Journal of Computer and System Sciences最新文献_第3页

The impact of state merging on predictive accuracy in probabilistic tree automata: Dietze's conjecture revisited 状态合并对概率树自动机预测准确性的影响：迪茨猜想再探讨

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-06-27 DOI: 10.1016/j.jcss.2024.103563

{"title":"The impact of state merging on predictive accuracy in probabilistic tree automata: Dietze's conjecture revisited","authors":"","doi":"10.1016/j.jcss.2024.103563","DOIUrl":"10.1016/j.jcss.2024.103563","url":null,"abstract":"<div>Dietze's conjecture concerns the problem of equipping a tree automaton M with weights to make it probabilistic, in such a way that the resulting automaton N predicts a given corpus <math><mi>C</mi></math> as accurately as possible. The conjecture states that the accuracy cannot increase if the states in M are merged with respect to an equivalence relation ∼ so that the result is a smaller automaton <math><msup><mrow><mi>M</mi></mrow><mrow><mo>∼</mo></mrow></msup></math>. Put differently, merging states can never improve predictions. This is under the assumption that both M and <math><msup><mrow><mi>M</mi></mrow><mrow><mo>∼</mo></mrow></msup></math> are bottom-up deterministic and accept every tree in <math><mi>C</mi></math>. We prove that the conjecture holds, using a construction that turns any probabilistic version <math><msup><mrow><mi>N</mi></mrow><mrow><mo>∼</mo></mrow></msup></math> of <math><msup><mrow><mi>M</mi></mrow><mrow><mo>∼</mo></mrow></msup></math> into a probabilistic version N of M, such that N assigns at least as great a weight to each tree in <math><mi>C</mi></math> as <math><msup><mrow><mi>N</mi></mrow><mrow><mo>∼</mo></mrow></msup></math> does.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"146 ","pages":"Article 103563"},"PeriodicalIF":1.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000024000588/pdfft?md5=9e1c1d599bbcfc040fd29b857c6c21e8&pid=1-s2.0-S0022000024000588-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571800","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}

引用次数: 0

Corrigendum to “Homomorphism preservation on quasi-wide classes” [J. Comput. Syst. Sci. 76 (5) (2010) 324–332] 准广类上的同态保存》更正 [J. Comput. Syst.

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-06-10 DOI: 10.1016/j.jcss.2024.103553

Anuj Dawar

引用次数: 0

The g-extra connectivity of graph products 图积的 g 外连接性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-29 DOI: 10.1016/j.jcss.2024.103552

Zhao Wang , Yaping Mao , Sun-Yuan Hsieh , Ralf Klasing , Yuzhi Xiao

{"title":"The g-extra connectivity of graph products","authors":"Zhao Wang , Yaping Mao , Sun-Yuan Hsieh , Ralf Klasing , Yuzhi Xiao","doi":"10.1016/j.jcss.2024.103552","DOIUrl":"10.1016/j.jcss.2024.103552","url":null,"abstract":"<div>Connectivity is one of important parameters for the fault tolerant of an interconnection network. In 1996, Fàbrega and Fiol proposed the concept of g-extra connectivity. A subset of vertices S is said to be a cutset if <math><mi>G</mi><mo>−</mo><mi>S</mi></math> is not connected. A cutset S is called an <math><msub><mrow><mi>R</mi></mrow><mrow><mi>g</mi></mrow></msub></math>-cutset, where g is a non-negative integer, if every component of <math><mi>G</mi><mo>−</mo><mi>S</mi></math> has at least <math><mi>g</mi><mo>+</mo><mn>1</mn></math> vertices. If G has at least one <math><msub><mrow><mi>R</mi></mrow><mrow><mi>g</mi></mrow></msub></math>-cutset, the g-extra connectivity of G, denoted by <math><msub><mrow><mi>κ</mi></mrow><mrow><mi>g</mi></mrow></msub><mo>(</mo><mi>G</mi><mo>)</mo></math>, is then defined as the minimum cardinality over all <math><msub><mrow><mi>R</mi></mrow><mrow><mi>g</mi></mrow></msub></math>-cutsets of G. In this paper, we first obtain the exact value of g-extra connectivity for the lexicographic product of two general graphs. Next, the upper and lower sharp bounds of g-extra connectivity for the Cartesian product of two general graphs are given. In the end, we apply our results on grid graphs and 2-dimensional generalized hypercubes.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"145 ","pages":"Article 103552"},"PeriodicalIF":1.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141195346","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

