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L'aventure Framasoft, pour un Web collectif et convivial
No full textInternational audienceInternet, puis le Web, sont nés sous le signe de la décentralisation, fruit d'une improbable alliance entre contre-culture et stratégie militaire anti-atomique. À partir des années 2000 les géants étatsuniens recentralisent Internet via des services web et des médias sociaux qui reposent sur la captation d'un maximum d'utilisateurs et sur le profilage qui permettent de se repérer rapidement dans un monde numérique croissant à vitesse inhumaine.Afin de résister à l'hégémonie de ce capitalisme de surveillance, Framasoft propose dès 2014 de redécentraliser le Web via des services alternatifs, libres, gratuits, ouvert à tous sans collecte de données personnelles et sans contre-partie publicitaire. À partir de 2016, l'association organise l'essaimage de son modèle via le collectif CHATONS. Et en 2022, la campagne « Coin ! Coin ! » a pour ambition de voler dans les plumes du capitalisme de surveillance en accompagnant les milieux associatifs et militants dans leur dégafamisation.À travers ces modestes actions et grâce à un financement reposant sur les dons de ses utilisateurs, Framasoft cherche à montrer que préserver un petit coin de Web non soumis au pouvoir commercial des multinationales et non soumis au pouvoir central des états est encore possible, que la structure technique et historique d'Internet le permet, à condition qu'on en prenne tous soin
Adaptive Look-Ahead Distance Based on an Intelligent Fuzzy Decision for an Autonomous Vehicle
No full textInternational audienceAutonomous vehicles use a set of perceptual and localization data proceeding from sensor measurements, in order to plan a certain trajectory based on decision-making, and finally to track the generated path. Trajectory following is performed by adjusting the steering angle generated by a lateral controller based on a geometric or non-geometric approach. The objective of the lateral controller is to minimize the lateral error between the vehicle and the path at a target point at a look-ahead distance from the vehicle. This paper investigates the look-ahead distance due to its high impact on performance alteration, and energy consumption. An intuitive analysis will be performed to study the effect of three varying parameters on the look-ahead distance, and the necessity to consider them. Then, a Fuzzy Logic approach will be established to adjust the look-ahead distance in accordance with three parameters: longitudinal velocity, road curvature, and original consideration of road adherence. Finally, a non-geometric model-based lateral controller will be developed based on the Super-Twisting Sliding Mode Control technique to control the steering angle via the Active Front Steering. The membership functions and the rules of the inputs and output of the Fuzzy Logic approach are implemented in a Matlab/Simulink environment and tested on a validated full non-linear vehicle model. Simulation results indicate the effectiveness of the fuzzy decision approach on the performance and energy consumption of the autonomous vehicle
Système de détection de maladies respiratoires basé sur l'analyse de l'environnement sonore dans des habitats partagés : résultats préliminaires
No full textLa thématique de ce colloque est : «Dispositifs biomédicaux et technologies numériques en santé : des besoins aux usages».National audienceDans une société avec une augmentation de la proportion de personnes âgées, de nouvelles structures d’habitation se développent. L’habitat partagé en est un exemple. L’installation d’un système d’analyse multi-capteurs a été réalisée dans deux maisons de la région de Toulouse comprenant chacune 6 logements. Un système embarqué de classification permet, en local, de distinguer 13 classes sons. Des données ont été collectées sur une période de 7 mois. Une analyse préliminaire des événements sonores est présentée et concerne autant la détection d’un motif d’activités des personnes (heure de coucher et de réveil, heure des repas) mais aussi l’apparition de symptômes de maladies respiratoires grâce à la détection d’épisodes de toux
Mathematical issues in body water volume estimation using bio impedance analysis in e-Health
No full textInternational audienceBioImpedance Analysis (BIA) is a safe, simple, and noninvasivetechnology to measure body composition. The principle is todetermine the electric impedance of an electric current passingthrough body tissues. This technique is currently integrated intonumerous connected devices, for quick and easy self-assessment ofhealth condition. However, these measurements are indirectly relatedto body composition and intensively bear on strong assumptionsrelated to mathematical models that are limited and imprecise. Thissituation is the source of several methodological and experimentalissues. In this study, we analyze in details these issues based on acomplete and recent survey of literature.Obtained results suggest that it is clearly needed to multiplyreferences, to define personalized models, and to adjust mathematicalassumptions to improve BIA reliability and adoption in e-health orspecific applications
