• A mixed-FEM and BEM coupling for the approximation of the scattering of thermal waves in locally non-homogeneous media 

      Rapún Araiz, María Luisa Upna; Sayas, Francisco Javier (EDP Sciences, 2006)   Artículo / Artikulua  OpenAccess
      This paper proposes and analyzes a BEM-FEM scheme to approximate a time-harmonic diffusion problem in the plane with non-constant coefficients in a bounded area. The model is set as a Helmholtz transmission problem with ...
    • Modified Douglas splitting methods for reaction–diffusion equations 

      Arrarás Ventura, Andrés Upna Orcid; Hout, K. J. in ’t; Hundsdorfer, W.; Portero Egea, Laura Upna Orcid (Springer, 2017)   Artículo / Artikulua  OpenAccess
      We present modifications of the second-order Douglas stabilizing corrections method, which is a splitting method based on the implicit trapezoidal rule. Inclusion of an explicit term in a forward Euler way is straightforward, ...
    • New asymptotic expansion and error bound for Stirling formula of reciprocal Gamma function 

      Pagola Martínez, Pedro Jesús Upna (Ele-Math, 2018)   Artículo / Artikulua  OpenAccess
      Studying the problem about if certain probability measures are determinate by its moments [4, 8, 10] is useful to know the asymptotic behavior of the probability densities for large values of argument. This requires, ...
    • New multiplexing structures for fiber optic sensors 

      Leandro González, Daniel Upna Orcid (2016)   Tesis doctoral / Doktoretza tesia  OpenAccess
      El campo de la fibra óptica ha sufrido una rápida evolución durante las últimas décadas debido a sus buenas prestaciones en aplicaciones de telecomunicaciones. Aprovechando este avance científico y técnico en componentes ...
    • New series expansions of the 3F2 function 

      López García, José Luis Upna Orcid; Pagola Martínez, Pedro Jesús Upna; Pérez Sinusía, Ester Upna Orcid (2015)   Artículo / Artikulua  OpenAccess
      We can use the power series definition of 3F2(a1, a2, a3; b1, b2; z) to compute this function for z in the unit disk only. In this paper we obtain new expansions of this function that are convergent in larger domains. ...
    • A note on the asymptotic expansion of the Lerch’s transcendent 

      Cai, Xing Shi; López García, José Luis Upna Orcid (Taylor & Francis, 2018)   Artículo / Artikulua  OpenAccess
      In Ferreira and López [Asymptotic expansions of the Hurwitz–Lerch zeta function. J Math Anal Appl. 2004;298(1):210–224], the authors derived an asymptotic expansion of the Lerch's transcendent Φ(z,s,a) for large |a|, valid ...
    • On a modifcation of Olver's method: a special case 

      Ferreira González, Chelo Upna; López García, José Luis Upna Orcid; Pérez Sinusía, Ester Upna Orcid (Springer US, 2016)   Artículo / Artikulua  OpenAccess
      We consider the asymptotic method designed by Olver (Asymptotics and special functions. Academic Press, New York, 1974) for linear differential equations of the second order containing a large (asymptotic) parameter : ...
    • On the modeling of the concept: “The Contents of the Empty Set" using the activity orderings family (⊑w)w∈L in a distributive lattice ( L, ≤ ). An interpretation of those order relations ⊑w as alternative inclusions (“w-Inclusions") and of its associated inf- operators ⨅w as additional intersections (“w-Intersections”), both in the Intuitive set theory and in the L-fuzzy set theory. (In Spanish) 

      Fuentes González, Ramón Upna Orcid (2018)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      A mathematical model is presented to define new inclusions, intersections and unions as alternatives to the usual ones between crisp and fuzzy subsets. In particular, the concept of “the non-trivial content of the empty ...
    • Optimal monotonicity-preserving perturbations of a given Runge–Kutta method 

      Higueras Sanz, Inmaculada Upna Orcid; Ketcheson, David I.; Kocsis, Tihamér A. (Springer, 2018)   Artículo / Artikulua  OpenAccess
      Perturbed Runge–Kutta methods (also referred to as downwind Runge–Kutta methods) can guarantee monotonicity preservation under larger step sizes relative to their traditional Runge–Kutta counterparts. In this paper we study ...
    • Optimization and design of wireless systems for the implementation of context aware scenarios in railway passenger vehicles 

      Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Astrain Escola, José Javier Upna Orcid; López Iturri, Peio Upna Orcid; Granda, Fausto; Vargas Rosales, César; Villadangos Alonso, Jesús Upna Orcid; Perallos Ruiz, Asier; Bahillo, Alfonso; Falcone Lanas, Francisco Upna Orcid (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      In this paper, intra-wagon wireless communication performance is analyzed, in order to account for inherent scenario complexity in the deployment phase of wireless systems toward the implementation of a context-aware ...
    • Optimized strong stability preserving IMEX Runge-Kutta methods 

