Journal of Computer and System Sciences最新文献

{"title":"Monitoring the edges of a graph using distances with given girth","authors":"Chenxu Yang ,&nbsp;Gang Yang ,&nbsp;Sun-Yuan Hsieh ,&nbsp;Yaping Mao ,&nbsp;Ralf Klasing","doi":"10.1016/j.jcss.2024.103528","DOIUrl":"10.1016/j.jcss.2024.103528","url":null,"abstract":"<div><p>A set <em>M</em> of vertices of a graph <em>G</em> is a <em>distance-edge-monitoring set</em> if for every edge <span><math><mi>e</mi><mo>∈</mo><mi>G</mi></math></span>, there is a vertex <span><math><mi>x</mi><mo>∈</mo><mi>M</mi></math></span> and a vertex <span><math><mi>y</mi><mo>∈</mo><mi>G</mi></math></span> such that <em>e</em> belongs to all shortest paths between <em>x</em> and <em>y</em>. We denote by <span><math><mrow><mi>dem</mi></mrow><mo>(</mo><mi>G</mi><mo>)</mo></math></span> the smallest size of such a set in <em>G</em>. In this paper, we prove that <span><math><mi>dem</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>≤</mo><mi>n</mi><mo>−</mo><mo>⌊</mo><mi>g</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>/</mo><mn>2</mn><mo>⌋</mo></math></span> for any connected graph <em>G</em>, which is not a tree, of order <em>n</em>, where <span><math><mi>g</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> is the length of a shortest cycle in <em>G</em>, and give the graphs with <span><math><mi>dem</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>=</mo><mi>n</mi><mo>−</mo><mo>⌊</mo><mi>g</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>/</mo><mn>2</mn><mo>⌋</mo></math></span>. We also obtain that <span><math><mo>|</mo><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>|</mo><mo>≥</mo><mi>k</mi><mo>+</mo><mo>⌊</mo><mi>g</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>/</mo><mn>2</mn><mo>⌋</mo></math></span> for every connected graph <em>G</em> with <span><math><mrow><mi>dem</mi></mrow><mo>(</mo><mi>G</mi><mo>)</mo><mo>=</mo><mi>k</mi></math></span> and <span><math><mi>g</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>=</mo><mi>g</mi></math></span>. Furthermore, the lower bound holds if and only if <span><math><mi>g</mi><mo>=</mo><mn>3</mn></math></span> and <span><math><mi>k</mi><mo>=</mo><mi>n</mi><mo>−</mo><mn>1</mn></math></span> or <span><math><mi>g</mi><mo>=</mo><mn>4</mn></math></span> and <span><math><mi>k</mi><mo>=</mo><mn>2</mn></math></span>. We prove that <span><math><mrow><mi>dem</mi></mrow><mo>(</mo><mi>G</mi><mo>)</mo><mo>≤</mo><mn>2</mn><mi>n</mi><mo>/</mo><mn>5</mn></math></span> for <span><math><mi>g</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>≥</mo><mn>5</mn></math></span>.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"143 ","pages":"Article 103528"},"PeriodicalIF":1.1,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140053823","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}

