Showing papers by "University of Grenoble published in 1978"
TL;DR: A new approach to the conceptual design of logical schemata for relational databases by means of functional dependencies and multivalued dependencies is presented and first-order hierarchical decomposition is introduced.
Abstract: The purpose of this paper is to present a new approach to the conceptual design of logical schemata for relational databases. One-to-one, one-to-many, and many-to-many relationships between the attributes of database relations are modeled by means of functional dependencies and multivalued dependencies. A new type of dependency is introduced: first-order hierarchical decomposition. The properties of this new type of dependency are studied and related to the normalization process of relations. The relationship between the concept of first-order hierarchical decomposition and the notion of hierarchical organization of data is discussed through the normalization process.
159 citations
TL;DR: In this paper, the authors present preliminary results for π + − 16 O elastic scattering at 79, 114, 16, 240 and 343 MeV. Statistical uncertainties are about 5% for angular bins of 1.5°.
35 citations
TL;DR: The goal of the paper is to propose test methods for wired or microprogrammed control units without special test facilities: no special access path, i.e., no direct and exhaustive observation means, allowing an efficient test with respect to errors hypothesis.
Abstract: The goal of the paper is to propose test methods for wired or microprogrammed control units without special test facilities: no special access path, i.e., no direct and exhaustive observation means. Consequently, the control unit will be tested through the current control algorithms under "normal" sequencing facilities and through the controlled operative part; the proposed methodology consists of choosing an adequate set of algorithms and specific data, allowing an efficient test with respect to errors hypothesis.
23 citations
TL;DR: In this article, Π + and Π − data were taken for scattering from 18 O and 28 Si at 180 MeV for both elastic and inelastic cases. But the sensitivity of Π− to 2 additional neutrons was shown to be greater for both cases.
16 citations
TL;DR: In this paper, the coupling constants of piperidine, 4-t-butylpiperidine and five C-methyl substituted piperidines and of the corresponding N-methyl compounds have been measured.
Abstract: Carbon-13 chemical shifts and 1J(CH) coupling constants of piperidine, 4-t-butylpiperidine, five C-methyl substituted piperidines and of the corresponding N-methyl compounds have been measured. These NMR parameters have also been determined for the fourteen corresponding hydrochlorides. The N-methyl-C-methyl piperidinium salts showed two stereoisomers on the positive nitrogen atom. The effect of protonation is discussed in relation to charge and steric effects and the methyl substituent effects are compared with those of methyl-substituted cyclohexanes. Deviations from the general tendencies in the series are correlated with changes in ring conformations around the highly crowded substituted carbons.
16 citations
TL;DR: Various methods of approximating the eigenvalues and invariant subspaces of nonself-adjoint differential and integral operators are unified in a general theory.
13 citations
9 citations
TL;DR: In this paper, conditions optimales de preparation du bore, par vapodeposition chimique en phase gazeuse, a partir de melanges BCl3-H2 ou BBr3H2 au contact d'un substrat inerte (exces de bore), ont ete precisees a l'aide d'une approche thermodynamique.
Abstract: Resume Les conditions optimales de preparation du bore, par vapodeposition chimique en phase gazeuse a partir de melanges BCl3-H2 ou BBr3-H2 au contact d'un substrat inerte (exces de bore), ont ete precisees a l'aide d'une approche thermodynamique. La methode utilisee, qui suppose que des etats proches de l'equilibre sont atteints au voisinage du substrat, est basee sur la minimisation de la fonction enthalpie libre du systeme compte tenu des bilans de matiere. Entre 1200 et 1900 K et pour une pression totale d'une atmosphere, la reduction de BCl3 par l'hydrogene fait apparaitre deux types de sous-produits indesirables: BHCl2 a toutes temperatures, et les souschlorures BCl2 et BCl a haute temperature; BHCl2 est le produit principal de la reduction de BCl3 aux temperatures les plus basses. La reduction de BCl3 n'est pas quantitative dans les conditions habituelles de preparation du bore. La formation des sous-produits et l'importance du recyclage de BCl3 sont minimises en operant a partir de melanges BCl3-H2 riches en hydrogene. La quantite de bore forme passe par un maximum pour une temperature voisine de 1700 K. Des conclusions analogues ont ete obtenues pour BBr3. Toutefois, entre 1000 et 1500 K, la quantite de sous-produits formes (BHBr2 et/ ou BBr2) demeure plus faible que dans le cas de BCl3. Le rendement en bore est plus eleve et le taux de recyclage de BBr3 plus faible. BBr3 apparait donc comme une meilleure source de bore pour la vapodeposition chimique.
9 citations
TL;DR: In this paper, a system was built that increases the angular range of the SIN pion spectrometer from 135° to 180° which can be fairly easily inserted whenever large angle data is desired.
