Journal of Computer and System Sciences最新文献_第10页

Reducing the vertex cover number via edge contractions 通过边收缩减少顶点覆盖数

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-09-01 DOI: 10.1016/j.jcss.2023.03.003

Paloma T. Lima , Vinicius F. dos Santos , Ignasi Sau , Uéverton S. Souza , Prafullkumar Tale

{"title":"Reducing the vertex cover number via edge contractions","authors":"Paloma T. Lima , Vinicius F. dos Santos , Ignasi Sau , Uéverton S. Souza , Prafullkumar Tale","doi":"10.1016/j.jcss.2023.03.003","DOIUrl":"https://doi.org/10.1016/j.jcss.2023.03.003","url":null,"abstract":"<div>Given a graph G on n vertices and two integers k and d, the Contraction(vc) problem asks whether one can contract at most k edges to reduce the vertex cover number of G by at least d. Recently, Lima et al. [JCSS 2021] proved that Contraction(vc) admits an XP algorithm running in time <math><mi>f</mi><mo>(</mo><mi>d</mi><mo>)</mo><mo>⋅</mo><msup><mrow><mi>n</mi></mrow><mrow><mi>O</mi><mo>(</mo><mi>d</mi><mo>)</mo></mrow></msup></math>. They asked whether this problem is FPT under this parameterization. In this article, we prove that: (i) Contraction(vc) is W[1]-hard parameterized by <math><mi>k</mi><mo>+</mo><mi>d</mi></math>. Moreover, unless the ETH fails, the problem does not admit an algorithm running in time <math><mi>f</mi><mo>(</mo><mi>k</mi><mo>+</mo><mi>d</mi><mo>)</mo><mo>⋅</mo><msup><mrow><mi>n</mi></mrow><mrow><mi>o</mi><mo>(</mo><mi>k</mi><mo>+</mo><mi>d</mi><mo>)</mo></mrow></msup></math> for any function f. This answers negatively the open question stated in Lima et al. [JCSS 2021]. (ii) Contraction(vc) is NP-hard even when <math><mi>k</mi><mo>=</mo><mi>d</mi></math>. (iii) Contraction(vc) can be solved in time <math><msup><mrow><mn>2</mn></mrow><mrow><mi>O</mi><mo>(</mo><mi>d</mi><mo>)</mo></mrow></msup><mo>⋅</mo><msup><mrow><mi>n</mi></mrow><mrow><mi>k</mi><mo>−</mo><mi>d</mi><mo>+</mo><mi>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup></math>. This improves the algorithm of Lima et al. [JCSS 2021], and shows that when <math><mi>k</mi><mo>=</mo><mi>d</mi></math>, Contraction(vc) is FPT parameterized by d (or by k).</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"136 ","pages":"Pages 63-87"},"PeriodicalIF":1.1,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49725809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Galactic token sliding 银河令牌滑动

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-09-01 DOI: 10.1016/j.jcss.2023.03.008

Valentin Bartier , Nicolas Bousquet , Amer E. Mouawad

{"title":"Galactic token sliding","authors":"Valentin Bartier , Nicolas Bousquet , Amer E. Mouawad","doi":"10.1016/j.jcss.2023.03.008","DOIUrl":"https://doi.org/10.1016/j.jcss.2023.03.008","url":null,"abstract":"<div>Given a graph G and two independent sets <math><msub><mrow><mi>I</mi></mrow><mrow><mi>s</mi></mrow></msub></math> and <math><msub><mrow><mi>I</mi></mrow><mrow><mi>t</mi></mrow></msub></math> of size k, the Independent Set Reconfiguration problem asks whether there exists a sequence of independent sets that transforms <math><msub><mrow><mi>I</mi></mrow><mrow><mi>s</mi></mrow></msub></math> to <math><msub><mrow><mi>I</mi></mrow><mrow><mi>t</mi></mrow></msub></math> such that each independent set is obtained from the previous one using a so-called reconfiguration step. Viewing each independent set as a collection of k tokens placed on the vertices of a graph G, the two most studied reconfiguration steps are token jumping and token sliding. Over a series of papers, it was shown that the Token Jumping problem is fixed-parameter tractable (for parameter k) when restricted to sparse graph classes, such as planar, bounded treewidth, and nowhere dense graphs. As for the Token Sliding problem, almost nothing is known. We remedy this situation by showing that Token Sliding is fixed-parameter tractable on graphs of bounded degree, planar graphs, and chordal graphs of bounded clique number.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"136 ","pages":"Pages 220-248"},"PeriodicalIF":1.1,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49738230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Algebraic characterizations and block product decompositions for first order logic and its infinitary quantifier extensions over countable words 一阶逻辑的代数表征和块积分解及其可数词上的无限量词扩展

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-09-01 DOI: 10.1016/j.jcss.2023.04.002

Bharat Adsul , Saptarshi Sarkar , A.V. Sreejith

{"title":"Algebraic characterizations and block product decompositions for first order logic and its infinitary quantifier extensions over countable words","authors":"Bharat Adsul , Saptarshi Sarkar , A.V. Sreejith","doi":"10.1016/j.jcss.2023.04.002","DOIUrl":"https://doi.org/10.1016/j.jcss.2023.04.002","url":null,"abstract":"<div>We contribute to the refined understanding of language-logic-algebra interplay in a recent algebraic framework over countable words. Algebraic characterizations of the one variable fragment of FO as well as the boolean closure of the existential fragment of FO are established. We develop a seamless integration of the block product operation in the countable setting, and generalize well-known decompositional characterizations of FO and its two variable fragment. We propose an extension of FO admitting infinitary quantifiers to reason about inherent infinitary properties of countable words, and obtain a natural hierarchical block-product based characterization of this extension. Properties expressible in this extension can be simultaneously expressed in the classical logical systems such as WMSO and FO[cut]. We also rule out the possibility of a finite-basis for a block-product based characterization of these logical systems. Finally, we report algebraic characterizations of one variable fragments of the hierarchies of the new extension.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"136 ","pages":"Pages 302-326"},"PeriodicalIF":1.1,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49752944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wireless IoT sensors data collection reward maximization by leveraging multiple energy- and storage-constrained UAVs 通过利用多个能量和存储受限的无人机，无线物联网传感器数据收集奖励最大化

