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Variability of damping properties for viscoelastic composite plates of flax fibers
No full textInternational audienceThis paper aims at taking into account uncertainties of material and physical properties of flax/epoxy composite structures and evaluating their impacts onto the variability of free vibration responses. The natural character of the fiber indeed induces a quite important variability to properties of composite structures, leading to a noticeable variability of responses, possibly hindering its use. The variability of elastic moduli and thicknesses for flax/epoxy multi-layer structures is here modeled to investigate their influence on the variability of damping characteristics such as damping frequency and damping. The quantification of input uncertainties comes from an experimental campaign. The non-linear vibration problem of composite structures is solved by a High Order Newton method. The Monte Carlo Simulation method associated to a Modal Stability Procedure is here proposed using homotopy perturbation technique to deal with the frequency-dependent structure. Two viscoelastic constitutive laws are considered, the generalized Maxwell model and the Fractional derivative Zener model. The test case is a cantilever flax/epoxy rectangular plate and three stacking sequences are considered. The propagation of uncertainties is performed in order to determine the output variability level and the most influent parameters regarding damping characteristics of this structure
Multi-Priority-Based Strategy for Risk Assessment and Management in the Presence of Multiple Personal Light Electric Vehicles
No full textInternational audienceNavigating safely in environments populated by dynamic and multi-modal agents poses significant challenges to risk assessment and management for Autonomous Vehicles (AV). In particular, we consider urban scenarios involving Personal Light Electric Vehicles (PLEVs) that are known to exhibit varying maneuvers and velocity profiles. We propose a Fusion of Predictive Inter-Distance Profile (F-PIDP) to predict the inter-distances and capture the uncertainties in the motion of the AV and the PLEV's multiple trajectories. Building upon this, a multipriority-based trajectory sampling algorithm is developed for collision avoidance. This strategy is generalized to assess and prioritize multiple agents with varying motion across several driving lanes, enabling the system to identify and respond to the most dangerous agents. The proposed method is then integrated into a Model Predictive Control (MPC) trajectory tracking framework to perform risk management for safe and adaptive control of the AV's motion. The proposed method is validated through a series of simulations with critical driving scenarios.</div
Modélisation des systèmes narratifs interactifs : Approche formelle
No full textInternational audienceInteractive Narrative Systems (INS) have revolutionized digital experiences by empowering users to actively shape their stories,diverging from traditional passive storytelling. However, the field faces challenges due to fragmented research efforts and diversesystem representations. This paper introduces a formal representation framework for INS, inspired by diverse approaches from thestate of the art. By providing a consistent vocabulary and modeling structure, the framework facilitates the analysis, the descriptionand comparison of INS properties. Experimental validations on the "Little Red Riding Hood" scenario highlight the usefulness of theproposed formalism and its impact on improving the evaluation of INS. This work aims to foster collaboration and coherence withinthe INS research community by proposing a methodology for formally representing these systems.Les systèmes narratifs interactifs (SNI) ont révolutionné les expériences numériques en permettant aux utilisateurs de façonneractivement leurs histoires, s'écartant ainsi de la narration passive traditionnelle. Cependant, le domaine est confronté à des défis enraison de la fragmentation des efforts de recherche et de la diversité des représentations des systèmes. Cet article présente uncadre de représentation formel pour les SNI, inspiré par diverses approches de l'état de l'art. En fournissant un vocabulaire et unestructure de modélisation cohérents, le cadre facilite l'analyse, la description et la comparaison des propriétés de ces SNI. Desvalidations expérimentales sur le scénario du « Petit Chaperon Rouge » mettent en évidence l'utilité du formalisme proposé et sonimpact sur l'amélioration de l'évaluation des SNI. Ce travail vise à favoriser la collaboration et la cohérence au sein de lacommunauté de recherche sur les SNI en proposant une méthodologie pour représenter formellement ces systèmes
Degradation Study of NMC622/Graphite Second Life Li-ion Battery Packs
