Recent Submissions

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    An application of the Shapley value to the analysis of co-expression networks  [Article]

    Cesari, Giulia; Algaba Durán, Encarnación; Moretti, Stefano; Nepomuceno Chamorro, Juan Antonio (Springer Nature, 2018-08-24)
    We study the problem of identifying relevant genes in a co-expression network using a (cooperative) game theoretic approach. The Shapley value of a cooperative game is used to asses the relevance of each gene in interaction ...
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    On finding widest empty curved corridors  [Article]

    Bereg, Sergey; Díaz Báñez, José Miguel; Seara Ojea, Carlos; Ventura Molina, Inmaculada (Elsevier, 2007)
    An α-siphon of width w is the locus of points in the plane that are at the same distance w from a 1-corner polygonal chain C such that α is the interior angle of C. Given a set P of n points in the plane and a fixed angle ...
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    The class cover problem with boxes  [Article]

    Bereg, Sergey; Cabello, S.; Díaz Báñez, José Miguel; Pérez Lantero, Pablo; Seara Ojea, Carlos; Ventura Molina, Inmaculada (Elsevier, 2012)
    In this paper we study the following problem: Given sets R and B of r red and b blue points respectively in the plane, find a minimum-cardinality set H of axis-aligned rectangles (boxes) so that every point in B is covered ...
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    Fitting a two-joint orthogonal chain to a point set  [Article]

    Díaz Báñez, José Miguel; Amaro López, M. A.; Mora, M.; Seara Ojea, Carlos; Ventura Molina, Inmaculada (Elsevier, 2010)
    We study the problem of fitting a two-joint orthogonal polygonal chain to a set S of n points in the plane, where the objective function is to minimize the maximum orthogonal distance from S to the chain. We show that ...
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    Covering point sets with two disjoint disks or squares  [Article]

    Cabello, Sergio; Díaz Báñez, José Miguel; Seara Ojea, Carlos; Sellarés, J. Antoni; Urrutia, Jorge; Ventura Molina, Inmaculada (Elsevier, 2007)
    We study the following problem: Given a set of red points and a set of blue points on the plane, find two unit disks CR and CB with disjoint interiors such that the number of red points covered by CR plus the number of ...
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    Node aggregation for enhancing PageRank  [Article]

    Maestre Torreblanca, José María; Ishii, Hideaki; Algaba Durán, Encarnación (IEEE-Institute of Electrical and Electronics Engineers, 2017)
    In this paper, we study the problem of node aggregation under different perspectives for increasing PageRank of some nodes of interest. PageRank is one of the parameters used by the search engine Google to determine the ...
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    Non-hyperbolic boundary equilibrium bifurcations in planar Filippov systems: a case study approach  [Article]

    Di Bernardo, Mario; Pagano, Daniel Juan; Ponce Núñez, Enrique (WorldScientific Open Access, 2008)
    Boundary equilibrium bifurcations in piecewise smooth discontinuous systems are characterized by the collision of an equi- librium point with the discontinuity surface. Generically, these bi- furcations are of codimension ...
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    On the existence and uniqueness of limit cycles in Liénard differential equations allowing discontinuities  [Article]

    Llibre Saló, Jaume; Ponce Núñez, Enrique; Torres Peral, Francisco (IOP Science, 2008)
    In this paper we study the non-existence and the uniqueness of limit cycles for the Liénard differential equation of the form x'' − f(x)x' + g(x) = 0 where the functions f and g satisfy xf(x) > 0 and xg(x) > 0 for x ≠ 0 ...
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    Hopf bifurcation from infinity for planar control systems  [Article]

    Llibre Saló, Jaume; Ponce Núñez, Enrique (Universidad Autónoma de Barcelona. Departamento de Matemáticas, 1997)
    Symmetric piecewise linear bi-dimensional systems are very common in control engineering. They constitute a class of non-differentiable vector fields for which classical Hopf bifurcation theorems are not applicable. For ...
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    On the Takens-Bogdanov Bifurcation in the Chua’s Equation  [Article]

    Algaba Durán, Antonio; Freire Macías, Emilio; Gamero Gutiérrez, Estanislao; Rodriguez Luis, Alejandro José (Institute of Electronics, Information and Communication Engineers, 1999)
    The analysis of the Takens-Bogdanov bifurcation of the equilibrium at the origin in the Chua’s equation with a cubic nonlinearity is carried out. The local analysis provides, in first approximation, different bifurcation ...
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    Canards, Folded Nodes, and Mixed-Mode Oscillations in Piecewise-Linear Slow-Fast Systems  [Article]

