• Ultraproductos de f-anillos proyectables 

      Guier Acosta, Jorge Ignacio (2009-02-18)
      In [7], Keimel representes the projectable f-rings as continuous sections of Hausdorff sheaves of totally ordered rings. Here, we give a result about the representation of ultraporducts of projectable f-rings in terms of ...
    • Un enfoque diferente de las técnicas de clustering para el estudio de epidemias 

      Casas Cardoso, Gladys M.; Grau Abalo, Ricardo (2009-02-18)
      Classification of an outbreak with the category of epidemics requires that some epidemiological and statistical parameters, which have to be studied simultaneously, are satisfied; mathematical theory helps epidemiologists ...
    • Un frailty aditivo en modelos de supervivencia bivariante 

      Navarrete Álvarez, Esteban; García Leal, Julia; Lara Porras, Ana María (2009-02-18)
      Bivariate survival models based on the presence of an unobseved random covariate, grailty, tend to assume a proportional hazard hypothesis. A bivariate survival model is constructed. It is based on frailty model that acts ...