Propagation des contraintes tables souples Etude pr eliminaire

National audienceWCSP is a framework that has attracted a lot of at- tention during the last decade. In particular, there have been many developments of ltering approaches based on the concept of soft local consistencies such as node consistency (NC), arc consistency (AC), full directio- nal arc consistency (FDAC), existential directional arc consistency (EDAC), virtual arc consistency (VAC) and optimal soft arc consistency (OSAC). Almost all algo- rithms related to these properties have been introduced for binary weighted constraint networks, and most of the conducted experiments typically include constraint networks involving only binary and ternary constraints. In this paper, we focus on extensional soft constraints of large arity. We propose an algorithm to lter such constraints and embed it in PFC-MRDAC.Durant ces dix derni ères ann ées, de nombreuses études ont ét és r éalis ées pour le cadre WCSP (Weighted Constraint Satisfaction Problem). En particulier, ont ét é propos ées de nombreuses techniques de filtrage bas ées sur le concept de coh érence locale souple telle que la co- h érence de n oeud, et surtout la coh érence d'arc souple. Toutefois, la plupart de ces algorithmes ont ét és intro- duits pour le cas des contraintes binaires, et la plupart des exp érimentations ont ét és men ées sur des r éseaux de contraintes comportant uniquement des contraintes binaires et/ou ternaires. Dans cet article, nous nous in- t eressons aux contraintes tables souples de grande arit é. Nous proposons un premier algorithme pour filtrer ces contraintes et nous l'int égrons a PFC-MRDAC

Étude et modélisation de la polymérisation dynamique de composites à matrice thermodurcissable

La cuisson rapide de préimprégnés est une problématique d'actualité qui sous entend les nécessités de rentabilité dans l'industrie aéronautique. Cette étape est basée sur la maîtrise du degré d'avancement de réaction du système thermodurcissable au cours du cycle qui régit l'ensemble des propriétés finales des pièces composites. La caractérisation et la modélisation cinétique du préimprégné aéronautique M21/T700 sont réalisées en vue d'appliquer des dynamiques de mise en oeuvre rapides applicables sur une installation de thermocompression dotée d'un moule chaué par induction de technologie Cage System de Roctool. La construction de diagrammes Temps Température Transformation et la réalisation d'un couplage thermo-cinétique par éléments finis permettent de proposer des cycles optimisés d'une durée de moins de 2 heures (au lieu de 4h30 en cuisson autoclave), en préservant la présence de particules de thermoplastiques dans la matrice. L'étude des propriétés des plaques fabriquées montre des résultats comparables à ceux obtenus pour des pièces mises en oeuvre lors de cycles standards de fabrication à l'aide du procédé autoclave. ABSTRACT : The increase of composite content in aerospace structures requires an improvement of profitability through high curing processes. The curing step is based on the control of the degree of cure of the thermosetting system that governs the final properties of the composite parts. The Cage System technology from the Roctool company enables high curing rates thanks to induction heating system. Thus, the characterization and the kinetic modeling of the M21/T700 aeronautical prepreg have been realized for such sollicitations (i.e. high heating rates). To provide a better temperature control, the thermal and kinetic interactions are also considered by finite element modeling of composite thickness. Time Temperature Tranformation diagrams have been set up to build short curing cycle of less than 2h (instead of 4h30 in autoclave curing), considering the presence of thermoplastic particules. Finally, the part properties are in good agreement with the autoclave cycle recommended by the material supplier

Ingénierie cognitive pour l'aide à la conduite automobile de la personne âgée : analyse et modélisation de l'activité de conduite en situation naturelle pour la conception de fonctions de monitorage

