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Squeal occurrence classification using a harmonic balance vector signal model.
No full textInternational audienceBrake squeal is an instability that generates self-excited limit cycles which vary with time and operating conditions in real experiments. To analyze test results, it is proposed to use a Harmonic Balance Vector (HBV) signal model. It combines Harmonic Balance Method and analytic signal methodologies. From the Harmonic Balance Method, one uses the space-time decomposition where spatial distribution of each harmonic is described by a complex vector and frequency is common to all sensors. From analytic signal, one keeps the assumption that quantities are slowly varying in time. Synchronous demodulation and principal coordinate definitions are combined in a multistep algorithm that provides an HBV estimation. On an industrial brake test matrix, HBV estimation is shown to be robustly applicable. The HBV signal being slowly varying, time sub-sampling reduces the volume of test data by two orders of magnitude. Limit cycle frequency, amplitude and shapes can thus be added to the parallel coordinates that associate to each time sample the operating parameters: pressure, velocity, temperature, torque, disk position, disk/bracket distance, ... This opens a path to a range of analyzes otherwise difficult to perform. Classification of squeal occurrences is first discussed showing pressure and amplitude dependence. The effect of amplitude on both frequency and shape is next demonstrated. The entry and exit of instability when parameters change are then analyzed by proposing a transient root locus built from test. Thus squeal test results are related to the classical complex eigenvalue analysis. Intermittent growth/decay events are shown to be correlated with wheel position. Furthermore, distance measurements indicate that disk shape variations of a few microns play a clear parametric role. Parametric testing and clustering are then used to map the instability region and its edges. Pressure is shown to have an effect dominating other variations. Prospective uses of these results to combine test results and finite element models are discussed last
Opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) on the risks to human health associated with the proliferation of Ostreopsis spp. on the Basque coast
No full textN/AInternational audienceIn France, the presence of marine microalgae of the genus Ostreopsis has been identified repeatedly on the Mediterranean coast for several years, whereas on the French Basque coasts its presence is much more recent. In the summers of 2021 and 2022, major Ostreopsis flowering episodes were reported on the Basque coast, resulting in several hundred cases of intoxication among holidaymakers and residents. The main route of human exposure is inhalation of aerosols, although it is not yet known whether the agents responsible for poisoning are Ostreopsis cells, cell debris, known toxins produced by Ostreopsis, or other as yet unidentified compounds. Other routes of exposure (dermal contact, eye contact, ingestion of contaminated water or seafood) are also possible. Poisoning is manifested through various signs and symptoms, occurring within 48 hours of exposure (Neurosensory and neurological, respiratory, dermal and digestive). This document presents the opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), established from the work of its WATER and ERCA Expert Committees. ANSES received a request from the Directorate General for Health (DGS) and the Directorate General for Food (DGAL) to update knowledge about Ostreopsis that had been reported in the Agency's opinions from 2007 and 2008 (ANSES, 2007 and 2008), and draw up specific recommendations for managing Ostreopsis proliferation on the Basque coast. The literature review conducted as part of this expert appraisal revealed that knowledge about the genus Ostreopsis (diversity, biology, ecology, toxins produced) is still too fragmentary to characterise the hazard and risk to human health. Nevertheless to help local authorities affected by Ostreopsis blooms, Agency proposes a surveillance and quality monitoring strategy based on collaboration between site managers and the regional health agencies (ARSs), applicable to sites currently subject to bathing water quality monitoring and water sports sites that meet the conditions below
: Artificial intelligence and social justice: opportunity or illusion for the world of journalism? An information and communication analysis.
