259 research outputs found

    Une approche de vérification d'exécution de modèles par contrats

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    National audienceOne of the main goal of model-driven engineering is the manipulation of models as exclusive software artifacts. Model execution is in particular a means to substitute models for code. We focus in this paper on verifying model executions. We use a contract-based approach to specify an execution semantics for a meta-model. We show that an execution semantics is a seamless extension of a rigorous meta-model specification and composed of complementary levels, from static element definition to dynamic elements, execution specifications as well. We use model transformation contracts for controlling the dynamic consistent evolution of a model during its execution.Un des buts fondateurs de l'ingénierie des modèles est la manipulation des modèles en tant qu'éléments logiciels productifs. L'exécution de modèles est notamment un moyen de remplacer l'écriture du code. Nous nous intéressons dans cet article à la vérification d'exécution de modèles. Nous utilisons pour cela une approche par contrat pour spécifier une sémantique d'exécution pour un méta-modèle donné. Nous montrons qu'une sémantique d'exécution est un prolongement naturel d'un méta-modèle rigoureusement défini et est formée de niveaux complémentaires, de la définition d'éléments statiques et dynamiques ainsi que de spécifications d'exécution de ces éléments. Nous utilisons des contrats de transformation de modèles pour vérifier la cohérence de l'évolution dynamique d'un modèle pendant son exécution

    Analyse biomécanique multidimensionnelle du geste de tourner le volant chez les conducteurs sans déficiences motrices

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    Tourner le volant d une automobile peut s avérer difficile pour les conducteurs ayant des déficiences motrices des membres supérieurs. En effet, ce mouvement demande une grande mobilité et une force musculaire non négligeable. A ce jour, les directions assistées automobiles sont réglées uniquement sur le ressenti des conducteurs sans déficiences motrices. Le projet ANR VTT VolHand, dans lequel ce travail de recherche s inscrit, ambitionne d apporter une réponse à cette problématique. L objectif de cette thèse est de renseigner la biomécanique du geste déjà chez le conducteur sans déficiences motrices (sain). Pour cela, l interaction main/volant, ainsi que la cinématique (ex. angles articulaires) et la dynamique (ex. efforts sur volant, efforts articulaires) du geste de tourner le volant sont étudiés au travers de plusieurs analyses multidimensionnelles multivariables (atemporelle et temporelle). La méthode originale proposée s appuie sur un découpage flou du volant et des variables cinématiques et dynamiques. La population expérimentée compte une centaine de sujets, dont 23 sujets sans déficience motrice. La plateforme expérimentale regroupe principalement un simulateur automobile compact permettant le recueil des efforts développés par chaque main, une consigne de suivi de trajectoire incitant le conducteur à reproduire un angle désiré et un système optoélectronique mesurant le geste de tourner le volant.Les résultats de l analyse de l interaction main/volant mettent en évidence 3 profils de conducteurs : les conducteurs croiseurs, les conducteurs croiseurs asymétriques et les conducteurs non croiseurs. L analyse des variables cinématiques et dynamiques montrent que les variables dynamiques résultant du tirer/pousser le volant sont discriminantes. Deux nouveaux profils sont alors identifiés : les pousseurs moyens et les tireurs. En majorité, les conducteurs sains tendent à croiser les mains et à pousser sur le volant lors de la réalisation d un geste de tourner le volant à basse vitesse.Plusieurs perspectives sont proposées à court terme, à moyen terme et à long terme. L une d entre elles concerne l adaptation de l assistance aux caractéristiques motrices des conducteurs avec déficience motrice.Steering wheel can be difficult for divers with disabilities on upper limb. Indeed, the steering action might require a large range of motion of upper limb and some muscular strength. Power steering systems that are currently proposed in car were implemented to match non disabled driver feelings and needs. ANR VTT VolHand project wants to enlarge the field of power steering system to drivers with disabilities on upper limbs. The present work is a part of this project. As a preliminary approach, the objective was to analyze the upper limb motion of healthy drivers during a steering exercise. Different multivariable analyses (low level of time summarizing and high level of time summarizing) were done to study hand/wheel interactions, kinematics variables (e.g. joint angles) and dynamics variables (e.g. joint torques). An original fuzzy windowing was proposed to describe hand position on steering wheel, kinematic and dynamics variables. One hundred subjects participated to experiment, included 23 healthy subjects, which consisted on a low speed steering task. The experimental platform was composed of a compact driving simulator, that allow the measurement of each hand effort on the steering wheel, a steering exercise based on a line following protocol, and a motion capture system.Analysis of hand/wheel interaction showed the existence of three driver profiles: hand crossing, asymmetric hand crossing and non hand crossing. Analysis of kinematics and dynamics variables showed that pulling/pushing forces were also discriminating. As a consequence, two additional profiles were identified: mean pushing drivers and pulling drivers. Overall, healthy drivers were hand crossing and mean pushing drivers during a low speed steering task.Short, middle and long prospects are proposed. One of them concerns automotive power steering system adaptation for disabled drivers.VALENCIENNES-Bib. électronique (596069901) / SudocSudocFranceF

