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Tinkering for soil care
No full textThe authors would like to thank the farmers and their associations for taking part in the survey about tinkering. We also acknowledge the contribution of the academic and industrial members of the Chaire Agro-Machinisme et Nouvelles Technologies in understanding the trends in the agricultural machinery sector.International audienceThis study discusses the concept of tinkering with agricultural equipment, framed within the philosophical realist concept of “technical fact” and subsequent agronomic literature. This concept emphasises the time-bound realisation of technical tendencies in agriculture and highlights the critical role of farmers’ actions, mediated by equipment, in shaping farming practices. Tinkering, characterised by small, ingenious adaptations to existing tools, contrasts with the structured engineering approach, and exemplifies the flexibility and creativity inherent in farmers’ practices. Through a three-phase study involving stakeholders in the French agricultural sector, we investigate how farmers adapt equipment through tinkering to meet the challenges of soil management in the face of climate change and socio-technical dynamics. The results show that tinkering allows farmers to bridge the gap between conceptual farming practices and their practical implementation, thus promoting innovation and adaptability. Tinkering is motivated by limited availability of adapted equipment and economic constraints, especially in the context of conservation agriculture. It contributes to sustainability by promoting resource efficiency, reducing costs and increasing farmers’ autonomy. However, tinkering also poses challenges, including potential safety issues and the need for technical evaluation before widespread adoption. The study highlights the importance of modular and adaptable equipment design to facilitate farmer-driven innovation. We conclude that tinkering is an important strategy for farmers to translate broader technical trends into specific, contextualised technical facts, ultimately contributing to more sustainable and resilient agricultural systems
Méthode des éléments finis. Preuves détaillées en vue d'une formalisation en Coq
No full textTo obtain the highest confidence on the correction of numerical simulation programs for the resolution of Partial Differential Equations (PDEs), one has to formalize the mathematical notions and results that allow to establish the soundness of the approach. The finite element method is one of the popular tools for the numerical resolution of a wide range of PDEs. The purpose of this document is to provide the formal proof community with very detailed pen-and-paper proofs for the construction of the Lagrange finite elements of any degree on simplices in positive dimension.Pour obtenir la plus grande confiance dans l'exactitude des résultats de programmes de simulation numérique pour la résolution d'Équations aux Dérivées Partielles (EDPs), il faut formaliser les notions mathématiques sur lesquelles ils sont basés. La méthode des éléments finis est l'un des outils les plus utilisés pour la résolution de larges gammes d'EDPs. L'objectif de ce document est de fournir à la communauté des chercheurs en preuve formelle des preuves papiers très détaillées pour la construction des éléments finis de Lagrange de tout degré sur des simplexes en dimension quelconque
Endometriosis detection on ultrasound videos
No full textInternational audienceEndometriosis is a chronic condition where tissue similar to the uterine lining grows outside the uterus, affecting up to 10% of reproductive-aged women. It causes severe pain during periods, sexual intercourse, and other activities, and its diagnosis typically requires invasive methods like laparoscopy and biopsy. Our project aims to develop a model using YOLO v8n to detect endometriosis lesions on the rectum via ultrasound, assisting medical professionals in identifying the condition. The model is trained on 17 ultrasound videos, utilizing cross-validation, data augmentation, and key performance metrics such as precision and recall for classification, and mAP for object detection
Histoire du projet des Research Domain Criteria : de la refonte conceptuelle au programme de recherche
