Now showing items 77-96 of 153

    • Mathematical and Statistical models as tools for the control ofmosquito-borne diseases: The experience of Costa Rica 

      Sánchez Peña, Fabio Ariel; Barboza Chinchilla, Luis Alberto; Vásquez Brenes, Paola Andrea; García Puerta, Yury Elena; Calvo Alpízar, Juan Gabriel; Chou Chen, Shu Wei; Mery, Gustavo (2021-06-25)
      The modeling of infectious diseases provides valuable input in the development of mitigating strategies and implementation of public health interventions. We highlight results and current research conducted in Costa Rica ...
    • Métodos de particionamiento bimodal y trimodal 

      Castillo Elizondo, William (1999)
    • Minimum depth of double cross product extensions 

      Hernández Alvarado, Alberto José (2020)
      In this paper we explore minimum odd and minimum even depth sub- algebra pairs in the context of double cross products of finite dimensional Hopf algebras. We start by defining factorization algebras and outline how subring ...
    • Models of torsors and the fundamental group scheme 

      Antei, Marco; Emsalem, Michel (2018)
      Given a relative faithfully at pointed scheme over the spectrum of a discrete valuation ring X !S, this paper is motivated by the study of the natural morphism from the fundamental group scheme of the generic ber X ...
    • Models of torsors over affine spaces 

      Antei, Marco; Esquivel Araya, Jorge Arturo (2019)
      Let X := A n R be the n-dimensional affine space over a discrete valuation ring R with fraction field K. We prove that any pointed torsor Y over A n K under the action of an affine finite-type group scheme can be extended ...
    • New mixed finite element methods for natural convection with phase-change in porous media 

      Álvarez Guadamuz, Mario Andrés; Gatica, Gabriel N.; Gómez Vargas, Bryan Andrés; Ruiz Baier, Ricardo (2019)
      This article is concerned with the mathematical and numerical analysis of a steady phase change problem for non-isothermal incompressible viscous flow. The system is formulated in terms of pseudostress, strain rate and ...
    • Nonnegative mixed states in Weyl–Wigner–Moyal theory 

      Gracia Bondía, José M.; Várilly Boyle, Joseph C. (1988-03-21)
      We classify the gaussian Wigner functions corresponding to mixed states and show that, unlike the case of pure states, not all nonnegative mixed states are gaussian.
    • Nori fundamental gerbe of essentially finite covers and Galois closure of towers of torsors 

      Antei, Marco; Biswas, Indranil; Emsalem, Michel; Tonini, Fabio; Zhang, Lei (2019)
      We prove the existence of a Galois closure for towers of torsors under finite group schemes over a proper, geometrically connected and geometrically reduced algebraic stack X over a field k. This is done by describing the ...
    • Notas de lógica EMALCA 2019 

      Zamora Calero, Rafael (2019)
      Estas notas fueron utilizadas en el curso Introducción a la Lógica durante la EMALCA organizada por el CIMPA en la sede del Atlántico en 2019. La lógica matemática es un área de matemática que estudia el lenguaje formal ...
    • Obtención de conjuntos aproximados mediante algoritmos genéticos 

      Espinoza, José Luis (Tesis para optar al grado de Magister Scientiae en Computación. ITCR, Cartago, 1999., 1999)
      En términos generales, la teoría de conjuntos aproximados, propuesta por Pawlak, consiste en explorar las particiones asociadas a las relaciones de equivalencia generadas por cada subconjunto de los atributos observados, ...
    • On asymptotic expansions of twisted products 

      Estrada Navas, Ricardo; Gracia Bondía, José M.; Várilly Boyle, Joseph C. (1989-12)
      The series development of the quantum-mechanical twisted product is studied. The series is shown to make sense as a moment asymptotic expansion of the integral formula for the twisted product, either pointwise or in the ...
    • On the approximation of a virtual coarse space for domain decomposition methods in two dimensions 

      Calvo Alpízar, Juan Gabriel (2018)
      A new extension operator for a virtual coarse space is presented which can be used in domain decomposition methods for nodal elliptic problems in two dimensions. In particular, a two-level overlapping Schwarz algorithm is ...
    • On the Colmez conjecture for non-abelian CM fields 

      Barquero Sánchez, Adrián Alberto; Masri, Riad (2018-02-08)
      The Colmez conjecture relates the Faltings height of an abelian variety with complex multiplication by the ring of integers of a CM field E to logarithmic derivatives of Artin L-functions at s=0. In this paper, we prove ...
    • On the kinematics of the last Wigner particle 

      Gracia Bondía, José M.; Várilly Boyle, Joseph C. (2019)
      Wigner's particle classification provides for "continuous spin" representations of the Poincaré group, corresponding to a class of (as yet unobserved) massless particles. Rather than building their induced realizations by ...
    • On the one dimensional spectral Heat content for stable processes 

      Acuña Valverde, Luis Guillermo (2016-09)
      This paper provides the second term in the small time asymptotic expansion of the spectral heat content of a rotationally invariant α-stable process, 0 < α ≤ 2, for the bounded interval (a, b). The small time behavior ...
    • On the Ramanujan–Lodge harmonic number expansion 

      Mortici, Cristinel; Villarino Bertram, Mark (2015-01-15)
      The aim of this paper is to extend and refine the Ramanujan–Lodge harmonic number expansion into negative powers of a triangular number. We construct a faster asymptotic series and some new sharp inequalities for the ...
    • On the standard form of the Bloch equation 

      Emch, Gérard G.; Várilly Boyle, Joseph C. (1979-03)
      The requirement is often made in non-equilibrium statistical mechanics that a transport equation should be derived as that which governs the subdynamics relative to a (small) part of a (large) conservative dynamical ...
    • Parallel Sums and Adaptive BDDC Deluxe 

      Widlund, Olof B.; Calvo Alpízar, Juan Gabriel (2017)
      There has recently been a considerable activity in developing adaptive methods for the selection of primal constraints for BDDC algorithms and, in particular, for BDDC deluxe variants. The primal constraints of a BDDC or ...
    • Parameter estimates of the 2016-2017 Zika outbreak in Costa Rica: An Approximate Bayesian Computation (ABC) approach 

      Sánchez Peña, Fabio Ariel; Barboza Chinchilla, Luis Alberto; Vásquez Brenes, Paola Andrea (2019-03-28)
      In Costa Rica, the first known cases of Zika were reported in 2016. We looked at the 2016-2017 Zika outbreak and explored the transmission dynamics using weekly reported data. A nonlinear differential equation single-outbreak ...
    • Parte prima a p del esquema fundamental en grupos sobre anillos de valuación discreta 

      Calvo Monge, Jimmy José (2020-11-17)
      Si X es un esquema propio, suave y conexo sobre Spec(R), para R un anillo de valuación discreta completo, dotado de una sección x: Spec(R) -> X, es posible construir los esquemas fundamentales en grupos pi_1(X,x) y ...