Showing papers by "University of Lorraine published in 2002"

Droit, gouvernement d'entreprise et marchés de capitaux

Abstract: Cet article discute du role du droit dans les structures de gouvernement d’entreprise et dans le developpement des marches financiers. Il met en evidence les effets des regles de droit sur les performances comparees des systemes financiers dans les pays de common law et dans les pays de droit civil. La relation entre protection des investisseurs et developpement des marches financiers est plus particulierement mise en avant et la these de l’efficience economique de la common law est debattue. L’article passe en revue les travaux recents du Law and Finance qui recherchent l’origine de l’efficacite des formes de gouvernement d’entreprise dans des facteurs juridiques. La nature et les performances des systemes financiers dans les pays de l’OCDE apparaissent en effet correlees aux traditions juridiques de ces pays. Nous soulignons que non seulement le contenu des regles mais aussi leurs conditions d’application influencent l’architecture financiere. Mais les systemes juridiques sont egalement le produit de systemes financiers et de systemes de gouvernance differents qui font peser des demandes specifiques sur les institutions juridiques. Ce papier montre en definitive que les systemes juridiques peuvent contribuer a faconner les structures financieres mais que l’evolution de ces systemes est en partie la consequence de l’action des forces economiques. Ces forces participent a la formation des regles juridiques et vice versa. Cette approche conduit a remettre en cause l’idee d’un systeme optimal de gouvernement d’entreprise tel qu’elle ressort des travaux sur la convergence des systemes.

Acquisition automatique de sens à partir d'opérations morphologiques en français: études de cas

Abstract: Cet article propose une methode de codage automatique de traits lexicaux semantiques en francais. Cette approche exploite les relations fixees par l’instruction semantique d’un operateur de construction morphologique entre la base et le mot construit. En cela, la reflexion s’inspire des travaux de Marc Light (Light 1996) tout en exploitant le fonctionnement d’un systeme d’analyse morphologique existant : l’analyseur DeriF. A ce jour, l’analyse de 12 types morphologiques conduit a l’etiquetage d’environ 10 % d’un lexique compose de 99000 lemmes. L’article s’acheve par la description de deux techniques utilisees pour valider les traits semantiques.

Micromechanical modeling of viscoelastic voided composites in the low-frequency approximation

Abstract: The self-consistent model of Cherkaoui et al. [J. Eng. Mater. Technol. 116, 274–278 (1994)] is used to compute the effective material moduli of a viscoelastic material containing coated spherical inclusions. Losses are taken into account by introducing the frequency-dependent, complex shear modulus of the viscoelastic matrix. Mode conversion appears through the localization tensors that govern the micromechanical behavior near the inclusions. The results are compared with the scattering model and the data of Baird et al. [J. Acoust. Soc. Am. 105, 1527–1538 (1999)]. The two models are in good agreement. the advantage of the self-consistent model is that it is applicable to the case of nonspherical inclusions embedded in anisotropic materials.

From term variants to research topics

Abstract: In a scientific and technological watch (STW) task, an expert user needs to survey the evolution of research topics in his area of specialization in order to detect interesting changes. The majority of methods proposing evaluation metrics (bibliometrics and scientometrics studies) for STW rely solely on statistical data analysis methods (co-citation analysis, co-word analysis). Such methods usually work on structured databases where the units of analysis (words, keywords) are already attributed to documents by human indexers. The advent of huge amounts of unstructured textual data has rendered necessary the integration of natural language processing (NLP) techniques to first extract meaningful units from texts. We propose a method for STW which is NLP-oriented. The method not only analyses texts linguistically in order to extract terms from them, but also uses linguistic relations (syntactic variations) as the basis for clustering. Terms and variation relations are formalised as weighted di-graphs which the clustering algorithm, CPCL (Classification by Preferential Clustered Link) will seek to reduce in order to produce classes. These classes ideally represent the research topics present in the corpus. The results of the classification are subjected to validation by an expert in STW.

Dominating Pair Graphs

Abstract: A pair of vertices of a graph is called a dominating pair if the vertex set of every path between these two vertices is a dominating set of the graph. A graph is a weak dominating pair graph if it has a dominating pair. Further, a graph is called a dominating pair graph if each of its connected induced subgraphs is a weak dominating pair graph. Dominating pair graphs form a class of graphs containing interval, permutation, cocomparability, and asteroidal triple-free graphs. Our purpose is to study the structural properties of dominating pair graphs. Our main results are a polar theorem for the dominating pairs in weak dominating pair graphs and an existence theorem for minimum cardinality connected dominating sets that induce a simple path in connected dominating pair graphs of diameter not equal to three. Furthermore, we present a forbidden induced subgraph characterization of chordal dominating pair graphs.

A Fourth Derivative Test for Exponential Sums

Abstract: We give an upper bound for the exponential sum PM¼1 e 2ipf ðmÞ in terms of M and l, where l is a small positive number which denotes the size of the fourth derivative of the real valued function f . The classical van der Corput's exponent 1/14 is improved into 1/13 by reducing the problem to a mean square value theorem for triple exponential sums. Mathematics Subject Classi¢cation (2000). 11L07

Tiling the Hyperbolic Plane with a Single Pentagonal Tile.

