HAL Portal Cnam (French National Conservatory for Arts and Crafts)
Not a member yet
31010 research outputs found
Sort by
Ce que le virage de la professionnalisation supérieure fait aux disciplines académiques : vers une « nouvelle disciplinarité » ? Les cursus universitaires en protection de l’enfance comme analyseur
No full textInternational audienceThe universitarization of vocational schools under the professionalization of the university can be likened to a gender transition, beyond the historical opposition between universities and vocational schools. The child protection system is an excellent analytical tool for understanding this transition to a new kind of university education. Despite a highly prescribed system, the university retains significant leeway, taking multiple paths in its ways of staging training in its relations to the research knowledge and the expertise of the actors involved. Thus, contrasting figures emerge in the new ways of doing academic discipline, linked to dynamics of hybridization within various epistemic communities.L’universitarisation des écoles professionnelles sous professionnalisation de l’université peut être assimilée à une transition de genre, par-delà l’opposition historique université-écoles professionnelles. Le dispositif de la protection de l’enfance constitue un excellent analyseur de cette transition vers un nouveau genre de formation universitaire. Malgré un système très prescrit, l’université garde une réelle marge de manœuvre, empruntant de multiples chemins dans ses façons de mettre en scène la formation dans ses rapports aux savoirs de la recherche et aux expertises des acteurs mobilisés. Se dessinent ainsi des figures contrastées dans les nouvelles façons de faire discipline, en lien avec des dynamiques d’hybridation de diverses communautés épistémiques
Experimental study of two low tip-speed ratio micro wind turbines operating in tandem
No full textInternational audienceThis paper presents a parametric experimental study of a dual-rotor wind turbine system operating at low tip-speed ratios of the order of 1. The flow-field in the wake of such a multibladed-high solidity micro-scale windturbine is measured and characterized at distances up to 15Rt , with Rt = 70 mm the tip radius of the turbine.At the best operating point of a single rotor, the near wake presents on the one hand an axial velocity deficitof the order of 40% of the infinite upstream velocity and on the other hand an average tangential velocity ofthe order of 30% of it. The far wake recovery is almost achieved at 15Rt but tangential velocity of the orderof 10% remains. The performances of two identical corotating and counter-rotating wind turbines separatedby distances in the range 3Rt to 12Rt are then experimentally studied. The counter-rotating configurationgives 6% more power than the co-rotating configuration at the shortest distance 3Rt . However, the velocityfield analysis reveals notable interference between the front and rear rotors, degrading the performance ofthe first turbine. This study provides an experimental foundation that guides in d
Stress toxique de la vie fœtale à la petite enfance : une approche transversale en santé publique, entre terrain clinique, prévention et recherche translationnelle
No full textToxic stress in early childhood constitutes a major early determinant of health inequalities. Based on a professional background as a midwife in hospital and humanitarian settings, this study offers a cross-analysis of field experiences, current scientific evidence, and a doctoral research project in public health. The proposed protocol adopts a mixed-methods approach (retrospective and prospective), aiming to clarify the links between adverse prenatal exposures and the emergence of non-communicable diseases in adulthood. The article follows a research-action dynamic, highlighting conditions for the transferability of preventive tools in low-resource settings.Le stress toxique infantile constitue un déterminant précoce majeur des inégalités de santé. À partir d’un parcours professionnel de sage-femme en milieu hospitalier et humanitaire, cette étude propose une analyse croisée entre les expériences de terrain, les données scientifiques actuelles et un projet de recherche doctorale en santé publique. Le protocole présenté adopte une approche mixte (rétrospective et prospective), visant à éclairer les liens entre expositions prénatales adverses et maladies non transmissibles à l’âge adulte. L’article s’inscrit dans une dynamique de recherche-action, mettant en évidence les conditions de transposabilité des outils de prévention dans des contextes à ressources limitées
Bien-être, numérique, technologies
No full textThere is a great deal at stake in focusing the academic community's attention on the links between the different meanings of well-being, both individual and collective, that result from or nourish interactive practices. As such, this new thematic issue of the journal Interfaces numériques aims to examine emerging manifestations and processes in all their diversity and underlying stakes. These questions will be addressed in articles by researchers from a variety of disciplines, as well as practitioners in education, art, information, communication, change management, transition management and more.Il y a un enjeu fort à concentrer le regard de la communauté universitaire sur les liens entre les différentes acceptions du bien-être, tant individuel que collectif, qui résulte ou nourrit les pratiques interactives. De la sorte, ce nouveau numéro thématique de la revue Interfaces numériques souhaite interroger les manifestations et les processus émergents dans leur diversité et leurs enjeux sous-jacents. De tels questionnements rassembleront des articles de chercheurs issus de diverses disciplines, ainsi que des praticiens en éducation, art, information, communication, conduite du changement, gestion des transitions, etc
Clustering et réduction de la dimension avec données manquantes
