Search results for "Méthode"

Characterisation of mechanical behavior of a sub surface drilled polymer, under hertzian contact load

2013

This research concerns the understanding of the sub-surface behaviour of a component presenting controlled heterogeneities and subjected to a Hertzian type load. The purpose is to qualify the stress field in the subsurface. Practically, defects of cylindrical shape are located where the stress field is maximal in sub surface. The contact is sized to be able to observe, by photoelasticity, the stress field and to develop a numerical model to simulate the behaviour (static and dynamic) of the friction area. It is highlighted that the presence of a hole on the z axis of symmetry (x = 0) is the dominating factor. The characteristics which allow decreasing the shearing stress on the symmetry axi…

Optimal control and applications to orbital transfer and almost-riemannian geometry

2010

In this thesis we focus on optimal control techniques as well as geometric control techniques applied to the orbital transfer problem and to almost-Riemannian geometry. In these cases, Pontryagin’s Maximum Principle allows to analyse the extremal flow of affine control systems.In the case of a satellite with low-thrust propulsion, averaging techniques give an approximated system. Averaging is explicit in the energy minimization case and is directly related to almost-riemannian problems. The geometric analysis of such problems is generalized by the study of metrics on the two-sphere of revolution. In this way it is possible to classify the situations considering the transcendance of the solu…

Geometric optimal control : homotopic methods and applications

2012

This work is about geometric optimal control applied to celestial and quantum mechanics. We first dealt with the minimum fuel consumption problem of transfering a satellite around the Earth. This brought to the creation of the code HamPath which permits first of all to solve optimal control problem for which the command law is smooth. It is based on the Pontryagin Maximum Principle (PMP) and on the notion of conjugate point. This program combines shooting method, differential homotopic methods and tools to compute second order optimality conditions. Then we are interested in quantum control. We study first a system which consists in two different particles of spin 1/2 having two different r…

ScaleSem : model checking and semantic web

2012

The increasing development of networks and especially the Internet has greatly expanded the gap between heterogeneous information systems. In a review of studies of interoperability of heterogeneous information systems, we find that all the work in this area tends to be in solving the problems of semantic heterogeneity. The W3C (World Wide Web Consortium) standards proposed to represent the semantic ontology. Ontology is becoming an indispensable support for interoperability of information systems, and in particular the semantics. The structure of the ontology is a combination of concepts, properties and relations. This combination is also called a semantic graph. Several languages have bee…

Planification expérimentale en agroalimentaire

2006

Geostatistical computing of acoustic maps in the presence of barriers

2009

Acoustic maps are the main diagnostic tools used by authorities for addressing the growing problem of urban acoustic contamination. Geostatistics models phenomena with spatial variation, but restricted to homogeneous prediction regions. The presence of barriers such as buildings introduces discontinuities in prediction areas. In this paper we investigate how to incorporate information of a geographical nature into the process of geostatistical prediction. In addition, we study the use of a Cost-Based distance to quantify the correlation between locations.

Analyse de la variabilité génétique mitochondriale et chloroplastique de deux espèces du genre Lupinus (L.Albus et L. Mutabilis)

1988

Notice présente dans BelInra (https://belinra.inra.fr/gestion/catalog.php?categ=isbd&id=90015); il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION; Analyse de la variabilité génétique mitochondriale et chloroplastique de deux espèces du genre Lupinus (L.Albus et L. Mutabilis)

Effect of calculation methods and presence of false positives on perception thresholds

2023

Perception thresholds are commonly used in food science to discriminate between those compounds that are more or less odour-active. It is not rare to use values from other studies and apply them to our data, however, we observed that the procedure to evaluate and calculate perception thresholds is not standardised. The aim of this study was to explore the influence of calculation methods on threshold values. To do so, we used a 3-AFC sensory procedure to determine the orthonasal and retronasal detection values of 26 compounds, amongst them some compounds that usually contribute to the aroma of strawberry and caramel (e.g. vanillin, Furaneol and damascenone). The thresholds were calculated b…

Porcher visionnaire... - Alerte, Monsieur Thibaut est revenu et il a vendu le Bec Bunsen ! Objectifs spécifiques, activité et besoins des apprenants …

2015

Cet article revient sur quarante années de didactique du français, langue non native, avec la relecture d’un article fameux de Louis Porcher, Monsieur Thibaut et le bec Bunsen, dans lequel il montrait que la question utile n’était pas d’abord celle des objectifs (spécifiques ou pas) mais celle de la méthodologie, « pratiques, méthodes, stratégies » pour apprendre et enseigner. Hélas, cet article a souvent été compris comme un refus des objectifs spécifiques, du FOS, etc., mais à tort : relisons ! Le constat actuel est implacable : Porcher avait vu juste, la réflexion méthodologique est toujours en panne, chacun se focalise sur les domaines, au lieu de se demander comment enseigner à partir …

Méthode d'analyse des haies : Protocole d'observation et gestion informatisée des données

1995

Subvention 93/182 "Organisation paysagère, agricole, écologique, sociale des structures linéaires boisées" Programme "Field boundary habitats for wildlife, crop and environmental protection"; Méthode d'analyse des haies : Protocole d'observation et gestion informatisée des données