No full textInternational audienceUnderstanding the aging behavior of lithium-ion battery packs is essential for optimizing system sizing and improving performance, particularly in applications involving second-life use. This study presents aging data from an accelerated cycling campaign on battery packs equipped with Battery Management Systems (BMS) featuring cell balancing functionality. A detailed analysis is conducted to quantify the impact of intercell heterogeneity, specifically capacity and resistance dispersion, on theactivation of balancing circuits. The results show that increased capacity spread leads to significantly higher balancing activity and reduced available energy, emphasizing the importance ofmonitoring cell degradation for effective BMS design and pack utilizatio
Les pieds dans le plat : Réflexions sur la nature technique de l’alimentation
No full textMarine Bouzat, Gabriela Carrillo Codina et Gaëlle Stoltz sont toutes trois étudiantes dans le cursus Humanités et Technologie, à l’université de technologie de Compiègne. Dans ce cadre, elles sont amenées à réaliser des travaux de recherches dont l’objectif est de penser le rôle structurant de la technique dans les mondes humains. Cet article constitue une première publication académique ; il est issu d’un mémoire de recherche effectué dans le cadre de leurs études.International audienceSince the industrialization that occurred throughout the last centuries, food has been rationalized. One of the consequences of fooding becoming a scientific interest is not only how humans have completely changed their habits regarding the way they eat but also the way they feel about doing so. From fear to anxiety : people are more and more concerned about what they eat, the choice of their meal troubling them on a daily basis. In response, our Western society has pleaded for the “revival of natural fooding”, opposing it to industrial production. However, this revival seems unrealistic : how can fooding be only “natural” when it’s inherently technical ? Indeed, fooding is the expression of formal and informal know-hows, both constituent and indistinguishable elements of the human himself. Perhaps the solution lies in renewing contact with those know-hows.L’alimentation est aujourd’hui la cible d’injonctions contradictoires, symptôme archétypique d’un néolibéralisme culpabilisateur. Celui-ci a trouvé sa condition de possibilité dans le processus de rationalisation qui fut le fer de lance de l’industrialisation au cours des derniers siècles. La mise en science des savoir-faire artisanaux a abouti à la création d’une technoscience de l’alimentation, bouleversant le rapport que l’homme entretient avec ce qu’il mange. En réponse aux angoisses ainsi suscitées, la société occidentale a forgé l’illusion d’un retour à une alimentation « naturelle », en opposition à une alimentation technique, donc. Celui-ci est cependant impossible, puisqu’il s’ancre dans une vision réductrice de la technique, qui est pourtant l’expression de savoir-faire formels et informels indissociables et constitutifs de l’être humain. C’est dans la reconnexion avec ces savoir-faire et avec la matérialité de ce que l’on mange que réside, peut-être, une piste hors de la dépendance du sentier
Novel solventless strategies for the production of lipoamino acids
No full textInternational audienceThe demand for surfactants is steadily increasing due to their extensive applications in detergents, emulsifiers, cosmetics, food and pharmaceuticals. This growing need has placed pressure on manufacturers to develop surfactants that are non-toxic, natural, and biodegradable. Among the promising alternatives are amino acid-based surfactants, also known as lipoaminoacids. These surfactants can be derived from natural feedstocks such as amino acids and vegetable oils. Their simple and natural structures contribute to their low toxicity and rapid biodegradability that make them attractive for green chemistry. Linear lipoaminoacids are produced from α-amino acids linked to an aliphatic chain. The amino group of the amino acid can react with fatty acids and haloalkanes giving the corresponding Nacyl and N-alkyl derivatives. Alternatively, the carboxyl group of the amino acid can be condensed with alkyl amines or aliphatic alcohols to give N-alkyl amides and esters
Harnessing the power of anti-amyloidogenic polyglutamine binding peptide 1: A computational and biophysical approach to antimicrobial prediction
