170 research outputs found
Ampliación de estadística para la Ingeniería Técnica en Informática de Gestión
Enginyeria Tècnica en Informàtica de Gestió (Pla de 2001). IG23: Ampliació d'Estadístic
Estadística bàsica per a l'Enginyeria Tècnica en Informàtica de Gestió
Enginyeria Tècnica en Informàtica de Gestió (Pla de 2001). IG12: Estadístic
Type and Cotype in Vector-Valued Nakano Sequence Spaces
AbstractGiven a sequence of Banach spaces {Xn}n and a sequence of real numbers {pn}n in [1,∞), the vector-valued Nakano sequence spaces ℓ({pn},{Xn}) consist of elements {xn}n in ∏nXn for which there is a constant λ>0 such that ∑n(‖xn‖/λ)pn<∞. In this paper we find the conditions on the Banach spaces Xn and on the sequence {pn}n for the spaces ℓ({pn},{Xn}) to have cotype q or type p
Archimedean spectral densities for nonstationary space-time
In this work we investigate methods for modelling space-time nonstationary
data. We combine the approaches based on spatial adapting and spectral
tempering of spectral densities with the desirable features of Archimedean functionals.
We propose a class of spectral densities whose elements are shown to have a
natural ordering with respect to the set of functionals, and some interesting closed
forms for the covariance functions obtained as Fourier transform of the elements of
this new class are shown. Finally, we show a new class of nonstationary space-time
covariance functions, that are additionally asymmetric in time, and related to this
methodolog
Models of covariance functions of gaussian random fields escaping from isotropy, stationarity and non negativity
This paper represents a survey of recent advances in modeling of space or space-time Gaussian Random Fields (GRF), tools of Geostatistics at hand for the understanding of special cases of noise in image analysis. They can be used when stationarity or isotropy are unrealistic assumptions, or even when negative covariance between some couples of locations are evident. We show some strategies in order to escape from these restrictions, on the basis of rich classes of well known stationary or isotropic non negative covariance models, and through suitable operations, like linear combinations, generalized means, or with particular Fourier transforms
Sur la distribution de probabilité de l'indice d'intensité d'implication classique de Gras entre deux variables aléatoires binnaires
In this contribution we study the behavior of the classical Gras implication index as a
random variable, when applied to a couple of Bernoulli variables (X,Y) , independent
or not. We also show the effect of the conditional probability Y X p | on its probability
distribution, and specially on its mean value and quartiles.Dans cette contribution nous étudions le comportement de l'indice d'implication
classique de Gras comme une variable aléatoire quand celui-ci est associé à un couple
de variables de Bernouilli (X,Y) . Nous montrons également l'effet de la probabilité
conditionnelle Y X p | sur sa distribution de probabilité, plus particulièrement sur sa
moyenne et ses quartiles
Plug-Ins para el paquete R Commander de R: una aplicación al cálculo de probabilidades
R is a prestigious software for the analysis of statistical data, and R Commander is a graphical interface of R that provides menus and facilitates its use among the non-specialized public. In this work, it was analyzed the menu options offered by R Commander for the probabilities calculation in models of random variables, and built a plug-in to improve these options for students and users who are not familiar with the properties of the variables. The programming of the plug-ins requires the Tcl / Tk programming language, which can be used through the tcltk and tcltk2 of R libraries.R es un prestigioso software para el análisis de datos estadísticos, y R Commander es una interfaz gráfica de R que proporciona menús y facilita su uso entre el público no especializado. En este trabajo se analizaron las opciones de menú que ofrece R Commander para el cálculo de probabilidades en modelos de variables aleatorias, y se construye un plug-in para mejorar dichas opciones de cara a estudiantes y usuarios que no estén familiarizados con las propiedades de las probabilidades. La programación de los plug-ins precisa del lenguaje de programación Tcl/Tk, que se puede utilizar a través de las librerías tcltk y tcltk2 de R
On the probability distribution of the classical Gras implication index between two binary random variables
In this contribution we study the behavior of the classical Gras implication index as a random variable, when applied to a couple of Bernoulli variables, independent or not. We also show the effect of the conditional probabilityon its probability distribution, and specially on its mean value and quartiles
On potentially negative space time covariances obtained as sum of products of marginal ones
Most of the literature on spatio-temporal covariance models proposes structures
that are positive in the whole domain. However, problems of physical, biological or
medical nature need covariance models allowing for negative values or oscillations
from positive to negative values. In this paper we propose an easy-to-implement
and interpretable class of models that admits this type of covariances. We show
particular analytical examples that may be of interest in the biometrical contex
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