HAL Portal Cnam (French National Conservatory for Arts and Crafts)
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Comparative E2E Performance Analysis of O-RAN Designs in a 5G Standalone Testbed
No full textInternational audienceThe Open Radio Access Network (O-RAN) paradigm has attracted considerable attention from both academic researchers and industry stakeholders, owing to its capacity to significantly enhance the adaptability and flexibility of cellular network architectures. However, the disaggregation of Generation NodeB (gNB) in O-RAN introduces increased system complexity and potential variability in performance metrics, necessitating empirical evaluation to determine whether its performance can rival or exceed that of conventional monolithic designs. In this study, we developed a standalone (SA) testbed to quantitatively assess the downlink (DL) transmission performance of two O-RAN architectures, implemented on two widely adopted open-source platforms: srsRAN and OAI. To ensure a scientifically robust and comprehensive analysis, we meticulously selected key performance metrics, implemented measures to provide solid statistical results and eliminate residual effects between test iterations. Test results show that the split enhances network flexibility by offloading certain processing tasks to the Distributed Unit (DU), thereby reducing the overall hardware usage burden and potentially improving the computational efficiency and resource allocation in future RAN networks.</div
Management of diabetes in patients hospitalized for acute cardiac events: Joint position paper from the French Society of Cardiology and the French-speaking Diabetes Society
No full textInternational audiencePatients with type 2 diabetes, but also older patients with type 1 diabetes, are at major risk of cardiovascular morbidity and death. After an acute cardiac event, the prognosis of patients with diabetes is impaired, with clear increases in in-hospital and long-term morbidity and deaths. Both hyper- and hypoglycaemia are deleterious after an acute cardiac event, and the decision to start intravenous insulin is often challenging. Moreover, some antidiabetic treatments have cardioprotective effects, and the onset of an acute cardiac event provides an opportunity to shift to these treatments. The objective of this position statement is to offer practical tools to cardiologists seeking to improve the care of patients with diabetes hospitalized for an acute cardiac event, and to optimize collaboration between cardiologists and diabetologists. After a summary of the evidence for antidiabetic treatments in patients with acute cardiac events, we propose an algorithm to start and adapt intravenous insulin in the most severe patients, and conclude with standard insulin protocols or oral treatments at discharge. We also discuss appropriate antidiabetic treatment of these patients at discharge, based on the main cardiological diagnosis, kidney function and antidiabetic strategies. Finally, situations in which the diabetologist must be consulted are discussed
Une démocratie au travail est-elle possible ? Le droit d'expression directe et collective en pratiques
No full textInternational audienceAlors que le « dialogue professionnel » direct entre les travailleurs et travailleuses, leurs managers et la direction, est plébiscité par de nombreux acteurs du travail pour revigorer la participation dans les entreprises face à l'essoufflement du « dialogue social », ce numéro de Connaissance de l'emploi propose d'analyser cette démarche de démocratie directe au travail.À partir d'une enquête sociologique sur les entreprises qui ont choisi d'instaurer un droit d'expression directe et collective sur les conditions et l'organisation du travail, nous montrons les limites de ces expériences de démocratie directe qui restent le plus souvent à la main et au profit des managers et des directions. Identifier ces points de blocages nous permet de mettre au jour les conditions organisationnelles, relationnelles et individuelles requises pour qu'une démocratie directe au travail soit possible
Looking for Equivalence between Maximum Likelihood and Sparse DOA Estimators
No full textInternational audienceSparse Direction-of-Arrival estimators depend on the regularization parameter λwhich is often empirically tuned. In this work, conducted under the vectorized covariance matrix model, we are looking for theoretical equivalence between the Maximum Likelihood (ML) and sparse estimators. We show that under mild conditions, λ can be chosen thanks to the distribution of the minimum of the ML criterion in the case of two impinging sources. We derive this distribution under complex non-circular Gaussian noise. The corresponding λ choice is θ-invariant, only requiring an upper bound on the number of sources. Furthermore, it guarantees the global minimum of the sparse ℓ0-regularized criterion to be the ML solution. Numerical experiments confirm that, for the proposed λ, sparse and ML estimators yield the same statistical performance
Relationship between structure and thermal stability of fluorosilicones at high temperatures
