Now showing items 21-40 of 53

  • Fast shadowing computation in physical optics surface 

    Rius Casals, Juan Manuel; Carbo, Alex; Úbeda Farré, Eduard; Heldring, Alexander (2013)
    Conference report
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    GRECO code has been updated by replacing the graphical processing technique for computation of Physical Optics surface integral by a hybrid CPU-graphical processing approach. The resulting code needs more CPU power for ...
  • Frequency extrapolation of IE-MEI linear system Coefficients in 2D 

    Rius Casals, Juan Manuel; Heldring, Alexander; Úbeda Farré, Eduard (Institute of Electrical and Electronics Engineers (IEEE), 2017)
    Conference report
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    The Integral Equation MEI (IE-MEI) method for the sparsification of Method of Moments linear system matrix is revisited here. It achieves cpu computation time and storage memory requirements of order O(N ) (for 2D perfectly ...
  • GRECO: 30 years of graphical processing techniques for RCS computation 

    Rius Casals, Juan Manuel; Úbeda Farré, Eduard; Heldring, Alexander (2018)
    Conference report
    Open Access
    This contribution to the special session in honor of Prof. Rafael Gómez-Martín will address the 30 year development of graphical processing techniques (GRECO) for fast computation of Radar Cross Section (RCS) of ...
  • GRECO Code Rejuvenated: hybrid CPU-graphical processing 

    Rius Casals, Juan Manuel; Carbo, Alex; Úbeda Farré, Eduard; Heldring, Alexander (IEEE, 2013)
    Conference report
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    GRECO code has been updated by replacing the graphical processing technique for computation of Physical Optics surface integral by a hybrid CPU-graphical processing approach. The resulting code needs more CPU power for ...
  • Integral Equation MEI (IE-MEI) analysis of homogeneus dielectric and plasmonic media in 2D 

    Rius Casals, Juan Manuel; Planes Conangla, Gerard; Úbeda Farré, Eduard; Heldring, Alexander (2015)
    Conference report
    Open Access
    This paper revisits the IE-MEI method and proposes a new formulation for high-loss didectric piecewise-homogeneous media. The aim of this work is lo assess if the bigh localization of surface plasmon polarltons helps in ...
  • Iterative method of moments solution of problems involving electrically large and concave geometries 

    Heldring, Alexander; Rius Casals, Juan Manuel; Úbeda Farré, Eduard (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Conference report
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    This paper presents a study of the scaling with frequency (computational complexity) of preconditioned iterative solution, using the Multilevel Fast Multipole Method, of a class of radiation and scattering problems that ...
  • Multilevel adaptive cross approximation (MLACA) 

    Tamayo Palau, José María; Heldring, Alexander; Rius Casals, Juan Manuel (IEEE, 2009-06-30)
    Conference report
    Open Access
    In recent years, several methods have been developed for accelerating the iterative solution of the electromagnetic integral equations discretized by Method of Moments (MoM). Most of them are based on the compressibility ...
  • Multiscale compressed block decomposition for fast direct solution of method of moments linear system 

    Heldring, Alexander; Rius Casals, Juan Manuel; Tamayo Palau, José María; Parrón, Josep; Úbeda Farré, Eduard (2011-02)
    Article
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    The multiscale compressed block decomposition algorithm (MS-CBD) is presented for highly accelerated direct (non iterative) solution of electromagnetic scattering and radiation problems with the method of moments (MoM). ...
  • New block ILU preconditioner scheme for numerical analysis of very large electromagnetic problems 

    Heldring, Alexander; Rius Casals, Juan Manuel; Ligthart, Leo P. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2002-03-31)
    Article
    Open Access
    Large electromagnetic scattering and radiation problems are tackled by iterative solvers, which require the use of huge preconditioners. Most often, the incomplete LU decomposition (ILU) of the preconditioner is applied ...
  • New graphical processing technique for fast shadowing computation in PO surface integral 

