Browsing by Author "València Guitart, Marta"Més informacióMés informació

Now showing items 1-9 of 9

    • A singular initial value problem to construct density-equalizing maps 

      Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2011-12)
      Article
      Restricted access - publisher's policy
      The diffusion-based algorithm to produce density-equalizing maps interprets diffusion as an advection process. This algorithm uses the dynamics of a flow that is defined by an initial value problem that turns out to be ...

    • A singular initial value problem to construct density-equalizing maps 

      Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2011-05)
      Research report
      Open Access
      The diffusion-based algorithm to produce density-equalizing maps interprets diffusion as an advection process. This algorithm uses the dynamics of a flow that is defined by an initial value problem that turns out to be ...

    • Adiabatic invariant of the harmonic oscillator, complex matching and resurgence 

      Bonet Revés, Carles; Sauzin, D.; Martínez-Seara Alonso, M. Teresa; València Guitart, Marta (1997)
      Article
      Open Access
      The linear oscillator equation with a frequency depending slowly on time is used to test a method to compute exponentially small quantities. This work present the matching method in the complex plane as a tool to obtain ...

    • Bounded solutions of some nonlinear elliptic equations in cylindrical domains 

      Calsina Ballesta, Ángel; Solà-Morales Rubió, Joan de; València Guitart, Marta (1997)
      Article
      Open Access
      The existence of a (unique) solution of the second order semilinear elliptic equation $$ \sum^{n}_{i,j=0}a_{ij}(x)u_{x_{i}x_{j}}+f(\nabla u,u,x)=0 $$ with $x=(x_{0},x_{1},\dots, x_{n})\in (s_{0},\infty )\times \Omega '$, ...

    • Càlcul numèric 

      Bonet Revés, Carles; Jorba Monte, Angel; Martínez-Seara Alonso, M. Teresa; Masdemont Soler, Josep; Ollé Torner, Mercè; Susín Sánchez, Antonio; València Guitart, Marta (Edicions UPC, 1994)
      Book
      Restricted access to the UPC academic community
      El llibre Càlcul numèric conté les eines i bases fonamentals dels algotimes de computació. La seva presentació, exempta de formalismes excessivament teòrics, el fa molt adequat per al lector que, sense voler aprofundir ...

    • Diffeomorphisms with Given Jacobians involving the Heat Equation 

      Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2000-12)
      Article
      Open Access

    • EQUACIONS DIFERENCIALS 2 (Examen 2n quadrim) 

      València Guitart, Marta (Universitat Politècnica de Catalunya, 2007-05-21)
      Exam
      Restricted access to the UPC academic community

    • On maps with given jacobians involving the heat equation 

      Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2000)
      Article
      Open Access
      In this paper we presennt and analyze two new algorithms to construct a smooth diffeomorphism of a domain with prescribed jacobian function. The first one is free from any restriction on the boundary, while the second ...

    • On the diffusion algorithm for density-equalizing maps with piecewise constant initial data 

      Avinyó Andrés, Albert; Solà-Morales Rubió, Joan de; València Guitart, Marta (2012-07-15)
      Article
      Restricted access - publisher's policy
      We mathematically analyze the diffusion-based algorithm to produce maps with a given Jacobian, introduced independently by M. T. Gastner and M. E. J. Newman (2004) and ourselves (2003), but in particular cases where the ...