5 citations
01 Jan 1978
TL;DR: In this article, the stratified turbulent shear flow established by a cold wall jet issuing into an ambiant heated stream has been investigated experimentally and it was found that entrainment ceases when the Richardson number Ri, based on the scales of the free mixing zone of the wall jet, increased to a value of 1/3 and the same value has also been reported for the stop of the growth of a mixing layer.
Abstract: The stratified turbulent shear flow established by a cold wall jet issuing into an ambiant heated stream has been investigated experimentally. Conditions were such that buoyancy remained negligible in the jet establishment zone but became important further downstream. It was found previously that entrainment ceases when the “difference” Richardson number Ri, based on the scales of the free mixing zone of the wall jet, increased to a value of 1/3 and the same value has also been reported for the stop of the growth of a mixing layer. Flow visualisations carried out in a mixing layer with a Reynolds number close to that of the jet (≈103) _showed that it is the pairing process which is inhibited when Ri ≽ 1/3. From the results obtained in the jet it is inferred that a pairing process is also fundamental to the jet growth, even though no two-dimensional spanwise rolls exist in the jet and the spanwise temperature variation seems to indicate streamwise rolls. The turbulence becomes increasingly more anisotropic with increasing Ti and the vertical heat flux decreases relative to the longitudinal heat flux or the vertical momentum flux. These variations are explained using time scale arguments. When entrainment ceases the turbulence intensity was found to be still high and the Reynolds stress still appreciable, a result which is somewhat unexpected.
3 citations
01 Jan 1978
TL;DR: Relatively little is known about the small scale structure in fully developed turbulence and there is a great lack of experimental data, but on this aspect of turbulence, theories seem to be more advanced than experiments.
Abstract: Relatively little is known about the small scale structure in fully developed turbulence and there is a great lack of experimental data. The reasons for this lack are various inherent difficulties in getting reliable data on the statistics of the small scale structure, and in fact, on this aspect of turbulence, theories seem to be more advanced than experiments.
10 Oct 1978
TL;DR: In this article, the authors present, in a comprehensive manner, some important concepts that influenced the design of information systems in the last few years, focusing on recent progress in design methods, and on the development of tools that may be used to apply these methods.
Abstract: The purpose of this survey is to present, in a comprehensive manner, some important concepts that influenced the design of information systems in the last few years. Emphasis is placed on recent progress in design methods, and on the development of tools that may be used to apply these methods.
Journal Article•
TL;DR: A Cesar Vallejo se lo conoce sobre todo por su obra poetica Tungsteno, compuesta a principios de 1931, se han estudiado muy poco hasta ahora sus relatos literarios en prosa as mentioned in this paper.
Abstract: A Cesar Vallejo se lo conoce sobre todo por su obra poetica. Fuera de su novela proletaria Tungsteno, compuesta a principios de 1931, se han estudiado muy poco hasta ahora sus relatos literarios en prosa. Paco Yunque fue escrito en Madrid en abril de 1931 1, poco despues de terminada Tungsteno, para la editorial espanola Cenit que no accedio a publicarlo por considerarlo, segun afirma Georgette de Vallejo, "demasiado triste" para un cuento de ninos2• Interesa notar que tanto Paco Yunque como Tungsteno y posteriormente los Poemas humanos y Espana aparta de m( este caliz corresponden al periodo del compromiso ideologico del escritor con el marxismo.
TL;DR: In this article, the authors propose a caract6ris6es les sous-alg~bres de Lie de End (I/) who son l 'algSbre de Lie' de tels groupes.
Abstract: Soit V un espace vectoriel r6el de dimension finie. Pour route norme sur V, on peut consid6rer le plus grand sous-groupe de GL(V) qui la conserve. Dans [1] sont caract6ris6es les sous-alg~bres de Lie de End (I/) qui son l 'algSbre de Lie de tels groupes. Dans ce qui suit, on am61iore cette caract6risat ion de deux faqons: on l '6tend aux groupes eux-mames, et l 'on mont re qu 'on peut choisir la no rme str ic tement convexe et analytique.
01 Jan 1978
TL;DR: In this article, a methode d'adequation du processus multivariable Gaussien continu est proposee quand on a pour seule information le fait que sa densite spectrale est rationnelle.
Abstract: Une methode d'adequation du processus multivariable Gaussien continu est proposee quand on a pour seule information le fait que sa densite spectrale est rationnelle. L'utilisation d'une classe speciale de representations Markoviennes permet de specifier le processus observe a l'aide d'un ensemble de parametres non redondants. L'estimation de ces parametres est basee sur une fonction de vraisemblance approchee, qui fournit des estimateurs asymptotiquement normaux et efficaces.
10 Oct 1978
TL;DR: This paper describes a general model for distributed data (MOGADOR) together with a language for describing and manipulating dispersed data and shows how this can be used for modeling and manipulating distributed data.
Abstract: This paper describes a general model for distributed data (MOGADOR) together with a language for describing and manipulating dispersed data.