Exploració per tema "Integral equations"

Ara es mostren els items 1-20 de 60

    • A general electromagnetic simulation tool to predict the microwave nonlinear response of planar, arbitrarily-shaped HTS structures 

      Parrón Granados, Josep; Collado Gómez, Juan Carlos; Mateu Mateu, Jordi; Rius Casals, Juan Manuel; Duffo Ubeda, Núria; O'Callaghan Castellà, Juan Manuel (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2001-03-31)
      Article
      Accés obert
      This work describes a simulation tool being developed at UPC to predict the microwave nonlinear behavior of planar superconducting structures with very few restrictions on the geometry of the planar layout. The software ...

    • A hybrid modal-boundary element method for electromagnetic scattering from arbitrary conducting wedges 

      Cruellas Ibarz, Juan Carlos; Ferrando Bataller, Miquel (Institute of Electrical and Electronics Engineers (IEEE), 1990)
      Text en actes de congrés
      Accés obert
      A hybrid technique is used to determine the electromagnetic scattering contribution of arbitrary conducting wedges in electrically large objects. The boundary integral equation is discretized in a fictitious contour, and ...

    • Adapted ACA algorithm with improved efficiency and compression rate 

      Heldring, Alexander; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (2015)
      Text en actes de congrés
      Accés obert
      This contribution proposes an adapted version of the popular Adaptive Cross Approximation algorithm for block wise compression of Method of Moments impedance matrices. The estimation of the matrix block ...

    • AIterative algorithm for microwave imaging using the cgm-fft and the pseudoinverse method 

      Mallorquí Franquet, Jordi Joan; Llorens, V (Institute of Electrical and Electronics Engineers (IEEE), 1994)
      Text en actes de congrés
      Accés obert
      Within biomedical microwave tomography, a spatial iterative method for the reconstruction of the complex permittivity of inhomogeneous lossy dielectric objects with arbitrary shape from their scattered electric field is ...

    • Analysis of microstrip antennas by multilevel matrix decomposition algorithm 

      Parrón Granados, Josep; Rius Casals, Juan Manuel; Heldring, Alexander; Úbeda Farré, Eduard; Mosig, Juan R (ESA, 1999)
      Text en actes de congrés
      Accés obert
      Integral equation methods (IE) are widely used in conjunction with Method of Moments (MoM) discretization for the numerical analysis of microstrip antennas. However, their application to large antenna arrays is difficult ...

    • Application of the boundary elements method to 3-d radiation problem 

      Abad, J.; Duffo Ubeda, Núria; Rius Casals, Juan Manuel; Cruellas Ibarz, Juan Carlos (. REED EXHIBITION COMPANIES, 1993)
      Text en actes de congrés
      Accés obert
      In order to analyze the electromagnetic fields generated by perfectly conducting bodies composed by interconnected wires and solid objects, whichever its geometry, the Boundary Element Method is applied. The basic formulation ...

    • Application of the multilevel decomposition algorithm to the frequency analysis of large microstrip antenna arrays 

      Parrón Granados, Josep; Rius Casals, Juan Manuel; Mosig, Juan R. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2002-03-31)
      Article
      Accés obert
      The application of integral equation methods based in the method of moments discretization to solve large antenna arrays is difficult due to the fact that the computational requirements increase rapidly with the number ...

    • Discretization of the EFIE in Method of Moments without continuity of the normal current component across edges 

      Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The discretization in Method of Moments (MoM) of the Electric-Field Integral Equation (EFIE) is traditionally carried out by preserving the continuity of the normal component in the expansion of the current across the ...

    • Discretization of the electric-magnetic field integral equation with the Divergence-Taylor-Orthogonal basis functions 

      Úbeda Farré, Eduard; Tamayo Palau, José María; Rius Casals, Juan Manuel (2011)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We present the discretization in Method of Moments of the Electric-Magnetic Field Integral Equation (EMFIE) with the divergence-Taylor-Orthogonal basis functions, a facetoriented set of basis functions. The EMFIE stands ...