No full textInternational audienceCette communication analyse, dans une perspective de sciences de l’information et de la communication, les impacts de l’intelligence artificielle (IA) sur le monde du travail et les enjeux de justice sociale qui en découlent, avec un focus particulier sur le rôle des journalistes. L’IA est appréhendée comme un dispositif socio-technique articulant données, algorithmes et acteurs humains, porteur à la fois d’opportunités et de risques. À partir d’une revue de la littérature et de travaux empiriques contextualisés à Madagascar et en Afrique, trois axes sont explorés : (1) les usages de l’IA dans le travail et leur influence sur la division des tâches et les compétences ; (2) les risques éthiques identifiés, tels que les biais algorithmiques, la surveillance numérique, la fracture numérique, l’opacité décisionnelle et la dévalorisation du travail humain ; (3) les conditions d’un usage éthique et inclusif, incluant la mise en place d’un cadre juridique adapté, la co-construction des systèmes avec les parties prenantes, le développement d’une culture numérique critique, la promotion d’IA à finalité sociale et le renforcement du rôle des journalistes comme contre-pouvoir démocratique. L’étude mobilise un cadre théorique intégrant les apports de la sociologie des techniques, de l’analyse critique des algorithmes et des théories de la justice sociale, afin d’éclairer la nécessité d’un journalisme capable de maîtriser et de questionner l’IA pour qu’elle serve la justice sociale tout en améliorant les conditions de travail et de productivité
Le répertoire militant écologique ambigu de l’écriture sur Wikipédia pour influencer les imaginaires d’une planète habitable au futur
No full textInternational audienceLes notices Wikipédia participent largement à l’information des publics et partant, auforgeage des référentiels qui guident l’action politique. Elles racontent des évènementset fabriquent des identités autant qu'elles diffusent des acceptions de concepts auxdépens d’autres acceptions susceptibles de véhiculer d’autres conceptions du monde,d’autres conceptions du bien commun, d’un avenir désirable. Rares sont les visiteursdes notices de Wikipédia capables de juger de la qualité des définitions en lescomparant à d'autres. Encore plus rares sont ceux qui prennent le temps d'explorerles profondeurs de Wikipédia, les versions diachroniques des définitions et leursversions dans plusieurs langues, les points de tension manifestés par des ajouts etannulations successives, les pages de discussion et pages personnelles des auteurs.Peu importe l’activité dans le cadre de laquelle chacun s’inscrit, de rares personnessont capables de se questionner sur la qualité et l'auctorialité complexe et singulièredes notices consultées et prennent le temps de le faire et vont jusqu’à essayer dedeviner entre les lignes des stratégies d’influence de militants écologiques.Conjuguant les approches cognitives des politiques publiques et communicationnelles,cette proposition étudie la participation d’organisations militantes pratiquant leplaidoyer et de militants à la fabrique de notices Wikipédia en français. Elle se focalisesur une série de notices emblématiques par les polémiques qu’elles ont suscitées,qu’elles décrivent des ONGs de plaidoyer ou qu’elles aient été investies par elles demanière assumée ou non ainsi que par des sympathisants à leur cause. L’enquêtenetnographique se double d’entretiens semi directifs avec des contributeurs « engagés» désireux de peser sur les représentations du monde
Etude de l’alimentation totale française 3 (EAT3) - Rapport méthode
No full textCitation suggérée : Anses. (2025). Etude de l’alimentation totale française 3 (EAT3) - Rapport méthode. (saisine2019-SA-0010). Maisons-Alfort : Anses, 90 p
Towards a Situational Aware-Based Cybersecurity Remediation
No full textInternational audienceAs cyberattacks become increasingly sophisticated, structured remediation is essential to contain threats effectively. While existing semantic resources, such as cybersecurity vocabularies and ontologies, provide a foundation for remediation strategies, their practical application remains challenging due to the fragmentation of cybersecurity tools and the difficulty of integrating these resources into operational workflows. After exploring the state of the art relying on cybersecurity incident remediation and highlighting their drawbacks, we suggest through this paper to go towards a situational awareness-based remediation process. This process is roughly outlined in this paper. We also highlight the knowledge to be formalized and to be provided to the process in the perspective of its automation
Experimental Study of Axial Fan Performances Operating In Constrained Environment: Application of Axial and Combined Axial-Radial Blockage
