26 research outputs found
From natural hazards to outer space and to Plan9
International audienceAn information system for scholarly work on natural hazards calls for the design of a computer system for transmission of information over very long periods, and for traceability. An abstract analysis shows that these requirements are dual to the fundamental question of assisting the cognitive activity of a user using external memories, which reaches a very general scope. The solutions should be implemented at the operating system level, mainly the file system, and Plan9's file systems and other properties make it the soundest base for our work. We present our road-map for development
Self-labeling techniques for semi-supervised time series classification: an empirical study
An increasing amount of unlabeled time series data available render the semi-supervised paradigm a suitable approach to tackle classification problems with a reduced quantity of labeled data. Self-labeled techniques stand out from semi-supervised classification methods due to their simplicity and the lack of strong assumptions about the distribution of the labeled and unlabeled data. This paper addresses the relevance of these techniques in the time series classification context by means of an empirical study that compares successful self-labeled methods in conjunction with various learning schemes and dissimilarity measures. Our experiments involve 35 time series datasets with different ratios of labeled data, aiming to measure the transductive and inductive classification capabilities of the self-labeled methods studied. The results show that the nearest-neighbor rule is a robust choice for the base classifier. In addition, the amending and multi-classifier self-labeled-based approaches reveal a promising attempt to perform semi-supervised classification in the time series context
A decentralized approach to model national and global food and land use systems
The achievement of several sustainable development goals and the Paris Climate Agreement depends on rapid progress towards sustainable food and land systems in all countries. We have built a flexible, collaborative modeling framework to foster the development of national pathways by local research teams and their integration up to global scale. Local researchers independently customize national models to explore mid-century pathways of the food and land use system transformation in collaboration with stakeholders. An online platform connects the national models, iteratively balances global exports and imports, and aggregates results to the global level. Our results show that actions toward greater sustainability in countries could sum up to 1 Mha net forest gain per year, 950 Mha net gain in the land where natural processes predominate, and an increased CO2 sink of 3.7 GtCO2e yrâ1 over the period 2020â2050 compared to current trends, while average food consumption per capita remains above the adequate food requirements in all countries. We show examples of how the global linkage impacts national results and how different assumptions in national pathways impact global results. This modeling setup acknowledges the broad heterogeneity of socio-ecological contexts and the fact that people who live in these different contexts should be empowered to design the future they want. But it also demonstrates to local decision-makers the interconnectedness of our food and land use system and the urgent need for more collaboration to converge local and global priorities
How can diverse national food and land-use priorities be reconciled with global sustainability targets? Lessons from the FABLE initiative
There is an urgent need for countries to transition their national food and land-use systems toward food and nutritional security, climate stability, and environmental integrity. How can countries satisfy their demands while jointly delivering the required transformative change to achieve global sustainability targets? Here, we present a collaborative approach developed with the FABLEâFood, Agriculture, Biodiversity, Land, and EnergyâConsortium to reconcile both global and national elements for developing national food and land-use system pathways. This approach includes three key features: (1) global targets, (2) country-driven multi-objective pathways, and (3) multiple iterations of pathway refinement informed by both national and international impacts. This approach strengthens policy coherence and highlights where greater national and international ambition is needed to achieve global goals (e.g., the SDGs). We discuss how this could be used to support future climate and biodiversity negotiations and what further developments would be needed
Détermination automatique des zones de départ d'avalanches
