scispace - formally typeset
Search or ask a question

Showing papers in "Theoretical Computer Science in 2011"


Journal ArticleDOI
TL;DR: This paper builds upon recent results, that show that NP-complete problems that are 'or-compositional' do not have polynomial kernels, unless NP@?coNP/poly, by adding a notion of transformation.

269 citations



Journal ArticleDOI
TL;DR: In this article, the authors consider the problem of continuous-armed bandit and show that the simple regret of a bandit forecaster can be minimized with respect to a family of probability distributions if and only if the cumulative regret can be minimised for it.

230 citations


Journal ArticleDOI
TL;DR: It is demonstrated that a host of reconfiguration problems derived from NP-complete problems are PSPACE-complete, while some are also NP-hard to approximate.

213 citations


Journal ArticleDOI
TL;DR: A model for online computation in which the online algorithm receives, together with each request, some information regarding the future, referred to as advice, and its applicability is illustrated by considering two of the most extensively studied online problems, namely, metrical task systems (MTS) and the k-server problem.

162 citations


Journal ArticleDOI
TL;DR: It is proved that, in these networks, the standard PUSH-PULL strategy delivers the message to all nodes within O(log^2n) rounds with high probability; and by themselves, PUSH and PULL require polynomially many rounds.

146 citations


Journal ArticleDOI
TL;DR: The proposed reduction method is illustrated by its application to a multi-valued model of the fly segment polarity network, which is involved in the control of segmentation during early embryogenesis.

145 citations


Journal ArticleDOI
TL;DR: A hardness result for irr"f(G) is proved where f(v)=2 for every [email protected]?V(G), and a general reduction principle is described, which leads to efficient algorithms for graphs with simply structured blocks such as trees and chordal graphs.

141 citations


Journal ArticleDOI
TL;DR: Three design strategies for constructing new geometric transformations on quantum images from other transformations are proposed, providing high level tools to explore and analyze transformations which are necessary to build practical image processing applications on quantum computers.

126 citations


Journal ArticleDOI
TL;DR: This paper proposes a (4 +@e)-approximation algorithm for an MWDS based on a dynamic programming algorithm for a Min-Weight Chromatic Disk Cover and shows a polynomial-time approximation scheme for a Node-Weighted Steiner Tree problem when the given terminal set is c-local.

125 citations


Journal ArticleDOI
Bartek Klin1
TL;DR: This paper aims to introduce the reader to the basics of bialgebras for operational semantics, and to sketch the state of the art in this research area.

Journal ArticleDOI
TL;DR: This paper proposes an NN algorithm that uses the lower and upper approximations from fuzzy-rough set theory in order to classify test objects, or predict their decision value, and shows that it outperforms other NN approaches and is competitive with leading classification and prediction methods.

Journal ArticleDOI
TL;DR: It is shown that popular mixed matchings always exist and polynomial time algorithms for finding them are designed and they are studied to give tight bounds on the price of anarchy and price of stability of the popular matching problem.

Journal ArticleDOI
TL;DR: A proof is presented that proves Dejean's conjecture that the repetition threshold for a k-letter alphabet is kk-1 when k>=5 and Ochem's stronger version of the conjecture for 9@?k@?38.

Journal ArticleDOI
TL;DR: It is shown for any graph that its boolean-width is at most its clique-width and at most quadratic in its rank-width, and it is shown that Boolean- width is bounded on the same classes of graphs as cliques-width.

Journal ArticleDOI
TL;DR: The findings reveal a surprisingly sharp threshold behaviour for certain graphs, e.g., the d-dimensional torus with d>2 and hypercubes: there is a value T such that the speed-up is approximately min{T,k} for any 1=2, and the bounds are tight up to logarithmic factors.

Journal ArticleDOI
TL;DR: This work compares the fixed parameter complexity of various variants of coloring problems when parameterized by treewidth and by vertex cover number and concludes that parametrization by the vertex covernumber provides a significant drop in the complexity of the problems.

Journal ArticleDOI
TL;DR: The main feature of the extended model is to allow the edges of the interaction graph to have states that belong to a constant-size set, which allows the protocol rules for pairwise interactions to modify the corresponding edge state.

Journal ArticleDOI
TL;DR: It is proved that PIDS is APX-hard and a greedy algorithm with an approximation ratio of H(@d) is proposed where H is the harmonic function and @d is the maximum vertex degree of the graph representing a social network.

Journal ArticleDOI
TL;DR: It is proved that the shortest reconfiguration sequence can be exponential in the size of the graph and that it is NP-hard to compute the shortest recursion sequence even when the authors know that the sequence has polynomial length.

Journal ArticleDOI
TL;DR: Geometry of Interaction is a transcendental syntax developed in the framework of operator algebras that provides a built-in interpretation of cut-elimination as well as an explanation for light, i.e., complexity sensitive, logics.

Journal ArticleDOI
TL;DR: This work presents an exact algorithm with a running time of O^*(1.5171^n) on a graph with n vertices and provides a polynomial time randomized approximation algorithm with an expected approximation ratio of 2311 for the minimum 3-path vertex cover.

Journal ArticleDOI
TL;DR: By combining the quasi-interpretation method with termination tools (here term orderings), the authors obtained several characterizations of complexity classes starting from Ptime and Pspace.

Journal ArticleDOI
TL;DR: This paper presents a branching algorithm whose running time has been analyzed using the Measure-and-Conquer technique and provides a lower bound of ?

Journal ArticleDOI
TL;DR: It is proved that the corresponding “place version” of all the boundedness problems is undecidable for ν -PN, an extension of P/T nets with pure name creation and name management.

Journal ArticleDOI
TL;DR: It is argued that coalgebras unify the semantics of a large range of different modal logics (such as probabilistic, graded, relational, conditional) and discuss unifying approaches to reasoning at this level of generality.

Journal ArticleDOI
TL;DR: It is interesting to note that, for different reasons, for both discrete and continuous probabilistic systems it may be more convenient to work with behavioral equivalence than with bisimilarity.

Journal ArticleDOI
TL;DR: This paper first shows that the VCP"n problem is NP-hard for any integer n>=2, then restricts its attention to the V CP"3 problem and gives a 2-approximation algorithm using the primal-dual method.

Journal ArticleDOI
TL;DR: It is proved that if a set X@?Z^2 weakly self-assembles at temperature 1 in a deterministic (Winfree) tile assembly system satisfying a natural condition known as pumpability, then X is a semilinear set, which shows that only the most simple of infinite shapes and patterns can be constructed using pumpable temperature 1 tile assembly systems.

Journal ArticleDOI
TL;DR: This article defines a continuous degree of satisfaction of temporal logic formulae with constraints and shows how such a satisfaction measure can be used as a fitness function with state-of-the-art evolutionary optimization methods in order to find biochemical kinetic parameter values satisfying a set of biological properties formalized in temporal logic.