This thesis in Cognitics presents a Human Centered Design approach for thedevelopment of future driving assistance systems dedicated to elderly drivers orElderly Adapted Driver Assistance Systems (E-ADAS).To do so, this work relies on a multi-disciplinary approach for data collection andanalysis. Regarding Ergonomics, the aim is to better understand the specificrequirements of this population in order to identify their actual difficulties and actualneeds of assistance. In this frame, 76 drivers (aged from 70 to 87 years old) took partto an on-the-road experiment, driving an instrumented car. The dataset includes2100 km of ecological driving data and 1400 auto-evaluated driving situations,completed by 6 Focus Groups (involving 30 elderly drivers).The second part of this research, relying on Cognitive Engineering, explores thedesign and implementation of monitoring functions based on the aforementioneddataset. The objective is to have real-time models and analytical functions, able to:(1) supervise the driving activity as realized by an elderly driver, (2) taking in toconsideration the driving context or situational risks (3) in order to detect difficulties ordriving errors. Beyond this thesis, these diagnostics will have to be integrated inassistive systems to better adapt their support to the specific needs of elderly drivers.Specific monitoring functions related to basic vehicle control (speed management,lane positioning and headway regulation) are presented. Based on these results,integrated monitoring functions for intersection crossings in Left-Turn manoeuver,highway merging assistance, and, more broadly, lane change assistance areintroduced.Cette thèse en Cognitique se focalise sur la « Conception Centrée sur l'Humain » (Human Centred Design) de futures assistances à la conduite automobile, adaptées aux conducteurs âgés (ou Elderly Adapted Driver Assistance Systems).Pour ce faire, la démarche proposée repose sur une approche et une méthodologie pluridisciplinaire. Sur le plan ergonomique, il s'agit de mieux connaître les spécificitésde la population des conducteurs âgés, dans le but d'identifier des difficultés et des besoins en assistance. A cette fin, 76 conducteurs âgés (de 70 à 87 ans) ont conduitun véhicule instrumenté, immergé dans le trafic. Le corpus de données comporte2100 kilomètres de conduite et 1400 situations de conduite autoévaluées par lesconducteurs, complétés par 6 Focus Group (30 conducteurs âgés).Le second volet, relevant d'une démarche d'Ingénierie Cognitive, vise à concevoir et développer des fonctions de « monitorage » à partir du corpus de données. L'objectif est de disposer de modèles et de fonctions d'analyse temps-réel capables (1) de superviser l'activité de conduite des conducteurs âgés (2) en regard du contexte ou des risques situationnels, afin de (3) diagnostiquer des difficultés ou erreurs de conduite, à des fins d’adaptativité des assistances. Des fonctions de monitorage en lien avec les contrôles de base du véhicule (gestion de la vitesse, positionnement dans la voie et la gestion de l'espace inter-véhiculaire avant) sont développées. Sur cette base, des fonctions de monitorage plus intégrées pour l'aide aux franchissements d'intersections (Tourne-à-Gauche) et l'assistance à l'insertion sur voies rapides (et au changement de voie) sont également proposées

Transformation in cities and regions: current themes in Germany and France - three significant points of discussion

This chapter concentrates on institutional differences in France and Germany. The stability of the German institutional setting contrasts with the series of institutional reforms that have stretched over decades or even half a century in France. While in Germany transformation has taken the form of successive adaptations, in France the diverse reforms have been hotly debated and sometimes even contested. Often the metropolises and regions form the focus of such discussions in France. These contrasts between stability and change can also be seen in both spatial planning systems and the position of the highest level of territorial authority (régions in France and Länder in Germany). Starting from the national policy guidelines in both countries, the authors describe different territorial units, their areas of responsibility and their manifold planning instruments. They also address processes of democratisation, participation and metropolisation, the role of the European Union and various crises as drivers of the development of both systems

Résumé and outlook

International audienc

Primal-dual splitting algorithm for solving inclusions with mixtures of composite, Lipschitzian, and parallel-sum monotone operators

We propose a primal-dual splitting algorithm for solving monotone inclusions involving a mixture of sums, linear compositions, and parallel sums of set-valued and Lipschitzian operators. An important feature of the algorithm is that the Lipschitzian operators present in the formulation can be processed individually via explicit steps, while the set-valued operators are processed individually via their resolvents. In addition, the algorithm is highly parallel in that most of its steps can be executed simultaneously. This work brings together and notably extends various types of structured monotone inclusion problems and their solution methods. The application to convex minimization problems is given special attention

