Ara es mostren els items 1-20 de 29

  • A family of iterative methods that uses divided differences of first and second orders 

    Ezquerro, José Antonio; Grau Sánchez, Miguel; Hernández Verón, Miguel Angel; Noguera Batlle, Miquel (2015-11-01)
    Article
    Accés restringit per política de l'editorial
    The family of fourth-order Steffensen-type methods proposed by Zheng et al. (Appl. Math. Comput. 217, 9592-9597 (2011)) is extended to solve systems of nonlinear equations. This extension uses multidimensional divided ...
  • An improvement of Ostrowski root-finding method 

    Grau Sánchez, Miguel; Díaz Barrero, José Luis (2006-02)
    Article
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    An improvement to the iterative method based on the Ostrowski one to compute nonlinear equation solutions, which increases the local order of convergence is suggested. The adaptation of a strategy presented here gives a ...
  • An iterative model for fractal antennas: application to the Sierpinski gasket antenna 

    Puente Baliarda, Carles; Borja Borau, M.Carmen; Navarro Rodero, Mònica; Romeu Robert, Jordi (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2000-05-31)
    Article
    Accés obert
    A simple model that explains the behavior of the Sierpinski fractal antenna is presented. This model shows that the multiband behavior of the Sierpinski fractal antenna is a consequence of its fractal nature. The model is ...
  • 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 ...
  • Distributed multivariate regression with unknown noise covariance in the presence of outliers: an MDL approach 

    López Valcarce, Roberto; Romero Gonzalez, Daniel; Sala Álvarez, José; Pagès Zamora, Alba Maria (Institute of Electrical and Electronics Engineers (IEEE), 2016)
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    We consider the problem of estimating the coefficients in a multivariable linear model by means of a wireless sensor network which may be affected by anomalous measurements. The noise covariance matrices at the different ...
  • Distributed TLS estimation under random data faults 

    Silva Pereira, Silvana; Pagès Zamora, Alba Maria; López Valcarce, Roberto (Institute of Electrical and Electronics Engineers (IEEE), 2015)
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    This paper addresses the problem of distributed estimation of a parameter vector in the presence of noisy input and noisy output data, as well as data faults, performed by a wireless sensor network in which only local ...
  • Higher order multi-step iterative method for computing the numerical solution of systems of nonlinear equations: Application to nonlinear PDEs and ODEs 

    Ullah, Malik Zaka; Serra Capizzano, Stefano; Ahmad, Fayyaz; Alaidarous, Eman (2015-10-15)
    Article
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    In the present study, we consider multi-step iterative method to solve systems of nonlinear equations. Since the Jacobian evaluation and its inversion are expensive, in order to achieve a better computational efficiency, ...
  • Higher order multi-step Jarratt-like method for solving systems of nonlinear equations: application to PDEs and ODEs 

    Ahmad, Fayyaz; Tohidi, Emran; Ullah, Malik Zaka; Carrasco, Juan A. (2015-08-01)
    Article
    Accés obert
    This paper proposes a multi-step iterative method for solving systems of nonlinear equations with a local convergence order of 3m - 4, where in (>= 2) is the number of steps. The multi-step iterative method includes two ...
  • Hybrid sparse linear array synthesis applied to phased antenna arrays 

    Yepes, Leonardo Fabio; Covarrubias, David; Alonso, Miguel A.; Ferrús Ferré, Ramón Antonio (2014-01-16)
    Article
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    In this letter, a new hybrid technique to synthesize sparse linear arrays is proposed. This technique is based on the combination of two methods. As a first method, a deterministic synthesis algorithm is used to resolve ...
  • 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)
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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 ...
  • Maximum likelihood estimation of position in GNSS 

    Closas Gómez, Pau; Fernández Prades, Carlos; Fernández Rubio, Juan Antonio (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007-05)
    Article
    Accés obert
    In this letter, we obtain the Maximum Likelihood Estimator of position in the framework of Global Navigation Satellite Systems. This theoretical result is the basis of a completely different approach to the positioning ...
  • Method of moments enhancement technique for the analysis of Sierpinski pre-fractal antennas 

