首页 > 最新文献

Acta Informatica最新文献

英文 中文
A sharp lower bound on the independence number of k-regular connected hypergraphs with rank R 秩为R的k-正则连通超图独立数的一个尖锐下界
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-11-29 DOI: 10.1007/s00236-024-00468-6
Zhongzheng Tang, Haoyang Zou, Zhuo Diao

Let H(VE) be a k-regular connected hypergraph with rank R on n vertices and m edges. A set of vertices (Ssubseteq V) is an independent set if every two vertices in S are not adjacent. The independence number is the maximum cardinality of an independent set, denoted by (alpha (H)). In this paper, we prove the following inequality: (alpha (H)ge frac{m-(k-2)n-1}{R}), and the equality holds if and only if H is a hypertree with R-perfect matching. Based on the proofs, some combinatorial algorithms on the independence number are designed.

设H(V, E)是一个秩为R,有n个顶点和m条边的k正则连通超图。如果S中的每两个顶点不相邻,则顶点集(Ssubseteq V)是独立集。独立数是独立集的最大基数,用(alpha (H))表示。本文证明了一个不等式(alpha (H)ge frac{m-(k-2)n-1}{R}),当且仅当H是r -完全匹配的超树时,该不等式成立。在此基础上,设计了独立数的组合算法。
{"title":"A sharp lower bound on the independence number of k-regular connected hypergraphs with rank R","authors":"Zhongzheng Tang,&nbsp;Haoyang Zou,&nbsp;Zhuo Diao","doi":"10.1007/s00236-024-00468-6","DOIUrl":"10.1007/s00236-024-00468-6","url":null,"abstract":"<div><p>Let <i>H</i>(<i>V</i>, <i>E</i>) be a <i>k</i>-regular connected hypergraph with rank <i>R</i> on <i>n</i> vertices and <i>m</i> edges. A set of vertices <span>(Ssubseteq V)</span> is an independent set if every two vertices in <i>S</i> are not adjacent. The independence number is the maximum cardinality of an independent set, denoted by <span>(alpha (H))</span>. In this paper, we prove the following inequality: <span>(alpha (H)ge frac{m-(k-2)n-1}{R})</span>, and the equality holds if and only if <i>H</i> is a hypertree with <i>R</i>-perfect matching. Based on the proofs, some combinatorial algorithms on the independence number are designed.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"62 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
A binary integer programming-based method for qubit mapping in sparse architectures 基于二进制整数编程的稀疏架构中的量子位映射方法
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-11-28 DOI: 10.1007/s00236-024-00471-x
Hui Jiang, Jianling Fu, Yuxin Deng, Jun Wu

It is a current trend of sparse architectures employed for superconducting quantum chips, which have the advantage of low coupling and crosstalk properties. Existing qubit mapping algorithms do not take the sparsity of quantum architectures into account. To this end, we propose a qubit mapping method based on binary integer programming, called QMBIP. First, we slice a given quantum circuit by taking into account the sparsity of target architectures. Then, the constraints and the objective function are formulated and rendered to the binary integer programming problem by matrix transformation. The behavior of a (textbf{SWAP}) gate is characterized by an elementary row transformation on the mapping matrix between the physical and logical qubits. To reduce the search space, we introduce path variables and isomorphic pruning, as well as a look-ahead mechanism. Finally, we compare with typical qubit mapping algorithms such as SABRE and SATMAP on the sparse architectures ibmq_sydney, ibmq_manhattan, ibmq_singapore, and a dense architecture ibmq_tokyo. Experiments show that QMBIP effectively maintains the fidelity of the compiled quantum circuits. For example, on ibmq_sydney, the fidelity of the quantum circuits compiled by our approach outperforms SABRE and SATMAP by 53.9% and 46.8%, respectively.

