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Addressing the problem of lack of representativeness on syndromic surveillance schemes

Isabel Natário, M. Lucília Carvalho (2009)

Discussiones Mathematicae Probability and Statistics

A major concern with some contagious diseases has recently led to an enormous effort to monitor population health status by several different means. This work presents a modeling approach to overcome this poor data characteristic, allowing its use for the estimation of the true population disease picture. We use a state space model, where we run two processes in parallel - a process describing the non observable states of the population concerning the presence/absence of disease,...

Admissible invariant estimators in a linear model

Czesław Stępniak (2014)

Kybernetika

Let 𝐲 be observation vector in the usual linear model with expectation 𝐀 β and covariance matrix known up to a multiplicative scalar, possibly singular. A linear statistic 𝐚 T 𝐲 is called invariant estimator for a parametric function φ = 𝐜 T β if its MSE depends on β only through φ . It is shown that 𝐚 T 𝐲 is admissible invariant for φ , if and only if, it is a BLUE of φ , in the case when φ is estimable with zero variance, and it is of the form k φ ^ , where k ∈ 0 , 1 and φ ^ is an arbitrary BLUE, otherwise. This result is used in...

Advanced approach for the public transportation regulation system based on cybercars

Asma Melki, Slim Hammadi, Yves Sallez, Thierry Berger, Christian Tahon (2010)

RAIRO - Operations Research

In the last decade, the authorities require the use of safe, comfortable vehicles to assure a door to door aspect with respect of environment in the urban context. In this paper, we propose an advanced approach of transport regulation where we integrate cybercars into a regulation process as an alternative in disruption cases. For that, we propose an ITS architecture including public transportation and cybercars into the same framework. We will show that collaboration between these two systems...

Affinity between complex distribution functions.

Antonio Dorival Campos (1987)

Trabajos de Estadística

By analogy to the real case established by Matusita (1955) we introduce the concept of affinity between two complex distribution functions. We also establish a concrete expression for the affinity between two complex k-variate normal distributions when the covariance matrices assume a special form. Generalizations of these results are presented and the expressions here obtained are compared with those obtained by Matusita (1966, 1967) relative to the affinity between real k-variate normal distributions....

Afijación del tamaño de muestra en estrategias π PXM-estratificadas bajo un modelo superpoblacional.

Carlos N. Bouza (1982)

Trabajos de Estadística e Investigación Operativa

El problema de la afijación de los tamaños de muestra en estratos es abordado. Los sistemas de probabilidades desiguales se basan en una variable auxiliar Xt. La existencia de un modelo superpoblacional permite el desarrollo de criterios de afijación óptima. Las propiedades de los tamaños de muestra obtenidos son similares a los clásicos.

Algebraic Methods for Studying Interactions Between Epidemiological Variables

F. Ricceri, C. Fassino, G. Matullo, M. Roggero, M.-L. Torrente, P. Vineis, L. Terracini (2012)

Mathematical Modelling of Natural Phenomena

BackgroundIndependence models among variables is one of the most relevant topics in epidemiology, particularly in molecular epidemiology for the study of gene-gene and gene-environment interactions. They have been studied using three main kinds of analysis: regression analysis, data mining approaches and Bayesian model selection. Recently, methods of algebraic statistics have been extensively used for applications to biology. In this paper we present...

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