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The Observatory of Food Consumption in the Walloon Region (Belgium): why, how ? The behaviour of food products consumers is observed by several organisms. This paper gives some informations about situations abroad and in Belgium. It describes the Observatory of Food Consumption established in the Walloon Region.

Consequences of variable selection on the interpretation of the results in multiple linear regression. A priori or a posteriori variable selection is a common practise in multiple linear regression. The user is however not always aware of the consequences on the results due to this variable selection. In this note, the presence of omission bias and selection bias is explained by means of a Monte Carlo experiment. The consequences of variable selection on the regression coefficients and on the predicted values are then analysed. The user’s attention is drawn to the risk of misinterpretation of the regression coefficients, specially after variable selection. On the other hand, the consequences of variable selection on the predicted values of the response variable are rather limited, at least for the given example.

Use of bootstrap for statistical problems related to estimation of parameters. Use of bootstrap for statistical problems related to estimation of parameters. This paper describes bootstrapping for the estimation of the standard error and the bias of an estimator and for computing confidence intervals. The methods are illustrated by an example.

Twelve Gossypium genotypes (species, fertile interspecific allotetraploid and allohexaploid hybrids, backcross progeny of interspecific hybrids) characterized by drastic differences in their seed gossypol content were used to design a visual quantification method of the gossypol concentration in cotton seeds. After developing an high performance liquid chromatography (HPLC) method that allowed measurement of gossypol content in single seed samples, the results of 123 HPLC analyses carried out seed-by-seed were compared with different parameters characterizing the level of gossypol glands in the seed. A significant correlation was found between the gossypol content %G determined on single seeds by HPLC and the number N of gossypol glands per seed section area (S, expressed in [mm.sup.2]), leading to the establishment of the following model: %G = [b.sub.i] (N/S), where the regression coefficient [b.sub.i] depends on the cotton genotype considered. The estimation of %G directly from N/S is a rapid and accurate method which can be used in breeding programs to screen the progeny of cotton genotypes showing a high segregation for their seed gossypol content., ONE OF THE MAIN TRAITS of Gossypium L. is the presence of pigment glands throughout the plant (Altman et al., 1990). Gossypol, a triterpenoid aldehyde, and its derivatives are predominant [...]

We focus on the analysis and design of two different sliding mode observers for dynamic Takagi--Sugeno (TS) fuzzy systems. A nonlinear system of this class is composed of multiple affine local linear models that are smoothly interpolated by weighting functions resulting from a fuzzy partitioning of the state space of a given nonlinear system subject to observation. The Takagi-Sugeno fuzzy system is then an accurate approximation of the original nonlinear system. Our approach to the analysis and design of observers for Takagi-Sugeno fuzzy systems is based on extending sliding mode observer schemes to the case of interpolated multiple local affine linear models. Thus, our main contribution is nonlinear observers analysis and design methods that can effectively deal with model/plant mismatches. Furthermore, we consider the difficult case when the weighting functions in the Takagi--Sugeno fuzzy system depend on the estimated state. Index Terms--Dominant linear models, fuzzy sliding mode observers, interpolation of multiple linear local models, Luenberger fuzzy observers, Takagi-Sugeno (TS) fuzzy systems.