    Qualitative modelling and analysis of regulations in multi-cellular systems using Petri nets and topological collections

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    In this paper, we aim at modelling and analyzing the regulation processes in multi-cellular biological systems, in particular tissues. The modelling framework is based on interconnected logical regulatory networks a la Rene Thomas equipped with information about their spatial relationships. The semantics of such models is expressed through colored Petri nets to implement regulation rules, combined with topological collections to implement the spatial information. Some constraints are put on the the representation of spatial information in order to preserve the possibility of an enumerative and exhaustive state space exploration. This paper presents the modelling framework, its semantics, as well as a prototype implementation that allowed preliminary experimentation on some applications.Comment: In Proceedings MeCBIC 2010, arXiv:1011.005

    Sentinel-1 azimuth subbanding for multiple aperture interferometry - Test case over the Roi Baudoin ice shelf, east Antartica

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    peer reviewedAs an extension of Synthetic Aperture Radar Interferom- etry, Multiple Aperture Interferometry (MAI) is a spectral diversity technique that allows the determination of azimuth displace- ments from phase shift measurements. This is made possi- ble through the creation of backward- and forward-looking Single-Look-Complex (SLC) data. Then, the phase differ- ence between the backward and forward-looking interfero- gram is translated into a displacement. Using SLC data, MAI requires a proper azimuth splitband operator. Different tech- niques exist to split the azimuth band, but they are often too briefly described in the MAI literature. In this conference pa- per, we analyze the signal properties of the Sentinel-1 TOPS acquisition mode and define an azimuth subbanding proto- col. In particular, we look at the role of de-apodization and apodization in the band filtering operation. We focus our anal- ysis on Sentinel-1 data in Interferometric Wideswath mode over the Roi Baudouin Ice Shelf, East Antarctica.MIMO (Monitoring melt where Ice Meets Ocean); SMAIAD (Sentinel-1 Multiple Aperture Interferometry for Azimuth Displacement Retrieval

    Does a combined screw and dowel construct improve tibial fixation during anterior cruciate ligament reconstruction?

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    Purpose: The aims of the present study were to compare the biomechanical properties of tibial fixation in hamstring-graft ACL reconstruction using interference screw and a novel combination interference screw and dowel construct. Material and methods: We compared the fixation of 30 (2- and 4-stranded gracilis and semitendinosis tendons) in 15 fresh-frozen porcine tibiae with a biocomposite resorbable interference screw (Group 1) and a screw and dowel construct (Group 2). Each graft was subjected to load-to-failure testing (50 mm/min) to determine maximum load, displacement at failure and pullout strength. Results: There were no significant differences between the biomechanical properties of the constructs. Multivariate analysis demonstrated that combination constructs (β = 140.20, p = 0.043), screw diameter (β = 185, p = 0.006) and 4-strand grafts (β = 51, p = 0.050) were associated with a significant increase in load at failure. Larger screw diameter was associated with increased construct stiffness (β = 20.15, p = 0.020). Conclusion: The screw and dowel construct led to significantly increased fixation properties compared to interference screws alone in a porcine model. Increased screw diameter and utilization of 4-strand ACL grafts also led to improvement in load-to-failure of the construct. However, this is an in vitro study and additional investigations are needed to determine whether the results are reproducible in vivo. Level of evidence: Level V; Biomechanical study

