当前期刊: Theory of Computing Systems Go to current issue    加入关注   
显示样式:        排序: IF: - GO 导出
我的关注
我的收藏
您暂时未登录!
登录
  • Parameterized Complexity of Min-Power Asymmetric Connectivity
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-05-23
    Matthias Bentert, Roman Haag, Christian Hofer, Tomohiro Koana, André Nichterlein

    We investigate parameterized algorithms for the NP-hard problem Min-Power Asymmetric Connectivity (MinPAC) that has applications in wireless sensor networks. Given a directed arc-weighted graph, MinPAC asks for a strongly connected spanning subgraph minimizing the summed vertex costs. Here, the cost of each vertex is the weight of its heaviest outgoing arc in the chosen subgraph. We present linear-time

    更新日期:2020-05-23
  • Multiplication Algorithm Based on Collatz Function
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-05-15
    David Barina

    This article presents a new multiplication algorithm based on the Collatz function. Assuming the validity of the Collatz conjecture, the time complexity of multiplying two n-digit numbers is O(kn), where the k is the number of odd steps in the Collatz trajectory of the first multiplicand. Most likely, the algorithm is only of theoretical interest.

    更新日期:2020-05-15
  • Fast Algorithms for the Shortest Unique Palindromic Substring Problem on Run-Length Encoded Strings
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-05-09
    Kiichi Watanabe, Yuto Nakashima, Shunsuke Inenaga, Hideo Bannai, Masayuki Takeda

    For a string S, a palindromic substring S[i..j] is said to be a shortest unique palindromic substring (SUPS) for an interval [s,t] in S, if S[i..j] occurs exactly once in S, the interval [i,j] contains [s,t], and every palindromic substring containing [s,t] which is shorter than S[i..j] occurs at least twice in S. In this paper, we study the problem of answering SUPS queries on run-length encoded strings

    更新日期:2020-05-09
  • Unpopularity Factor in the Marriage and Roommates Problems
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-28
    Suthee Ruangwises, Toshiya Itoh

    Given a set A of n people, with each person having a preference list that ranks a subset of A as his/her acceptable partners in order of preference, we consider the Roommates Problem (rp) and the Marriage Problem (mp) of matching people with their partners. In rp there is no further restriction, while in mp only people of opposite genders can be acceptable partners. For a pair of matchings X and Y

    更新日期:2020-04-28
  • An Improved FPT Algorithm for Independent Feedback Vertex Set
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-25
    Shaohua Li, Marcin Pilipczuk

    We study the Independent Feedback Vertex Set problem — a variant of the classic Feedback Vertex Set problem where, given a graph G and an integer k, the problem is to decide whether there exists a vertex set \(S\subseteq V(G)\) such that G ∖ S is a forest and S is an independent set of size at most k. We present an \(\mathcal {O}^{\ast }((1+\varphi ^{2})^{k})\)-time FPT algorithm for this problem,

    更新日期:2020-04-25
  • Santha-Vazirani sources, deterministic condensers and very strong extractors
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-23
    Dmitry Gavinsky, Pavel Pudlák

    The notion of semi-random sources, also known as Santha-Vazirani (SV) sources, stands for a sequence of n bits, where the dependence of the i’th bit on the previousi − 1 bits is limited for every i ∈ [n]. If the dependence of the i’th bit on the remainingn − 1 bits is limited, then this is a strongSV-source. Even the strong SV -sources are known not to admit (universal) deterministic extractors, but

    更新日期:2020-04-23
  • Transition Property for Cube-Free Words
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-21
    Elena A. Petrova, Arseny M. Shur

    We study cube-free words over arbitrary non-unary finite alphabets and prove the following structural property: for every pair (u, v) of d-ary cube-free words, if u can be infinitely extended to the right and v can be infinitely extended to the left respecting the cube-freeness property, then there exists a “transition” word w over the same alphabet such that uwv is cube free. The crucial case is the