No full textInternational audienceThe thermal stability of fluorosilicones at high temperatures has been investigated with thermogravimetric analysis (TGA) based on their chemical structure (copolymerization and crosslinking), and compounding (incorporation of silica and titanium dioxide particle fillers). This allowed the comparison of thermal degradation kinetics of model samples and commercial fluorosilicones rubbers. Increasing dimethylsiloxane content in copolymers enhances thermal stability, while the presence of vinyl groups accelerates degradation by promoting depolymerization and crosslinking reactions at an earlier stage. In model filled fluorosilicone rubbers (FSR), untreated silica particles were found to destabilize the polymer matrix in the short term, whereas commercial filled FSRs exhibited greater thermal stability due to treated silica surfaces. Additionally, commercial samples crosslinked with DCP mixed with CaCO 3 resulted in the highest thermal stability. FTIR transmission analysis of copolymer residues revealed that degradation does not favor the preferential release of any monomer (dimethylsiloxane or trifluoropropylmethylsiloxane). Elemental analysis of a model homopolymer suggested that depolymerization is the dominant degradation mechanism, but side group scissions also contribute to this process
Au-delà des ruptures radicales : la diversité des parcours de reconversion des cadres diplômés de grandes écoles
No full textInternational audienceCes dernières années, les reconversions professionnelles de cadres hautement diplômés ont fait l'objet d'une attention médiatique croissante, mettant particulièrement en lumière certains métiers de destination, tels que l'artisanat ou les professions manuelles. Pourtant, cette focalisation tend à occulter la diversité des parcours de reconversion réellement observés.S'appuyant sur une enquête originale et des données quantitatives, ce numéro de Connaissance de l'emploi décrit la structuration de l'espace professionnel des reconverti·es, au sein duquel coexistent quatre profils, qui se distinguent à la fois par leur degré de rupture avec l'univers professionnel d'origine et par la pluralité des motivations qui sous-tendent la reconversion
Matérialité, accessibilité, frictions : une analyse des dispositifs socio-techniques autour de l’autisme et de la neurodiversité
No full textNeurodiversity social movements, mainly driven by people with autism, claim a different way of communicating, and a sometimes controversial epistemology. These claims are nonetheless manifested via ordinary communication devices (blogs, books, demonstrations), and raise the following issues: what roles do communication devices, their materiality and accessibility, play in controversies around autism and neurodiversity? What is the place of these devices and their accessibility in social science inquiry practices? To answer these questions, the thesis sheds light on data from several (n)ethnographic surveys, using a mixed theoretical framework combining approaches from information and communication sciences, sociology and crip approaches. In particular, it shows that digital devices contribute to normalizing discourses on autism and encourage individuals to mask their disability and their access frictions. It shows how these devices normalize face-to-face interactions, through participatory surveillance, and an attentional and bodily adjustment. In the latter case, it articulates accessibility and table training, opening on the place of institutional tables in social science practices. It concludes with an epistemological reflection on the accessibility of the communication devices mobilized at each stage of the field investigation and insists on the co-constitution of practices in social sciences and controversies around autism and neurodiversity.Les mouvements sociaux de la neurodiversité, surtout portés par des personnes autistes, revendiquent une manière différente de communiquer et une épistémologie parfois controversée. Ces revendications se manifestent néanmoins via des dispositifs de communication ordinaires (blogs, livres, manifestations) et soulèvent les problématiques suivantes : quels rôles les dispositifs de communication, leur matérialité et leur accessibilité, jouent-ils dans les controverses autour de l’autisme et de la neurodiversité ? Quelle est la place de ces dispositifs et de leur accessibilité dans les pratiques d’enquête en sciences sociales ? Pour répondre à ces problématiques, la thèse éclaire les données issues de plusieurs enquêtes (n)ethnographiques à la lumière d’un cadre théorique mixte, combinant approches en sciences de l’information et de la communication, en sociologie, et approches dites crip. Elle montre notamment que les dispositifs numériques contribuent à normaliser les discours sur l’autisme, et incitent les individus à masquer leur handicap et les frictions d’accès. Elle montre comment ces dispositifs normalisent les interactions en face-à-face, à travers une surveillance participative, et un ajustement attentionnel et corporel. Dans ce dernier cas, elle articule accessibilité et entraînement à la table, ouvrant sur la place des tables institutionnelles dans les pratiques en sciences sociales. Elle se termine par une réflexion épistémologique sur l’accessibilité des dispositifs de communication mobilisés à chaque étape de l’enquête de terrain, et insiste sur la co-constitution des pratiques en sciences sociales et des controverses autour de l’autisme et de la neurodiversité