No full textInternational audienceThis paper aimed to develop an experimental procedure for axial fans characterisation operating in constrained fields. The influence of an obstacle located downstream of a fan is studied experimentally on standardised test bench of the suction box type under different specific angular speeds. The axial fan of forward sweep category operates in free field referred as baseline configuration and in fields constrained by two blocking configurations axial and combined axial-radial. The blockages are produced by a flat plate, perpendicular to the axis of rotation of the fan for axial blockage case and two other plates placed radially for combined axial-radial blockage case, modelling, for example, the obstruction of a car internal combustion engine block. The four sets of global performances (pressure rise, flow rate, mechanical power and static efficiency) evolving with the different obstacles are compared to highlight their similarities. Variations in pressure rise as a function of flow rate were observed as the obstacle was changed depending upon the operating regime of the fan weather is working on axial or radial pattern discharge. The characteristic curves seem to evolve with substantial gain compared to the free field case especially when the blockage matched the flow configuration in the fans' wake
Data paper en humanités numériques : Adressbuch 1854
No full textInternational audienceThis chapter presents a data paper on the datasets related to the project "Adressbuch der Deutschen in Paris von 1854", a project on German immigration to Paris in the 19th century carried out at the German Historical Institute in Paris. During the research project, a database was built with over 4700 addresses of German individuals and companies who settled in Paris and its suburbs in 1854. The information is derived from a historical document, a kind of business directory or yellow pages of Germans in Paris established in 1854.In addition to the description of the data collection methods, this data paper presents the way in which the datasets are enriched, valorised, presented and visualised on historic city maps. Particular attention is paid to the respect of standards and values of digital humanities and open science alike, in coherence with the specific needs of the main users of the database (historians and genealogists).Ce chapitre présente un data paper qui porte sur les jeux de données liés au projet « Adressbuch der Deutschen in Paris von 1854 » au long cours d’histoire sur l’immigration des Allemands à Paris au XIXe siècle réalisé à l’Institut historique allemand de Paris. Le projet a pour objectif de mettre à la disposition des chercheuses et chercheurs et généalogistes, dans une interface, les informations sur les individus et entreprises allemands installés à Paris en 1854. Ces informations sont issues d’un document historique, une sorte de bottin de commerce ou pages jaunes des Allemands à Paris.Outre la description de méthodes de collecte des données, ce data paper présente la manière dont les jeux de données sont enrichis et valorisés dans le dispositif de consultation. Nous portons une attention particulière sur le respect des valeurs des humanités numériques et de la science ouverte, en cohérence avec les spécificités des historiennes et historiens, ainsi que les généalogistes amenés à le consulter
Life Cycle Assessment of an ultramicroelectrode array sensor for trace metal measurement in water, a cradle-to-gate approach
No full textInternational audienceThe environmental impact of manufacturing an electrochemical measurement system is evaluated using Life Cycle Assessment (LCA). This study focuses on identifying the most impactful materials and processes with the aim of eco-design on manufacturing an ultramicroelectrode array sensor: reducing environmental impacts through process modification, material changes and reducing electricity consumption. A cradle-to-gate approach is used. The results highlight that metal (i.e., gold and titanium) and insulator deposition are the most impactful steps, primarily due to high electricity consumption
Faire dialoguer les expériences pour accompagner l’appropriation de savoirs agroécologiques
No full textNational audienceIn this article, we address the question of favorable conditions for the sharing and appropriation of distributed and non-stabilized knowledge on complex agroecological systems. Our article is based on the study of an initiative aimed at renewing the modalities of production and circulation of knowledge : the « Cafés Agro ». We will show how this initiative supports the appropriation of agroecological knowledge between heterogeneous actors, by articulating three dimensions :the commitment to reflexivity of participants regarding their experiences ;the exploration of innovative practices through the sharing of experiences and knowledge between people with different professions ;the creation of a community of innovative practices.Cet article aborde la question des conditions favorables au partage et à l’appropriation de savoirs distribués et non stabilisés sur les systèmes agroécologiques complexes. Il présente un dispositif de partage d’expériences, porté par des agents de l’Institut national de recherche en agriculture et environnement (Inrae), autour de pratiques innovantes pour piloter des vergers agroécologiques et rassemblant des agriculteurs, chercheurs, conseillers et animateurs agricoles, formateurs : les Cafés Agros. Nous montrerons comment cette initiative accompagne l’appropriation de savoirs agroécologiques entre des acteurs hétérogènes, en articulant trois dimensions :l’engagement de la réflexivité des participants vis-à-vis de leurs expériences ;l’exploration de pratiques innovantes via le partage d’expériences et de savoirs entre des personnes aux métiers différents avec objectif de stabilisation ;la création d’une communauté de pratiques innovantes