Search results for "Modélisation"
showing 10 items of 222 documents
Conceptualisation et classification des problèmes de fatigue mécanique
2011
International audience; On propose de conceptualiser et de classifier les problèmes de calcul de structures dits de fatigue (dans le cadre de la Mécanique de lʼEndommagement). Parce que le concept de fatigue est avant tout un concept que lʼon peut estimer structural plutôt que local, cette classification est faite dʼabord sur des grandeurs structurales. Ensuite, on donne une classification faite sur des grandeurs locales. Lʼobjectif de ces classifications est de favoriser la résolution locale des problèmes de fatigue dʼune classe donnée en aidant à la justification du passage des lois dʼévolution obtenues par la Thermodynamique à celles écrites dans le cadre de la fatigue.
A holistic approach to design for 4D Printing
2019
Invented in 1983, as a rapid prototyping process, additive manufacturing (AM) is nowadays considered as a manufacturing process almost in the same way as conventional processes. For example, parts obtained by AM are found in aircraft structures. This AM evolution is mainly due to the shape complexity allowed by the process. The driving forces behind this evolution include: the development of various techniques on the layer-wise manufacturing principle and the improvement both in quantity and quality of the range of materials that can be processed. Many other AM techniques and materials continue to emerge. In the wake of the AM (usually referred to as 3D printing) another mode of manufacturi…
Modeling urban growth by cellular automata
1996
International audience; The structural development of human settlements can be characterized as a complex highly feedbacketed process. The assumption that this process is governed by rather few fundamental laws stimulated a considerable research in the field of urban growth during the last decade. Aiming at the comprehension of the basic underlying dynamics different approaches from the field of self-organizing systems have been proposed. In this paper we present a "cellular model" of urban growth dynamics based on the work of White, Engelen and Uljee. As a starting point this model throws some light on the mechanism of urban growth. But even more important, it raises a lot of questions con…
Numerical simulation of heat transfer, fluid flow and elements diffusion during laser welding of dissimilar steels
2017
The design of new steel grades offering equivalent mechanical performances for lower thicknesses and the added value with the possibility to join two different steel grades, require development and control of joining processes. Thanks to high precision and good flexibility, the laser welding became one of the most used processes for joining of dissimilar welded blanks. The prediction of local chemical composition in the weld formed between dissimilar steels in function of the welding parameters is essential because the dilution rate and the distribution of alloying elements in the melted zone determine the final tensile strength of the weld. The goal of the present study is to create and to…
Mobilités étudiantes et territoires universitaires : vers une uniformisation des pratiques ?
2005
Since French Society enters the so-called "Economy of knowledge", migrations of young people, especially these concerning students, are of most interest. Despite the fact that it could help to understand University as a system and ways regions can evolve, the study of students' migrations was not yet done. A set of results highlights first the main role of French capital region. It also shows main changes in migrations of students following vocational training in University. At least, it reveals that architectures of students' migrations look like these of migrations of the whole French population.
MIRO : des trajectoires individuelles à la ville en mouvement
2010
Verifying a medical protocol with temporal graphs: the case of a nosocomial disease.
2014
Abstract Objective Our contribution focuses on the implementation of a formal verification approach for medical protocols with graphical temporal reasoning paths to facilitate the understanding of verification steps. Materials and methods Formal medical guideline specifications and background knowledge are represented through conceptual graphs, and reasoning is based on graph homomorphism. These materials explain the underlying principles or rationale that guide the functioning of verifications. Results An illustration of this proposal is made using a medical protocol defining guidelines for the monitoring and prevention of nosocomial infections. Such infections, which are acquired in the h…
Modélisation de l’évolution d’un finage, du rural au périurbain (Montagne bourguignonne)
2007
La transformation accélérée des rapports entre les sociétés villageoises et leur territoire a des conséquences de nature à la fois organisationnelle, biophysique et agronomique: les opérations d'aménagement rural y trouvent leur justification. Une démarche de diagnostic de territoire a été élaborée et mise en oeuvre à l'occasion de ces opérations. Un itinéraire méthodologique permet de construire un «modèle morpho-historique» qui rend des interrelations entre milieu physique et histoire d'un lieu, à travers un système de relations territorialisé. Le modèle «MH» permet, dans le cadre de procédures d'aménagement, de repérer des portions de territoire «sensibles».
Context-aware intelligent video analysis for the management of smart buildings
2019
To date, computer vision systems are limited to extract digital data of what the cameras "see". However, the meaning of what they observe could be greatly enhanced by environment and human-skills knowledge.In this work, we propose a new approach to cross-fertilize computer vision with contextual information, based on semantic modelization defined by an expert.This approach extracts the knowledge from images and uses it to perform real-time reasoning according to the contextual information, events of interest and logic rules. The reasoning with image knowledge allows to overcome some problems of computer vision such as occlusion and missed detections and to offer services such as people guid…
Méthodes de contrôle de la rugosité à partir des propriétés différentiels de courbes autosimilaires.
2023
La rugosité a de nombreuses applications, l’industrie l’utilise comme outil pour avoir des propriétés de surface recherchés ou pour le contrôle qualité, le domaine de l’informatique graphique s’intéresse à la synthétiser pour la génération de terrains ou la génération de textures et aussi à simuler ses effets sur la lumière avec les BRDF. . . Dans cette présentation, nous proposeronsun rappel sur la rugosité, notamment sa définition plus précise que "surface ou courbe non lisse" et ses outils de quantification suivi d’une comparaison de certaines de ses méthodes de génération, illustrant l’intérêt d’une approche fractale pour l’étudier. Nous commencerons par des méthodes simples mais offran…