      Higueras Sanz, Inmaculada Upna Orcid; Happenhofer, Natalie; Koch, Othmar; Kupka, Friedrich (2014)   Artículo / Artikulua  OpenAccess
      We construct and analyze robust strong stability preserving IMplicit-EXplicit Runge-Kutta (IMEX RK) methods for models of flow with diffusion as they appear in astrophysics and in many other fields where equations with ...
    • Order barrier for low-storage DIRK methods with positive weights 

      Higueras Sanz, Inmaculada Upna Orcid; Roldán Marrodán, Teodoro Upna Orcid (Springer, 2018)   Artículo / Artikulua  OpenAccess
      In this paper we study an order barrier for low-storage diagonally implicit Runge-Kutta (DIRK) methods with positive weights. The Butcher matrix for these schemes, that can be implemented with only two memory registers in ...
    • Orthogonal basis for the optical transfer function 

      Ferreira González, Chelo Upna; López García, José Luis Upna Orcid; Navarro, Rafael; Pérez Sinusía, Ester Upna Orcid (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 

      Ferreira González, Chelo Upna; López García, José Luis Upna Orcid; Navarro, Rafael; Pérez Sinusía, Ester Upna Orcid (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      A rigorous and powerful theoretical framework is proposed to obtain systems of orthogonal functions (or shape modes) to represent optical surfaces. The method is general so it can be applied to different initial shapes and ...
    • Orthogonal basis with a conicoid first mode for shape specification of optical surfaces: reply 

      Ferreira González, Chelo Upna; López García, José Luis Upna Orcid; Navarro, Rafael; Pérez Sinusía, Ester Upna Orcid (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'.
    • Oscillatory motions in restricted N-body problems 

      Álvarez-Ramírez, Martha; Rodríguez García, Antonio Upna Orcid; Palacián Subiela, Jesús Francisco Upna Orcid; Yanguas Sayas, Patricia Upna Orcid (Elsevier, 2018)   Artículo / Artikulua  OpenAccess
      We consider the planar restricted N-body problem where the N−1 primaries are assumed to be in a central configuration whereas the infinitesimal particle escapes to infinity in a parabolic orbit. We prove the existence of ...
    • Parallel solution of nonlinear parabolic problems on logically rectangular grids 

      Arrarás Ventura, Andrés Upna Orcid; Portero Egea, Laura Upna Orcid; Jorge Ulecia, Juan Carlos Upna Orcid (Springer, 2007)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      This work deals with the efficient numerical solution of nonlinear transient flow problems posed on two-dimensional porous media of general geometry. We first consider a spatial semidiscretization of such problems by ...
    • The Pearcey integral in the highly oscillatory region 

      López García, José Luis Upna Orcid; Pagola Martínez, Pedro Jesús Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      We consider the Pearcey integral P(x, y) for large values of |y| and bounded values of |x|. The integrand of the Pearcey integral oscillates wildly in this region and the asymptotic saddle point analysis is complicated. ...
    • Radio characterization for ISM 2.4 GHz wireless sensor networks for judo monitoring applications 

      López Iturri, Peio Upna Orcid; Aguirre Gallego, Erik Upna Orcid; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Astrain Escola, José Javier Upna Orcid; Villadangos Alonso, Jesús Upna Orcid; Falcone Lanas, Francisco Javier Upna Orcid (MDPI, 2014)   Artículo / Artikulua  OpenAccess
      In this work, the characterization of the radio channel for ISM 2.4GHz Wireless Sensor Networks (WSNs) for judo applications is presented. The environments where judo activity is held are usually complex indoor scenarios ...
    • Radio wave propagation and WSN deployment in complex utility tunnel environments 

      Celaya Echarri, Mikel Upna Orcid; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; López Iturri, Peio Upna Orcid; Picallo Guembe, Imanol Upna Orcid; Aguirre Gallego, Erik Upna Orcid; Astrain Escola, José Javier Upna Orcid; Villadangos Alonso, Jesús Upna Orcid; Falcone Lanas, Francisco Javier Upna Orcid (MDPI, 2020)   Artículo / Artikulua  OpenAccess
      The significant growth of wireless communications systems in the last years has led to the adoption of a wide range of applications not only for the general public but, also, including utilities and administrative authorities. ...

      El Repositorio ha recibido la ayuda de la Fundación Española para la Ciencia y la Tecnología para la realización de actividades en el ámbito del fomento de la investigación científica de excelencia, en la Línea 2. Repositorios institucionales (convocatoria 2020-2021).
      Logo MinisterioLogo Fecyt