On computing large temporal (unilateral) connected components 关于计算大时间（单边）连接成分

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-22 DOI: 10.1016/j.jcss.2024.103548

Isnard Lopes Costa , Raul Lopes , Andrea Marino , Ana Silva

引用次数: 0

Backdoor DNFs 后门 DNF

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-21 DOI: 10.1016/j.jcss.2024.103547

Sebastian Ordyniak , Andre Schidler , Stefan Szeider

引用次数: 0

Temporal reachability minimization: Delaying vs. deleting 时间可达性最小化：延迟与删除

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-20 DOI: 10.1016/j.jcss.2024.103549

Hendrik Molter , Malte Renken , Philipp Zschoche

引用次数: 0

A new temporal interpretation of cluster editing 集群编辑的新时间解释

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-17 DOI: 10.1016/j.jcss.2024.103551

Cristiano Bocci , Chiara Capresi , Kitty Meeks , John Sylvester

{"title":"A new temporal interpretation of cluster editing","authors":"Cristiano Bocci , Chiara Capresi , Kitty Meeks , John Sylvester","doi":"10.1016/j.jcss.2024.103551","DOIUrl":"https://doi.org/10.1016/j.jcss.2024.103551","url":null,"abstract":"<div>The <math><mi>NP</mi></math>-complete graph problem Cluster Editing seeks to transform a static graph into a disjoint union of cliques by making the fewest possible edits to the edges. We introduce a natural interpretation of this problem in temporal graphs, whose edge sets change over time. This problem is <math><mi>NP</mi></math>-complete even when restricted to temporal graphs whose underlying graph is a path, but we obtain two polynomial-time algorithms for restricted cases. In the static setting, it is well-known that a graph is a disjoint union of cliques if and only if it contains no induced copy of <math><msub><mrow><mi>P</mi></mrow><mrow><mn>3</mn></mrow></msub></math>; we demonstrate that no general characterisation involving sets of at most four vertices can exist in the temporal setting, but obtain a complete characterisation involving forbidden configurations on at most five vertices. This characterisation gives rise to an <math><mi>FPT</mi></math> algorithm parameterised simultaneously by the permitted number of modifications and the lifetime of the temporal graph.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"144 ","pages":"Article 103551"},"PeriodicalIF":1.1,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000024000461/pdfft?md5=3c7ceb30b0bccaa972030b25aefb334f&pid=1-s2.0-S0022000024000461-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141156308","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}

引用次数: 0

The tree-child network inference problem for line trees and the shortest common supersequence problem for permutation strings 线状树的树-子网络推理问题和排列字符串的最短公共超序列问题

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-16 DOI: 10.1016/j.jcss.2024.103546

Laurent Bulteau , Louxin Zhang

{"title":"The tree-child network inference problem for line trees and the shortest common supersequence problem for permutation strings","authors":"Laurent Bulteau , Louxin Zhang","doi":"10.1016/j.jcss.2024.103546","DOIUrl":"10.1016/j.jcss.2024.103546","url":null,"abstract":"<div>One strategy for inference of phylogenetic networks is to solve the phylogenetic network problem, which involves inferring phylogenetic trees first and subsequently computing the smallest phylogenetic network that displays all the trees. This approach capitalizes on exceptional tools available for inferring phylogenetic trees from biomolecular sequences. Since the vast space of phylogenetic networks poses difficulties in obtaining comprehensive sampling, the researchers switch their attention to inferring tree-child networks from multiple phylogenetic trees, where in a tree-child network each non-leaf node must have at least one child that is an indegree-one node. Three results are obtained in this work: (1) The shortest common supersequence problem remains NP-hard even for permutation strings. (2) Derived from the first result, the tree-child network inference problem is also established as NP-hard even for line trees (also known as caterpillar trees). (3) The parsimonious tree-child networks that display all the line trees are the same as those displaying all the binary trees and their hybridization number is <math><mi>Θ</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>)</mo></math> for n taxa.</div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"144 ","pages":"Article 103546"},"PeriodicalIF":1.1,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141049268","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

On minimum vertex bisection of random d-regular graphs 论随机 d-Regular 图形的最小顶点平分

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-05-15 DOI: 10.1016/j.jcss.2024.103550

Josep Díaz , Öznur Yaşar Diner , Maria Serna , Oriol Serra

引用次数: 0

Online computation with untrusted advice 使用不可靠建议的在线计算

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-04-18 DOI: 10.1016/j.jcss.2024.103545

Spyros Angelopoulos , Christoph Dürr , Shendan Jin , Shahin Kamali , Marc Renault

引用次数: 0