Now showing items 1-20 of 183

  • A comparative study of two compact finite difference methods: standard vs. mimetic 

    Córdova, Luis Joaquin; Rojas, Otilio; Otero Calviño, Beatriz; Castillo, José (Sociedad Venezolana de Métodos Numéricos en Ingeniería, 2014)
    Conference report
    Restricted access - publisher's policy
    In this work, we implement two fourth-order compact finite differences (CFD) methods and use them to model wave propagation on a elastic string. The formulation of the first method employs the standard implicit CFD constructed ...
  • A direct elimination algorithm for quasi-static and dynamic contact problems 

    Capua, Daniel di; Agelet de Saracibar Bosch, Carlos (2015-01-01)
    Article
    Open Access
    This paper deals with the computational modeling and numerical simulation of contact problems at Unite deformations using the Finite element method. Quasi-static and dynamic problems are considered and two particular ...
  • A flux-free a posteriori error estimator for the incompressible Stokes problem using a mixed FE formulation 

    Larsson, Fredrik; Díez, Pedro; Huerta, Antonio (2010-08-01)
    Article
    Open Access
    In this contribution, we present an a posteriori error estimator for the incompressible Stokes problem valid for a conventional mixed FE formulation. Due to the saddle-point property of the problem, conventional error ...
  • A meshless finite point method for three-dimensional analysis of compressible flow problems involving moving boundaries and adaptivity 

    Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Flores Le Roux, Roberto Maurice (2013-10)
    Article
    Open Access
    A finite point method for solving compressible flow problems involving moving boundaries and adaptivity is presented. The numerical methodology is based on an upwind-biased discretization of the Euler equations, written ...
  • A multi-mesh adaptive scheme for air quality modeling with the finite element method 

    Monforte, Lluis; Pérez Foguet, Agustí (2012)
    Conference report
    Open Access
    A multi-mesh adaptive scheme for convection-diffusion-reaction problems is presented. The proposal is applied to air quality modeling, especifically to the simulation of a pollutant punctual emissions. The performance ...
  • A new adaptive method for image compression using Karhunen-Loeve transform 

    Torres Urgell, Lluís (Institute of Electrical and Electronics Engineers (IEEE), 1987)
    Conference report
    Open Access
    The Karhunen-Loeve transformation (KLT) is an optimal method for encoding images in the MSE sense. Only one spatially adaptive method is known to be reported in the literature. Many other suboptimal encoding methods have ...
  • A new approach for Delphi processes based on group consensus with linguistic terms 

    Agell Jané, Núria; van Ganzewinkel,, Christ Jan; Sánchez Soler, Monica; Roselló Saurí, Llorenç; Prats Duaygues, Francesc; Andriessen, Peter (Institute of Electrical and Electronics Engineers (IEEE), 2014)
    Conference lecture
    Restricted access - publisher's policy
    A new approach for Delphi processes including a measure of consensus based on linguistic terms is introduced in this paper. The measure of consensus involves qualitative reasoning techniques and is based on the concept ...
  • A note on the convergence of the secant method for simple and multiple roots 

    Díez, Pedro (Elsevier, 2003-11)
    Article
    Open Access
    The secant method is one of the most popular methods for root finding. Standard text books in numerical analysis state that the secant method is super linear: the rate of convergence is set by the gold number. Never- theless, ...
  • A numerical simulation of fluid-structure interaction for flow through valves of a hermetic compressor with immersed boundary method 

    Mushyam, Aditya; Bergadà Granyó, Josep Maria (2012)
    Conference report
    Restricted access - publisher's policy
  • A recovery-explicit error estimator in energy norm for linear elasticity 

    Nadal, E.; Díez, Pedro; Ródenas García, Juan José; Tur, M; Fuenmayor, F. J. (2015-04-15)
    Article
    Restricted access - publisher's policy
    Significant research effort has been devoted to produce one-sided error estimates for Finite Element Analyses, in particular to provide upper bounds of the actual error. Typically, this has been achieved using residual-type ...
  • A review of Beliche Dam 

