scispace - formally typeset
Search or ask a question

Showing papers by "University of Grenoble published in 1976"


Journal ArticleDOI
TL;DR: In this paper, the decay law of the turbulence generated by a vertically oscillating grid in a water tank and the entrainment across a salinity interface caused by this turbulence have been investigated experimentally.
Abstract: The turbulence generated by a vertically oscillating grid in a water tank and the entrainment across a salinity interface caused by this turbulence have been investigated experimentally. Measurements were carried out in a homogeneous layer of fluid as well as a two-layered fluid, which permitted us to determine the decay law of this turbulence and the way in which the structure of the turbulence depends on the mesh size and on the frequency and amplitude of the grid oscillation. It was found that the turbulent kinetic energy decays with distance from the grid according to a power law , the Peclet number being high. While the bearing of these results on the problem of the thermocline or an inversion is clear we wish to emphasize that the spatial decay of turbulence is interesting in itself.

378 citations


Journal ArticleDOI
TL;DR: The model reference adaptive system approach together with the positivity lemma for time varying discrete systems are used to construct recursive identifiers with a parallel adjustable model, using adaptation algorithms having a decreasing gain.
Abstract: The model reference adaptive system approach together with the positivity lemma for time varying discrete systems are used to construct recursive identifiers with a parallel adjustable model, using adaptation algorithms having a decreasing gain. Identification of single input-single output systems and of multivariable systems is discussed. The identifiers assure an asymptotic unbiased parameter estimation in the presence of noise obscured measurements. Experimental results obtained from simulated data and from the identification of a paper machine are presented. The comparison with the performances of other identification methods is discussed.

273 citations


Book ChapterDOI
01 Jan 1976
TL;DR: It is shown that, when Max‖t i+1−t i‖=δN goes to zero, the resulting estimate (resp, maximum likelihood estimate based on observations at t 0,…,t N ), is bounded in probability.
Abstract: This paper is concerned with the problem of estimation of the drift parameter ϑ in a linear stochastic differential equation, with constant coefficients. When continuous sampling of the solution process is available, the maximum likelihood estimate \(\hat \theta _\tau\), based on observation in [0, T] is defined in terms of stochastic and ordinary integrals. So, in practice, to compute \(\hat \theta _\tau\)one has to approximate these integrals by appropriate finite sums which only depend on some discrete sampling in {t 0, t 1,…,t N } ⊂[0, T]. If \(\hat \theta _{N, T}\)(resp. \(\tilde \theta _{N, T}\)) denotes the resulting estimate (resp, maximum likelihood estimate based on observations at t 0,…,t N ), we show that, when Max‖t i+1−t i‖=δN goes to zero, \(P - \lim \hat \theta _{N, T} = P - \lim \tilde \theta _{N, T} = \hat \theta _{\rm T} , \delta _N^{ - 1/2} (\hat \theta _{N, T} )\) and \(\delta _N^{ - 1/2} (\tilde \theta _{N, T} - \hat \theta _T )\) both bounded in probability.

75 citations


Journal ArticleDOI
TL;DR: The first Euromech Colloquium on Magnetohydrodynamics (MHD) as discussed by the authors was organized in conjunction with the Centre National de la Recherche Scientifique and held at Grenoble from 16-19 March 1976 with 60 participants from 10 countries present.
Abstract: This paper is a summary of the first Euromech Colloquium to be held on Magnetohydrodynamics (MHD). It was organized in conjunction with the Centre National de la Recherche Scientifique and held at Grenoble from 16–19 March 1976 with 60 participants from 10 countries present. Papers were presented on laminar and turbulent MHD duct flows; heat transfer and two-phase flows in MHD; the effects of magnetic fields on instabilities and turbulence; the motion of and forces on solid objects in MHD flows; flow-measurement methods, and applications of MHD in the metallurgical industries, in sodium technology and in liquid-metal power generation. Our main conclusion is that there are many industrial applications of the existing body of research findings in MHD, but that quite new research problems have arisen as a result of the new applications, and that these need investigation. MHD lives!

29 citations




Book ChapterDOI
01 Jan 1976
TL;DR: The LL(1) techniques described in this chapter were discovered by Foster and received a theoretical treatment in Knuth 71 and are topdown, deterministic with one character of look-ahead.
Abstract: Since this course is not solely concerned with syntax analysis, a choice has had to be made amongst a large number of possible methods. We have chosen to present the two methods which seem to be the most fundamental in theoretical terms. The choice was, of course, much easier amongst top-down methods, of which there are few. The LL(1) techniques described in this chapter were discovered by Foster [Foster 68] and received a theoretical treatment in [Knuth 71]. The method is topdown, deterministic with one character of look-ahead.

14 citations


Journal ArticleDOI
TL;DR: In this paper, the preferential conformations and relative stabilities of six para-substituted, three ortho-sub-stitussed and two diortho-succotransformed benzyl fluorides were studied using PCILO 2 and CNDO/2.

10 citations


Journal ArticleDOI
TL;DR: The purpose is to define a methodology for writing (micro) programs to test CPU's for which no or few test facilities are available.
Abstract: Our purpose is to define a methodology for writing (micro) programs to test CPU's for which no or few test facilities are available.