超导量子芯片采用稀疏架构是当前的一种趋势,这种架构具有低耦合和低串扰特性的优势。现有的量子比特映射算法没有考虑量子架构的稀疏性。为此,我们提出了一种基于二进制整数编程的量子比特映射方法,称为 QMBIP。首先,我们考虑目标架构的稀疏性,对给定的量子电路进行切分。然后,制定约束条件和目标函数,并通过矩阵变换将其转化为二进制整数编程问题。物理比特和逻辑比特之间的映射矩阵的基本行变换可以描述一个门的行为。为了缩小搜索空间,我们引入了路径变量、同构剪枝以及前瞻机制。最后,我们在稀疏架构 ibmq_sydney、ibmq_manhattan、ibmq_singapore 和稠密架构 ibmq_tokyo 上比较了 SABRE 和 SATMAP 等典型的量子比特映射算法。实验表明,QMBIP 有效地保持了编译量子电路的保真度。例如,在 ibmq_sydney 上,用我们的方法编译的量子电路的保真度分别比 SABRE 和 SATMAP 高出 53.9% 和 46.8%。
{"title":"A binary integer programming-based method for qubit mapping in sparse architectures","authors":"Hui Jiang,&nbsp;Jianling Fu,&nbsp;Yuxin Deng,&nbsp;Jun Wu","doi":"10.1007/s00236-024-00471-x","DOIUrl":"10.1007/s00236-024-00471-x","url":null,"abstract":"<div><p>It is a current trend of sparse architectures employed for superconducting quantum chips, which have the advantage of low coupling and crosstalk properties. Existing qubit mapping algorithms do not take the sparsity of quantum architectures into account. To this end, we propose a qubit mapping method based on binary integer programming, called QMBIP. First, we slice a given quantum circuit by taking into account the sparsity of target architectures. Then, the constraints and the objective function are formulated and rendered to the binary integer programming problem by matrix transformation. The behavior of a <span>(textbf{SWAP})</span> gate is characterized by an elementary row transformation on the mapping matrix between the physical and logical qubits. To reduce the search space, we introduce path variables and isomorphic pruning, as well as a look-ahead mechanism. Finally, we compare with typical qubit mapping algorithms such as SABRE and SATMAP on the sparse architectures <i>ibmq_sydney</i>, <i>ibmq_manhattan</i>, <i>ibmq_singapore</i>, and a dense architecture <i>ibmq_tokyo</i>. Experiments show that QMBIP effectively maintains the fidelity of the compiled quantum circuits. For example, on <i>ibmq_sydney</i>, the fidelity of the quantum circuits compiled by our approach outperforms SABRE and SATMAP by 53.9% and 46.8%, respectively.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"62 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Homeostasis tissue-like P systems with cell separation 具有细胞分离功能的同态组织类 P 系统
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-11-27 DOI: 10.1007/s00236-024-00470-y
Yueguo Luo, Yuzhen Zhao, Wenqin Li, Ping Guo

P systems are distributed, parallel computing models inspired by biology. Tissue-like P systems are an important variant of P systems, where the environment can provide objects for cells. Hence, the environment plays a critical role. Nevertheless, in actual biological tissues, there exists a peculiar biological phenomenon called “homeostasis”; that is, the internal organisms maintain stable, thereby reducing their dependence on external conditions (i.e., the environment). In this work, considering cell separation, we construct a novel variant to simulate the mechanism of biological homeostasis, called homeostasis tissue-like P systems with cell separation. In this variant, the number of object is finite, and certain substance changes occur inside the cells; moreover, an exponential workspace can be obtained with cell separation in feasible time. The computational power of this model is studied by simulating register machines, and the results show that the variant is computationally complete as number computing devices. Furthermore, to explore the computational efficiency of the model, we use the variant to solve a classic (textbf{NP})-complete problem, the SAT problem, obtaining a uniform solution with a rule length of at most 3.

