Mise en oeuvre d'un outil d'alerte et de cartographie temps réel des aléas naturels liés aux précipitations dans les régions montagneuses et méditerranéennes du Sud-Est de la France

International audienceDue to its mountainous topography and its Mediterranean climate, the Provence-Alpes-Côte d'Azur (PACA) region in Southeastern France is particularly prone to flash floods, debris flows and mass movements (landslides and rockfall). A mapping system for these rainfall induced hazards has been tested by local and regional authorities and Government agencies since 2011 as part of the RHYTMME project. This system allows, thank to radar rainfall estimation and rainfall-runoff modelling, the real-time warning and monitoring of flash floods wherever they may occur in the PACA territory. It is also intended to enable, during intense rainfall events, the localisation of the streams susceptible to generate debris flows and of the slopes the more likely to trigger landslides and/or rockfalls

Energy autonomous wearable sensors for smart healthcare: a review

Energy Autonomous Wearable Sensors (EAWS) have attracted a large interest due to their potential to provide reliable measurements and continuous bioelectric signals, which help to reduce health risk factors early on, ongoing assessment for disease prevention, and maintaining optimum, lifelong health quality. This review paper presents recent developments and state-of-the-art research related to three critical elements that enable an EAWS. The first element is wearable sensors, which monitor human body physiological signals and activities. Emphasis is given on explaining different types of transduction mechanisms presented, and emerging materials and fabrication techniques. The second element is the flexible and wearable energy storage device to drive low-power electronics and the software needed for automatic detection of unstable physiological parameters. The third is the flexible and stretchable energy harvesting module to recharge batteries for continuous operation of wearable sensors. We conclude by discussing some of the technical challenges in realizing energy-autonomous wearable sensing technologies and possible solutions for overcoming them

Temperature and Voltage Aware Timing Analysis

International audienceIn the nanometer era, the physical verification of CMOS digital circuit becomes a complex task. Designers must account of new factors that impose a significant change in validation methods. One of these major changes in timing verification to handle process variation lies in the progressive development of statistical static timing engines. However the statistical approach cannot capture accurately the deterministic variations of both the voltage and temperature variations. Therefore, we define a novel method, based on non-linear derating coefficients, to account of these environmental variations. Based on temperature and voltage drop CAD tool reports, this method allows computing the delay of logical paths considering more realistic operating conditions for each cell. Application is given to the analysis of voltage drop effects on timings

Statistical Characterization of Library Timing Performance

International audienceWith the scaling of technology, the variability of timing performances of digital circuits is increasing. In this paper, we propose a first order analytical modeling of the standard deviations of basic CMOS cell timings. The proposed model is then used to define a statistical characterization protocol which is fully compliant with standard characterization flows. Validation of this protocol is given for a 90nm process

Logical Effort Model Extension to Propagation Delay Representation

International audienceThe logical effort method is widely recognized as a pedagogical way allowing designers to quickly estimate and optimize single paths by modeling equivalently propagation delay and transition time. However, this method necessitates a calibration of all the gates of the library and appears suboptimal in real combinatorial paths for satisfying tight timing constraints. This is due to the inability of the logical effort model in capturing I/O coupling and input ramp effects that distinguish the transition time from the propagation delay. Using an analytical modeling of the supply current that flows in simple gates during their switching process, this paper introduces an extension of the logical effort model that considers the I/O coupling capacitance and the input ramp effect. Validation of this model is performed on 130-nm STMicroelectronics technology. A compact representation of CMOS library timing performance is given as a possible application of the proposed model. The choice of sampling points to be used in look-up tables as representative steps of the design range is also discusse

(2009)" Un Nouveau Système d’Instrumentation en Ligne pour la Caractérisation et l’Adaptation Dynamique aux Variations

Résumé — Des dispositifs de surveillance embarqués du processus de fabrication et des paramètres environnementaux sont aujourd’hui indispensables à la lutte contre les effets de la variabilité. Ils permettent également une recherche du point de fonctionnement optimal qui permet de s’affranchir des marges conception, et autorise la baisse de la consommation par des systèmes d’adaptation dynamique. Ce papier présente un nouveau système de surveillance en ligne permettant d’anticiper en temps réel toute violation de temps en observant les variations des marges temporelles. Ce système est composé de structures spécifiques situées près des bascules, couplées avec un générateur de fenêtre de détection localisé sur l’arbre d’horloge. Validation et performances sont données en technologie 45 nm basse consommation et démontrent la faisabilité et l’efficacité de ce système. Mots clés — Variabilité, Surveillance en ligne, Marge temporelle, Compensation, Point de fonctionnement optimal, Basse consommation, adaptation dynamique

Anticiper les fortes pluies et leurs conséquences avec la plateforme RHYTMME

National audienceLa quasi-totalité des communes de la région Provence-Alpes-Côte d’Azur sont concernées par les aléas naturels liés aux fortes pluies : inondations, laves torrentielles et mouvements de terrain. Les pluies intenses et les crues soudaines bénéficient d’un dispositif de surveillance et d’anticipation mais ce dispositif existant souffre d’une résolution spatiale limitée (Vigilance météorologique à l’échelle départementale, avertissements APIC à l’échelle communale, service Vigicrues sur les cours d’eau surveillés) qui n’est pas toujours adaptée aux besoins de suivi plus ciblés des gestionnaires locaux des risques. Les aléas gravitaires – laves torrentielles et mouvements de terrain – quant à eux ne disposent pas à l’heure actuelle de dispositif de surveillance. Le projet RHYTMME (Risques hydrométéorologiques en territoires de montagnes et méditerranéens), porté par Irstea et Météo-France et financé par la Région Provence-Alpes-Côte d’Azur, le Ministère en charge de l’Écologie et l’Union Européenne, a permis l’élaboration d’une plateforme internet de services d’aide à la gestion de ces risques naturels (Fouchier et al., 2015). Cette plateforme affiche en temps réel des cartes qui permettent de surveiller et tenter d’anticiper les pluies intenses et les crues soudaines associées et d’identifier les territoires les plus sensibles aux mouvements de terrain et aux phénomènes de laves torrentielles