    Parrón Granados, Josep; Romeu Robert, Jordi; Rius Casals, Juan Manuel; Mosig, Juan R. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2003-08-31)
    Article
    Accés obert
    The numerical analysis of highly iterated Sierpinski microstrip patch antennas by method of moments (MoM) involves many tiny subdomain basis functions, resulting in a very large number of unknowns. The Sierpinski ...
  • Mètodes iteratius per a la resolució d'equacions no lineals 

    Fernández Sánchez, Marc (Universitat Politècnica de Catalunya, 2012-06-28)
    Projecte/Treball Final de Carrera
    Accés obert
    El projecte consisteix en un estudi tant teòric com pràctic d'alguns dels mètodes iteratius sense memòria, emprats per la resolució d'equacions no lineals. Es plantegen i analitzen els cinc mètodes següents: Newton, Txebixev, ...
  • Un método simplificado de Newton para calcular la raíz cuadrada de una matriz real simétrica definida positiva 

    Mendoza Mexía, Alfredo; Gómez Aldama, Óscar Rubén (Universitat Politècnica de Catalunya, 2010)
    Article
    Accés obert
  • ML estimator and hybrid beamformer for multipath and interference mitigation in GNSS receivers 

    Seco Granados, Gonzalo; Fernández Rubio, Juan Antonio; Fernández Prades, Carlos (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-05-31)
    Article
    Accés obert
    This paper addresses the estimation of the code-phase(pseudorange) and the carrier-phase of the direct signal received from a direct-sequence spread-spectrum satellite transmitter. The signal is received by an antenna ...
  • Multiresolution hierarchy co-clustering for semantic segmentation in sequences with small variations 

    Varas González, David; Alfaro Vendrell, Mónica; Marqués Acosta, Fernando (Institute of Electrical and Electronics Engineers (IEEE), 2015)
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    This paper presents a co-clustering technique that, given a collection of images and their hierarchies, clusters nodes from these hierarchies to obtain a coherent multiresolution representation of the image collection. We ...
  • Multiuser resource allocation optimization using bandwidth-power product in cognitive radio networks 

    Tachwali, Yahia; Lo, B.F.; Akyildiz, Ian; Agustí Comes, Ramon (2013-03)
    Article
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    In this paper, the problem of resource allocation optimization is studied for a single-cell multiuser cognitive radio network in the presence of primary user networks. The spectral access of the cognitive radio network is ...
  • Nonlinear actuation model for lateral electrostatically-actuated DC-contact RF MEMS series switches. 

    Lázaro Guillén, Antoni; Girbau Sala, David; Pradell i Cara, Lluís; Nebot Serra, Àlvar (JOHN WILEY & SONS INC, 2007-06-01)
    Article
    Accés obert
    In this work, a nonlinear model to predict actuation characteristics in lateral electrostatically-actuated DC-contact MEMS switches is proposed. In this case a parallel-plate approximation cannot be applied. The model ...
  • Practical algorithms for a family of waterfilling solutions 

    Pérez Palomar, Daniel; Rodríguez Fonollosa, Javier (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-02-28)
    Article
    Accés obert
    Many engineering problems that can be formulated as constrained optimization problems result in solutions given by a waterfilling structure; the classical example is the capacity-achieving solution for a frequency-selective ...
  • Preconditioning techniques in the analysis of finite metamaterial slabs 

    Úbeda Farré, Eduard; Rius Casals, Juan Manuel; Romeu Robert, Jordi (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2006-01-31)
    Article
    Accés obert
    In the method of moments (MoM) electric field integral equation (EFIE) analysis of slabs of metamaterials, we show that a left-preconditioning scheme by blocks gathering interactions between basis functions belonging to ...