No full textInternational audienceLe projet des Research Domain Criteria (RDoC), porté depuis 2009 par le National Institute of Mental Health (NIMH) étatsunien, est un projet de refonte conceptuelle du trouble mental à des fins de recherche. Il a été majoritairement commenté sur ce versant conceptuel. Cependant, le projet disposant d’une enveloppe budgétaire finançant des recherches extra-muros, il est doté d’un pouvoir économique s’ajoutant à sa proposition conceptuelle, et ce pouvoir contribue à normer ce que devrait être la psychiatrie. Dans ce working paper, issu de versions intermédiaires d’un manuscrit de thèse en cours de rédaction, je propose d’enrichir les analyses qui ont été produites concernant les RDoC. A partir d’une restitution détaillée des étapes de leur développement avec une perspective internaliste, je suggère que, sans nier l’importance des enjeux conceptuels, il faut également prendre en compte le volet de financement de la recherche des RDoC. Ce volet invite à les aborder comme un programme de transformation de la psychiatrie dans son ensemble, et non pas seulement comme une classification pour la recherche
High Temperature Intergranular Oxidation of Nickel Based Superalloy Inconel 718
No full textInternational audienceIntergranular oxidation (IGO) of the Ni-based superalloy Inconel 718 was studied at 650 °C, 700 °C and 900 °C. The oxidized samples were characterized by X -ray diffraction and scanning electron microscopy. For all the studied temperatures, the external scale was mainly composed of Cr 2 O 3 , while the oxides along the grain boundaries were rich in Al and, to a minor extent, Ti. This was consistent with thermodynamic computations. The time evolution of the maximum depth of IGO was found to be parabolic with an apparent activation energy of 164 kJ/mol. The results of this study confirm with three temperatures that IGO kinetics can be described using an extension of the Wagner’s theory of internal oxidation, as recently suggested in the literature at 850 °C. According to this description, the mechanisms controlling the IGO kinetics of Inconel 718 are the aluminum diffusion in the alloy matrix and the oxygen diffusion along the interface between the alloy matrix and the oxidized grain boundary
Life Cycle Assessment of Piezoelectric Devices Implemented in Wind Turbine Condition Monitoring Systems
No full textInternational audienceAssessing the vibration signature produced by a rotating component of the wind turbine enables the identification of operational conditions and the detection of potential faults at an early stage. The main purpose is to enhance the sustainability of wind turbines while increasing the lifespan and uptime of their operational systems. This vibration analysis is based on the processing of the signal provided by sensors, which often incorporates piezoelectric transducers. This paper evaluates the consequences of employing piezoelectric sensors used for vibration measurement on electrical machines integrated into wind turbines by conducting a life cycle assessment (LCA). The widespread use of piezoelectric materials is due to their high sensitivity to vibrations, although their selection is also influenced by regulatory restrictions. This research focuses on the environmental impact of piezoelectric accelerometers used commonly in condition monitoring systems. The collected literature data on the manufacturing processes are inputted into the LCA model which is powered by the Ecoinvent 3 database. The impact assessment is carried out using the European ILCD 2011 Midpoint+ method by calculating the unique scores of the selected impact categories. The results are presented and discussed in terms of environmental indicators, as well as ecological recommendations on the design
Le bricolage comme cadre d’analyse de l’adaptation des agroéquipements pour une durabilité des systèmes agricoles
No full textThe thesis explores the role of tinkering as a framework for analyzing the adaptation of agricultural equipment to promote the sustainability of agricultural systems. The initial results of surveys conducted with dealers and agricultural advisors highlight shortcomings such as commercial bias and terminological confusions. An additional study based on YouTube videos sheds lights on the importance of agricultural DIY, particularly focusing on soil and seed drills. Interviews with farmers reveal their growing interest in soil conservation agriculture as a response to climate change, as well as their tendency to customize their equipment, especially seed drills, to make them more suitable for new agricultural practices. The modularity of agricultural equipment emerges as a necessity to meet the evolving needs of farmers and promote more resilient and sustainable agriculture. Lastly, the interaction between technical advances in agronomy and equipment DIY is emphasized, underscoring the importance of technology innovation tailored to the practical needs of farmers for a more flexible and sustainable agriculture.La thèse explore le rôle du bricolage en tant que cadre d’analyse pour l’adaptation des agroéquipements en vue de promouvoir la durabilité des systèmes agricoles. Les résultats initiaux des enquêtes