{"title":"Deep kernelization for the Tree Bisection and Reconnection (TBR) distance in phylogenetics","authors":"Steven Kelk ,&nbsp;Simone Linz ,&nbsp;Ruben Meuwese","doi":"10.1016/j.jcss.2024.103519","DOIUrl":"10.1016/j.jcss.2024.103519","url":null,"abstract":"<div><p>We describe a kernel of size <span><math><mn>9</mn><mi>k</mi><mo>−</mo><mn>8</mn></math></span> for the NP-hard problem of computing the Tree Bisection and Reconnection (TBR) distance <em>k</em> between two unrooted binary phylogenetic trees. To achieve this, we extend the existing portfolio of reduction rules with three new reduction rules. Two of these are based on the idea of topologically transforming the trees in a distance-preserving way in order to guarantee execution of earlier reduction rules. The third rule extends the local neighborhood approach introduced in <span>[20]</span> to more global structures, allowing new situations to be identified when the deletion of a leaf definitely reduces the TBR distance by one. The bound on the kernel size is tight up to an additive term. Our results also apply to the equivalent problem of computing a maximum agreement forest between two unrooted binary phylogenetic trees. We anticipate that our results are widely applicable for computing agreement-forest based dissimilarity measures.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"142 ","pages":"Article 103519"},"PeriodicalIF":1.1,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S002200002400014X/pdfft?md5=d95807a5290b9b72c4034f27a39f9776&pid=1-s2.0-S002200002400014X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139587066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SAT backdoors: Depth beats size","authors":"Jan Dreier ,&nbsp;Sebastian Ordyniak ,&nbsp;Stefan Szeider","doi":"10.1016/j.jcss.2024.103520","DOIUrl":"10.1016/j.jcss.2024.103520","url":null,"abstract":"<div><p>For several decades, much effort has been put into identifying classes of CNF formulas whose satisfiability can be decided in polynomial time. Classic results are the linear-time tractability of Horn formulas (Aspvall, Plass, and Tarjan, 1979) and Krom (i.e., 2CNF) formulas (Dowling and Gallier, 1984). Backdoors, introduced by Williams, Gomes and Selman (2003), gradually extend such a tractable class to all formulas of bounded distance to the class. Backdoor size provides a natural but rather crude distance measure between a formula and a tractable class. Backdoor depth, introduced by Mählmann, Siebertz, and Vigny (2021), is a more refined distance measure, which admits the utilization of different backdoor variables in parallel. We propose FPT approximation algorithms to compute backdoor depth into the classes Horn and Krom. This leads to a linear-time algorithm for deciding the satisfiability of formulas of bounded backdoor depth into these classes.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"142 ","pages":"Article 103520"},"PeriodicalIF":1.1,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000024000151/pdfft?md5=aa98f57a25f01ddf20d9eccf4811314c&pid=1-s2.0-S0022000024000151-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139501386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The maximal coordination principle in regulatory Boolean networks","authors":"Alexis Poindron","doi":"10.1016/j.jcss.2024.103518","DOIUrl":"10.1016/j.jcss.2024.103518","url":null,"abstract":"<div><p>We introduce a coordination index in regulatory Boolean networks and we expose the maximal coordination principle (MCP), according to which a cohesive society reaches the dynamics characterized by the highest coordination index. Based on simple theoretical examples, we show that the MCP can be used to infer the influence graph from opinion dynamics/gene expressions. We provide some algorithms to apply the MCP and we compare the coordination index with existing statistical indexes (likelihood, entropy). The advantage of the coordination approach is its simplicity; in particular, we do not need to impose restrictions on the aggregation functions.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"142 ","pages":"Article 103518"},"PeriodicalIF":1.1,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139501327","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}

{"title":"On coresets for fair clustering in metric and Euclidean spaces and their applications","authors":"Sayan Bandyapadhyay ,&nbsp;Fedor V. Fomin ,&nbsp;Kirill Simonov","doi":"10.1016/j.jcss.2024.103506","DOIUrl":"10.1016/j.jcss.2024.103506","url":null,"abstract":"<div><p>Fair clustering is a constrained clustering problem where we need to partition a set of colored points. The fraction of points of each color in every cluster should be more or less equal to the fraction of points of this color in the dataset. The problem was recently introduced by Chierichetti et al. (2017) <span>[1]</span>. We propose a new construction of coresets for fair clustering for Euclidean and general metrics based on random sampling. For the Euclidean space <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span>, we provide the first coreset whose size does not depend exponentially on the dimension <em>d</em>. The question of whether such constructions exist was asked by Schmidt et al. (2019) <span>[2]</span> and Huang et al. (2019) <span>[5]</span>. For general metrics, our construction provides the first coreset for fair clustering. New coresets appear to be a handy tool for designing better approximation and streaming algorithms for fair and other constrained clustering variants.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"142 ","pages":"Article 103506"},"PeriodicalIF":1.1,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000024000011/pdfft?md5=8effb294ac14fcc95086200a05194229&pid=1-s2.0-S0022000024000011-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139423640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Special Issue on the 1st Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2022)","authors":"James Aspnes (Guest Editor and SAND 2022 Program Chair),&nbsp;Othon Michail","doi":"10.1016/j.jcss.2023.103503","DOIUrl":"10.1016/j.jcss.2023.103503","url":null,"abstract":"","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"141 ","pages":"Article 103503"},"PeriodicalIF":1.1,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138493944","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}

{"title":"PAC learning halfspaces in non-interactive local differential privacy model with public unlabeled data","authors":"Jinyan Su ,&nbsp;Jinhui Xu ,&nbsp;Di Wang","doi":"10.1016/j.jcss.2023.103496","DOIUrl":"10.1016/j.jcss.2023.103496","url":null,"abstract":"<div><p>In this paper, we study the problem of PAC learning halfspaces in the non-interactive local differential privacy<span> model (NLDP). To breach the barrier of exponential sample complexity, previous results studied a relaxed setting where the server has access to some additional public but unlabeled data. We continue in this direction. Specifically, we consider the problem under the standard setting instead of the large margin setting studied before. Under different mild assumptions on the underlying data distribution, we propose two approaches that are based on the Massart noise model and self-supervised learning and show that it is possible to achieve sample complexities that are only linear in the dimension and polynomial in other terms for both private and public data, which significantly improve the previous results. Our methods could also be used for other private PAC learning problems.</span></p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"141 ","pages":"Article 103496"},"PeriodicalIF":1.1,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138493945","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}

