Now showing items 1-20 of 67

    • A framework for polynomial time query learnability 

      Watanabe, Osamu (1990)
      External research report
      Open Access
    • A new subdivision algorithm for the flow propagation using polynomial algebras 

      Pérez Palau, Daniel; Gómez Muntané, Gerard; Masdemont Soler, Josep (2018-08-01)
      Article
      Open Access
      The Jet Transport method has emerged as a powerful tool for the numerical integration of ordinary differential equations; it uses polynomial expansions to approximate the flow map associated to the differential equation ...
    • A polynomial bound for untangling geometric planar graphs 

      Bose, Prosenjit; Dujmovic, Vida; Hurtado Díaz, Fernando Alfredo; Langerman, Stefan; Morin, Pat; Wood, David (2009-12)
      Article
      Open Access
      To untangle a geometric graph means to move some of the vertices so that the resulting geometric graph has no crossings. Pach and Tardos (Discrete Comput. Geom. 28(4): 585–592, 2002) asked if every n-vertex geometric planar ...
    • A polynomial-time algorithm for the Lambek calculus with brackets of bounded order 

      Kanovich, Max; Kuznetsov, Stepan; Morrill, Glyn; Scedrov, Andre (Dagstuhl Publishing, 2017)
      Conference report
      Open Access
      Lambek calculus is a logical foundation of categorial grammar, a linguistic paradigm of grammar as logic and parsing as deduction. Pentus (2010) gave a polynomial-time algorithm for determining provability of bounded depth ...
    • A simple proof of the spectral excess theorem for distance-regular graphs 

      Fiol Mora, Miquel Àngel; Gago Álvarez, Silvia; Garriga Valle, Ernest (Elsevier, 2010-04-15)
      Article
      Restricted access - publisher's policy
      The spectral excess theorem provides a quasi-spectral characterization for a (regular) graph Γ with d+1 distinct eigenvalues to be distance-regular graph, in terms of the excess (number of vertices at distance d) of each ...
    • A solution to the tennis ball problem 

      Mier Vinué, Anna de; Noy Serrano, Marcos (2005)
      Article
      Open Access
      We present a complete solution to the so-called tennis ball problem, which is equivalent to counting the number of lattice paths in the plane that use North and East steps and lie between certain boundaries. The solution ...
    • A unified position analysis of the Dixon and the generalized Peaucellier linkages 

      Rojas Libreros, Nicolás Enrique; Dollar, Aaron M.; Thomas, Federico (2015-12-01)
      Article
      Open Access
      This paper shows how, using elementary Distance Geometry, a closure polynomial of degree 8 for the Dixon linkage can be derived without any trigonometric substitution, variable elimination, or artifice to collapse mirror ...
    • An alternative procedure to obtain the mortality rate with non-linear functions: Application to the case of the Spanish population 

      Postigo Boix, Marcos; Agüero Calvo, Ramón; Melus Moreno, José Luis (Public Library of Science (PLOS), 2019-10-15)
      Article
      Open Access
      This paper presents an alternative calculation procedure to calculate the mortality rate, exploiting the data available in the Eurostat demography database for Spain. This methodology has been devised based on two of the ...
    • Annuli for the zeros of a polynomial 

      Díaz Barrero, José Luis (2014-10)
      Article
      Restricted access - publisher's policy
    • Approximate results for rainbow labelings 

      Lladó Sánchez, Ana M.; Miller, Mirka (2017-03)
      Article
      Open Access
      A simple graph G=(V,E) is said to be antimagic if there exists a bijection f:E¿[1,|E|] such that the sum of the values of f on edges incident to a vertex takes different values on distinct vertices. The graph G is distance ...
    • Automating Resolution is NP-hard 

      Atserias, Albert; Muller, Moritz Martin (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Conference report
      Open Access
      We show that the problem of finding a Resolution refutation that is at most polynomially longer than a shortest one is NP-hard. In the parlance of proof complexity, Resolution is not automatizable unless P = NP. Indeed, ...
    • Basis expansions and roots of Ehrhart polynomials 

      Pfeifle, Julián; Beck, Matthias; Loera, Jesús de; Develin, Mike; Richard, Stanley (2004)
      Article
      Open Access
    • Boolean decomposition using two-literal divisors 

      Modi, Nilesh A.; Cortadella, Jordi (Institute of Electrical and Electronics Engineers (IEEE), 2004)
      Conference report
      Open Access
      This paper is an attempt to answer the following question: how much improvement can be obtained in logic decomposition by using Boolean divisors? Traditionally, the existence of too many Boolean divisors has been the main ...
    • Boundary value problems for Schrödinger operators on a path 

      Carmona Mejías, Ángeles; Encinas Bachiller, Andrés Marcos; Gago Álvarez, Silvia (2012-05-25)
      External research report
      Open Access
      In this work, we concentrate on determining explicit expressions, via suitable orthogonal polynomials on the line, for the Green function associated with any regular boundary value problem on a weighted path, whose weights ...
    • Capturing points with a rotating polygon (and a 3D extension) 

      Alegría Galicia, Carlos; Orden, David; Palios, Leonidas; Seara Ojea, Carlos; Urrutia Galicia, Jorge (2019-04)
      Article
      Open Access
      We study the problem of rotating a simple polygon to contain the maximum number of elements from a given point set in the plane. We consider variations of this problem where the rotation center is a given point or lies on ...
    • Channel estimation for transform modulations in mobile communications 

      Lamarca Orozco, M. Meritxell; Vázquez Grau, Gregorio (1996)
      Conference report
      Open Access
      This paper deals with data-aided channel estimation in systems using OFDM modulation. We formulate a pilot symbol-based channel estimator and compare it with the pilot-tone one proposed in [1]. Although this paper focuses ...
    • Characterizing tractability by tissue-like P-systems 

      Rius Font, Miquel; Gutiérrez Escudero, Rosa; Pérez Jiménez, Mario J. (Springer, 2010)
      Part of book or chapter of book
      Restricted access - publisher's policy
      In the framework of recognizer cell–like membrane systems it is well known that the construction of exponential number of objects in polynomial time is not enough to efficiently solve NP–complete problems. Nonetheless, ...
    • Classes of bounded nondeterminism 

      Díaz Cort, Josep; Torán Romero, Jacobo (1988)
      External research report
      Open Access
      We study certain language classes located between P and N P that are defined by polynomial time machines with a bounded amount of nondeterminism. We observe that these classes have complete problems and find a characterization ...
    • Comparison of B-spline and Zernike fitting techniques in complex wavefront surfaces 

      Ares Rodríguez, Miguel; Royo Royo, Santiago; Caum Aregay, Jesús; Pizarro Bondia, Carlos (Proc.SPIE Press, 2005-06-13)
      Article
      Open Access
    • Darboux integrals for Schrödinger planar vector fields via Darboux transformations 

      Acosta Humánez, Primitivo Belén; Pantazi, Chara (2012-07-14)
      Article
      Open Access
      In this paper we study the Darboux transformations of planar vector fields of Schr odinger type. Using the isogaloisian property of Darboux transformation we prove the \invariance" of the objects of the \Darboux theory ...