http://archives.univ-biskra.dz/handle/123456789/1201 2026-04-06T22:08:36Z http://archives.univ-biskra.dz/handle/123456789/1241 Titre: APPROCHE REGIONALE POUR L’ESTIMATION DES PRECIPITATIONS JOURNALIERES EXTREMES DU NORD EST ALGERIEN Auteur(s): TAMARA BENABDESSELAM; HOCINE AMARCHI Résumé: Information on precipitation magnitudes and their frequencies is needed in various projects related to water. In this study, the regional frequency analysis based on L-moments was used to improve the quality of estimating of the annual maximum daily precipitations of the north eastern area of Algeria represented by 50 measuring stations. The investigated area was divided into two regions statistically homogeneous in terms of L-moments ratios. Among the different tested distributions, (i) the Generalized Extreme Value (GEV) distribution has been identified as the most appropriate regional distribution for modeling precipitation in the northern region (region 1) characterized by a Mediterranean climate and (ii) the generalized lognormal distribution (LN3) for region 2 of southern part subject to semi-arid climate. Growth curves, derived from the regional distributions, were established for each homogeneous region. The growth curves shapes difference reflects the difference between the two homogeneous regions precipitation patterns. Therefore, to estimate the different return period’s precipitation quantiles in a given site of the region, the mean precipitation of the site has to be multiplied by the corresponding regional quantile. Comparison of estimated quantiles given by the regional and local approach showed that for 50.4 % of stations, atsite model underestimates the quantiles having high return periods. 2013-01-11T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/1240 Titre: L’INTÉGRALE FLOUE DANS LA FUSION D’UN SYSTÈME MULTICLASSIFIEURS POUR LA RECONNAISSANCE DE VISAGES Auteur(s): MÉBARKA BELAHCENE; ABDELMALIK OUAMANE Résumé: Notre objectif c’est l’identification des personnes par la modalité visage en se basant sur une fusion multi classifieurs. Donc, la fusion est prise en considération. Nous traitons la question de la fusion et ses différents niveaux. Particulièrement la fusion des scores qui fait objet de notre travail. Les principales méthodes de normalisation des scores Znorm, QLQ et function double sigmoide associées à la combinaison par la logique floue sont étudiées. Nous proposons l’application des intégrales floues de Sugeno et de Choquet pour la fusion des scores d’un système multi-classifieurs de vérification faciale. Les systèmes de combinaison des scores sont construits par l’extraction des caractéristiques de visage par l’utilisation des ondelettes de Gabor et l’Analyse en Composantes Principales (ACP) plus le modèle discriminant Linéaire Amélioré de Fisher (EFM) comme méthode de réduction d’espace de données 2013-01-11T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/1239 Titre: PROPRIETES MECANIQUES ET ANTICORROSIVES DES REVETEMENTS ELECTRODEPOSES A BASE DE NICKEL RENFORCES PAR DES NANOPARTICULES DE TIO2 Auteur(s): C. SIAD; S. LARDJANI; A. MEKKAOUI Résumé: The need for improved the coatings with better properties has developed the requirement for the use of composite electrodeposits, by embedding solid particles in the structure of nickel, such as titanium oxide (TiO2) which is a hard compound, chemically stable and irreducible. The objective of this work is the characterization of the composite deposits nickel titanium on mild steel substrate E 34. These deposits are obtained from watts bath of electrodeposition chlorinated. The characterization has been carried out by XR diffraction and scanning electronic microscopy SEM for the structural and morphological characterization. Mechanical measurements and corrosion tests in a 3,5 % NaCl solution are used to confirm the riability of the deposited films. The techniques used are the weight loss and polarization. The results have revealed a higher corrosion resistance of the composite deposits. 2013-01-11T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/1238 Titre: INCREASING FLUX DENSITY BY HTS SHIELDING PELLET IN SUPERCONDUCTING SYNCHRONOUS MACHINE BASED ON FLUX CONCENTRATION Auteur(s): R. BOUMARAF; S. M. MIMOUNE; L. ALLOUI; M. L. KHENE Résumé: In this paper, we propose a solution which enhances the performance of the inductor in high-power superconducting synchronous machines based on the flux concentration. The work is done by keeping the same topology and using a high temperature superconducting shielding pellet located between the two coils of the inductor. This pellet permits to recover the magnetic field which vanishes in the medium region due to the opposite direction of the coils. We did a 3D magnetostatic field analysis using the control volume method with unstructured grid. This analysis showed that the suggested solution allowed obtaining a maximum efficiency of about 8% in the flux density. 2013-01-11T00:00:00Z