    • Divergence-Taylor-Orthogonal basis functions for the discretization of second-kind surface integral equations in the Method of Moments 

      Úbeda Farré, Eduard; Tamayo Palau, José María; Rius Casals, Juan Manuel (2011)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We present new implementations in the method of moments of two types of second-kind integral equations: (i) the recently proposed electric-magnetic field integral equation (EMFIE) for perfectly conducting objects, and ...

    • Efficient analysis of homogeneous dielectric and plasmonic media with integral equation MEI (IE-MEI) 

      Rius Casals, Juan Manuel; Planes Conangla, Gerard; Úbeda Farré, Eduard; Heldring, Alexander (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      This paper revisits the IE-MEI method and proposes a new formulation for high-loss dielectric piecewise-homogeneous media. The aim of this work is to assess if the fast attenuation of fields in highly lossy media helps in ...

    • Efficient analysis of sheets with nonzero thickness 

      Úbeda Farré, Eduard; Rius Casals, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2021)
      Comunicació de congrés
      Accés obert
      The conventional scattering analysis of perfectly conducting plates neglects the scattering contribution of the rim in the discretization of the Electric-Field Integral Equation. This so-called thin-plate scheme manages ...

    • Efficient analysis of thick curved metal sheets 

      Úbeda Farré, Eduard; Rius Casals, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2021)
      Text en actes de congrés
      Accés obert
      The scattering analysis of perfectly conducting plates with the method-of-moment discretization of the Electric-Field Integral Equation has been traditionally carried out according to the thin-sheet approximation, which ...

    • Examples of integrable and non-integrable systems on singular symplectic manifolds 

      Miranda Galcerán, Eva; Delshams Valdés, Amadeu; Kiesenhoferb, Anna (2016)
      Article
      Accés obert
      We present a collection of examples borrowed from celestial mechanics and projective dynamics. In these examples symplectic structures with singularities arise naturally from regularization transformations, Appell’s ...

    • Facet-oriented discretization of the electric-magnetic field integral equation for the accurate scattering analysis of perfectly conducting sharp-edged objects 

      Tamayo Palau, José María; Úbeda Farré, Eduard; Rius Casals, Juan Manuel (2011)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In this paper, we present the discretization in Method of Moments of the Electric-Magnetic Field Equation with the divergence-Taylor-Orthogonal basis functions, a facetoriented set of basis functions. We show for a ...

    • Fast and Accurate Computation of Hypersingular Integrals in Galerkin Surface Integral Equation Formulations via the Direct Evaluation Metho 

      Polimeridis, Athanasios G.; Tamayo Palau, José María; Rius Casals, Juan Manuel; Mosig, Juan Ramón (2011-04)
      Article
      Accés restringit per política de l'editorial
      Hypersingular 4-D integrals, arising in the Galerkin discretization of surface integral equation formulations, are computed by means of the direct evaluation method. The proposed scheme extends the basic idea of the ...

    • 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)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      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 ...

    • Geometric algebra formulation of the Calderon Projector 

      López Menchón, Héctor; Rius Casals, Juan Manuel; Úbeda Farré, Eduard; Heldring, Alexander (2019)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      Geometric Algebra provides a mathematical frame-work that allows to express many equations of physics in a more compact way [1]. It unifies the electric and the magnetic field in a single mathematical object: a multivector. ...

    • Grid-robust discretization of integral equations in the electromagnetic scattering analysis of homogeneous targets with geometric singularities 

      Úbeda Farré, Eduard; Sekulic, Ivan; Rius Casals, Juan Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The conventional method-of-moment schemes of discretization for the scattering analysis of homogeneous targets, perfectly conducting or dielectric, rely on edge-based basis functions. This restricts the modelling of the ...

    • Handling missing values in kernel methods with application to microbiology data 

      Kobayashi, Vladimer; Aluja Banet, Tomàs; Belanche Muñoz, Luis Antonio (2013)
      Text en actes de congrés
      Accés obert
      We discuss several approaches that make possible for kernel methods to deal with missing values. The first two are extended kernels able to handle missing values without data preprocessing methods. Another two methods are ...