No full textInternational audienceTo address the challenge of clustering highdimensional data, subspace clustering methods, such as Reduced K-means (RKM) have been proposed. These methods identify clusters by simultaneously finding the low-dimensional subspaces and the matching partition, making them particularly effective in high-dimensional settings. Moreover, high-dimensional data can also mechanically lead to missing data, thereby challenging the subspace clustering. Two new methods are proposed, based on two widely used approaches for missing data: direct methods and multiple imputation (MI). Firstly, the RKPOD direct method accounts for incomplete data through a criterion based on observed values to provide the partition and the associated subspace. Secondly, based on multiple imputed datasets, the MI-RKM method, yields several partitions and associated subspaces which are aggregated through Non-Negative Matrix Factorization and Multiple Factor Analysis, respectively. The two methods are evaluated through a study based on simulated data and a real dataset. For the simulation case, under the MCAR and MAR mechanisms, with the appropriate missing data initialization method, both methods recover the initial clusters and corresponding subspaces in the reference case, as well as in the unbalanced and overlapping case. However, in the scenario with correlated noise variables, both methods struggle slightly more to recover the subspace and the corresponding partition
Multi-proxy sediment trend analysis (MSTA): sedimentary dynamics from source to sink
No full textInternational audienceTo study the surface sediment dynamics of the Cherbourg roadstead, the grain-size end-members of a set of 199 sediment samples are computed and integrated into a multi-proxy sediment trend analysis (MSTA). Cherbourg harbor is a sheltered area where the finest sediments mix with "fossil" sands, gravels from local erosion and shell debris from outside. Using the finest sediment of the data set, this new approach allows us to highlight marine or continental sources and sinks of this fraction
Automatic Functions Annotations through Concrete Procedural Debugging and ELF Libification
No full textInternational audienceIn this article, we present a novel approach to program analysis through selective concrete execution. While static analysis of ELF binaries is necessarily limited by the theoretical undecidability of control-flow and data-flow analysis algorithms, we detail a new approach to reverse engineering through selective concrete execution of arbitrary functions within a x86_64 GNU/Linux binary by transforming ELF applications into shared libraries. This approach, named "procedural debugging", allows us to empirically recover information about function parameters and return values without resorting to any disassembly or decompilation, which are undecidable in general. In turn, this dynamic approach may be used as a feedback loop into existing program analyzers, being them static, fuzzing, symbolic, or concolic, to enrich their understanding of application interfaces. We publish an open-source framework, named the Witchcraft Compiler Collection, under a permissive MIT/BSD license, implementing binary libification, procedural debugging, and automatic function prototype annotations with the hope of benefiting the security community
Terrestrial Very-Long-Baseline Atom Interferometry: summary of the second workshop
No full textInternational audienceThis summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024 (Second Terrestrial Very-Long-Baseline Atom Interferometry Workshop, Imperial College, April 2024), building on the initial discussions during the inaugural workshop held at CERN in March 2023 (First Terrestrial Very-Long-Baseline Atom Interferometry Workshop, CERN, March 2023). Like the summary of the first workshop (Abend et al. in AVS Quantum Sci. 6:024701, 2024), this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions (Memorandum of Understanding for the Terrestrial Very Long Baseline Atom Interferometer Study)
Covariance Fitting Interferometric Phase Linking: Modular Framework and Optimization Algorithms
No full textInternational audienc
Time-Dependent Growth of ZnO Nanowires: Unveiling Antibacterial and Photocatalytic Properties
No full textInternational audienceThis study investigates the synthesis, characterization, and functional properties of well-aligned zinc oxide (ZnO) nanowires (NWs) obtained by a two-step hydrothermal method. ZnO NWs were grown on silicon substrates precoated with a ZnO seed layer. The growth process was conducted at 90 °C for different durations (2, 3, and 4 h) to examine the time-dependent evolution of the nanowire properties. A comprehensive characterization of the ZnO NWs was performed using several analytical techniques. Scanning electron microscopy (SEM) revealed the morphological progression, specifically tracking changes in length and diameter as a function of the growth time. Ultraviolet (UV)visible spectroscopy was employed to determine the optical band gap, while photoluminescence (PL) analysis provided insight into the concentration of structural defects and its evolution as a function of nanowire growth. The photocatalytic efficiency of the ZnO NWs was evaluated through the degradation of the organic dye methylene blue (MB) under UV light irradiation (365 nm). The kinetic of MB degradation was monitored for each growth time, with non-purgeable organic carbon (NPOC) analysis providing a detailed perspective on the photocatalytic activity over time. The antibacterial properties were tested against Pseudomonas putida, a Gram-negative bacterium, to determine the efficiency of the synthesized ZnO NWs as antimicrobial agents. The release of zinc ions (Zn), a key factor in the antibacterial mechanism, was quantified using inductively coupled plasma (ICP) analysis for each sample. By exploration of the relationship between the growth time, nanostructure morphology, and functional properties, this study provides insights into optimizing the synthesis of ZnO NWs for enhanced photocatalytic and antibacterial applications. These findings contribute to the development of advanced materials for environmental and biomedical applications