    Alonso Pérez de Agreda, Eduardo; Olivella Pastallé, Sebastià; Pinyol Puigmartí, Núria Mercè (Institution of Civil Engineers (http://www.ice.org.uk/), 2005)
    Article
    Open Access
    Beliche Dam, a zoned earthdam with rockfill shouldersand a central clay core, experienced large collapse settlements due to reservoir impounding and direct action of rainfall. Long-term field records of vertical and ...
  • A technique to composite a modified Newton's method for solving nonlinear equations 

    Grau Sánchez, Miguel; Díaz Barrero, José Luis (2011-05-02)
    External research report
    Open Access
    A zero-finding technique for solving nonlinear equations more efficiently than they usually are with traditional iterative methods in which the order of convergence is improved is presented. The key idea in deriving this ...
  • A variational inequality reformulation of a congested transit assignment model by Cominetti, Correa, Cepeda, and Florian 

    Codina Sancho, Esteve (2012-08-02)
    Article
    Open Access
    In the paper by Cominetti and Correa (2001) [Common-lines and passenger assignment in congested transit networks. Transportation Science 35 (3), pp 250-267], an extension to the common-lines problem for general multidestination ...
  • Accurate recovery-based upper error bounds for the extended finite element framework 

    Ródenas García, Juan José; González Estrada, O. A.; Díez, Pedro; Fuenmayor, F. J. (2010-08-01)
    Article
    Open Access
    This paper introduces a recovery-type error estimator yielding upper bounds of the error in energy norm for linear elastic fracture mechanics problems solved using the extended finite element method (XFEM). The paper can ...
  • Advanced composite material simulation 

    Oller Martínez, Sergio Horacio; Martínez, X; Barbat Barbat, Horia Alejandro; Rastellini, F (2008-01)
    Article
    Open Access
    A computational methodology is presented for modeling the non-linear mechanical behavior of composite structures made of FRP (Fiber-Reinforced Polymers) laminates. The model is based on the appropriate combination of the ...
  • Advanced harmonic techniques for solving the transient heat equation 

    Aguado, José Vicente; Huerta, Antonio; Chinesta, Francisco; Cueto Prendes, Elias; Leygue, Adrien (Sociedad Española de Métodos Numéricos en Ingeniería (SEMNI), 2013)
    Conference report
    Restricted access - publisher's policy
    Simulation-based management of processes has always been a big challenge because of the difficulty to merge two apparently opposed idea s: the real time handling demanded by the process, and the traditionally strong ...
  • Algorithm 942: Semi-Stencil 

    de la Cruz, Raúl; Araya-Polo, Mauricio (ACM Digital Library, 2014-04-01)
    Article
    Open Access
    Finite Difference (FD) is a widely used method to solve Partial Differential Equations (PDE). PDEs are the core of many simulations in different scientific fields, such as geophysics, astrophysics, etc. The typical FD ...
  • An approximate expression to estimate signal-to-noise improvement in cylindrical near-field measurements 

    Romeu Robert, Jordi; Jofre Roca, Lluís; Cardama Aznar, Ángel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1994-07-01)
    Article
    Open Access
    A very simple approximate expression for the process gain (PG) for the cylindrical case is derived. The different approximations and assumptions required to obtain this expression are shown. This expression might be useful ...
  • An involution on bicubic maps and beta(0,1)-trees 

    Claesson, Anders; Kitaev, Sergey; Mier Vinué, Anna de (2015)
    Article
    Open Access
    Bicubic maps are in bijection with (0 ; 1)-trees. We introduce two new ways of decomposing (0 ; 1)-trees. Using this we de ne an endofunc- tion on (0 ; 1)-trees, and thus also on bicubic maps. We show that ...
  • Analysing visual receptive fields through generalised additive models with interactions 

    Rodríguez Álvarez, María Xosé; Cadarso-Suárez, Carmen; González, Francisco (Institut d'Estadística de Catalunya, 2012)
    Article
    Open Access
    Visual receptive fields (RFs) are small areas of the visual fie ld where a stimulus induces a re- sponses of a particular neuron from the visual system. RFs ca n be mapped using reverse cross- correlation technique, ...