Browsing Artículos científicos by Title
Now showing items 1-20 of 170
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A Microscopic Model for a One Parameter Class of Fractional Laplacians with Dirichlet Boundary Conditions
(Springer Science and Business Media Deutschland GmbH, 2021)We prove the hydrodynamic limit for the symmetric exclusion process with long jumps given by a mean zero probability transition rate with infinite variance and in contact with infinitely many reservoirs with density α ... -
A mixed virtual element method for a pseudostress-based formulation of linear elasticity
(Elsevier B.V., 2019)In this paper we introduce and analyze a mixed virtual element method (mixed-VEM) for a pseudostress-displacement formulation of the linear elasticity problem with non homogeneous Dirichlet boundary conditions. We follow ... -
A mixed virtual element method for quasi-Newtonian stokes flows
(SIAM, 2018)In this paper we introduce and analyze a virtual element method (VEM) for an augmented mixed variational formulation of a class of nonlinear Stokes models arising in quasi-Newtonian fluids. While the original unknowns are ... -
A mixed virtual element method for the boussinesq problem on polygonal meshes
(Global Science Press, 2021)In this work we introduce and analyze a mixed virtual element method (mixed-VEM) for the two-dimensional stationary Boussinesq problem. The continuous formulation is based on the introduction of a pseudostress tensor ... -
A mixed virtual element method for the Brinkman problem
(Mathematical Models and Methods in Applied Sciences vol.27 no.4 707-743 2017, 2017)In this paper, we introduce and analyze a mixed virtual element method (mixed-VEM) for the two-dimensional Brinkman model of porous media flow with non-homogeneous Dirichlet boundary conditions. More precisely, we employ ... -
A Monte Carlo Study of the Photon Spectrum due to the Different Materials Used in the Construction of Flattening Filters of LINAC
(Hindawi, 2017-07-10)Different types the spectrum of photons were studied; they were emitted from the flattening filter of a LINAC Varian 2100 C/D that operates at 15 MV. The simplified geometry of the LINAC head was calculated using the MCNPX ... -
A posteriori error analysis of a mixed virtual element method for a nonlinear Brinkman model of porous media flow
(Elsevier Ltd, 2020-06-25)In this paper we present an a posteriori error analysis of a mixed-VEM discretization for a nonlinear Brinkman model of porous media flow, which has been proposed by the authors in a previous work. Therein, the system ... -
A priori and a posteriori error analyses of a pseudostress-based mixed formulation for linear elasticity
(Computers and Mathematics with Applications vol.71 no.2 585-614 2016, 2016-01-02)In this paper we present the a priori and a posteriori error analyses of a non-standard mixed finite element method for the linear elasticity problem with non-homogeneous Dirichlet boundary conditions. More precisely, the ... -
A Priori and a Posteriori Error Analyses of an Augmented HDG Method for a Class of Quasi-Newtonian Stokes Flows
(Springer, 2016-12)In a recent work we developed a new hybridizable discontinuous Galerkin (HDG) method for a class of nonlinear Stokes models arising in quasi-Newtonian fluids. The approach there uses the incompressibility condition to ... -
A priori and a posteriori error analyses of an HDG method for the Brinkman problem
(Elsevier, 2018-01-15)In this paper we introduce and analyze a hybridizable discontinuous Galerkin (HDG) method for the linear Brinkman model of porous media flow in two and three dimensions and with non-homogeneous Dirichlet boundary conditions. ... -
A RTk - P-k approximation for linear elasticity yielding a broken H(div) convergent postprocessed stress
(Universidad Nacional, Costa Rica, 2015)We present a non-standard mixed finite element method for the linear elasticity problem in R-n with non-homogeneous Dirichlet boundary conditions. More precisely, our approach is based on a simplified interpretation of the ... -
Abandono temprano en estudiantes universitarios: un estudio de cohorte sobre sus posibles causas
(Universidad Nacional, Costa Rica, 2021-01-31)El objetivo principal de esta investigación es conocer las razones por las cuales un estudiante de primer ingreso se puede convertir en un desertor temprano; se estudia el caso particular de la Universidad ... -
Abelian covers of alternating groups
(Archiv der Mathematik 107 135-150, 2016-07-07)Let G = A n , a finite alternating group. We study the commuting graph of G and establish, for all possible values of n barring 13, 14, 17, and 19 whether or not the independence number is equal to the clique-covering number. -
Acciones y desafíos en la formación de docentes de matemáticas en el contexto de la pandemia en la Universidad Nacional - Costa Rica
(Universidad Nacional (Costa Rica), 2021)A raíz de la pandemia de Covid-19, muchas de las actividades que se realizan en la formación de docentes de matemáticas sufrieron afectaciones. En la Escuela de Matemática de la Universidad Nacional en Costa Rica se han ... -
Las actitudes hacia la matemática, el desarrollo social, el nivel educativo de la madre y la autoeficacia como factores asociados al rendimiento académico en matemática
(Universidad Nacional (Costa Rica), 2020-01)El documento trata sobre la problemática del bajo rendimiento académico en matemática (RAM) y, como objetivo principal, analiza de qué manera se relaciona este con las actitudes hacia la materia, la autoeficacia percibida, ... -
Administración de proyectos con Excel usando PERT/CPM
(Universidad Nacional (Costa Rica), 2002)Se presenta la técnica PERT/CPM de la ciencia administrativa, que ayuda a comprobar y controlar aquellos proyectos que involucran muchas tareas interrelacionadas, mediante la resolución de un problema de la administración ... -
Alfabetización, razonamiento y pensamiento estadísticos: competencias específicas que requieren promoverse en el aula
(Red de Investigadores Educativos Chihuahua AC, 2021-09)El objetivo principal del ensayo consiste en analizar cómo el enfoque por competencias puede contribuir al cumplimiento de los fines de la educación estadística. Se realiza una revisión sobre el concepto de competencias, ... -
Algunos métodos para la solución de problemas de la física-matemática
(Universidad Nacional (Costa Rica), 1994)En este trabajo, se exponen algunos métodos para la solución de problemas de frontera, en regiones donde esta frontera es desconocida y se encuentra en movimiento (problema tipo Stefan). Como ejemplo se resuelve analíticamente ... -
Analysis of the School Climate Scale in University Environments (ECEAU)
(Universidad Nacional (Costa Rica), 2024-01)[Objective] The aim of this paper is to verify the factorial structure of the School Climate Scale in University Environments (ECEAU) through structural equation models (SEM). [Methodology] A non-experimental ... -
Analysis of an Augmented HDG Method for a Class of Quasi-Newtonian Stokes Flows
(Springer, 2015)In this paper we introduce and analyze a hybridizable discontinuous Galerkin (HDG) method for numerically solving a class of nonlinear Stokes models arising in quasi-Newtonian fluids. Similarly as in previous papers dealing ...