P 系统是受生物学启发的分布式并行计算模型。类组织 P 系统是 P 系统的一个重要变体,其中环境可以为细胞提供对象。因此,环境起着至关重要的作用。然而,在实际的生物组织中,存在一种奇特的生物现象,即 "稳态";也就是说,内部有机体保持稳定,从而减少对外部条件(即环境)的依赖。在这项工作中,考虑到细胞分离,我们构建了一种新的变体来模拟生物平衡机制,称为具有细胞分离的类平衡组织 P 系统。在这一变体中,物体的数量是有限的,细胞内会发生某些物质变化;此外,在可行的时间内,细胞分离可获得指数工作空间。我们通过模拟寄存器对该模型的计算能力进行了研究,结果表明,作为数字计算设备,该变量在计算上是完整的。此外,为了探索该模型的计算效率,我们用该变体求解了一个经典的(textbf{NP})-完全问题--SAT问题,得到了规则长度最多为3的统一解。
{"title":"Homeostasis tissue-like P systems with cell separation","authors":"Yueguo Luo,&nbsp;Yuzhen Zhao,&nbsp;Wenqin Li,&nbsp;Ping Guo","doi":"10.1007/s00236-024-00470-y","DOIUrl":"10.1007/s00236-024-00470-y","url":null,"abstract":"<div><p>P systems are distributed, parallel computing models inspired by biology. Tissue-like P systems are an important variant of P systems, where the environment can provide objects for cells. Hence, the environment plays a critical role. Nevertheless, in actual biological tissues, there exists a peculiar biological phenomenon called “homeostasis”; that is, the internal organisms maintain stable, thereby reducing their dependence on external conditions (i.e., the environment). In this work, considering cell separation, we construct a novel variant to simulate the mechanism of biological homeostasis, called homeostasis tissue-like P systems with cell separation. In this variant, the number of object is finite, and certain substance changes occur inside the cells; moreover, an exponential workspace can be obtained with cell separation in feasible time. The computational power of this model is studied by simulating register machines, and the results show that the variant is computationally complete as number computing devices. Furthermore, to explore the computational efficiency of the model, we use the variant to solve a classic <span>(textbf{NP})</span>-complete problem, the SAT problem, obtaining a uniform solution with a rule length of at most 3.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"62 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Connected feedback vertex set on AT-free graphs 无AT图上的连接反馈顶点集
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-11-26 DOI: 10.1007/s00236-024-00469-5
Joydeep Mukherjee, Tamojit Saha

A connected feedback vertex set of a graph is a connected subgraph of the graph whose removal makes the graph cycle free. In this paper, we provide an approximation algorithm for connected feedback vertex set in AT-free graphs. Given an (alpha )-approximate solution for feedback vertex set on 2-connected AT-free graph, our algorithm produces a solution of size (((alpha +0.9091)OPT+6)) for connected feedback vertex set on the same graph. The complexity of our algorithm is (O(f(n)+(m+n))), where the time required to obtain the (alpha )-approximate solution is O(f(n)). Our result leads to the following two observations. The optimal feedback vertex set algorithm for AT-free graphs combined with our result provides an algorithm which produces a solution of size ((1.9091OPT+6)) with running time (O(n^8m^2)) for 2-connected AT-free graphs. The 2-approximation algorithm for feedback vertex set in general graphs along with our result provides an algorithm which produces a solution of size ((2.9091OPT+6)) with running time (O(min{m(log(n)),n^2})). Using the same method we also obtain a (((alpha +1)OPT+6))-approximation for this problem on general AT-free graphs. We note that, the complexity status of this problem is not known.

