• Convergent and asymptotic methods for second-order difference equations with a large parameter 

  Ferreira, Chelo; López García, José Luis; Pérez Sinusía, Ester (Springer, 2018)   Artículo / Artikulua

  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 ...

• Uniform convergent expansions of the Gauss hypergeometric function in terms of elementary functions 

  Ferreira, Chelo; López García, José Luis; Pérez Sinusía, Ester (Taylor & Francis, 2018)   Artículo / Artikulua

  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; Pérez Sinusía, Ester (Kent State UniversityJohann Radon Institute (RICAM), 2018)   Artículo / Artikulua  

  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 ...

• Convergent expansions of the confluent hypergeometric functions in terms of elementary functions 

  Bujanda Cirauqui, Blanca ; López García, José Luis; Pagola Martínez, Pedro Jesús (American Mathematical Society, 2018)   Artículo / Artikulua  

  We consider the confluent hypergeometric function M(a, b; z) for z ∈ C and Rb >Ra > 0, and the confluent hypergeometric function U(a, b; z) for b ∈ C, Ra > 0, and Rz > 0. We derive two convergent expansions of M(a, b; z); ...

• The use of two-point Taylor expansions in singular one-dimensional boundary value problems I 

  Ferreira, Chelo; López García, José Luis; Pérez Sinusía, Ester (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 ; López García, José Luis; Pagola Martínez, Pedro Jesús (World Scientific Publishing, 2017)   Artículo / Artikulua  

  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 (Kent State UniversityJohann Radon Institute (RICAM), 2017)   Artículo / Artikulua  

  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; Pagola Martínez, Pedro Jesús (Springer US, 2018)   Artículo / Artikulua  

  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 ...

• The Pearcey integral in the highly oscillatory region 

  López García, José Luis; Pagola Martínez, Pedro Jesús (Elsevier, 2016)   Artículo / Artikulua  

  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. ...

• Orness measurements for lattice m-dimensional interval-valued OWA operators 

  Miguel Turullols, Laura de ; Paternain Dallo, Daniel ; Lizasoain Iriso, María Inmaculada ; Ochoa Lezaun, Gustavo ; Bustince Sola, Humberto  (Elsevier, 2018)   Artículo / Artikulua

  Ordered weighted average (OWA) operators are commonly used to aggregate information in multiple situations, such as decision making problems or image processing tasks. The great variety of weights that can be chosen to ...

• Effects of a soft-core coulomb potential on the dynamics of a hydrogen atom near a metal surface 

  Iñarrea, Manuel; Lanchares, Víctor; Palacián Subiela, Jesús Francisco ; Pascual, Ana Isabel; Salas, José Pablo; Yanguas Sayas, Patricia  (Elsevier, 2019)   Artículo / Artikulua

  The goal of this paper is to investigate the effects that the replacement of the Coulomb potential by a soft-core Coulomb potential produces in the classical dynamics of a perturbed Rydberg hydrogen atom. As example, we ...

• Application of eco-design and life cycle assessment standards for environmental impact reduction of an industrial product 

  Navajas León, Alberto; Uriarte Elizaga, Leire; Gandía Pascual, Luis (MDPI, 2017)   Artículo / Artikulua  

  Eco-design is included within the framework of the standard for “Environmental management systems—Guidelines for incorporating Eco-design” (ISO 14006:2011). Eco-design process, as defined in standard, has six steps: (i) ...

• Study of optical fiber sensors for cryogenic temperature measurements 

  Miguel Soto, Verónica de; Leandro González, Daniel ; López Aldaba, Aitor ; Beato López, Juan Jesús; Pérez de Landazábal Berganzo, José Ignacio; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel  (MDPI, 2017)   Artículo / Artikulua  

  In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg ...

• Giant direct and inverse magnetocaloric effect linked to the same forward martensitic transformation 

  Pérez de Landazábal Berganzo, José Ignacio; Recarte Callado, Vicente ; Sánchez-Alarcos Gómez, Vicente ; Beato López, Juan Jesús; Rodríguez Velamazán, José Alberto; Sánchez Marcos, J.; Gómez Polo, Cristina; Cesari, Eduard (Springer Nature, 2017)   Artículo / Artikulua  

  Metamagnetic shape memory alloys have aroused considerable attraction as potential magnetic refrigerants due to the large inverse magnetocaloric effect associated to the magnetic-field-induction of a reverse martensitic ...

• Spatial gender-age-period-cohort analysis of pancreatic cancer mortality in Spain (1990-2013) 

  Etxeberria Andueza, Jaione ; Goicoa Mangado, Tomás ; López Abente, Gonzalo; Riebler, Andrea; Ugarte Martínez, María Dolores  (Public Library of Science, 2017)   Artículo / Artikulua  

  Recently, the interest in studying pancreatic cancer mortality has increased due to its high lethality. In this work a detailed analysis of pancreatic cancer mortality in Spanish provinces was performed using recent data. ...

• Structurally oriented nano-sheets in Co thin films: changing their anisotropic physical properties by thermally-induced relaxation 

  Vergara Platero, José ; Favieres Ruiz, Cristina ; Magén, César; Teresa, José María de; Ibarra, Manuel Ricardo; Madurga Pérez, Vicente  (MDPI, 2017)   Artículo / Artikulua  

  We show how nanocrystalline Co films formed by separated oblique nano-sheets display anisotropy in their resistivity, magnetization process, surface nano-morphology and optical transmission. After performing a heat treatment ...

• Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption 

  Echeverría Morrás, Jesús ; Calleja, Ignacio; Moriones Jiménez, Paula ; Garrido Segovia, Julián José  (Beilstein-Institut, 2017)   Artículo / Artikulua  

  We investigated the response of three fiber optic sensing elements prepared at pH 10 from phenyltriethoxysilane (PhTEOS) and tetraethylsilane (TEOS) mixtures with 30, 40, and 50% PhTEOS in the silicon precursor mixture. ...

• Normalization through invariants in n-dimensional Kepler problems 

  Meyer, Kenneth Ray; Palacián Subiela, Jesús Francisco ; Yanguas Sayas, Patricia  (Pleiades Publishing, 2018)   Artículo / Artikulua  

  We present a procedure for the normalization of perturbed Keplerian problems in n dimensions based on Moser regularization of the Kepler problem and the invariants associated to the reduction process. The approach allows ...

• Dynamics of axially symmetric perturbed Hamiltonians in 1:1:1 resonance 

  Carrasco, Dante; Palacián Subiela, Jesús Francisco ; Vidal, Claudio; Vidarte, Jhon; Yanguas Sayas, Patricia  (Springer, 2018)   Artículo / Artikulua  

  We study the dynamics of a family of perturbed three-degree-of-freedom Hamiltonian systems which are in 1:1:1 resonance. The perturbation consists of axially symmetric cubic and quartic arbitrary polynomials. Our analysis ...

• Singular reduction of resonant Hamiltonians 

  Meyer, Kenneth Ray; Palacián Subiela, Jesús Francisco ; Yanguas Sayas, Patricia  (IOP PublishingLondon Mathematical Society, 2018)   Artículo / Artikulua

  We investigate the dynamics of resonant Hamiltonians with n degrees of freedom to which we attach a small perturbation. Our study is based on the geometric interpretation of singular reduction theory. The flow of the ...

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