An efficient and compact supply for electroactive polymers
No full textInternational audienceNew trends in electroactive-polymers (EAP) based devices for soft actuators and for electrocaloric cooling revive studies on compact, efficient, reversible and low power supply. High electrode resistance, high voltage and small capacitance of EAPs represent a major hindrance for an efficient charge/discharge. Because Joule losses in EAP are entwined with the voltage profile of the converter, we study an inductor based coupling, focusing on a multistep voltage profile produced by a Solid-State Marx Modulator. The energy stored in the inductor, its volume, and the efficiency of the charge/discharge process are studied as a function of the number of steps and of the RLC damping factor. Furthermore, to avoid detrimental current surge related to resonance, a pre and post charge protocol are implemented.The tradeoff between inductor size, efficiency and the number of steps is discussed using an analytical model, and through comparison with measurements performed using a specifically developed Solid-State Marx Modulator. This study shows that the multistep charge of EAPs represents an efficient tool for tackling the Joule losses vs. volume reduction issue offering a key tool to guide the design of the new generation of EAP based devices.Les nouvelles tendances dans les dispositifs à base de polymères électroactifs (EAP) pour les actionneurs souples et le refroidissement électrocalorique relancent les études sur les alimentations compactes, efficaces, réversibles et à faible consommation d'énergie. La résistance élevée des électrodes, la tension élevée et la faible valeur de capacité des EAP constituent un obstacle majeur à une charge/décharge efficace. Comme les pertes Joule dans les EAP sont liées au profil de tension du convertisseur, nous étudions un couplage basé sur une inductance, en nous concentrant sur un profil de tension à plusieurs niveaux produit par un Solid-State Marx Modulator. L'énergie stockée dans l'inductance, son volume et l'efficacité du processus de charge/décharge sont étudiés en fonction du nombre d'étage et du facteur d'amortissement du RLC. En outre, pour éviter les surtensions de courant nuisibles liées à la résonance, un protocole de précharge et de postcharge est mis en œuvre.Le compromis entre la taille de l'inductance, l'efficacité et le nombre d'étapes est discuté à l'aide d'un modèle analytique et d'une comparaison avec les mesures effectuées à l'aide d'un Solid-State Marx Modulator spécialement conçu à cet effet. Cette étude montre que la charge en plusieurs étapes des EAP constitue un outil efficace pour résoudre le problème des pertes par effet Joule par rapport à la réduction du volume, offrant ainsi un outil clé pour guider la conception de la nouvelle génération de dispositifs basés sur les EAP
Cartographie des communautés de macroalgues Intertidales d'estran rocheux par combinaison de données LiDAR et de relevés in-situ
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Transcriptomic analysis of chronic chikungunya in the Reunionese CHIKGene cohort uncovers a shift in gene expression more than 10 years after infection
No full textInternational audienceIn 2005-2006, a chikungunya epidemic of unprecedented magnitude hit Reunion Island, which raised a public health concern through the substantial proportions of long-lasting manifestations. To understand the pathophysiology underlying chronic chikungunya (CC), we designed the CHIKGene cohort study and collected blood samples from 133 subjects diagnosed with CC and from 86 control individuals that had recovered within 3 months, 12-to-15 years after exposure.We conducted bulk RNAseq analysis on peripheral blood mononuclear cells to find differentially expressed genes (DEGs), gene set enrichment analysis (GSEA) and gene ontologies to uncover top-level enriched terms associated with DEGs, and weighted gene correlation network analysis (WGCNA) to elucidate underlying cellular processes.Among 1549 DEGs, gene expression analysis identified 10 top genes including NR4A2 and TRIM58 (upregulated in CC), IGHG3 and IGHV3-49 (downregulated in CC) linked to immune regulation, OSBP2 (upregulated in CC) and SEMA6B (downregulated in CC) linked to neuronal homeostasis and axon guidance, respectively. GSEA and WGCNA unveiled cellular processes such as "Metabolism of RNA" and "Cell Cycle”.This study uncovers a shift in gene expression of CC subjects. IGHG3 and IGHV3-49 gene shut-offs spotlight the importance of neutralizing antibodies against chikungunya virus in the progression to chronic disease. Human diseases associations highlight connections to rheumatoid arthritis, nervous and cardiac systems. GSEA and WGCNA bounce the hypotheses of a persistent viral reservoir or an increased susceptibility to RNA viral pathogens with new onset infections. Together, our findings might offer potential targets for therapeutic options aimed at alleviating chronic chikungunya