Les productions animales en région wallonne, d'une économie de l'offre à une économie de la demande

Conference (2005, January 25)

L’Observatoire de la Consommation alimentaire en Région wallonne : pourquoi, comment ?

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2005), 9(3), 207-212

A stepwise selection technique of the most discriminant parameters of two groups applied to isoberlinia stands in Benin.

in Global Journal of Mathematical Sciences (2005), 4(1 & 2), 107-111

We describe for two groups a stepwise selection method of the most discriminant parameters, based on the logistic rule and the e632 error rate estimator in discriminant analysis. This stepwise ... [more ▼]

We describe for two groups a stepwise selection method of the most discriminant parameters, based on the logistic rule and the e632 error rate estimator in discriminant analysis. This stepwise discriminant method can be used as an alternative method in non-normality or heteroscedasticity situations, where the stepwise linear discriminant analysis is not suitable. The implementation of this stepwise method on Isoberlinia woodland and tree savannah identifies the most discriminant parameters as the global dominant height, the dominant height of Isoberlinia trees and the number of species per hectare. For these parameters, the value of the error rate associated with the logistic rule and estimated by th e632 estimators is 24,6 %. [less ▲]

Observatory of food consumption in Walloon Region (Belgium).

Scientific conference (2005)

This paper describes tasks entrusted to the Gembloux Agricultural University in the context of the Observatory of Food Consumption. At first, the document presents the establishment and the targets of ... [more ▼]

This paper describes tasks entrusted to the Gembloux Agricultural University in the context of the Observatory of Food Consumption. At first, the document presents the establishment and the targets of this organism. The database available, a consumption panel, is then described. Finally, some results, from studies carried out on the "structure of consumption", illustrate the use of the database. [less ▲]

Performance relative des règles linéaire, quadratique et logistique en analyse discriminante

in XXXVIèmes Journées de Statistique (2004, May)

Monte Carlo study is achieved to compare linear, quadratic and logistic classification rules for two groups, in 480 situations related to the type of distribution, the overlap of the populations, the ... [more ▼]

Monte Carlo study is achieved to compare linear, quadratic and logistic classification rules for two groups, in 480 situations related to the type of distribution, the overlap of the populations, the number of variables, the sample size and the heteroscedasticity degree of the model, which is measured by a parameter gamma defined in the study. The results of this study show that the quadratic rule is the best only for severe heteroscedastic normal or moderate non-normal models with high overlap. The linear rule is the best for homoscedastic normal or moderate non-normal models with low overlap. The logistic rule is the best for severe non-normal models except when homoscedasticity occurs. In the order situations linear and logistic rules have almost the same performance. By considering the parameters computed on the data samples, the linear rule gives the best performance for high values of r whereas logistic rule performs is best for low or moderate values of the same parameter. [less ▲]

L'Observatoire de la consommation alimentaire

in Vers une politique de qualité, à quel prix ? (2003, October 08)

Interprétation géométrique de la régression

in Notes de Statistique et d'Informatique (2003), (2), 1-28

L'Observatoire de la consommation alimentaire

in Vers une politique de qualité, à quel prix ? (2003)

Description de l'utilisation d'une base de données relative aux achats de produits alimentaires effectués par des ménages.

Macros Minitab pour la définition du plan d'échantillonnage à la réception dans le cas de mesures.

Software (2003)

Macros Minitab pour le calcul des courbes d'efficacité des cartes de contrôle Shewhart.

Software (2003)