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-09-01 DOI: 10.1016/j.jcss.2023.103475

Francesco Betti Sorbelli , Alfredo Navarra , Lorenzo Palazzetti , Cristina M. Pinotti , Giuseppe Prencipe

{"title":"Wireless IoT sensors data collection reward maximization by leveraging multiple energy- and storage-constrained UAVs","authors":"Francesco Betti Sorbelli , Alfredo Navarra , Lorenzo Palazzetti , Cristina M. Pinotti , Giuseppe Prencipe","doi":"10.1016/j.jcss.2023.103475","DOIUrl":"https://doi.org/10.1016/j.jcss.2023.103475","url":null,"abstract":"<div>We consider Internet of Things (IoT) sensors deployed inside an area to be monitored. Drones can be used to collect the data from the sensors, but they are constrained in energy and storage. Therefore, all drones need to select a subset of sensors whose data are the most relevant to be acquired, modeled by assigning a reward. We present an optimization problem called Multiple-drone Data-collection Maximization Problem (MDMP) whose objective is to plan a set of drones' missions aimed at maximizing the overall reward from the collected data, and such that each individual drone's mission energy cost and total collected data are within the energy and storage limits, respectively. We optimally solve MDMP by proposing an Integer Linear Programming based algorithm. Since MDMP is NP-hard, we devise suboptimal algorithms for single- and multiple-drone scenarios. Finally, we thoroughly evaluate our algorithms on the basis of random generated synthetic data.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"139 ","pages":"Article 103475"},"PeriodicalIF":1.1,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49725578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Addition machines, automatic functions and open problems of Floyd and Knuth 加法机，自动功能和Floyd和Knuth的开放问题

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-09-01 DOI: 10.1016/j.jcss.2023.04.003

Sanjay Jain , Xiaodong Jia , Ammar Fathin Sabili , Frank Stephan

引用次数: 0

Perpetual maintenance of machines with different urgency requirements 对不同紧急需求的机器进行永久维护

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-08-29 DOI: 10.1016/j.jcss.2023.103476

Leszek Gąsieniec , Tomasz Jurdziński , Ralf Klasing , Christos Levcopoulos , Andrzej Lingas , Jie Min , Tomasz Radzik

引用次数: 0

Mengerian graphs: Characterization and recognition Mengerian图：表征与识别

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-08-29 DOI: 10.1016/j.jcss.2023.103467

Allen Ibiapina, Ana Silva

引用次数: 0

On the complexity of the storyplan problem 关于故事计划问题的复杂性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-08-11 DOI: 10.1016/j.jcss.2023.103466

Carla Binucci , Emilio Di Giacomo , William J. Lenhart , Giuseppe Liotta , Fabrizio Montecchiani , Martin Nöllenburg , Antonios Symvonis

引用次数: 0

Etherless Ethereum tokens: Simulating native tokens in Ethereum 以太坊代币:在以太坊中模拟原生代币

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-08-01 DOI: 10.1016/j.jcss.2023.02.001

John Andrews , Michele Ciampi , Vassilis Zikas

引用次数: 0

Parameterized complexity of graph planarity with restricted cyclic orders 受限循环阶图平面性的参数化复杂度

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2023-08-01 DOI: 10.1016/j.jcss.2023.02.007

Giuseppe Liotta , Ignaz Rutter , Alessandra Tappini

{"title":"Parameterized complexity of graph planarity with restricted cyclic orders","authors":"Giuseppe Liotta , Ignaz Rutter , Alessandra Tappini","doi":"10.1016/j.jcss.2023.02.007","DOIUrl":"https://doi.org/10.1016/j.jcss.2023.02.007","url":null,"abstract":"<div>We study the complexity of testing whether a biconnected graph <math><mi>G</mi><mo>=</mo><mo>(</mo><mi>V</mi><mo>,</mo><mi>E</mi><mo>)</mo></math> is planar with the constraint that some cyclic orders of the edges incident to its vertices are allowed while some others are forbidden. The allowed cyclic orders are described by associating every vertex v of G with a set <math><mi>D</mi><mo>(</mo><mi>v</mi><mo>)</mo></math> of FPQ-trees. Let tw be the treewidth of G and let <math><msub><mrow><mi>D</mi></mrow><mrow><mi>max</mi></mrow></msub></math> be the maximum number of FPQ-trees per vertex. We show that the problem is FPT when parameterized by <math><mtext>tw</mtext><mo>+</mo><msub><mrow><mi>D</mi></mrow><mrow><mi>max</mi></mrow></msub></math>, paraNP-hard when parameterized by <math><msub><mrow><mi>D</mi></mrow><mrow><mi>max</mi></mrow></msub></math>, and W[1]-hard when parameterized by tw. We also consider NodeTrix planar representations of clustered graphs, where clusters are adjacency matrices and inter-cluster edges are non-intersecting simple curves. We prove that NodeTrix planarity with fixed sides is FPT when parameterized by the size of clusters plus the treewidth of the graph obtained by collapsing clusters to single vertices, provided that this graph is biconnected.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"135 ","pages":"Pages 125-144"},"PeriodicalIF":1.1,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49739733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0