    Desroches, Mathieu; Guillamon, Antoni; Ponce Núñez, Enrique; Prohens, Rafael; Rodrigues, Serafim; Teruel Aguilar, Antonio Esteban (Society for Industrial and Applied Mathematics, 2016)
    Canard-induced phenomena have been extensively studied in the last three decades, from both the mathematical and the application viewpoints. Canards in slow-fast systems with (at least) two slow variables, especially ...
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    Stabilization of Galerkin Finite Element Approximations to Transient Convection-Diffusion Problems  [Article]

    Frutos, Javier de; García Archilla, Juan Bosco; Novo, Julia (Society for Industrial and Applied Mathematics, 2010)
    A postprocessing technique to improve Galerkin finite element approximations to linear evolutionary convection-reaction-diffusion equations is considered. A steady convection-reactiondiffusion problem with data based on ...
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    A Value for Games Restricted by Augmenting Systems  [Article]

    Algaba Durán, Encarnación; Bilbao Arrese, Jesús Mario; Slikker, M. (Society for Industrial and Applied Mathematics, 2010)
    This paper deals with cooperative games in which only certain coalitions are allowed to form. There have been previous models developed to confront the problem of nonfeasible coalitions. Games restricted by a communication ...
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    The Postprocessed Mixed Finite-Element Method for the Navier--Stokes Equations  [Article]

    Ayuso, Blanca; García Archilla, Juan Bosco; Novo, Julia (Society for Industrial and Applied Mathematics, 2005)
    A postprocessing technique for mixed finite-element methods for the incompressible Navier–Stokes equations is studied. The technique was earlier developed for spectral and standard finite-element methods for dissipative ...
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    The Focus-Center-Limit Cycle Bifurcation in Symmetric 3D Piecewise Linear Systems  [Article]

    Freire Macías, Emilio; Ponce Núñez, Enrique; Ros Padilla, Francisco Javier (Society for Industrial and Applied Mathematics, 2005)
    The birth of limit cycles in 3D (three-dimensional) piecewise linear systems for the relevant case of symmetrical oscillators is considered. A technique already used by the authors in planar systems is extended to cope ...
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    The Postprocessed Mixed Finite-Element Method for the Navier–Stokes Equations: Refined Error Bounds  [Article]

    Frutos, Javier de; García Archilla, Juan Bosco; Novo, Julia (Society for Industrial and Applied Mathematics, 2007)
    A postprocessing technique for mixed finite-element methods for the incompressible Navier–Stokes equations is analyzed. The postprocess, which amounts to solving a (linear) Stokes problem, is shown to increase the order ...
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    Postprocessing finite-element methods for the Navier–Stokes Equations: the Fully discrete case  [Article]

    Frutos, Javier de; García Archilla, Juan Bosco; Novo, Julia (Society for Industrial and Applied Mathematics, 2008)
    An accuracy-enhancing postprocessing technique for finite-element discretizations of the Navier–Stokes equations is analyzed. The technique had been previously analyzed only for semidiscretizations, and fully discrete ...
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    Bifurcation behavior of a superlattice model  [Article]

    Moscoso, M.; Galán Vioque, Jorge Francisco; Bonilla, L. L. (Society for Industrial and Applied Mathematics, 2006)
    We present a complete description of the stationary and dynamical behavior of semiconductor superlattices in the framework of a discrete drift model by means of numerical continuation, singular perturbation analysis, and ...
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    Postprocessing the Galerkin method: the finite-element case  [Article]

    García Archilla, Juan Bosco; Titi, Edriss S. (Society for Industrial and Applied Mathematics, 2006)
    A postprocessing technique, developed earlier for spectral methods, is extended here to Galerkin nite-element methods for dissipative evolution partial di erential equations. The postprocessing amounts to solving a ...
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    On Pták's generalization of Hankel operators  [Article]

    Hernández Mancera, Carmen; Paúl Escolano, Pedro José (Springer, 2001)
    In 1997 Pták defined generalized Hankel operators as follows: Given two contractions T1 ∈ B(H1) and T2 ∈ B(H2), an operator X: H1 → H2 is said to be a generalized Hankel operator if T2X = XT ∗ 1 and X satisfies a ...

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