Nanoparticle size and surface chemistry effects on mechanical and physical properties of nano-reinforced polymers: The case of PVDF-Fe3O4 nano-composites
No full textInternational audienceIn the present work, PVDF - Fe3O4 nanoparticle (NP) nanocomposite films were produced using the electrospinning method. We investigated the effect of NP size on the film's morphology (fiber size), mechanical properties, and physical properties (β-phase percentage). Surprisingly, while nanoparticle size acts as an enhancer for mechanical properties, it appeared to act as an inhibitor in terms of its effects on the crystallization of the β-polymorph. This result seemed in discordance with many previous results. A focus on local interactions between the NP surface chemistry and PVDF chains revealed the influence of grafted ligands at the nanoparticle surface on the crystallization of the piezoelectric phase of PVDF. The results from the molecular dynamics (MD) simulations for systems of PVDF chains with slabs of –OH and oleic acid-grafted magnetite, showed that the probability of beta phase configuration decreases when the nanoparticles are functionalized with oleic acid and becomes more probable for –OH terminated magnetite. These computational results are in accordance with our experimental results. To verify this hypothesis, we prepared films with washed nanoparticles to eliminate the excess oleic acid that acts as a β-polymorph inhibitor. As a result, the amount of β-phase obtained for washed nanoparticles increased and the difference in the amount of β-phase between the different samples decreased. Moreover, when heated, the films of nanocomposite with washed NP developed more β-phase for smaller sizes of nanoparticles. At 140 °C, isomerization occurred, and oleic acid was converted into elaidic acid, reducing the steric hindrance, and promoting the interaction between PVDF chains and the surface of the nanoparticles. This isomerization reaction seems to be an enhancer of the α- to β-phase transition. Our results prove that optimizing multiple properties in nano-reinforced polymers requires consideration of different aspects, such as NP size, surface chemistry, and processing methods.Our results based on mixed experimental and modeling approach proved the usefulness of simulation in understanding and guiding our experimental results. Our results suggest that for enhancing piezoelectric properties in PVDF magnetite nano-composites, the chemistry and the molecular morphology of the grafted ligands when combined with NP size could lead to multi-properties enhancement simultaneously
Droit, consentement et « dark patterns »: Étude de l’évolution des bandeaux cookies entre 2020 et 2021
No full textInternational audienceUne majorité des sites web populaires dans l’Union européenne affichent aujourd’hui une interface de recueil du consentement à l’activation de cookies et au pistage de la navigation de leurs visiteurs lorsque ceux-ci s’y rendent pour la première fois. Cet affichage découle d’obligations légales, et notamment de l’article 5 paragraphe 3 de la directive européenne 2002/58/CE lu en combinaison avec le Règlement général de protection des données. La façon dont le droit de l’Union conceptualise le consentement au traitement de données à caractère personnel n’est toutefois pas la seule acception possible du terme « consentement », dont de nombreux travaux ont souligné une polysémie qui s’incarne dans la diversité du design des bandeaux cookies. Si, lors d’une étude réalisée sur les 90 bandeaux cookies identifiés sur les 99 noms de domaine les plus visités en France en 2020, tous incarnaient une conception traduisant l’adage « qui ne dit mot consent ». Nous avons observé en 2021 une diminution sensible de certains dark patterns qui conduisent les internautes à des comportements de consentement résigné, ainsi qu’une nette augmentation de la proportion de bandeaux cookies mettant en scène, par leurs textes et par les interactions proposées, un consentement opt-in qui traduit l’adage : « si c’est pas oui, c’est non ». Cette évolution est corrélée à des sanctions d’autorités de protection des données, mais aussi au passage à une nouvelle version du standard technique qui sous-tend le fonctionnement de la majorité des bandeaux cookies de notre corpus : le Transparency and Control Framework. Le présent article présente quelques résultats intermédiaires du projet WebConsentement de l’Université Rennes 2, et dessine des pistes de recherche pour la suite de ce projet
FROG interface de livres numériques inclusifs pour lecteurs dyslexiques.
