Browsing by Subject "Complexitat computacional"
Now showing items 2140 of 136

Analysis of methods for generating octree models of objects from their silhouettes
(199701)
Article
Restricted access  publisher's policyReconstructing 3D models from their projection images has been an interesting research topic in computer vision and geometric modeling. In this paper, we review several methods that generate octree models of objects from ... 
Approximate formulae for a logic that capture classes of computational complexity
(Oxford University Press, 200902)
Article
Open AccessThis paper presents a syntax of approximate formulae suited for the logic with counting quantifiers SOLP. This logic was formalised by us in [1] where, among other properties, we showed the following facts: (i) In the ... 
Augmenting the power of (partial) MaxSat resolution with extension
(AAAI Press, 2020)
Conference lecture
Restricted access  publisher's policyThe refutation power of SAT and MaxSAT resolution is challenged by problems like the soft and hard Pigeon Hole Problem PHP for which short refutations do not exist. In this paper we augment the MaxSAT resolution proof ... 
Automating resolution is NPHard
(202009)
Article
Open AccessWe show that the problem of finding a Resolution refutation that is at most polynomially longer than a shortest one is NPhard. In the parlance of proof complexity, Resolution is not automatable unless P = NP. Indeed, we ... 
Automating Resolution is NPhard
(Institute of Electrical and Electronics Engineers (IEEE), 2019)
Conference report
Open AccessWe show that the problem of finding a Resolution refutation that is at most polynomially longer than a shortest one is NPhard. In the parlance of proof complexity, Resolution is not automatizable unless P = NP. Indeed, ... 
Average complexity of algorithms on trees
(1985)
External research report
Open AccessIn this work we count the number of structures resulting from the application of different kinds of structure modifying algorithms on binary trees 
Averagecase analysis of equality of binary trees under the BST probability model
(199103)
External research report
Open AccessIn this paper a simple algorithm to test equality of binary trees currently used in symbolic computation, unification, etc. is investigated. Surprisingly enough, it takes 0(1) steps on average to decide if a given pair of ... 
Best response computation: efficient algorithm to compute the best response for strategic network formation with attack and immunization
(Universitat Politècnica de Catalunya, 20210525)
Bachelor thesis
Open AccessEn aquest projecte, ens centrem en investigar el model de Network Creation Games with attack and immunization introduït per Goyal et al.. Freqüentment, el cost computacional de computar una Best Response o de comprovar si ... 
Bounded queries to arbitrary sets
(199109)
External research report
Open AccessWe prove that if P superA[k] = P superA[k+1] for some k and an arbitrary set A, then A is reducible to its complement under a relativized nondeterministic conjunctive reduction. This result shows the first known property ... 
Boundedwidth QBF is PSPACEcomplete
(Schloss Dagstuhl  LeibnizZentrum für Informatik, 2013)
Conference report
Open AccessTreewidth is a wellstudied parameter of structures that measures their similarity to a tree. Many important NPcomplete problems, such as Boolean satisﬁability (SAT), are tractable on bounded treewidth instances. In ... 
Boundedwidth QBF is PSPACEcomplete
(20141101)
Article
Open AccessTreewidth and pathwidth are two wellstudied parameters of structures that measure their similarity to a tree and a path, respectively. We show that QBF on instances with constant pathwidth, and hence constant treewidth, ... 
Celebrity games
(20161004)
Article
Open AccessWe introduce Celebrity games, a new model of network creation games. In this model players have weights (W being the sum of all the player's weights) and there is a critical distance ß as well as a link cost a. The cost ... 
Circular (yet sound) proofs
(Springer, 2019)
Conference report
Open AccessWe introduce a new way of composing proofs in rulebased proof systems that generalizes treelike and daglike proofs. In the new definition, proofs are directed graphs of derived formulas, in which cycles are allowed as ... 
Clique is hard on average for regular resolution
(Association for Computing Machinery (ACM), 2018)
Conference report
Open AccessWe prove that for k ≪4√n regular resolution requires length nΩ(k) to establish that an Erdős–Rényi graph with appropriately chosen edge density does not contain a kclique. This lower bound is optimal up to the multiplicative ... 
Complexity in safetycritical systems
(20121003)
Article
Open Access 
Complexity measures for resolution
(Universitat Politècnica de Catalunya, 20031215)
Doctoral thesis
Open AccessEsta obra es una contribución al campo de la Complejidad de la Demostración, que estudia la complejidad de los sistemas de demostración en términos de los recursos necesarios para demostrar o refutar fórmulas proposicionales. ... 
Computational complexity of small descriptions
(19901119)
External research report
Open AccessFor a set L that is polynomial time reducible (in short, = sub T super Preducible) to some sparse set, we investigate the computational complexity of such sparse sets relative to L. We construct sets A and B such that ... 
Connections among non uniform models for problems requiring high amount of resources
(198511)
External research report
Open AccessWe characterize in terms of oracle Turing machines the classes defined by exponential lower bounds on some nonuniform complexity measures. After, we use the same methods to give a new characterization of classes defined ... 
Constanttime approximate sliding window framework with error control
(Institute of Electrical and Electronics Engineers (IEEE), 2019)
Conference report
Open AccessStream Processing is a crucial element for the Edge Computing paradigm, in which large amount of devices generate data at the edge of the network. This data needs to be aggregated and processed onthemove across different ... 
Cooperation through social influence
(Elsevier, 20150501)
Article
Open AccessWe consider a simple and altruistic multiagent system in which the agents are eager to perform a collective task but where their real engagement depends on the willingness to perform the task of other influential agents. ...