一个图的连通反馈顶点集是该图的一个连通子图,去除该子图可使该图无循环。本文提供了一种无AT图中连通反馈顶点集的近似算法。给定一个 2 连无 AT 图上反馈顶点集的(α )近似解,我们的算法会为同一图上的连通反馈顶点集生成一个大小为(((α +0.9091)OPT+6))的解。我们算法的复杂度是(O(f(n)+(m+n)),其中获得 (alpha )-近似解所需的时间是 O(f(n))。我们的结果引出了以下两个观察结果。无AT图的最优反馈顶点集算法与我们的结果相结合,提供了一种算法,对于2连接的无AT图,它能产生大小为 ((1.9091OPT+6))的解,运行时间为 (O(n^8m^2))。一般图中反馈顶点集的 2-approximation 算法与我们的结果一起提供了一种算法,它可以产生大小为 ((2.9091OPT+6))的解,运行时间为 ((O(min{m(log(n)),n^2})。用同样的方法,我们还得到了这个问题在一般无AT图上的(((alpha +1)OPT+6))近似值。我们注意到,这个问题的复杂性状况尚不清楚。
{"title":"Connected feedback vertex set on AT-free graphs","authors":"Joydeep Mukherjee,&nbsp;Tamojit Saha","doi":"10.1007/s00236-024-00469-5","DOIUrl":"10.1007/s00236-024-00469-5","url":null,"abstract":"<div><p>A connected feedback vertex set of a graph is a connected subgraph of the graph whose removal makes the graph cycle free. In this paper, we provide an approximation algorithm for connected feedback vertex set in AT-free graphs. Given an <span>(alpha )</span>-approximate solution for feedback vertex set on 2-connected AT-free graph, our algorithm produces a solution of size <span>(((alpha +0.9091)OPT+6))</span> for connected feedback vertex set on the same graph. The complexity of our algorithm is <span>(O(f(n)+(m+n)))</span>, where the time required to obtain the <span>(alpha )</span>-approximate solution is <i>O</i>(<i>f</i>(<i>n</i>)). Our result leads to the following two observations. The optimal feedback vertex set algorithm for AT-free graphs combined with our result provides an algorithm which produces a solution of size <span>((1.9091OPT+6))</span> with running time <span>(O(n^8m^2))</span> for 2-connected AT-free graphs. The 2-approximation algorithm for feedback vertex set in general graphs along with our result provides an algorithm which produces a solution of size <span>((2.9091OPT+6))</span> with running time <span>(O(min{m(log(n)),n^2}))</span>. Using the same method we also obtain a <span>(((alpha +1)OPT+6))</span>-approximation for this problem on general AT-free graphs. We note that, the complexity status of this problem is not known.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"62 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Comparative genomics with succinct colored de Bruijn graphs 利用简洁彩色德布鲁因图进行比较基因组学研究
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-11-21 DOI: 10.1007/s00236-024-00467-7
Lucas P. Ramos, Felipe A. Louza, Guilherme P. Telles

DNA technologies have evolved significantly in the past years enabling the sequencing of a large number of genomes in a short time. Nevertheless, the underlying problem of assembling sequence fragments is computationally hard and many technical factors and limitations complicate obtaining the complete sequence of a genome. Many genomes are left in a draft state, in which each chromosome is represented by a set of sequences with partial information on their relative order. Recently, some approaches have been proposed to compare draft genomes by comparing paths in de Bruijn graphs, which are constructed by many practical genome assemblers. In this article we describe in more detail a method for comparing genomes represented as succinct colored de Bruijn graphs directly and without resorting to sequence alignments, called (texttt {gcBB}), that evaluates the entropy and expectation measures based on the Burrows-Wheeler Similarity Distribution. We also introduce an improved version of (texttt {gcBB}), called (texttt {multi-gcBB}), that improves the time and space performance considerably through the selection of different data structures. We have compared phylogenies of 12 Drosophila species obtained by other methods to those obtained with (texttt {gcBB}), achieving promising results.