Today, avalanche hazard zoning can benefit numerical simulations of their propagation. But determining their release areas remains a manual operation, which has the potential to strongly bias the conclusions. This work aims at providing a publicly available operational method to determine large avalanche release areas. We apply image processing methods to a digital elevation model of the relief, with filters and combinations between image planes, navigating the scale space.Le zonage du risque d'avalanches s'appuie aujourd'hui sur des simulations de leur propagation. Mais la dĂ©termination des zones de dĂ©part reste une opĂ©ration manuelle, qui peut ĂȘtre critique pour les conclusions. On propose de dĂ©terminer les zones de dĂ©part en appliquant Ă un modĂšle numĂ©rique du relief des mĂ©thodes de traitement d'image, des filtres et des combinaisons entre plans images, en naviguant dans l'espace d'Ă©chelle
Détermination des zones de départ d'avalanches par filtrages multi-échelles sur un modÚle numérique de terrain, dans une perspective de zonage des risques
National audienceToday, avalanche hazard zoning can benefit numerical simulations of their propagation. But determining their release areas remains a manual operation, which has the potential to strongly bias the conclusions. This work aims at providing a publicly available operational method to determine large avalanche release areas. We apply image processing methods to a digital elevation model of the relief, with filters and combinations between image planes, navigating the scale space.Le zonage du risque dâavalanches sâappuie aujourdâhui sur des simulations de leur propagation. Mais la dĂ©termination des zones de dĂ©part reste une opĂ©ration manuelle, qui peut ĂȘtre critique pour les conclusions. Le travail exposĂ© vise Ă se doter de moyens opĂ©rationnels et disponibles publiquement pour dĂ©terminer les zones de dĂ©part d'avalanches de grande ampleur dans le domaine pyrĂ©nĂ©o-alpin. On propose dâappliquer Ă un modĂšle numĂ©rique du relief des mĂ©thodes de traitement dâimage, des filtres et des combinaisons entre plans images, en naviguant dans lâespace dâĂ©chelle
Schéma directeur pour les données de l'environnement de la Corse
ĂlĂ©ments clefs en support au dĂ©ploiement du schĂ©ma directeur des donnĂ©es de l'environnement de la Corse : la mise en ligne de donnĂ©es administratives soulĂšve, au-delĂ des questions techniques et des bouleversements de pratiques de chaque institution, l'enjeu de les rendre aussi comprĂ©hensibles Ă tout public (interopĂ©rabilitĂ© intellectuelle). C'est un enjeu majeur du mouvement vers un dĂ©veloppement durable : une exigence de transparence, une obligation Ă aboutir dans un schĂ©ma de communication. Une analyse portant sur les principes fondamentaux en jeu montre que toute administration est avant tout, depuis ses lointaines origines historiques, une administration de donnĂ©es. Il en rĂ©sulte que la meilleure explication d'un jeu de donnĂ©es ou systĂšme d'information actuel se fait en restituant les Ă©tapes historiques qui ont conduit Ă son Ă©tablissement. Ce sont les (mĂ©ta)donnĂ©es clefs pour les rendre intelligibles, et rĂ©pondre Ă la question clef de savoir si elles se prĂȘtent Ă tel ou tel usage dĂ©tournĂ© par rapport Ă leur fonction premiĂšre. Ensuite seulement, les types de mĂ©tadonnĂ©es courants permettent de les exploiter correctement, notamment sur le plan technique
Esquisse d'un programme pour une extension de la Maison de la télédétection
Essai sur la notion de développement durable appliquée au confort (c'est-à -dire notamment le caractÚre fonctionnel) du bùtiment, mise en contexte régional et historique, territorial, institutionnel et de projet scientifique et technique du programme, analyse détaillée du fonctionnement dans le bùtiment actuel, spécification détaillée des besoins découlant du mode et du type de travail. Un essai d'approche totale, conforme aux vues de la Charte de l'environnement (constitutionnelle), et aux intentions profondes du code des marchés publics, en matiÚre de développement durable
Modéliser la qualité de l'emmental
The objective is to find a representation of the final quality of the emmental cheese. Sensory parameters related to production parameters are used. The idea is to go beyond dissimilar assembling elements by integrating the entire industry in the mathematical expressions. This very general approach can be a priori used for any type of food product. / L'objectif est de trouver une reprĂ©sentation de la qualitĂ© finale de l'emmental. Des paramĂštres sensoriels, reliĂ©s Ă des paramĂštres de fabrication sont utilisĂ©s. L'idĂ©e de ce modĂšle est de dĂ©passer un niveau d'assemblage d'Ă©lĂ©ments disparates en intĂ©grant l'ensemble de la filiĂšre dans des expressions mathĂ©matiques. Cette dĂ©marche, trĂšs gĂ©nĂ©rale, peut ĂȘtre utilisĂ©e a priori pour tout type de produit alimentaire
Alcoholic fermentation under oenological conditions
The possibility of predicting sluggish fermentations under oenological conditions was investigated by studying 117 musts of different French grape varieties using an automatic device for fermentation monitoring. The objective was to detect sluggish or stuck fermentation at the halway point of fermentation. Seventy nine percent of fermentations were correctly predicted by combining data analysis and neural networks. / En étudiant les courbes de cinétique fermentaire de 117 moûts de différentes variétés françaises de vigne, on recherche la possibilité de prédire les fermentations languissantes. Une combinaison de méthodes d'analyse de données et de réseaux de neurones conduit à 79% de prédictions correctes au vu de la courbe jusqu'à mi-réaction