{"title":"Blackout-tolerant temporal spanners","authors":"Davide Bilò ,&nbsp;Gianlorenzo D'Angelo ,&nbsp;Luciano Gualà ,&nbsp;Stefano Leucci ,&nbsp;Mirko Rossi","doi":"10.1016/j.jcss.2023.103495","DOIUrl":"10.1016/j.jcss.2023.103495","url":null,"abstract":"<div><p>We introduce the notions of <em>blackout-tolerant</em> temporal <em>α</em>-spanner of a temporal graph <em>G</em> which is a subgraph of <em>G</em> that preserves the distances between pairs of vertices of interest in <em>G</em> up to a multiplicative factor of <em>α</em>, even when the graph edges at a single time-instant become unavailable. In particular, we consider the <em>single-source</em>, <em>single-pair</em>, and <em>all-pairs</em> cases and, for each case we look at three quality requirements: <em>exact</em> distances (i.e., <span><math><mi>α</mi><mo>=</mo><mn>1</mn></math></span>), <em>almost-exact</em> distances (i.e., <span><math><mi>α</mi><mo>=</mo><mn>1</mn><mo>+</mo><mi>ε</mi></math></span> for an arbitrarily small constant <span><math><mi>ε</mi><mo>&gt;</mo><mn>0</mn></math></span>), and <em>connectivity</em> (i.e., unbounded <em>α</em>). We provide almost tight bounds on the <em>size</em> of such spanners for <em>general</em> temporal graphs and for <em>temporal cliques</em>, showing that they are either very sparse (i.e., they have <span><math><mover><mrow><mi>O</mi></mrow><mrow><mo>˜</mo></mrow></mover><mo>(</mo><mi>n</mi><mo>)</mo></math></span> edges) or they must have size <span><math><mi>Ω</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> in the worst case, where <em>n</em> is the number of vertices of <em>G</em>. We also investigate multiple blackouts and <em>k-edge fault-tolerant temporal spanners</em>.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"141 ","pages":"Article 103495"},"PeriodicalIF":1.1,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000023001009/pdfft?md5=35a28914507288d7957b1fcfa27d6087&pid=1-s2.0-S0022000023001009-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138493942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lifting query complexity to time-space complexity for two-way finite automata","authors":"Shenggen Zheng ,&nbsp;Yaqiao Li ,&nbsp;Minghua Pan ,&nbsp;Jozef Gruska ,&nbsp;Lvzhou Li","doi":"10.1016/j.jcss.2023.103494","DOIUrl":"10.1016/j.jcss.2023.103494","url":null,"abstract":"<div><p><span><span>Time-space tradeoff has been studied in a variety of models, such as Turing machines, branching programs, and </span>finite automata, etc. While communication complexity as a technique has been applied to study finite automata, it seems it has not been used to study time-space tradeoffs of finite automata. We design a new technique showing that separations of query complexity can be lifted, via communication complexity, to separations of time-space complexity of two-way finite automata. As an application, one of our main results exhibits the first example of a language </span><em>L</em> such that the time-space complexity of two-way probabilistic finite automata with a bounded error (2PFA) is <span><math><mover><mrow><mi>Ω</mi></mrow><mrow><mo>˜</mo></mrow></mover><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span>, while of exact two-way quantum finite automata with classical states (2QCFA) is <span><math><mover><mrow><mi>O</mi></mrow><mrow><mo>˜</mo></mrow></mover><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>5</mn><mo>/</mo><mn>3</mn></mrow></msup><mo>)</mo></math></span><span>, that is, we demonstrate for the first time that exact quantum computing has an advantage in time-space complexity comparing to classical computing.</span></p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"141 ","pages":"Article 103494"},"PeriodicalIF":1.1,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138493943","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}

{"title":"Corrigendum to “Prediction, learning, uniform convergence, and scale-sensitive dimensions” [J. Comput. Syst. Sci. 56 (2) (1998) 174–190]","authors":"Peter L. Bartlett ,&nbsp;Philip M. Long","doi":"10.1016/j.jcss.2023.103465","DOIUrl":"https://doi.org/10.1016/j.jcss.2023.103465","url":null,"abstract":"","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"140 ","pages":"Article 103465"},"PeriodicalIF":1.1,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000023000703/pdfft?md5=5fea357eab14a31f7d2bb2a0d38598ad&pid=1-s2.0-S0022000023000703-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92122518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}