132 research outputs found

    Algebraic treatment of the confluent Natanzon potentials

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    Using the so(2,1) Lie algebra and the Baker, Campbell and Hausdorff formulas, the Green's function for the class of the confluent Natanzon potentials is constructed straightforwardly. The bound-state energy spectrum is then determined. Eventually, the three-dimensional harmonic potential, the three-dimensional Coulomb potential and the Morse potential may all be considered as particular cases.Comment: 9 page

    Combinaison de codeurs par algorithme génétique : Application à la vérification du locuteur

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    Le domaine de la vérification du locuteur regroupe les applications pour lesquelles on désire identifier l'identité d'une personne à partir de sa voix. Le champ d'application couvre de nombreux secteurs tels que l'accès sécurisé, les transactions téléphoniques, la surveillance, l'indexation audio ou encore l'expertise judiciaire. Notre étude porte sur l'étape d'extraction de caractéristiques du système de reconnaissance du locuteur. Ce module a pour fonction d'extraire du signal de parole les informations pertinentes du point de vue de la discrimination inter-locuteur. Nous proposons dans cet article d'utiliser un algorithme génétique pour optimiser un système d'extraction de caractéristiques adapté à la reconnaissance du locuteur. La méthode proposée permet d'obtenir une amélioration significative du taux de reconnaissance sur la base Nist SRE 2005

    Methionine derivatives as green corrosion inhibitors: Review

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    This review exposed the inhibitory effect of methionine as green compound and its derivatives. The efficacy of these kind of molecules is related to two combined groups: amine and carboxylic acid as well as the presence of sulphur atom. Search on Scopus showed that a hundred publications in various aggressive solutions as HCl, H2SO4, H3PO4, HNO3, NaCl. The corrosion of iron, aluminium, lead, copper, nickel, tin … can be retarded using methionine derivatives which adsorbed on several kind of adsorption isotherms depending on the nature of metal/solution interface

    3D wedge filling and 2D random-bond wetting

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    Fluids adsorbed in 3D wedges are shown to exhibit two types of continuous interfacial unbinding corresponding to critical and tricritical filling respectively. Analytic solution of an effective interfacial model based on the transfer-matrix formalism allows us to obtain the asymptotic probability distribution functions for the interfacial height when criticality and tricriticality are approached. Generalised random walk arguments show that, for systems with short-ranged forces, the critical singularities at these transitions are related to 2D complete and critical wetting with random bond disorder respectively.Comment: 7 pages, 3 figures, accepted for publication in Europhysics Letter
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