9 citations


Journal ArticleDOI
TL;DR: This correspondence shows how recursion can be used to simplify testing of combinational circuits and the extension of the concept of simple iteration to complex iteration that may realize more complex recursive functions, is defined.
Abstract: This correspondence shows how recursion can be used to simplify testing of combinational circuits. Necessary and sufficient conditions for testing simple iterative arrays (one-dimensional) with a fixed number of tests (independent of the number of cells) are given. Multiple faults and diagnosis in such circuits are also studied. The extension of the concept of simple iteration to complex iteration that may realize more complex recursive functions, is defined. Examples of such complex iterative circuits are studied.

5 citations



Journal ArticleDOI
TL;DR: In this paper, a partir de mesures spectrophotometriques et potentiometrizques, nous avons determine la constante d'autoprotolyse de l'acide formique puis, dans ce solvant, les constantes acides.

Journal ArticleDOI
TL;DR: In this article, the electron densities at the nucleus were estimated from measurements of the change in electron capture rate of /sup 52/Fe in different iron compounds, leading to a calibration constant alpha for the /sup 57/Fe isomer shift: alpha =-0.31+/-0.04 a/sub 0/ /sup 3/ mm s/sup -1/.
Abstract: Electron densities at the nucleus are estimated from measurements of the change in electron capture rate of /sup 52/Fe in different iron compounds. This leads to a calibration constant alpha for the /sup 57/Fe isomer shift: alpha =-0.31+/-0.04 a/sub 0/ /sup 3/ mm s/sup -1/.

Book ChapterDOI
01 Jan 1976
TL;DR: It may seem misleading to talk so much about language definition methods when the authors wish to examine the state of the art in compiler-compilers, but the one is directly dependent on the other.
Abstract: It may seem misleading to talk so much about language definition methods when we wish to examine the state of the art in compiler-compilers, but the one is directly dependent on the other. Compiler implementers have always complained that the language definers ignore their problems, but both sides should listen more carefully to what the other has to say.

Book ChapterDOI
01 Jan 1976
TL;DR: The generation of executable machine code is obviously completely conditioned by the storage allocation techniques which are to be used at run-time, and an extremely wide variety of techniques exist.
Abstract: The generation of executable machine code is obviously completely conditioned by the storage allocation techniques which are to be used at run-time. We have tried to give some idea of the basic storage allocation mechanisms, without going into too much detail. It should be noted that an extremely wide variety of techniques exist, and many interesting ideas have not been discussed here. However, most of the variety stems from efforts to improve the basic themes that we have developped, or to adapt them to particular machines.


Proceedings ArticleDOI
07 Jun 1976
TL;DR: A new computer organization which allows the pipeline execution of a polish-string code with a FI-FO queue, that holds values just accessed by an Access Station until they are used as operands by an Execution Station for an arithmetic or logical operation.
Abstract: This paper describes a new computer organization which allows the pipeline execution of a polish-string code. The central characteristic of the proposed organization is a FI-FO queue, that holds values just accessed by an Access Station, until they are used as operands by an Execution Station for an arithmetic or logical operation. Operands are taken out of the queue by means of two pointers whose modifications are managed by a Control Station. This new computer organization is capable of high performance, since access to variables and execution of operations are performed in parallel with control functions required by the input program. A solution to access conflicts is proposed, using a content addressable memory that holds the names of the variables whose modification is deferred. This architecture is currently in application for the design of a high-level PASCAL computer.


Proceedings ArticleDOI
01 Sep 1976
Abstract: We discuss in this paper, the design of a very large scale integrated memory. This memory is composed of partly faulty LSI chips and reconfiguration circuitry masking the faulty bits. Different reconfiguration policies are given leading to memory structures. Practical solutions for 4 K × 9 bits and 16 K × 1 bit memories are given.