No full textInternational audienceIn this work, we demonstrate for the first time the antimicrobial activity of poly-Q binding peptide 1 (QBP1), an anti-amyloidogenic molecule previously identified by phage display for its ability to bind and inhibit the aggregation of polyglutamine proteins like Huntingtin, but also α-synuclein and prion models. Intriguingly, sequence analysis by the ADAPTABLE web server highlighted QBP1's potential antifungal and antibacterial activity, which we have now confirmed experimentally. A theoretical basis for the predicted mechanism of action was provided by molecular dynamics simulations revealing the role of QBP1 aggregates promoting membrane disruption and specific interactions between QBP1 and bacterial and fungal phospholipids, further substantiated by solid-state NMR studies. Using primary human cells, we demonstrated that QBP1 does not display toxicity at high concentrations. Finally, our data demonstrate QBP1's efficacy against some strains of Bacillus cereus, B. mojavensis, Staphylococcus aureus, S. epidermidis, Micrococcus luteus, Enterococcus faecalis, Escherichia coli, and Candida. This unexpected dual function of QBP1 opens new avenues for therapeutic development, potentially restoring the putative antimicrobial protection exerted by many amyloidogenic proteins
Current challenges of magnetic resonance elastography to quantify in vivo muscle behavior
No full textInternational audienc
Usages des intelligences artificielles génératives en santé – État des lieux
No full textProjet proposé et suivi par : J. FOLLET, Université de Technologie de Compiègne (France), Département Génie Biologique, Master Ingénierie de la Santé, UMR CNRS 7338 BioMécanique et BioIngénierie, et G. CARNINO, Université de Technologie de Compiègne (France), EA2223 Connaissance Organisation et Systèmes TECHniquesSince their release to the public a few years ago, generative artificial intelligences (GenAI), such as ChatGPT, have been adopted across a wide range of fields. Their ability to generate text, images and videos makes them particularly appealing for a large variety of tasks. The medical field is no exception to the rise of these new tools : start-ups specializing in this type of AI are emerging, and many healthcare professionals are coming together to discuss how these tools might be integrated into hospital services, etc. However, there remains a significant gap between the enthusiasm surrounding GenAI and its actual use in practice. In reality, very few doctors are using or are even aware of the tools currently available on the market. How can this gap be explained ? What challenges are potential users in the medical field facing ? In this study, we compare the existing knowledge with a field survey. We also address the ethical issues related to AI, and more specifically to AI used in healthcare. We conclude our study by exploring how AI could potentially reshape various roles within the medical profession.Depuis leur mise à disposition au grand public il y a quelques années, les intelligences artificielles génératives (IA Gen), telles que Chat GPT, ont intégré de nombreux domaines. Leurs capacités à générer du texte, des images et des vidéos les rendent très intéressantes pour de nombreuses tâches. Le domaine médical n’échappe pas à l’essor de ces nouveaux outils, des start-ups proposant ce type d’IA se créent, de nombreux experts de la santé se réunissent pour discuter de leur intégration dans les différents services des hôpitaux, etc. Cependant, il existe un décalage important entre l'engouement autour des IA Gen et leur réelle utilisation sur le terrain. En effet, très peu de médecins utilisent ou même connaissent les différents outils mis à disposition sur le marché. Comment expliquer cet écart ? Quelles problématiques rencontrent les potentiels utilisateurs du domaine médical ? Dans cette étude, nous confrontons les connaissances disponibles avec une enquête sur le terrain. Nous abordons également les enjeux éthiques liés aux IA et plus particulièrement aux IA utilisées dans le domaine de la santé. Nous terminons notre étude sur les potentielles reconfigurations que pourraient engendrer les IA dans les différents corps de métier
Maximize advantages in hard and soft-switching applications with optimal use of a modern SiC MOSFET with low output capacitance
No full textInternational audienceSilicon carbide (SiC) MOSFETs have superior properties at high voltage and high power compared to silicon (Si) devices in almost all aspects due to their material advantages such as three times larger band gap, three times larger thermal conductivity, ten times higher critical electric field, two times higher saturation velocity and so on. SiC MOSFETs can thus significantly improve the performance of the system. In addition to the well-known advantages of SiC MOSFETs over Si MOSFETs and IGBTs, a deeper understanding and right usage of SiC MOSFETs can help enhance device performance and maximize system value propositions. In this paper, a parameters-oriented approach is proposed to select the right SiC MOSFET device corresponding to the requirements of each application. The proposed approach has been validated by PLECS simulation results of representative hard and soft switching applications