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Regards sur l’approche du Canada à l’égard des réfugiés à travers deux siècles et demi (1770-2023)
No full textFRAGMENTED OR UNIFIED? EXAMINING THE PARADIGM OF VULNERABILITIES IN SEXUAL HEALTH
No full textInternational audienceAbstract Objectives This study examines the scientific literature on vulnerabilities in the field of sexuality to investigate the existence of a coherent paradigm. Is there an identifiable scientific interest in this topic? What are the central questions asked? How have these questions evolved over time? Finally, can this paradigm be considered sexological, meaning centered around sexual health, sexual rights, and pleasure? Methods PubMed and Web of Science databases were queried using (vulnerability OR vulnerable) AND (sexuality OR sexual health), resulting in the collection and analysis of 21 343 articles published between 1968 and 2023. We examined the temporal evolution of the number of publications, the number of authors involved, and the interrelations between these authors to reveal research communities. The main keywords in these publications were analyzed to observe temporal evolution and their interconnections, using text-mining methods. Results Findings reveal a growing interest in vulnerabilities in sexual health since 2006, likely linked to the holistic definition of sexual health proposed by the WHO. Although numerous authors (77460) have contributed to this field, 86% have published only one article, indicating intermittent contributions. Only 2% of authors, considered experts with five or more publications, are distributed across 314 distinct communities, indicating field fragmentation and a lack of integration between research groups. The diversity of keywords (eg, infectious diseases, reproductive health, psychosocial dimensions) highlights a polymorphic field. Temporal analysis reveals three distinct periods between 2006 and 2023, demonstrating a paradigmatic shift: an initial focus on epidemiological and biomedical issues (2006–2013), followed by a transition towards a more holistic, social, and interactional approach (2019–2022). However, concepts related to pleasure and sexual rights remain marginal within the network of conceptual interrelations, limiting the unification of the field under a fully sexological paradigm. Conclusions The paradigm of vulnerabilities in sexual health remains fragmented, primarily oriented towards social and biomedical needs, and lacks proactive integration of sexological perspectives centered on sexual rights and pleasure. This fragmentation hinders the theorization of sexology as an autonomous field and reduces the specificity of the discipline within sexual health. Conflicts of Interest None
Exoskeletons as potential devices to support and enhance rescuers’ chest compression performance during out-of-hospital cardiac arrest
No full textInternational audienceExoskeletons are wearable structures that support and assist movement, or augment the capabilities of the human body. These functionalities could theoretically assist bystanders or rescuers performing manual chest compressions during out-of-hospital cardiac arrest, as this emergency procedure is prone to physical exhaustion. Compressions are an intense muscular effort involving a dynamic muscular pattern with conflicting postural constraints. Rescuer fatigue sets in rapidly, leading to postural instability and a lack of mechanical power delivered by the arms to the patient's torso, which affects hemodynamic efficiency. Physical augmentation and postural stabilization are two functions that could be provided by an exoskeleton during cardiopulmonary resuscitation. This device would combine the advantages of manual and mechanical chest compressions, bypassing anthropometric parameters such as the rescuer's aerobic capacity and muscle mass to maintain efficient chest compressions, and avoiding the negative issues associated with over-assistance through a servomotor function. This concept paper examines the specifications of an ideal theoretical device in this context, noting the potential technical difficulties and barriers to implementation.</div
A Wavelet Transform-Based Transfer Learning Approach for Enhanced Shaft Misalignment Diagnosis in Rotating Machinery
No full textInternational audienceRotating machines are vital for ensuring reliability, safety, and operational availability across various industrial sectors. Among the faults that can affect these machines, shaft misalignment is particularly critical due to its impact on other components connected to the shaft, making it a key focus for diagnostic systems. Misalignment can lead to significant energy losses, and therefore, early detection is crucial. Vibration analysis is an effective method for identifying misalignment at an early stage, enabling corrective actions before it negatively impacts equipment efficiency and energy consumption. To improve monitoring efficiency, it is essential that the diagnostic system is not only intelligent but also capable of operating in real-time. This study proposes a methodology for diagnosing shaft misalignment faults by combining wavelet transform for feature extraction and transfer learning for fault classification. The accuracy of the proposed soft real-time solution is validated through a comparison with other time-frequency transformation techniques and transfer learning networks. The methodology also includes an experimental procedure for simulating misalignment faults using a laser measurement tool. Additionally, the study evaluates the thermal impacts and vibration signature of each type of misalignment fault through multi-sensor monitoring, highlighting the effectiveness and robustness of the approach. First, wavelet transform is used to obtain a good representation of the signal in the time-frequency domain. This step allows for the extraction of key features from multi-sensor vibration signals. Then, the transfer learning network processes these features through its different layers to identify the faults and their severity. This combination provides an intelligent decision-support tool for diagnosing misalignment faults, enabling early detection and real-time monitoring. The proposed methodology is tested on two datasets: the first is a public dataset, while the second was created in the laboratory to simulate shaft misalignment using a laser alignment tool and to demonstrate the effect of this defect on other components through thermal imaging. The evaluation is carried out using various criteria to demonstrate the effectiveness of the methodology. The results highlight the potential of implementing the proposed soft real-time solution for diagnosing shaft misalignment faults