    更新日期:2020-04-21
  • Effective Categoricity of Automatic Equivalence and Nested Equivalence Structures
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-08
    Jacob Carson, Douglas Cenzer, Jeffrey B. Remmel

    We study automatic equivalence and nested equivalence structures. The goal is to compare and contrast these automatic structures with computable equivalence and nested equivalence structures. Equivalence structures \(\mathcal {A}\) may be characterized by their characters \(\chi ({\mathcal {A}})\) which encodes the number of equivalence classes of any given size. The characters of computably categorical

    更新日期:2020-04-08
  • Complexity of Fall Coloring for Restricted Graph Classes
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-08
    Juho Lauri, Christodoulos Mitillos

    We strengthen a result by Laskar and Lyle (Discrete Appl. Math. 157, 330–338 2009) by proving that it is NP-complete to decide whether a bipartite planar graph can be partitioned into three independent dominating sets. In contrast, we show that this is always possible for every maximal outerplanar graph with at least three vertices. Moreover, we extend their previous result by proving that deciding

    更新日期:2020-04-08
  • On the Fixed-Parameter Tractability of the Maximum Connectivity Improvement Problem
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-07
    Federico Corò, Gianlorenzo D’Angelo, Vahan Mkrtchyan

    In the Maximum Connectivity Improvement (MCI) problem, we are given a directed graph G = (V,E) and an integer B and we are asked to find B new edges to be added to G in order to maximize the number of connected pairs of vertices in the resulting graph. The MCI problem has been studied from the approximation point of view. In this paper, we approach it from the parameterized complexity perspective in

    更新日期:2020-04-07
  • First-Order Orbit Queries
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-04-04
    Shaull Almagor, Joël Ouaknine, James Worrell

    Orbit Problems are a class of fundamental reachability questions that arise in the analysis of discrete-time linear dynamical systems such as automata, Markov chains, recurrence sequences, and linear while loops. Instances of the problem comprise a dimension \(d\in \mathbb {N}\), a square matrix \(A\in \mathbb {Q}^{d\times d}\), and a query regarding the behaviour of some sets under repeated applications

    更新日期:2020-04-04
  • Correction to: Special Issue on Approximation and Online Algorithms
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-02-28
    Leah Epstein, Thomas Erlebach

    The original version of the article was inadvertently published with misinterpretations on author’s proof corrections on mathematical expressions.

    更新日期:2020-02-28
  • Longest Increasing Subsequence under Persistent Comparison Errors
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-02-20
    Barbara Geissmann

    We study the problem of computing a longest increasing subsequence in a sequence S of n distinct elements in the presence of persistent comparison errors. In this model, Braverman and Mossel (Noisy sorting without resampling, SODA 2008, pages 268–276, 2008) every comparison between two elements can return the wrong result with some fixed (small) probability p, and comparisons cannot be repeated. Computing

    更新日期:2020-02-20
  • Approximating Node-Weighted k -MST on Planar Graphs
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-02-03
    Jarosław Byrka, Mateusz Lewandowski, Joachim Spoerhase

    We study the problem of finding a minimum weight connected subgraph spanning at least k vertices on planar, node-weighted graphs. We give a (4 + ε)-approximation algorithm for this problem. We achieve this by utilizing the recent Lagrangian-multiplier preserving (LMP) primal-dual 3-approximation for the node-weighted prize-collecting Steiner tree problem by Byrka et al. (SWAT’16) and adopting an approach

    更新日期:2020-02-03
  • Deterministic Min-Cost Matching with Delays
    Theory Comput. Syst. (IF 0.603) Pub Date : 2020-01-06
    Yossi Azar, Amit Jacob Fanani

    We consider the online Minimum-Cost Perfect Matching with Delays (MPMD) problem introduced by Emek et al. (STOC 2016), in which a general metric space is given, and requests for points in space are submitted in different times in this space by an adversary. The goal is to match requests, while minimizing the sum of distances between matched pairs in addition to the time intervals passed from the moment

