• Clifford Geometry: a Seminar 

      Várilly Boyle, Joseph C.; Gracia Bondía, José M. (1995-12-15)
      Este documento fue desarrollado durante el seminario de posgrado SP--1313 (Seminario en Matemática A) en 1995; por razones de difusión, fue redactado en inglés. Se trata de una exposición de los aspectos de la geometría ...
    • Climate-based descriptive models of dengue fever: The 2002 epidemic in Colima, Mexico 

      Chowell, Gerardo; Sánchez Peña, Fabio Ariel (2006-06)
      Dengue is a public health problem on the rise in many tropical regions and affects approximately 100 million people every year worldwide. In this paper, the authors retrospectively assess the association between five ...
    • Climate-Driven Statistical Models as Effective Predictors of Local Dengue Incidence in Costa Rica: A Generalized Additive Model and Random Forest Approach 

      Vásquez Brenes, Paola Andrea; Loría García, Antonio; Sánchez Peña, Fabio Ariel; Barboza Chinchilla, Luis Alberto (2019-12)
      Climate has been an important factor in shaping the distribution and incidence of dengue cases in tropical and subtropical countries. In CostaRica, a tropical country with distinctive micro-climates, dengue has been endemic ...
    • Clustering binary data by application of combinatorial optimization heuristics 

      Trejos Zelaya, Javier; Amaya Briceño, Luis Eduardo; Jiménez Romero, Alejandra; Murillo Fernández, Alex; Piza Volio, Eduardo; Villalobos Arias, Mario Alberto (2019-08-09)
      We study clustering methods for binary data, first defining aggregation criteria that measure the compactness of clusters. Five new and original methods are introduced, using neighborhoods and population behavior combinatorial ...
    • Clustering via ant colonies: Parameter analysis and improvement of the algorithm 

      Chavarría Molina, Jeffry; Fallas Monge, Juan José; Trejos Zelaya, Javier (2020-04-18)
      An ant colony optimization approach for partitioning a set of objects is proposed. In order to minimize the intra-variance, or within sum-of-squares, of the partitioned classes, we construct ant-like solutions by a ...
    • Combinatorics of renormalization as matrix calculus 

      Ebrahimi Fard, Kurusch; Gracia Bondía, José M.; Guo, Li; Várilly Boyle, Joseph C. (2006)
      We give a simple presentation of the combinatorics of renormalization in perturbative quantum field theory in terms of triangular matrices. The prescription, that may be of calculational value, is derived from first ...
    • Comparative analysis of dengue versus chikungunya outbreaks in Costa Rica 

      Sánchez Peña, Fabio Ariel; Barboza Chinchilla, Luis Alberto; Burton, David; Cintrón Arias, Ariel (2018-06)
      For decades, dengue virus has been a cause of major public health concern in Costa Rica, due to its landscape and climatic conditions that favor the circumstances in which the vector, Aedes aegypti, thrives. The emergence ...
    • Connes' noncommutative differential geometry and the Standard Model 

      Várilly Boyle, Joseph C.; Gracia Bondía, José M. (1993-11)
      In this paper, the Connes-Lott approach to the phenomenological Lagrangian of the standard theory of elementary particles is reviewed in detail. The paper is self-contained, in that the necessary foundations in noncommutative ...
    • Connes' tangent groupoid and strict quantization 

      Cariñena Marzo, José F.; Clemente Gallardo, Jesús; Follana, Eduardo; Gracia Bondía, José M.; Rivero, Alejandro; Várilly Boyle, Joseph C. (1999-12)
      We address one of the open problems in quantization theory recently listed by Rieffel. By developing in detail Connes' tangent groupoid principle and using previous work by Landsman, we show how to construct a strict flabby ...
    • Contribuciones al estudio de las métricas en análisis de datos 

      Bolaños Guerrero, Fabricio (2012-10-25)
      Nos hemos planteado estudiar la dependencia de los resultados al cambiar las métricas para el mtodo de Análisis en Componentes Principales (A.C.P.). En efecto, para este análisis el problema de la escogencia de la distancia ...
    • Contributions to the continuity problem for Lyapunov exponents 

      Sánchez Chavarría, Adriana Cristina (2018)
      O objetivo deste trabalho é estudar a continuidade e a semi-continuidade dos expoentes de Lyapunov em dois contextos diferentes. O primeiro diz respeito a cociclos lineares sobre dinâmicas parcialmente hiperbólicas. É ...
    • Correction to: The chirality theorem 

      Gracia Bondía, José M.; Mund, Jens; Várilly Boyle, Joseph C. (2018-10)
    • Dataducto para construir Emuladores Estadísticos con datos de NARCCAP 

      Fonseca Rivera, Johan; Alfaro Córdoba, Marcela; Barboza Chinchilla, Luis Alberto (2019-01-25)
      El proyecto de investigación B7166 de la Universidad de Costa Rica tiene como objetivo principal presentar un marco estadístico para realizar una emulación de variables obtenidas por medio del Modelo Climático Regional ...
    • Definable Additive Subgroups of Partial Differential Fields of Characteristic Zero with an Automorphism 

      Bustamante Medina, Ronald F. (2020-10-19)
      Abstract.The theory of partial differential fields of characteristic zero withan automorphism has a model companion denoted DCFmA. This theory isnot complete, but its completions are easily discribed. They are supersimpleand ...
    • Dengue model with early-life stage of vectors and age-structure within host 

      Sánchez Peña, Fabio Ariel; Calvo Alpízar, Juan Gabriel (2019-12)
      We construct an epidemic model for the transmission of dengue fever with an early-life stage in the vector dynamics and age-structure within hosts. The early-life stage of the vector is modeled via a general function that ...
    • Density functional theory on phase space 

      Blanchard, Philippe; Gracia Bondía, José M.; Várilly Boyle, Joseph C. (2012)
      Forty-five years after the point de départ [Hohenberg and Kohn, Phys. Rev. 1964, B864, 136] of density functional theory, its applications in chemistry and the study of electronic structures keep steadily growing. However, ...
    • Desarrollo y análisis del comportamiento humano adaptativo en modelos con relapso no lineal 

      Calvo Monge, Jimmy José (2023)
      En este proyecto proponemos estudiar las propiedades teóricas y nuevas aplicaciones de un algoritmo de formulación recuente para modelar las decisiones de contacto humanas en modelos epidemiológicos, que es llamado el ...
    • Dilation of a non-quasifree dissipative evolution 

      Várilly Boyle, Joseph C. (1981-03)
      A semigroup evolution for the 1/2-spin which admits a conservative dilation is known to be governed by a Bloch equation in a standard form. Here we construct a conservative dilation directly from the Bloch equation, thus ...
    • Diseño de fórmulas integrales 

      Alarcón Athens, Winston (1992)
      Presentamos una nueva metodología de diseño de fórmulas integrales que no utiliza explícitamente sumas de Riemann ni procesos de límite. El método consiste en partir de un modelo elemental con solución conocida, e interpretar ...
    • Distinguished Hamiltonian theorem for homogeneous symplectic manifolds 

      Cariñena Marzo, José F.; Gracia Bondía, José M.; Ibort Latre, Luis Alberto; López, Carlos; Várilly Boyle, Joseph C. (1991-09)
      A diffeomorphism of a finite-dimensional flat symplectic manifold which is canonoid with respect to all linear and quadratic Hamiltonians preserves the symplectic structure up to a factor: so runs the "quadratic Hamiltonian ...