Étude et modélisation des propriétés en fatigue à très grand nombre de cycles à partir de mesures d’auto-échauffement sous sollicitation cyclique
No full textMaterial fatigue is the main cause of failure of parts in service. Taking it into account is therefore essential when dimensioning a system. Fatigue testing is a simple but time-consuming way of obtaining a Wöhler curve. Because of the limited load frequency of conventional machines, it used to be assumed that a material had an endurance limit at 107 cycles. However, some systems in service are subjected to up to 1010 cycles, due to low-amplitude vibrations for example, and show signs of failure. The appearence of ultrasonic fatigue machines operating at 20 kHz in the middle of the 20th century made it possible to study these ranges of service life. The aim of this study is to investigate the value of thermometric measurements for understanding VHCF fatigue behavior.In order to calculate the dissipation of our material in an ultrasonic configuration, a 1D analysis protocol was proposed and validated. This protocol enabled us to obtain a self-heating curve at very high frequencies, and to study the effect of frequency on the material's thermal response. A bimodal fatigue model was then proposed, based on a core/skin distinction of our specimens and an energy criterion. This predictive model uses solely the self-heating curve and material parameters. High-frequency fatigue tests validated the model on ML340 steel up to 1010 cycles which has a bimodal fatigue behaviour.La fatigue des matériaux est le facteur principal de rupture de pièces en service. Sa prise en compte est donc primordiale dans le dimensionnement d’un système. La réalisation d’essais de fatigue est un moyen simple mais chronophage d’obtenir une courbe de Wöhler. A cause de la fréquence de sollicitation limitée des machines conventionnelles, il était considéré qu’un matériau avait une limite d’endurance à 107 cycles. Toutefois, certains systèmes en services subissent jusqu’à 1010 cycles, à cause de vibrations de faibles amplitudes par exemple, et présentent des ruptures. L’apparition des machines de fatigues ultrasoniques sollicitant à 20 kHz au milieu du 20ème siècle a rendu possible l’étude de ces gammes de durées de vie. L’objectif de cette étude est d’étudier l’intérêt des mesures thermométriques pour la compréhension du comportement en fatigue VHCF. Afin de pouvoir calculer la dissipation de notre matériau dans une configuration ultrasonique, un protocole de dépouillement 1D a été proposé puis validé. Ce protocole a permis de pouvoir obtenir une courbe d’auto-échauffement à très haute fréquence et d’étudier l’effet de la fréquence sur la réponse thermique du matériau. Un modèle de fatigue bimodale a ensuite été proposé à l’aide d’une distinction coeur/peau de nos éprouvettes et d’un critère énergétique. Ce modèle prédictif est basé uniquement sur la courbe d’auto-échauffement et des paramètres matériaux. Des essais de fatigue à très haute fréquence ont permis de valider ce modèle sur l’acier ML340 jusqu’à 1010 cycles qui présente un comportement bimodal
Multi-Prototype Hyperbolic Learning Guided by Class Hierarchy
No full textInternational audienceIn many computer vision applications, datasets often exhibit an underlying taxonomy within the label space. To adhere to this hierarchical structure, hyperbolic spaces have emerged as an effective manifold for representation learning, thanks to their ability to encode hierarchical relationships, with little distortion, even for low-dimensional embeddings. Hyperbolic prototypical learning, where class labels are represented by prototypes, has recently demonstrated strong potential in this setting. However, existing methods generally assume a uniform distribution of prototypes, overlooking the hierarchical organization of labels that may be available for a given task. To better exploit this prior knowledge, we propose a hierarchically informed method for prototype positioning. Our approach leverages the Gromov-Wasserstein distance to align the hierarchical relationships between labels with the initial uniform spherical distribution of prototypes, leading to more structured and semantically meaningful representations. Additionally, within a deep learning framework, we propose an alternative characterization of decision boundaries using horospheres, which are level sets of the Busemann function. Geometrically, horospheres correspond to spheres tangent to the boundary of hyperbolic space at a virtual point analogous to a prototype, which makes them a compliant tool in the prototypical learning context. Accordingly, we define a new horospherical layer that can be adapted to any neural network backbone. This layer is particularly advantageous when the number of prototypes exceeds the number of classes, offering enhanced flexibility to the classifier. Through our experiments, we demonstrate that the combination of proper initialization and optimized prototype positioning significantly enhances baseline performance for image classification on hierarchical datasets. Additionally, we validate our approach in two semantic segmentation tasks, using both image and point cloud datasets, confirming its effectiveness in leveraging hierarchical label structures for improved classification performance
Local Paper, International News: Feminist Print Cultures and Women’s Centres Newsletters in 1970s-1980s Belgium, France and Britain
