Now showing items 78-92 of 92

    • Reeb’s theorem and periodic orbits for a rotating Hénon–Heiles potential 

      Lanchares, Víctor; Pascual, Ana Isabel; Iñarreta, Manuel; Salas, José Pablo; Palacián Subiela, Jesús Francisco Upna; Yanguas Sayas, Patricia Upna (Springer, 2019)   Artículo / Artikulua
      We apply Reeb’s theorem to prove the existence of periodic orbits in the rotating Hénon– Heiles system. To this end, a sort of detuned normal form is calculated that yields a reduced system with at most four non degenerate ...
    • Scale recoding in sociological research: a new validation methodology. An application to a political survey 

      Abascal Fernández, Elena Upna; Díaz de Rada Igúzquiza, Vidal Upna; García Lautre, Ignacio Upna; Landaluce, M. Isabel (CSIC, 2019)   Artículo / Artikulua  OpenAccess
      La recodificación de variables es una etapa habitual en el análisis de datos de encuesta. No está exenta de riesgos, como pueden ser la introducción de sesgos o las posibles deformaciones de los datos originales. En este ...
    • Short- and mid-term evaluation of the use of electric vehicles in urban freight transport collaborative networks: a case study 

      Muñoz Villamizar, Andrés; Quintero Araújo, Carlos L.; Montoya Torres, Jairo R.; Faulín Fajardo, Javier Upna (Taylor & Francis, 2019)   Artículo / Artikulua  OpenAccess
      Despite its negative impacts, freight transportation is a primary component of all supply chains. Decision makers have considered diverse strategies, such as Horizontal Collaboration (HC) and the usage of alternative types ...
    • Strengthened ordered directionally monotone functions. Links between the different notions of monotonicity 

      Sesma Sara, Mikel Upna; Lafuente López, Julio Upna; Roldán, Antonio; Mesiar, Radko; Bustince Sola, Humberto Upna (Elsevier, 2019)   Artículo / Artikulua
      In this work, we propose a new notion of monotonicity: strengthened ordered directional monotonicity. This generalization of monotonicity is based on directional monotonicity and ordered directional monotonicity, two recent ...
    • Strong stability preserving properties of composition Runge-Kutta schemes 

      Higueras Sanz, Inmaculada Upna; Roldán Marrodán, Teodoro Upna (Springer, 2019)   Artículo / Artikulua  OpenAccess
      In this paper Strong Stability Preserving (SSP) properties of Runge Kutta methods obtained by com- posing k different schemes with different step sizes are studied. The SSP coefficient of the composition method is obtained ...
    • Tailoring the structural and magnetic properties of Co-Zn nanosized ferrites for hyperthermia applications 

      Gómez Polo, Cristina Upna; Recarte Callado, Vicente Upna; Cervera Gabalda, Laura María Upna; Beato López, Juan Jesús Upna; López García, Javier Upna; Rodríguez Velamazán, José Alberto; Ugarte Martínez, María Dolores Upna; Mendonça, E. C.; Duque, J. G. S. (Elsevier, 2018)   Artículo / Artikulua
      A comparative study of the magnetic properties (magnetic moment, magnetocrystalline anisotropy) and hyperthermia response in Co-Zn spinel nanoparticles is presented. The CoxZn1-xFe2O4 nanoparticles (x = 1, 0.5, 0.4, 0.3, ...
    • Temperature and water availability during maturation affect the cytokinins and auxins profile of radiata pine somatic embryos 

      Moncaleán, Paloma; García Mendiguren, Olatz; Novák, Ondrej; Strnad,Miroslav; Goicoa Mangado, Tomás Upna; Ugarte Martínez, María Dolores Upna; Montalbán, Itziar A. (Frontiers Media, 2018)   Artículo / Artikulua  OpenAccess
      Somatic embryogenesis (SE) provides us a potent biotechnological tool to manipulate the physical and chemical conditions (water availability) along the process and to study their effect in the final success in terms of ...
    • Three categories of set-valued generalisations from fuzzy sets to interval-valued and Atanassov intuitionistic fuzzy sets 

      Couso, Inés; Bustince Sola, Humberto Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      Many different notions included in the fuzzy set literature can be expressed in terms of functionals defined over collections of tuples of fuzzy sets. During the last decades, different authors have independently generalised ...
    • Topologies for semicontinuous Richter–Peleg multi-utilities 

      Bosi, Gianni; Estevan Muguerza, Asier Upna; Raventós Pujol, Armajac Upna (Springer, 2020)   Artículo / Artikulua
      The present paper gives a topological solution to representability problems related to multi-utility, in the field of Decision Theory. Necessary and sufficient topologies for the existence of a semicontinuous and finite ...
    • Trend analysis in L-fuzzy contexts with absent values 

      Alcalde, Cristina; Burusco Juandeaburre, Ana Upna; Bustince Sola, Humberto Upna; Sesma Sara, Mikel Upna (University of Sistan and Baluchestan (Irán), 2020)   Artículo / Artikulua  OpenAccess
      Sometimes we have to work with L-fuzzy context sequences where one or more values are missing. These sequences can represent, among other things, the evolution in time of an L-fuzzy context. The studies of tendencies that ...
    • Unconditional and quasi-greedy bases in L-p with applications to Jacobi polynomials Fourier series 

      Albiac Alesanco, Fernando José Upna; Ansorena, José L.; Ciaurri, Óscar; Varona, Juan L. (European Mathematical Society, 2019)   Artículo / Artikulua  OpenAccess
      We show that the decreasing rearrangement of the Fourier series with respect to the Jacobi polynomials for functions in L-p does not converge unless p = 2. As a by-product of our work on quasi-greedy bases in L-p(µ), we ...
    • A unified view of different axiomatic measures defined on L-fuzzy sets 

      Couso, Inés; Bustince Sola, Humberto Upna; Sánchez, Luciano (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      The recent literature contains a multitude of extensions of (axiomatic) notions from the context of ordinary fuzzy sets to more general contexts. Using the language of lattices, we provide a general and compact formulation ...
    • Uniformly convergent expansions for the generalized hypergeometric functions p –1Fp and pFp 

      López García, José Luis Upna; Pagola Martínez, Pedro Jesús Upna; Karp, D. B. (Taylor & Francis, 2020)   Artículo / Artikulua
      We derive a convergent expansion of the generalized hypergeometric function p−1 F p in terms of the Bessel functions 0 F 1 that holds uniformly with respect to the argument in any horizontal strip of the complex plane. We ...
    • Use of Choquet integrals in multivalued contexts 

      Burusco Juandeaburre, Ana Upna; Alcalde, Cristina (Springer, 2020)   Artículo / Artikulua  OpenAccess
      In this work, multivalued contexts are studied, in which the different observations are related to each other. Continuing the studies already carried out in previous works, the use of Choquet integrals can be an adequate ...
    • Weak and directional monotonicity of functions on Riesz spaces to fuse uncertain data 

      Sesma Sara, Mikel Upna; Mesiar, Radko; Bustince Sola, Humberto Upna (Elsevier B.V., 2019)   Artículo / Artikulua
      In the theory of aggregation, there is a trend towards the relaxation of the axiom of monotonicity and also towards the extension of the definition to other domains besides real numbers. In this work, we join both approaches ...