Now showing items 1-20 of 57

    • Eventual consistency: origin and support 

      Muñoz Escoí, Francesc D.; García Escrivá, José Ramón; Sendra Roig, Juan Salvador; Bernabéu Aubán, José M.; González de Mendívil Moreno, José Ramón Upna (Slovak Academy of Sciences, Institute of Informatics, 2018)   Artículo / Artikulua  OpenAccess
      Eventual consistency is demanded nowadays in geo-replicated services that need to be highly scalable and available. According to the CAP constraints, when network partitions may arise, a distributed service should choose ...
    • Order barrier for low-storage DIRK methods with positive weights 

      Higueras Sanz, Inmaculada Upna; Roldán Marrodán, Teodoro Upna (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 ...
    • An efficient numerical method for singularly perturbed time dependent parabolic 2D convection-diffusion systems 

      Clavero, C.; Jorge Ulecia, Juan Carlos Upna (Elsevier, 2018)   Artículo / Artikulua
      In this paper we deal with solving efficiently 2D linear parabolic singularly perturbed systems of convection–diffusion type. We analyze only the case of a system of two equations where both of them feature the same diffusion ...
    • Educational games to enhance museum visits for schools 

      Bossavit, Benoît Upna; Pina Calafi, Alfredo Upna; Sánchez Gil, Isabel Upna; Urtasun, Aitziber (National Taiwan Normal University, 2018)   Artículo / Artikulua  OpenAccess
      Museums usually look for new educational tools to enhance their exhibition. The Oteiza's museum in Navarre (Spain) especially gives importance to the dissemination of Jorge Oteiza's work to children at schools. Consequently, ...
    • A note on the asymptotic expansion of the Lerch’s transcendent 

      Cai, Xing Shi; López García, José Luis Upna (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 ...
    • An extension of the multiple Erdélyi-Kober operator and representations of the generalized hypergeometric functions 

      Karp, D. B.; López García, José Luis Upna (De Gruyter, 2018)   Artículo / Artikulua  OpenAccess
      In this paper we investigate the extension of the multiple Erd elyi-Kober fractional integral operator of Kiryakova to arbitrary complex values of parameters by the way of regularization. The regularization involves ...
    • Convergent asymptotic expansions of Charlier, Laguerre and Jacobi polynomials 

      López García, José Luis Upna; Temme, Nico M. (Cambridge University Press, 2004)   Artículo / Artikulua  OpenAccess
      Convergent expansions are derived for three types of orthogonal polynomials: Charlier, Laguerre and Jacobi. The expansions have asymptotic properties for large values of the degree. The expansions are given in terms of ...
    • 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, ...
    • Generalization of Zernike polynomials for regular portions of circles and ellipses 

      Navarro, Rafael; López García, José Luis Upna; Díaz, José A.; Pérez Sinusía, Ester Upna (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      Zernike polynomials are commonly used to represent the wavefront phase on circular optical apertures, since they form a complete and orthonormal basis on the unit circle. Here, we present a generalization of this Zernike ...
    • Convergent and asymptotic methods for second-order difference equations with a large parameter 

      Ferreira, Chelo; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Springer, 2018)   Artículo / Artikulua  OpenAccess
      We consider the second-order linear difference equation y(n+2)−2ay(n+1)−Λ2y(n)=g(n)y(n)+f(n)y(n+1) , where Λ is a large complex parameter, a≥0 and g and f are sequences of complex numbers. Two methods are proposed to find ...
    • The asymptotic expansion of the swallowtail integral in the highly oscillatory region 

      Ferreira, Chelo; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Elsevier, 2018)   Artículo / Artikulua
      The mathematical models of many short wavelength phenomena, specially wave propagation and optical diffraction, contain, as a basic ingredient, oscillatory integrals with several nearly coincident stationary phase or ...
    • Uniform convergent expansions of the Gauss hypergeometric function in terms of elementary functions 

      Ferreira, Chelo; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Taylor & Francis, 2018)   Artículo / Artikulua  OpenAccess
      We consider the hypergeometric function 2F1(a, b; c; z) for z ∈ C \ [1,∞). For Ra ≥ 0, we derive a convergent expansion of 2F1(a, b; c; z) in terms of the function (1 − z)−a and of rational functions of z that is uniformly ...
    • Uniform representation of the incomplete beta function in terms of elementary functions 

      Ferreira, Chelo; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Kent State UniversityJohann Radon Institute (RICAM), 2018)   Artículo / Artikulua  OpenAccess
      We consider the incomplete beta function Bz(a, b) in the maximum domain of analyticity of its three variables: a, b, z ∈ C, −a /∈ N, z /∈ [1, ∞). For <b ≤ 1 we derive a convergent expansion of z−aBz(a, b) in terms of the ...
    • Asymptotic and convergent expansions for solutions of third-order linear differential equations with a large parameter 

      Ferreira, Chelo; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Shanghai Normal UniversityWilmington Scientific Publisher, 2018)   Artículo / Artikulua  OpenAccess
      In previous papers [6–8,10], we derived convergent and asymptotic expansions of solutions of second order linear differential equations with a large parameter. In those papers we generalized and developed special cases not ...
    • The use of two-point Taylor expansions in singular one-dimensional boundary value problems I 

      Ferreira, Chelo; López García, José Luis Upna; Pérez Sinusía, Ester Upna (Elsevier, 2018)   Artículo / Artikulua
      We consider the second-order linear differential equation (x + 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 ...
    • Convergent expansions of the incomplete gamma functions in terms of elementary functions 

      Bujanda Cirauqui, Blanca Upna; López García, José Luis Upna; Pagola Martínez, Pedro Jesús Upna (World Scientific Publishing, 2017)   Artículo / Artikulua  OpenAccess
      We consider the incomplete gamma function γ(a,z) for Ra>0 and z∈C. We derive several convergent expansions of z−aγ(a,z) in terms of exponentials and rational functions of z that hold uniformly in z with Rz bounded from ...
    • A simplification of the stationary phase method: application to the Anger and Weber functions 

      López García, José Luis Upna (Kent State UniversityJohann Radon Institute (RICAM), 2017)   Artículo / Artikulua  OpenAccess
      The main difficulty in the practical use of the stationary phase method in asymptotic expansions of integrals is originated by a change of variables. The coefficients of the asymptotic expansion are the coefficients of the ...
    • Convergent expansions of the Bessel functions in terms of elementary functions 

      López García, José Luis Upna; Pagola Martínez, Pedro Jesús Upna (Springer US, 2018)   Artículo / Artikulua  OpenAccess
      We consider the Bessel functions Jν (z) and Yν (z) for ν > −1/2 and z ≥ 0. We derive a convergent expansion of Jν (z) in terms of the derivatives of (sin z)/z, and a convergent expansion of Yν (z) in terms of derivatives ...
    • Analytic formulas for the evaluation of the Pearcey integral 

      López García, José Luis Upna; Pagola Martínez, Pedro Jesús Upna (American Mathematical Society, 2017)   Artículo / Artikulua  OpenAccess
      We can find in the literature several convergent and/or asymptotic expansions of the Pearcey integral P(x, y) in different regions of the complex variables x and y, but they do not cover the whole complex x and y ...
    • Orthogonal basis with a conicoid first mode for shape specification of optical surfaces 

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