过去几年中,DNA 技术取得了长足发展,能够在短时间内完成大量基因组的测序工作。然而,组装序列片段的基本问题在计算上是很困难的,而且许多技术因素和限制使得获得基因组的完整序列变得更加复杂。许多基因组都处于草稿状态,其中每条染色体都由一组序列表示,并附有关于其相对顺序的部分信息。最近,人们提出了一些通过比较德布鲁因图(de Bruijn graph)中的路径来比较草拟基因组的方法,许多实用的基因组组装器都会构建德布鲁因图。在本文中,我们更详细地描述了一种直接比较以简洁彩色 de Bruijn 图表示的基因组的方法,无需借助序列比对,称为 (texttt {gcBB}),它基于 Burrows-Wheeler 相似性分布来评估熵和期望度量。我们还引入了 (texttt {gcBB}) 的改进版本,称为 (texttt {multi-gcBB}),它通过选择不同的数据结构大大提高了时间和空间性能。我们比较了用其他方法和用(texttt {gcBB})得到的12种果蝇的系统发生,取得了很好的结果。
{"title":"Comparative genomics with succinct colored de Bruijn graphs","authors":"Lucas P. Ramos,&nbsp;Felipe A. Louza,&nbsp;Guilherme P. Telles","doi":"10.1007/s00236-024-00467-7","DOIUrl":"10.1007/s00236-024-00467-7","url":null,"abstract":"<div><p>DNA technologies have evolved significantly in the past years enabling the sequencing of a large number of genomes in a short time. Nevertheless, the underlying problem of assembling sequence fragments is computationally hard and many technical factors and limitations complicate obtaining the complete sequence of a genome. Many genomes are left in a draft state, in which each chromosome is represented by a set of sequences with partial information on their relative order. Recently, some approaches have been proposed to compare draft genomes by comparing paths in de Bruijn graphs, which are constructed by many practical genome assemblers. In this article we describe in more detail a method for comparing genomes represented as succinct colored de Bruijn graphs directly and without resorting to sequence alignments, called <span>(texttt {gcBB})</span>, that evaluates the entropy and expectation measures based on the Burrows-Wheeler Similarity Distribution. We also introduce an improved version of <span>(texttt {gcBB})</span>, called <span>(texttt {multi-gcBB})</span>, that improves the time and space performance considerably through the selection of different data structures. We have compared phylogenies of 12 Drosophila species obtained by other methods to those obtained with <span>(texttt {gcBB})</span>, achieving promising results.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"62 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Editorial 2024: moving forwards in the electronic age 社论 2024:在电子时代向前迈进
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-10-26 DOI: 10.1007/s00236-024-00466-8
Henning Fernau
{"title":"Editorial 2024: moving forwards in the electronic age","authors":"Henning Fernau","doi":"10.1007/s00236-024-00466-8","DOIUrl":"10.1007/s00236-024-00466-8","url":null,"abstract":"","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"61 4","pages":"331 - 332"},"PeriodicalIF":0.4,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Serial and parallel algorithms for order-preserving pattern matching based on the duel-and-sweep paradigm 基于 "决斗-扫荡 "范式的保序模式匹配串行和并行算法
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-08-31 DOI: 10.1007/s00236-024-00464-w
Davaajav Jargalsaikhan, Diptarama Hendrian, Yohei Ueki, Ryo Yoshinaka, Ayumi Shinohara

Given a text and a pattern over an alphabet, the classic exact matching problem searches for all occurrences of the pattern in the text. Unlike exact matching, order-preserving pattern matching (OPPM) considers the relative order of elements, rather than their exact values. In this paper, we propose efficient algorithms for the OPPM problem using the “duel-and-sweep” paradigm. For a pattern of length m and a text of length n, our serial algorithm runs in (O(n + mlog m)) time, and our parallel algorithm runs in (O(log ^2 m)) time and (O(n log ^2 m)) work with (O(log m)) time and (O(m log m)) work pattern preprocessing on the Priority Concurrent Read Concurrent Write Parallel Random-Access Machines (P-CRCW PRAM).