menées auprès des concessionnaires et des conseillers agricoles soulignent des lacunes telles qu'un biais commercial et des confusions terminologiques. Une étude complémentaire basée sur des vidéos YouTube met en lumière l'importance du bricolage agricole, en se focalisant notamment sur le sol et le semoir. Les entretiens avec les agriculteurs mettent en évidence leur intérêt croissant pour l'agriculture de conservation des sols en tant que réponse au changement climatique, ainsi que leur propension à adapter leurs équipements, notamment les semoirs, pour les rendre plus adaptés aux nouvelles pratiques agricoles. La modularité des équipements agricoles émerge comme une nécessité pour répondre aux besoins évolutifs des agriculteurs et encourager une agriculture plus résiliente et durable. Enfin, l'interaction entre les avancées techniques en agronomie et le bricolage des équipements est mise en avant, soulignant l'importance de l'innovation technologique adaptée aux besoins pratiques des agriculteurs pour une agriculture plus flexible et durable
Protéger le parc des dispositifs médicaux connectés et l’intégrité physique des patients face aux cyberattaques : des outils pour les équipes biomédicales
No full textInternational audienceLa numérisation croissante des systèmes d’information des établissements de santé a ouvert de nouvelles voies pour l’amélioration des soins. Cependant, cette avancée technologique s’accompagne d’un défi majeur : garantir la sécurité des soins en contexte de cyberattaques hebdomadaires. À cet effet, la protection des données médicales sensibles, la préservation de l’intégrité des systèmes informatiques, et la garantie du bon fonctionnement des équipements biomédicaux sont des impératifs cruciaux. Face à l’émergence des risques cyber, il est nécessaire d’outiller les ingénieurs biomédicaux dans la prévention des cyberattaques. En s’appuyant sur les travaux du groupe de travail dédié à la « sécurité numérique des équipements biomédicaux » de l’Association Française des Ingénieurs Biomédicaux publiés en 2021, quatre outils ont été élaborés pour définir les modalités de collaboration entre professionnels biomédicaux et des systèmes informatiques au sein des établissements de santé, sécuriser l’environnement des équipements biomédicaux, favoriser l’intégration de la sécurité numérique dans les procédures d’achat de tels équipements, et évaluer leur criticité. Les outils proposés ont fait l’objet de tests auprès d’ingénieurs biomédicaux pour vérifier leur adéquation aux besoins de la communauté biomédicale et dégager des perspectives d’évolution
MAGNETIC RESONANCE ELASTOGRAPHY (MRE) LUNG STIFFNESS: APPLICATION TO LONG COVID PATIENTS
No full textInternational audienc
Limit Theorems in the Nonparametric Conditional Single-Index U-Processes for Locally Stationary Functional Random Fields under Stochastic Sampling Design
No full textInternational audienceIn his work published in (Ann. Probab. 19, No. 2 (1991), 812–825), W. Stute introduced the notion of conditional U-statistics, expanding upon the Nadaraya–Watson estimates used for regression functions. Stute illustrated the pointwise consistency and asymptotic normality of these statistics. Our research extends these concepts to a broader scope, establishing, for the first time, an asymptotic framework for single-index conditional U-statistics applicable to locally stationary random fields {Xs,An:sinRn} observed at irregularly spaced locations in Rn, a subset of Rd. We introduce an estimator for the single-index conditional U-statistics operator that accommodates the nonstationary nature of the data-generating process. Our method employs a stochastic sampling approach that allows for the flexible creation of irregularly spaced sampling sites, covering both pure and mixed increasing domain frameworks. We establish the uniform convergence rate and weak convergence of the single conditional U-processes. Specifically, we examine weak convergence under bounded or unbounded function classes that satisfy specific moment conditions. These findings are established under general structural conditions on the function classes and underlying models. The theoretical advancements outlined in this paper form essential foundations for potential breakthroughs in functional data analysis, laying the groundwork for future research in this field. Moreover, in the same context, we show the uniform consistency for the nonparametric inverse probability of censoring weighted (I.P.C.W.) estimators of the regression function under random censorship, which is of its own interest. Potential applications of our findings encompass, among many others, the set-indexed conditional U-statistics, the Kendall rank correlation coefficient, and the discrimination problems