08 Dec 1976
TL;DR: In this paper, the authors decrivons ici deux cases which viennent s'ajouter aux onze cases deja decrits dans la litterature.
Abstract: L'application a la pathologie renale de la technique d'immunofluorescence renale a permis de mettre en evidence, dans la cirrhose hepatique d'origine alcoolique, l'existence de glomerulonephrites a depots mesangiaux d'Ig A. Nous en decrivons ici deux cas qui viennent s'ajouter aux onze cas deja decrits dans la litterature. En dehors des signes lies a l'existence de la cirrhose hepatique, la symptomatologie est soit nulle, soit peu abondante. Dans ce deuxieme cas, on peut cependant note : - la survenue d'episodes d'hematuries macroscopiques ; - l'existence d'une proteinurie moderee ou dans de rares cas d'un syndrome nephrotique ; - l'existence d'une HTA moderee ; - l'existence d'une insuffisance renale chronique dans de rares cas. Le bilan immunologique d'orientation est peu perturbe : on note simplement l'augmentation isolee de l'Ig A serique dans la plupart des cas. Les lesions histologiques renales sont representees en microscopie optique : - Au niveau du Glomerule : par la hyalinose mesangiale et par l'hyperplasie cellulaire endo-capillaire. Ces lesions sont soit diffuses, soit focales. Il n'y a pas d'hyperplasie cellulaire extra-capillaire dans la majorite des cas, pas de necrose des basales et il y a peu de phenomenes exsudatifs. - Au niveau des Vaisseaux : par les lesions vasculaires degeneratives nettement plus marquees que ne le voudrait l'âge du sujet. - Au niveau des Tubes : par des phenomenes degeneratifs de l'epithelium tubulaire. - Au niveau du Tissu Interstitiel : par une atteinte inflammatoire ou fibreuse. En microscopie electronique, les lesions se situent presque exclusivement dans le mesangium et surtout sur la matrice mesangiale ou il existe des phenomenes degeneratifs varies. L'interposition de cellules mesangiales dans les parois capillaires du floculus est rare et permet alors de porter le diagnostic de GN parieto-proliferative. En immunofluorescence, les depots d'Ig A sont trouves dans tous les cas, associes dans 9 cas sur 13 au C3, dans 8 cas sur 13 a l'Ig G, et dans 7 cas sur 13 a l'Ig M. Tous ces caracteres font qu'on peut faire rentrer cette glomerulonephrite dans le cadre des GN a depots mesangiaux d'Ig A. Mais nous savons que ce cadre reunit de facon artificielle un certain nombre de GN dont on ne peut expliquer, pour l'instant ni l'etiologie, ni la pathologie. Les deux cas de GN que nous decrivons representent pour nous un moyen d’etude des GNM Ig A, puisque survenant dans un contexte tres particulier, celui d'une cirrhose hepatique d'origine alcoolique. Le mecanisme de cette GN semble etre lie a deux facteurs : l'Ig A et le mesangium. L'Ig A est pathologique ; elle est elevee en quantite et anormale en qualite, intermediaire entre l'Ig A anormale et myelomateuse. Elle pourrait-alors former : - soit par l'agregation de plusieurs molecules d'Ig A ; - soit par liaison avec un antigene, de gros complexes allant se loger en position mesangiale. Le mesangium quant a lui, voit se deposer au niveau de son tissu conjonctif intercellulaire ces complexes immuns. On peut donc evoquer soit un deficit de la fonction de « decrassage » des cellules mesangiales, soit la creation de liaison de type antigene-anticorps entre ces complexes et certains composants du tissu conjonctif. Enfin, on peut supposer que l'existence de ces complexes immuns a un role pathogene vis a vis d'autres organes, et en particulier du foie.

06 May 1976
TL;DR: In this paper, a revue generale detaillee des cellules endocrines de la muqueuse gastrique is presented, with a focus on the identification of cellule endocines.
Abstract: 1) Le present travail a pour objectif une revue generale detaillee des cellules endocrines de la muqueuse gastrique 2) Depuis les travaux initiaux de KULTSCHITZKY et de P MASSON, de nombreux auteurs ont identifie dans la portion antrale de la muqueuse gastrique des elements de morphologie particuliere dont l'un des caracteres etait un pouvoir d'argento-reduction (argentaffinite) ou d'argyrophilie Actuellement, ces types cellulaires sont consideres comme identiques et responsables d'une fabrication d'aerotonine 3) Cinq grands types de cellules endocrines peuvent etre rencontres dans la muqueuse gastrique, et definis par des criteres morphologiques et histochimiques : - la cellule "EC" ou cellule a serotonine - la cellule "G" ou cellule a gastrine - la cellule "ECL" - la cellule "A" - la cellule "D" Ces trois derniers types cellulaires etant presumes responsables de l'elaboration respective de l'histamine, du glucagon, de secretine, et peut etre d'autres amines Cette classification aujourd'hui admise par tous les chercheurs a cependant ete discutee pendant son elaboration Des distinctions en sous-groupes morphologiques reposant sur de simples variations de taille des granules secretoires, peuvent etre la source de difficulte de comprehension pour les non inities 4) L'unite de ce systeme endocrinien de la muqueuse gastrique est d'ordre fonctionnel et soutenue par des proprietes biochimiques et histochimiques : elles entrent a la fois dans le systeme APUD (PEARSE) et dans le systeme endocrinien diffus 5) Ces diverses notions conduisent actuellement a une meilleure connaissance des tumeurs carcinoides et des carcinomes a cellules basophiles de l'estomac Il existe vraisemblablement, d'une part des tumeurs monomorphes - soit purement "carcinoide", a cellule "EC", - soit a cellule "G" ou "gastrinomes", et d'autre part des tumeurs composites a cellules "EC", associees aux cellules "ECL", "A", ou "B", dans des proportions variables 6) Enfin, l'appartenance de ces cellules au SED permet de mieux comprendre des associations morbides comme celle du syndrome de Llyod : polyadenomatose endocrinienne avec syndrome de ZOLLINGER-ELLISON Dans ce domaine de la pathologie, les progres de nos connaissances sont lies a la mise en commun pluridisciplinaire des techniques d'investigations cliniques, biochimiques, et morphologiques : l'histochimie, la microscopie electronique, l'immunofluorescence y prenant une place de choix