    It starts at home? Climate policies targeting household consumption and behavioral decisions are key to low-carbon futures

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    Through their consumption behavior, households are responsible for 72% of global greenhouse gas emissions. Thus, they are key actors in reaching the 1.5 °C goal under the Paris Agreement. However, the possible contribution and position of households in climate policies is neither well understood, nor do households receive sufficiently high priority in current climate policy strategies. This paper investigates how behavioral change can achieve a substantial reduction in greenhouse gas emissions in European high-income countries. It uses theoretical thinking and some core results from the HOPE research project, which investigated household preferences for reducing emissions in four European cities in France, Germany, Norway and Sweden. The paper makes five major points: First, car and plane mobility, meat and dairy consumption, as well as heating are the most dominant components of household footprints. Second, household living situations (demographics, size of home) greatly influence the household potential to reduce their footprint, even more than country or city location. Third, household decisions can be sequential and temporally dynamic, shifting through different phases such as childhood, adulthood, and illness. Fourth, short term voluntary efforts will not be sufficient by themselves to reach the drastic reductions needed to achieve the 1.5 °C goal; instead, households need a regulatory framework supporting their behavioral changes. Fifth, there is a mismatch between the roles and responsibilities conveyed by current climate policies and household perceptions of responsibility. We then conclude with further recommendations for research and policy

    Progress Report on Target Development

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    The present document is the D08 deliverable report of work package 1 (Target Development) from the MEGAPIE TEST project of the 5th European Framework Program. Deliverable D08 is the progress report on the activities performed within WP 1. The due date of this deliverable was the 5th month after the start of the EU project. This coincided with a technical status meeting of the MEGAPIE Initiative, that was held in March 2002 in Bologna (Italy). The content of the present document reflects the status of the MEGAPIE target development at that stage. It gives an overview of the Target Design, the related Design Support activities and the progress of the work done for the safety assessment and licensing of the target

    AGuIX® from bench to bedside-Transfer of an ultrasmall theranostic gadolinium-based nanoparticle to clinical medicine

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    International audienceAGuIX® are sub-5 nm nanoparticles made of a polysiloxane matrix and gadolinium chelates. This nanoparticle has been recently accepted in clinical trials in association with radiotherapy. This review will summarize the principal preclinical results that have led to first in man administration. No evidence of toxicity has been observed during regulatory toxicity tests on two animal species (rodents and monkeys). Biodistributions on different animal models have shown passive uptake in tumours due to enhanced permeability and retention effect combined with renal elimination of the nanoparticles after intravenous administration. High radiosensitizing effect has been observed with different types of irradiations in vitro and in vivo on a large number of cancer types (brain, lung, melanoma, head and neck…). The review concludes with the second generation of AGuIX nanoparticles and the first preliminary results on human

    Des routes et des hommes : la construction des échanges par les itinéraires et les transports

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    Les circulations humaines façonnent le paysage montagnard, traçant les routes qui permettent de franchir les obstacles, de créer un lien avec la plaine, de développer les activités économiques. Portant sur une diversité de territoires, cet ouvrage nous invite à mieux comprendre comment l’homme a ouvert des passages pour dépasser les frontières naturelles et culturelles des montagnes. La présentation de découvertes archéologiques, l’analyse de sources méconnues, l’étude du rôle de la technique et de la cartographie en dressent un panorama allant de l’Antiquité au xxe siècle. Le Congrès national des sociétés historiques et scientifiques rassemble chaque année universitaires, membres de sociétés savantes et jeunes chercheurs. Ce recueil est issu de travaux présentés lors du 142e Congrès sur le thème « Circulations montagnardes, circulations européennes »

    Euclid Near Infrared Spectrometer and Photometer instrument concept and first test results obtained for different breadboards models at the end of phase C

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    The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision program with its launch planned for 2020 (ref [1]). The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900- 2000nm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal model (STM)
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