No full textInternational audienceIn the wake of the 1970s revival of women's liberation movements in Western Europe, women's centres set up by local feminist groups often served as meeting and production premises for newsletter collectives. This article explores the part this form of grassroots feminism played in the transformations of West-European feminist print cultures by interrogating the ambitions and limitations of these local collectives when it comes to transnational circulations of texts and ideas. Drawing on selected archived women's centres newsletters and archives of editorial collectives from Belgium, Britain and France, this article approaches these newsletters as translocal social movement technologies, and highlights their location at a productive yet sometimes uneasy position in between the local constitution of a women's movement and the transnational ambitions of that same movement. It explores the circulation of these newsletters by drawing out the spatial contours of their readerships, before examining the diverse inconsistently successful editorial practices aiming to make international news appear on the pages.</div
Complementarities of nanoindentation and atomic force microscopy for exploring micromechanical features of ancient flax fibres
No full textInternational audienceThe use of flax (Linum usitatissimum L.) fibres for textile dates back to several millennia; in Ancient Egypt flax was widely used in many everyday items. While flax fibres continue to diversify today as composite reinforcements, the study of their historical use is highly relevant when it comes to their durability; archaeological samples offer unique lenses for understanding changes in intrinsic fibre properties after long–time periods. Through a comprehensive examination of ancient Egyptian flax fibres from four archaeological artefacts, this study carries out a detailed characterisation of the fibre ultrastructure and micromechanical properties by combining nanoindentation (NI) and atomic force microscopy (AFM). This work highlights the complementary of these techniques for both heritage and materials science; it demonstrates on some samples, the remarkable cell wall stiffness, even after thousands of years, which is a key element for the bio-based composites sector, to better understand the degradation mechanisms of plant fibres
Étude des motivations des contributeurs des campagnes de crowdfunding portées par les collectivités territoriales
No full textInternational audienceCette recherche a pour objet d’étudier les pratiques de crowdfunding public sous l’angle des motivations des contributeurs. Nous cherchons à identifier ce qui pousse le contributeur à participer à une campagne de crowdfunding portée par une collectivité en distinguant la nature du projet et le mode de financement. Par ailleurs, cette recherche répond à une demande spécifique de la plateforme Collecticity, dédiée au financement participatif des collectivités territoriales. Pour la réalisation de cette étude, nous avons adopté une approche exploratoire en analysant des données quantitatives, collectées par l’administration d’un questionnaire auprès de l’ensemble des contributeurs de la plateforme Collecticity. Compte tenu de la nature exploratoire de notre recherche et du nombre important de variables à analyser, nous avons fait le choix d’utiliser des analyses en composantes principales. Ces dernières nous ont permis d’identifier les principales motivations qui amènent les contributeurs à participer à des campagnes de crowdfunding portées par les collectivités. Cinq dimensions ont été identifiées : « Ancrage territorial », « Attrait du projet », « Incitation », « Participation à la vie de la collectivité » et « Utilisation ». La première fait référence aux motivations relatives à la recherche de liens avec la collectivité, la volonté de participer au développement du territoire et de s’y intégrer davantage. La seconde concerne les aspects plaisants de l’opération et du projet, ainsi que les valeurs véhiculées par celui-ci. La troisième a trait aux aspects ludiques et novateurs de l’opération, qui amènent le contributeur à participer. Nous y trouvons également la pression exercée par les pairs avec l’acte de participer parce que d’autres l’ont fait. La quatrième est une motivation qui s’explique par l’envie de se rendre utile au territoire dans un esprit de solidarité collective et de démocratie participative. Enfin, la dernière concerne des motivations liées à l’utilisation même du projet par soi-même ou ses proches. L’intérêt et l’originalité de ces travaux est d’enrichir le débat académique sur la connaissance des motivations des contributeurs et leur importance relative dans l’acte de contribuer, selon la nature du projet et le type de financement, dans le cadre spécifique des campagnes de crowdfunding portées par les collectivités. D’un point de vue managérial, ces résultats présentent un intérêt pour les plateformes comme pour les collectivités, en leur permettant de mettre en avant dans la présentation des projets les éléments pour lesquels les contributeurs sont les plus sensibles, comme l’attrait du projet pour le don et les biens communaux, l’ancrage territorial pour le prêt et l’incitation pour le patrimoine. Tous ces éléments sont autant de facteurs clefs de succès des campagnes de crowdfunding
A semi-analytical model for low-density impact-based surface treatments: Application to the abrasive waterjet texturing of thermoplastic polymers
No full textInternational audienceSurface roughness is critical for bonding applications, as it directly influences the mechanisms occurring at the adhesive interface. Abrasive Waterjet texturing has emerged as a promising technique for functionalizing surfaces, but predicting the surface characteristics from stochastic impact-based processes remains a challenge. This study aimed to develop a numerical model capable of forecasting key morphological parameters for AWJ-textured surfaces with pilotable treatment coverage. The proposed model was optimized through theoretical analysis and confronted to topographical data from polymer samples treated with low-density AWJ using standard parameters. Profilometry measurements were supported by a custom post-treatment algorithm to remove artefacts and assess the characteristics of individual particle impacts (number, repartition, dimensions). The predicted roughness showed a 94 % concordance to the measured values