给定一段文本和一个字母表上的模式,经典的精确匹配问题是搜索文本中模式的所有出现次数。与精确匹配不同,保序模式匹配(OPPM)考虑的是元素的相对顺序,而不是它们的精确值。在本文中,我们提出了使用 "决斗和扫荡 "范式来解决 OPPM 问题的高效算法。对于长度为 m 的模式和长度为 n 的文本,我们的串行算法运行时间为 (O(n + mlog m))、而我们的并行算法在优先并发读取并发写入并行随机存取机(P-CRCW PRAM)上的运行时间为(O(log ^2 m)),工作模式预处理时间为(O(log m)),工作模式预处理时间为(O(n log ^2 m))。
{"title":"Serial and parallel algorithms for order-preserving pattern matching based on the duel-and-sweep paradigm","authors":"Davaajav Jargalsaikhan,&nbsp;Diptarama Hendrian,&nbsp;Yohei Ueki,&nbsp;Ryo Yoshinaka,&nbsp;Ayumi Shinohara","doi":"10.1007/s00236-024-00464-w","DOIUrl":"10.1007/s00236-024-00464-w","url":null,"abstract":"<div><p>Given a text and a pattern over an alphabet, the classic exact matching problem searches for all occurrences of the pattern in the text. Unlike exact matching, <i>order-preserving pattern matching</i> (OPPM) considers the relative order of elements, rather than their exact values. In this paper, we propose efficient algorithms for the OPPM problem using the “duel-and-sweep” paradigm. For a pattern of length <i>m</i> and a text of length <i>n</i>, our serial algorithm runs in <span>(O(n + mlog m))</span> time, and our parallel algorithm runs in <span>(O(log ^2 m))</span> time and <span>(O(n log ^2 m))</span> work with <span>(O(log m))</span> time and <span>(O(m log m))</span> work pattern preprocessing on the Priority Concurrent Read Concurrent Write Parallel Random-Access Machines (P-CRCW PRAM).</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"61 4","pages":"415 - 444"},"PeriodicalIF":0.4,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Linear-size suffix tries and linear-size CDAWGs simplified and improved 简化和改进线性大小后缀尝试和线性大小 CDAWG
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-08-23 DOI: 10.1007/s00236-024-00465-9
Shunsuke Inenaga

The linear-size suffix tries (LSTries) (Crochemore et al. in Theor Comput Sci 638:171–178, 2016) are a version of suffix trees in which the edge labels are single characters, yet are able to perform pattern matching queries in optimal time. Instead of explicitly storing the input text, LSTries have some extra non-branching internal nodes called type-2 nodes. The extended techniques are then used in the linear-size compact directed acyclic word graphs (LCDAWGs) (Takagi et al., in: SPIRE 2017, pp. 304–316, 2017), which can be stored with (O(textsf{el}(T)+textsf{er}(T))) space (i.e. without the text), where (textsf{el}(T)) and (textsf{er}(T)) are the numbers of left- and right-extensions of the maximal repeats in the input text string T, respectively. In this paper, we present simpler alternatives to the aforementioned indexing structures, called the simplified LSTries (simLSTries) and the simplified LCDAWGs (simLCDAWGs), in which most of the type-2 nodes are removed. In particular, our simLCDAWGs require only (O(textsf{er}(T))) space and work in a weaker model of computation (i.e. the pointer machine model). This contrasts the (O(textsf{er}(T)))-space CDAWG representation of Belazzougui and Cunial (in: Proceedings of the 24th international symposium on string processing and information retrieval, pp. 161–175, 2017), which works on the word RAM model.