    更新日期:2020-01-06
  • Optimal Dislocation with Persistent Errors in Subquadratic Time
    Theory Comput. Syst. (IF 0.603) Pub Date : 2019-12-03
    Barbara Geissmann, Stefano Leucci, Chih-Hung Liu, Paolo Penna

    We study the problem of sorting N elements in the presence of persistent errors in comparisons: In this classical model, each comparison between two elements is wrong independently with some probability up to p, but repeating the same comparison gives always the same result. In this model, it is impossible to reliably compute a perfectly sorted permutation of the input elements. Rather, the quality

    更新日期:2019-12-03
  • Advice Complexity of Priority Algorithms
    Theory Comput. Syst. (IF 0.603) Pub Date : 2019-11-13
    Allan Borodin, Joan Boyar, Kim S. Larsen, Denis Pankratov

    The priority model of “greedy-like” algorithms was introduced by Borodin, Nielsen, and Rackoff in 2002. We augment this model by allowing priority algorithms to have access to advice, i.e., side information precomputed by an all-powerful oracle. Obtaining lower bounds in the priority model without advice can be challenging and may involve intricate adversary arguments. Since the priority model with

    更新日期:2019-11-13
  • Sitting Closer to Friends than Enemies, Revisited.
    Theory Comput. Syst. Pub Date : 2015-08-25
    Marek Cygan,Marcin Pilipczuk,Michał Pilipczuk,Jakub Onufry Wojtaszczyk

    Signed graphs, i.e., undirected graphs with edges labelled with a plus or minus sign, are commonly used to model relationships in social networks. Recently, Kermarrec and Thraves (2011) initiated the study of the problem of appropriately visualising the network: They asked whether any signed graph can be embedded into the metric space [Formula: see text] in such a manner that every vertex is closer

    更新日期:2019-11-01
  • [Formula: see text]-Approximation for Graphic TSP.
    Theory Comput. Syst. Pub Date : 2014-01-01
    Marcin Mucha

    The Travelling Salesman Problem is one of the fundamental and intensively studied problems in approximation algorithms. For more than 30 years, the best algorithm known for general metrics has been Christofides's algorithm with an approximation factor of [Formula: see text], even though the so-called Held-Karp LP relaxation of the problem is conjectured to have the integrality gap of only [Formula:

    更新日期:2019-11-01
  • Improved Distance Queries and Cycle Counting by Frobenius Normal Form.
    Theory Comput. Syst. Pub Date : null
    Piotr Sankowski,Karol Węgrzycki

    Consider an unweighted, directed graph G with the diameter D. In this paper, we introduce the framework for counting cycles and walks of given length in matrix multiplication time O ~ ( n ω ) . The framework is based on the fast decomposition into Frobenius normal form and the Hankel matrix-vector multiplication. It allows us to solve the All-Nodes Shortest Cycles, All-Pairs All Walks problems efficiently

    更新日期:2019-11-01
  • Limits of Schema Mappings.
    Theory Comput. Syst. Pub Date : null
    Phokion G Kolaitis,Reinhard Pichler,Emanuel Sallinger,Vadim Savenkov

    Schema mappings have been extensively studied in the context of data exchange and data integration, where they have turned out to be the right level of abstraction for formalizing data inter-operability tasks. Up to now and for the most part, schema mappings have been studied as static objects, in the sense that each time the focus has been on a single schema mapping of interest or, in the case of

    更新日期:2019-11-01
  • Complexity and Expressive Power of Weakly Well-Designed SPARQL.
    Theory Comput. Syst. Pub Date : null
    Mark Kaminski,Egor V Kostylev

    SPARQL is the standard query language for RDF data. The distinctive feature of SPARQL is the OPTIONAL operator, which allows for partial answers when complete answers are not available due to lack of information. However, optional matching is computationally expensive-query answering is PSPACE-complete. The well-designed fragment of SPARQL achieves much better computational properties by restricting