    Rius Casals, Juan Manuel; Carbó Meseguer, Alexis; Bjerkemo, Jakob; Úbeda Farré, Eduard; Heldring, Alexander; Mallorquí Franquet, Jordi Joan; Broquetas Ibars, Antoni (2014-05-01)
    Article
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    This paper presents a new graphical processing technique for fast computation of PO surface integral. In contrast with the original graphical processing approach introduced by the authors in 1993, the new one combines a ...
  • Nonconforming discretization of the combined-field integral equation with volumetric testing 

    Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2015)
    Conference report
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    Recent attention has been devoted to the development of nonconforming method-of-moment (MoM) implementations of the Electric-Field Integral Equation (EFIE), which provide current solutions with no continuity constraints ...
  • Nonconforming discretization of the electric-field integral equation for closed perfectly conducting objects 

    Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Heldring, Alexander (2014-08-01)
    Article
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    Galerkin implementations of the method of moments (MoM) of the electric-field integral equation (EFIE) have been traditionally carried out with divergence-conforming sets. The normal-continuity constraint across edges gives ...
  • Nonconforming discretization of the Magnetic-Field Integral Equation with volumetric testing 

    Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2014)
    Conference report
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    The RWG-discretization in Method of Moments (MoM) of the Magnetic-Field and Electric-Field Integral Equations (MFIE, EFIE) show evident discrepancy in the computed RCS, especially for small objects with edges and corners. ...
  • On the accuracy of the Adaptive Cross Approximation algorithm 

    Heldring, Alexander; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (Universidad de Oviedo, 2016)
    Conference report
    Open Access
    This contribution identifies an often ignored source of uncertainty in the accuracy of the Adaptive Cross Approximation (ACA) algorithm.
  • On the accuracy of the adaptive cross aproximation algorithm 

    Heldring, Alexander; Úbeda Farré, Eduard; Sekulic, Ivan; Rius Casals, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2017)
    Conference report
    Open Access
    This contribution identifies an often ignored source of uncertainty in the accuracy of the adaptive cross approximation algorithm, and proposes a combination of adaptations that reduce this uncertainty with negligible ...
  • On the convergence of the ACA algorithm for radiation and scattering problems 

    Heldring, Alexander; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (2014-07-01)
    Article
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    The adaptive cross approximation (ACA) algorithm, when used to accelerate the numerical solution of integral equations for radiation and scattering problems, sometimes suffers from inaccuracies. These inaccuracies occur ...
  • On the degrees of freedom in the interaction between sets of elementary scatterers 

    Heldring, Alexander; Tamayo Palau, José María; Rius Casals, Juan Manuel (2009)
    Conference report
    Open Access
    A series of numerical experiments has been executed to investigate the number of degrees of freedom in the interaction between large scattering bodies. The relation between degrees of freedom and operating frequency ...
  • Preconditioning the Electric Field Integral Equation with the MS-CBD method 

    Heldring, Alexander; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (2013)
    Conference report
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    A novel preconditioning scheme for Method of Moment computations is proposed. It consists of an adapted version of an accelerated direct solution method, the Multiscale Compressed Block Decomposition. It is of particular ...
  • Regularization of the 2D TE-EFIE for homogeneous objects discretized by the Method of Moments with discontinuous basis functions 

    Sekulic, Ivan; Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Heldring, Alexander (2014)
    Conference report
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    The discretization of the Electric-Field Integral Equation (EFIE) by the Method of Moments (MoM) for a transversal electric (TE) illuminating wave impinging on an infinitely long cylinder (2D-object) is traditionally carried ...
  • Simulation of shipborne small HF antennas with RWG discretization and fast solver 

    Rius Casals, Juan Manuel; Jofre Roca, Lluís; Tamayo Palau, José María; Heldring, Alexander; Úbeda Farré, Eduard (2010)
    Conference report
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    In this paper, an alternative approach has been used to analyze an electrically small antenna (1.2m in the 2-30 MHz band) in a large ship (238m length) using a generic EFIE simulation code with Rao, Wilton and Glisson (RWG) ...