No full textInternational audienceEvery year, thousands of children suffer the repercussions of DYS disorders characterised by difficulties in processing information that impact their ability to communicate, interact and learn. Thus MOBiDYS, with its FROG digital book format reading solution, allows DYS audiences to have better access to written material. This format offers fifteen reading aids to help dyslexic readers decipher, understand and retain better. FROG’s first version needed ergonomic improvements, so MOBiDYS worked with the Digital Design Lab at the école de design Nantes Atlantique to redesign the user interface of the FROG reading tools, moving from a flat menu interface with confusing navigation to an intuitive interface with a logical hierarchization of the tools. Design proposals were then prototyped and tested in two phases by DYS children, leading to FROG’s second version currently being implemented.Chaque année, des milliers d’enfants subissent les répercussions des troubles DYS caractérisés par des difficultés de traitement de l’information qui impactent leur capacité à communiquer, interagir et apprendre. Ainsi, MOBiDYS, avec son format de livre numérique FROG, permet aux publics DYS d’avoir un meilleur accès à la langue écrite. Ce format propose quinze aides à la lecture pour aider les lecteurs dyslexiques à mieux déchiffrer, comprendre et retenir. La première version de FROG avait besoin d’améliorations ergonomiques. MOBiDYS a donc travaillé avec le Digital Design Lab de l’école de design Nantes Atlantique pour refaire l’interface utilisateur des outils de lecture. Les propositions ont ensuite été prototypées et testées en deux phases par les enfants de la DYS, ce qui a conduit à la seconde version de FROG actuellement en cours de déploiement
Nourriture de l’exil : alimentation pour mélanger le proche et le lointain, l’exceptionnel et le conventionnel.
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A convergent finite-volume scheme for nonlocal cross-diffusion systems for multi-species populations
No full textAn implicit Euler finite-volume scheme for a nonlocal cross-diffusion system on the one-dimensional torus, arising in population dynamics, is proposed and analyzed. The kernels are assumed to be in detailed balance and satisfy a weak cross-diffusion condition. The latter condition allows for negative off-diagonal coefficients and for kernels defined by an indicator function. The scheme preserves the nonnegativity of the densities, conservation of mass, and production of the Boltzmann and Rao entropies. The key idea is to "translate" the entropy calculations for the continuous equations to the finite-volume scheme, in particular to design discretizations of the mobilities, which guarantee a discrete chain rule even in the presence of nonlocal terms. Based on this idea, the existence of finite-volume solutions and the convergence of the scheme are proven. As a by-product, we deduce the existence of weak solutions to the continuous cross-diffusion system. Finally, we present some numerical experiments illustrating the behavior of the solutions to the nonlocal and associated local models
Turnover of the extracellular polymeric matrix of granules performing biological phosphate removal
No full textInternational audienceAbstract Polyphosphate accumulating organisms (PAOs) are responsible for enhanced biological phosphate removal (EBPR) from wastewater, where they grow embedded in a matrix of extracellular polymeric substances (EPS). EPSs comprise a mixture of biopolymers like polysaccharides or (glyco)proteins. Despite previous studies, little is known about the dynamics of EPS in mixed cultures, and their production by PAOs and potential consumption by flanking microbes. EPSs are biodegradable and have been suggested to be a substrate for other organisms in the community. Studying EPS turnover can help elucidate their biosynthesis and biodegradation cycles. We analyzed the turnover of proteins and polysaccharides in the EPS of an enrichment culture of PAOs relative to the turnover of internal proteins. An anaerobic-aerobic sequencing batch reactor (SBR) simulating EBPR conditions was operated to enrich for PAOs. After achieving a stable culture, carbon source was switched to uniformly 13 C-labeled acetate. Samples were collected at the end of each aerobic phase. EPSs were extracted by alkaline treatment. 13 C enrichment in proteins and sugars (after hydrolysis of polysaccharides) in the extracted EPS were measured by mass spectrometry. The average turnover rate of sugars and proteins (0.167 and 0.192 d −1 respectively) was higher than the expected value based on the solid removal rate (0.132 d −1 ), and no significant difference was observed between intracellular and extracellular proteins. This indicates that EPS from the PAO enriched community is not selectively degraded by flanking populations under stable EBPR process conditions. Instead, we observed general decay of biomass, which corresponds to a value of 0.048 d −1