    更新日期:2019-11-01
  • Motivating Time-Inconsistent Agents: A Computational Approach.
    Theory Comput. Syst. Pub Date : null
    Susanne Albers,Dennis Kraft

    We study the complexity of motivating time-inconsistent agents to complete long term projects in a graph-based planning model proposed by Kleinberg and Oren (2014). Given a task graph G with n nodes, our objective is to guide an agent towards a target node t under certain budget constraints. The crux is that the agent may change its strategy over time due to its present-bias. We consider two strategies

    更新日期:2019-11-01
  • Finding Cactus Roots in Polynomial Time.
    Theory Comput. Syst. Pub Date : null
    Petr A Golovach,Dieter Kratsch,Daniël Paulusma,Anthony Stewart

    A graph H is a square root of a graph G, or equivalently, G is the square of H, if G can be obtained from H by adding an edge between any two vertices in H that are of distance 2. The Square Root problem is that of deciding whether a given graph admits a square root. The problem of testing whether a graph admits a square root which belongs to some specified graph class ℋ is called the ℋ -Square Root

    更新日期:2019-11-01
  • Designing Cost-Sharing Methods for Bayesian Games.
    Theory Comput. Syst. Pub Date : null
    George Christodoulou,Stefano Leonardi,Alkmini Sgouritsa

    We study the design of cost-sharing protocols for two fundamental resource allocation problems, the Set Cover and the Steiner Tree Problem, under environments of incomplete information (Bayesian model). Our objective is to design protocols where the worst-case Bayesian Nash equilibria have low cost, i.e. the Bayesian Price of Anarchy (PoA) is minimized. Although budget balance is a very natural requirement

    更新日期:2019-11-01
  • An Optimally-Competitive Algorithm for Maximum Online Perfect Bipartite Matching with i.i.d. Arrivals
    Theory Comput. Syst. (IF 0.603) Pub Date : 2019-09-07
    Minjun Chang, Dorit S. Hochbaum, Quico Spaen, Mark Velednitsky

    We present an optimally-competitive algorithm for the problem of maximum online perfect bipartite matching with i.i.d. arrivals. In this problem, we are given a known set of workers, a distribution over job types, and non-negative utility weights for each pair of worker and job types. At each time step, a job is drawn i.i.d. from the distribution over job types. Upon arrival, the job must be irrevocably

    更新日期:2019-09-07
  • On the Tree Conjecture for the Network Creation Game
    Theory Comput. Syst. (IF 0.603) Pub Date : 2019-08-16
    Davide Bilò, Pascal Lenzner

    Selfish Network Creation focuses on modeling real world networks from a game-theoretic point of view. One of the classic models by Fabrikant et al. (2003) is the network creation game, where agents correspond to nodes in a network which buy incident edges for the price of α per edge to minimize their total distance to all other nodes. The model is well-studied but still has intriguing open problems

    更新日期:2019-08-16
  • Additive Number Theory via Automata Theory
    Theory Comput. Syst. (IF 0.603) Pub Date : 2019-05-29
    Aayush Rajasekaran, Jeffrey Shallit, Tim Smith

    We show how some problems in additive number theory can be attacked in a novel way, using techniques from the theory of finite automata. We start by recalling the relationship between first-order logic and finite automata, and use this relationship to solve several problems involving sums of numbers defined by their base-2 and Fibonacci representations. Next, we turn to harder results. Recently, Cilleruelo

    更新日期:2019-05-29
Contents have been reproduced by permission of the publishers.
导出
全部期刊列表>>
如何通过Nature平台传播科研成果
跟Nature、Science文章学绘图
隐藏1h前已浏览文章
课题组网站
新版X-MOL期刊搜索和高级搜索功能介绍
中洪博元
ACS材料视界
x-mol收录
南开大学
朱守非
廖良生
郭东升
西湖大学
伊利诺伊大学香槟分校
徐明华
中山大学化学工程与技术学院
试剂库存
天合科研
down
wechat
bug