线性大小后缀树(linear-size suffix tries,LSTries)(Crochemore 等人,载于 Theor Comput Sci 638:171-178, 2016)是后缀树的一个版本,其中的边标签是单字符,但却能在最佳时间内执行模式匹配查询。LSTries 不明确存储输入文本,而是有一些额外的非分支内部节点,称为 Type-2 节点。扩展技术随后被用于线性大小的紧凑有向无环词图(LCDAWGs)(Takagi et al、in: SPIRE 2017, pp. 304-316, 2017),它可以用 (O(textsf{el}(T)+textsf{er}(T)))空间存储(即不含文本),其中 (textsf{el}(T))和 (textsf{er}(T))分别是输入文本串 T 中最大重复次数的左扩展和右扩展的数量。在本文中,我们提出了上述索引结构的简化替代方案,称为简化 LSTries(simLSTries)和简化 LCDAWGs(simLCDAWGs),其中去除了大部分类型 2 节点。特别是,我们的 simLCDAWGs 只需要 (O(textsf{er}(T))) 空间,并且可以在较弱的计算模型(即指针机模型)中工作。这与 Belazzougui 和 Cunial 的 (O(textsf{er}(T)) )空间 CDAWG 表示(in:第 24 届字符串处理与信息检索国际研讨会论文集》(Proceedings of the 24th international symposium on string processing and information retrieval, pp.
{"title":"Linear-size suffix tries and linear-size CDAWGs simplified and improved","authors":"Shunsuke Inenaga","doi":"10.1007/s00236-024-00465-9","DOIUrl":"10.1007/s00236-024-00465-9","url":null,"abstract":"<div><p>The <i>linear-size suffix tries</i> (<i>LSTries</i>) (Crochemore et al. in Theor Comput Sci 638:171–178, 2016) are a version of suffix trees in which the edge labels are single characters, yet are able to perform pattern matching queries in optimal time. Instead of explicitly storing the input text, LSTries have some extra non-branching internal nodes called <i>type-2</i> nodes. The extended techniques are then used in the <i>linear-size compact directed acyclic word graphs</i> (<i>LCDAWGs</i>) (Takagi et al., in: SPIRE 2017, pp. 304–316, 2017), which can be stored with <span>(O(textsf{el}(T)+textsf{er}(T)))</span> space (i.e. without the text), where <span>(textsf{el}(T))</span> and <span>(textsf{er}(T))</span> are the numbers of left- and right-extensions of the maximal repeats in the input text string <i>T</i>, respectively. In this paper, we present simpler alternatives to the aforementioned indexing structures, called the <i>simplified LSTries</i> (<i>simLSTries</i>) and the <i>simplified LCDAWGs</i> (<i>simLCDAWGs</i>), in which most of the type-2 nodes are removed. In particular, our simLCDAWGs require only <span>(O(textsf{er}(T)))</span> space and work in a weaker model of computation (i.e. the pointer machine model). This contrasts the <span>(O(textsf{er}(T)))</span>-space CDAWG representation of Belazzougui and Cunial (in: Proceedings of the 24th international symposium on string processing and information retrieval, pp. 161–175, 2017), which works on the word RAM model.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"61 4","pages":"445 - 468"},"PeriodicalIF":0.4,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Parameterized aspects of distinct Kemeny rank aggregation 不同凯门尼等级聚合的参数化方面
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-08-15 DOI: 10.1007/s00236-024-00463-x
Koustav De, Harshil Mittal, Palash Dey, Neeldhara Misra

The Kemeny method is one of the popular tools for rank aggregation. However, computing an optimal Kemeny ranking is (textsf{NP})-hard. Consequently, the computational task of finding a Kemeny ranking has been studied under the lens of parameterized complexity with respect to many parameters. We study the parameterized complexity of the problem of computing all distinct Kemeny rankings. We consider the target Kemeny score, number of candidates, average distance of input rankings, maximum range of any candidate, and unanimity width as our parameters. For all these parameters, we already have (textsf{FPT}) algorithms. We find that any desirable number of Kemeny rankings can also be found without substantial increase in running time. We also present (textsf{FPT}) approximation algorithms for Kemeny rank aggregation with respect to these parameters.

Kemeny 方法是排名聚合的常用工具之一。然而,计算一个最优的凯美尼排名是非常困难的。因此,人们在参数化复杂性的视角下研究了寻找凯美尼排序的计算任务。我们研究计算所有不同的凯门尼排名问题的参数化复杂度。我们将目标凯门尼得分、候选者数量、输入排名的平均距离、任何候选者的最大范围和一致度宽度作为参数。对于所有这些参数,我们已经有了(textsf{FPT})算法。我们发现,在不大幅增加运行时间的情况下,也可以找到任何理想数量的凯门尼排名。我们还提出了与这些参数相关的凯门尼排序聚合的 (textsf{FPT}) 近似算法。
{"title":"Parameterized aspects of distinct Kemeny rank aggregation","authors":"Koustav De,&nbsp;Harshil Mittal,&nbsp;Palash Dey,&nbsp;Neeldhara Misra","doi":"10.1007/s00236-024-00463-x","DOIUrl":"10.1007/s00236-024-00463-x","url":null,"abstract":"<div><p>The Kemeny method is one of the popular tools for rank aggregation. However, computing an optimal Kemeny ranking is <span>(textsf{NP})</span>-hard. Consequently, the computational task of finding a Kemeny ranking has been studied under the lens of parameterized complexity with respect to many parameters. We study the parameterized complexity of the problem of computing all distinct Kemeny rankings. We consider the target Kemeny score, number of candidates, average distance of input rankings, maximum range of any candidate, and unanimity width as our parameters. For all these parameters, we already have <span>(textsf{FPT})</span> algorithms. We find that any desirable number of Kemeny rankings can also be found without substantial increase in running time. We also present <span>(textsf{FPT})</span> approximation algorithms for Kemeny rank aggregation with respect to these parameters.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"61 4","pages":"401 - 414"},"PeriodicalIF":0.4,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Word-representable graphs from a word’s perspective 从单词的角度看可表示单词的图表
IF 0.4 4区 计算机科学 Q4 COMPUTER SCIENCE, INFORMATION SYSTEMS Pub Date : 2024-08-10 DOI: 10.1007/s00236-024-00462-y
Pamela Fleischmann, Lukas Haschke, Tim Löck, Dirk Nowotka