The development of metropolises in Germany and France

The evolution of city regions and metropolises in both countries illustrates the theoretical debates on this particular geographical object. Political legitimacy, significant autonomy and a 'relevant' territorial area should form the basis of these regions. But there is a long way to go from this theoretical vision to practice. In Germany, a slow and contingent bottom-up process can be observed, whereas in France, following a long history of intermunicipality, institutional metropolises are emerging (MAPTAM law of 2014). Metropolregionen and métropoles thus differ. Germany shows incomplete and variable forms of metropolitan organisation, whereas French metropolises are satisfied with simple criteria of competences and resources. However, these 'intermunicipal' métropoles (one exception: Lyon) can also be compared with the large German cities, which are highly individualised political entities, with the city-states (e. g. Hamburg) being the most extreme cases. Two examples, Frankfurt and Lille, illustrate the comparison

Exposure of hairdressing apprentices to airborne hazardous substances

BACKGROUND: Few studies have investigated exposure of hairdressing apprentices to airborne irritants. This study describes exposure levels of apprentices to chemical products used in hairdressing salons in relation with their activity. METHODS: Following a two stages study design, a group of 300 students completed a questionnaire on their work activities and environment. Among these, a group of 28 subjects volunteered to undergo personal exposure and workplace concentrations measurements over a work shift, during a cold and a hot season, with the agreement of the salon owners. Three chemical substances were studied (ammonia, hydrogen peroxide and persulfates) because they are respiratory tract irritants and because their concentrations could be quantified within a 5 to 8 hour shift period. RESULTS: Personal exposure values for H(2)O(2)and NH(3) (averages [standard deviations] are 0.05 [0.04] and 0.90 [0.76] mg.m(-3), respectively) were greater than workplace ambient air concentrations (corresponding values of 0.04 [0.03] and 0.68 [0.42] mg.m(-3)) for H(2)O(2 )and NH(3), with no significant seasonal variation. By contrast, workplace concentrations of persulfates (0.019 [0.018] mg.m(-3)) were greater than personal exposure (0.016 [0.021] mg.m(-3), a finding that is consistent with the fact that bleaching is more often undertaken by senior hairdressers. However, all exposure values were lower than the current TLV TWA values. This study also shows that over half of technical spaces where chemical substances used for dying, permanenting or bleaching are manipulated, have no ventilation system, and not even a door or a window opening outside. CONCLUSION: The study hairdressing salons, on average, were small, the most probable reason why occupational hygiene measures such as appropriate ventilation were too seldom implemented. As a consequence, young apprentices and senior hairdressers experience substantial exposure to known airways irritants

Exploration of the phase composition of activated calcined clay-slag mixtures using 27Al and 29Si MAS NMR spectroscopy

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Wear mechanisms of WC-Co drill bit inserts against alumina counterface under dry friction: Part 2 — Graded WC-Co inserts

The tribological behaviour of innovative graded cemented carbide inserts were studied by using a rotary tribometer and abrasive alumina counterfaces. This work completes the study made on commercial inserts with homogeneous cobalt content. Inserts with three types of graduation processes were considered: inserts with borides WCoB phases, imbibed inserts and inserts combining both processes (i.e. inserts with reactive imbibition). Physicochemical and mechanical measurements show that the WCoB phases increase the hardness towards the active surface and the imbibition increases the insert core fracture toughness. The wear tests indicate that the boride phases lower the friction coefficient. In addition, as for the commercial inserts, cemented carbide volumes with higher cobalt content also reduce the friction coefficient. Concerning the wear results, the boride phases improve the abrasion resistance. By applying a third body approach, the WCoB phases limit the introduction of cobalt binder in the source flow, the cohesion of alumina particles in the internal flow and the formation of an abrasive paste in the contact. The imbibition process, where the cobalt migration is controlled, does not affect the wear resistance by avoiding a cobalt enrichment of the cemented carbide near the active surface