Now showing items 1-6 of 6

    • Analysis of singular one-dimensional linear boundary value problems using two-point Taylor expansions 

      Ferreira González, Chelo Upna; López García, José Luis Upna; Pérez Sinusía, Ester Upna (University of Szeged (Hungría), 2020)   Artículo / Artikulua  OpenAccess
      We consider the second-order linear differential equation (x2 − 1)y'' + f (x)y′ + g(x)y = h(x) in the interval (−1, 1) with initial conditions or boundary conditions (Dirichlet, Neumann or mixed Dirichlet–Neumann). The ...
    • Aprender matemáticas con el ordenador 

      Bujanda Cirauqui, Blanca Upna; Ferreira González, Chelo Upna (Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2004)   Libro / Liburua  OpenAccess
      Los futuros perfiles profesionales de nuestros actuales alumnos universitarios están cambiando vertiginosamente. Uno de los grandes cambios es el que viene dado por la incorporación del ordenador a la mayoría (casi todos) ...
    • Convergent and asymptotic expansions of solutions of differential equations with a large parameter: Olver cases II and III 

      Ferreira González, Chelo Upna; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Rocky Mountain Mathematics Consortium, 2015)   Artículo / Artikulua  OpenAccess
      This paper continues the investigation initiated in [Lopez, 2013]. We consider the asymptotic method designed by F. Olver [Olver, 1974] for linear differential equations of the second order containing a large (asymptotic) ...
    • Orthogonal basis for the optical transfer function 

      Ferreira González, Chelo Upna; López García, José Luis Upna; Navarro, Rafael; Pérez Sinusía, Ester Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      We propose systems of orthogonal functions qn to represent optical transfer functions (OTF) characterized by including the diffraction-limited OTF as the first basis function q0 OTF perfect. To this end, we apply a powerful ...
    • Orthogonal basis with a conicoid first mode for shape specification of optical surfaces: reply 

      Ferreira González, Chelo Upna; López García, José Luis Upna; Navarro, Rafael; Pérez Sinusía, Ester Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      We present some comments to the paper 'Orthogonal basis with a conicoid first mode for shape specification of optical surfaces: comment'.
    • The swallowtail integral in the highly oscillatory region 

      Ferreira González, Chelo Upna; López García, José Luis Upna; Pérez Sinusía, Ester Upna (2020)   Artículo / Artikulua  OpenAccess
      We analyze the asymptotic behavior of the swallowtail integral R ∞ −∞ e i(t 5+xt3+yt2+zt)dt for large values of |y| and bounded values of |x| and |z|. We use the simpli ed saddle point method introduced in [López et ...