Word-representable graphs were introduced in 2008 by Kitaev and Pyatkin in the context of semigroup theory. Graphs are called word-representable if there exists a word with the graph’s nodes as letters such that the letters in the word alternate iff there is an edge between them in the graph. Until today numerous works investigated the word-representability of graphs but mostly from the graph perspective. In this work, we change the perspective to the words, i.e., we take classes of words and investigate the represented graphs. Our first subject of interest are the conjugates of words: we determine exactly which graphs are represented if we rotate the word. Afterwards, we look at k-local words introduced by Day et al. (FSTTCS LIPIcs, 2017) in order to gain more insights into this class of words. Here, we investigate especially which graphs are represented by 1-local words. Lastly, we prove that the language of all words representing a graph is regular. We were also able to characterise k-representable graphs, solving an open problem.

词可表示图是 Kitaev 和 Pyatkin 于 2008 年在半群理论的背景下提出的。如果存在一个以图的节点为字母的单词,且单词中的字母交替出现在图中,则该图被称为单词可表示图。迄今为止,研究图的单词可表示性的著作不胜枚举,但大多是从图的角度进行研究的。在这项工作中,我们将视角转向单词,即从单词的类别出发,研究其所代表的图。我们首先关注的是单词的共轭词:如果旋转单词,我们就能准确地确定哪些图被表示出来。之后,我们研究了 Day 等人(FSTTCS LIPIcs, 2017)引入的 k 本地单词,以深入了解这类单词。在这里,我们特别研究了哪些图是由 1 本地词表示的。最后,我们证明所有表示图的词的语言都是有规律的。我们还能够表征 k 可表示图,解决了一个未决问题。
{"title":"Word-representable graphs from a word’s perspective","authors":"Pamela Fleischmann,&nbsp;Lukas Haschke,&nbsp;Tim Löck,&nbsp;Dirk Nowotka","doi":"10.1007/s00236-024-00462-y","DOIUrl":"10.1007/s00236-024-00462-y","url":null,"abstract":"<div><p>Word-representable graphs were introduced in 2008 by Kitaev and Pyatkin in the context of semigroup theory. Graphs are called word-representable if there exists a word with the graph’s nodes as letters such that the letters in the word alternate iff there is an edge between them in the graph. Until today numerous works investigated the word-representability of graphs but mostly from the graph perspective. In this work, we change the perspective to the words, i.e., we take classes of words and investigate the represented graphs. Our first subject of interest are the conjugates of words: we determine exactly which graphs are represented if we rotate the word. Afterwards, we look at <i>k</i>-local words introduced by Day et al. (FSTTCS LIPIcs, 2017) in order to gain more insights into this class of words. Here, we investigate especially which graphs are represented by 1-local words. Lastly, we prove that the language of all words representing a graph is regular. We were also able to characterise <i>k</i>-representable graphs, solving an open problem.\u0000</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"61 4","pages":"383 - 400"},"PeriodicalIF":0.4,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00236-024-00462-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
期刊
Acta Informatica
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1