_3) requires distinct representations to minimize area and perimeter. Similarly, such graphs exist to demonstrate the independence of all other pairs of these parameters. Among graphs with (n le 6) vertices, the empty graph (E_n) requires largest area. But for graphs with (n=7) and (n=8) vertices, we show that the complete graphs (K_7) and (K_8) require larger area than (E_7) and (E_8), respectively. Using this, we show that for all (n ge 8), the empty graph (E_n) does not have largest area, perimeter, height, or width among all RVGs on n vertices.","PeriodicalId":50231,"journal":{"name":"Journal of Combinatorial Optimization","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71509507","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}

引用次数: 0

Discrete facility location games with different preferences 不同偏好的离散设施定位游戏

IF 1 4区数学

Journal of Combinatorial Optimization Pub Date : 2023-09-13 DOI: 10.1007/s10878-023-01082-x

Ling Gai, Mengpei Liang, Chenhao Wang

引用次数: 0