Abstract: In this paper, we study the number of tilings of the hyperbolic plane that can be constructed, starting from a single pentagonal tile, the only permitted transformations on the basic tile being the replication by displacement along the lines of the pentagrid We obtain that there is no such tiling with five colours, that there are exactly two of them with four colours and a single trivial tiling with one colour For three colours, the number of solutions depends of the assortment of the colours For half of them, there is a continuous number of such tilings, for one of them there are four solutions, for the two other ones, there is no such tiling For two colours, there is always a continuous number of such tilings By contrast, there is no such analog in the euclidean plane with the similar constraints

Effect of exercise on lung-perfusion scanning in patients with bronchogenic carcinoma

Abstract: The aim of this study was to determine whether perfusion-scintillation scanning, used as a predictive pre-operative index of lung functionality in patients with lung cancer, is affected by the level of pulmonary blood flow (PBF). Twenty patients with primary lung cancer underwent spirometry and a radionuclide-perfusion scan (macroaggregated albumin particles labelled with 99mTechnetium) both at rest and during the last minute of a ramp-like increase in work rate until exhaustion. On average, the perfusion of the lung with the tumour was significantly reduced by the same magnitude at rest and during exercise (mean±sd: −9±6% versus −10±4% of the cardiac output), regardless of the extent of the tumour. However, subject-by-subject analysis revealed that in two patients, a larger decrease in the perfusion of the lung with the tumour was observed during exercise than at rest (−11% and −17%, respectively). This leads to an underestimation of predictive postoperative functional parameters if resting values are used in these patients. The use of perfusion scintigraphy at rest therefore gives a clear picture of the functionality of the lung before resection in most patients requiring surgery.

New synthesis of substituted 6-methylbenzo(b)furo-, -thieno-, and -seleno(2,3-c)quinolines, and heterocyclic analogues

Abstract: Substituted 6-methylbenzo(b)furo, -thieno-, and -seleno(2,3-c)quinolines were synthetized either by thermal electrocyclisation of the 2-ethanonoximes of 3-phenyl- and 3-hetaryl-substituted benzo(b)furans, -thiophenes, and selenophene, or by treatment of the corresponding O-2,4- dinitrophenyl oximes with sodium hydride.

The Effects of Human Resources Management Practices on the Organizational Performances of Canadian Financial Co-Operatives

Abstract: Reading through academic literature with a critical eye shows that the relation between human resources management (HRM) and the performance of the firm is a relatively unknown phenomenon. This relation is sometimes described as a "black box". Far from claiming to have closed the debate, this article sets forth an original approach that represents an undisputable input which allows a better understanding of this phenomenon. Even if there are many theories that try to explain this relation, only the universalistic approach of human resources will be of interest. While using both a qualitative and a quantitative approach, our research shows that some HRM practices do seem to give a competitive advantage to Canadian financial co-operative enterprises.

Pauvreté des enfants et impact des transferts sociaux

Abstract: Nous analysons l’impact, sur la pauvrete des enfants, des transferts destines aux enfants et/ou aux familles pauvres. Cet impact est successivement analyse en termes d’efficacite, d’efficience et d’equite. L’efficacite est mesuree par la reduction de l’intensite de la pauvrete. L’indicateur d’efficience compare cette reduction au cout des transferts. Enfin, l’equite est mesuree par les changements de rang dans la distribution des revenus des enfants pauvres avant transferts. La comparaison des resultats, en particulier entre, d’un cote, les deux pays anglo-saxons et, de l’autre, les deux pays d’Europe continentale, amene a une discussion generale portant sur le caractere universel versus cible des systemes de transferts beneficiant aux enfants.

La prise en compte de la vie familiale du salarié dans les normes légales et conventionnelles du travail

Abstract: Cette recherche vise a determiner de quelle maniere et dans quelle mesure le droit du travail, apprehende a travers ses sources tant legales que conventionnelles, se saisit a l'heure actuelle de la dimension familiale de la vie des salaries et parvient a faciliter la conciliation entre vie de famille et vie de travail

Analyse de la croissance radiale dans des hêtraies régulières du Nord-Est de la France. Évolution de la vitesse de croissance radiale au cours du XXe siècle

Abstract: L'objectif de cette etude est de chercher a identifier une derive positive a long terme de la vitesse de croissance radiale sur des series d'accroissements issues de 87 arbres dominants de 12 hetraies regulieres domaniales du Nord-Est de la France Constitue de couples de peuplements geographiquement apparies et d'âge differents, cet echantillon est concu pour permettre un controle de la fertilite stationnelle L'analyse de la croissance en hauteur de ce meme echantillon, realisee anterieurement (Herve & al, 2000) a permis d'identifier une derive de la vitesse de croissance de l'ordre de +50% depuis 1900 Dans un premier temps, nous avons recherche un modele de croissance radiale qui s'adapte a l'heterogeneite de nos profils de croissance Les modeles les plus classiques se sont reveles insuffisants et nous avons retenu un modele de croissance original Nous avons ensuite realise l'analyse des arrieres-effets structuraux sur la croissance (influence de la taille des cernes des annees anterieures sur le cerne courant) au moyen de modeles d'auto-correlation appartenant a la classe des modeles ARMA (AutoRegressive Moving Average models) Un modele commun de forme AR (1) (effet du cerne de l'annee precedente uniquement) s'adapte a l'ensemble des series d'accroissements Ces deux resultats ont alors ete integres dans un modele de croissance decrivant aussi les differences de fertilite stationnelle entre peuplements au moyen de parametres a effets aleatoires, et incluant un effet date qui represente la derive de productivite recherchee La meilleure description de cette tendance est obtenue avec une fonction spline cubique comportant un nœud tous les 15 ans, et differenciee dans sa phase finale selon la generation des peuplements Elle permet de conclure a la realite d'une augmentation de la vitesse de croissance depuis 1850 Cette derniere apparait complexe dans sa chronologie, assez nettement distincte selon la generation des peuplements a partir des annees 1950 bien que ce fait demeure a clarifier, et se situe a un niveau de l'ordre de 50% depuis 1900 Un fort effet depressif des secheresses estivales est mis en evidence