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Comment articuler des méthodes quantitatives et qualitatives pour avoir une preuve en sciences de l’éducation ?
No full textInternational audienceLa communication présente un projet d'innovation pédagogique en recherche-action qui a eu lieu à Paris 1, en licence d'économie où des étudiants en TD expérimentaux ont réalisé des vidéos de cours. L'expérience a été étudiée à la fois avec des méthodes quantitatives (notes à l'examen, questionnaires, analyse de données sociodémographiques) et des méthodes qualitatives (entretiens avec les chargés de TD, les étudiants, observation des TD). Elle vise à réfléchir à l'articulation de ces différentes méthodes et de ce qui est transformateur ou non en éducation
Massive merging cluster PSZ2G091 as seen by the NIKA2 camera
No full textISBN 979-10-96879-16-8International audiencePSZ2 G091.83+26.11 is a galaxy cluster with M500 = 7.43 x 10^14 Msun at z = 0.822 1. This object exhibits a complex morphology with a clear bimodality observed in X-rays. However, it was detected and analysed in the Planck sample as a single, spherical cluster following a universal profile 2. This model can lead to miscalculations of thermodynamical quantities, like the pressure profile. As future multiwavelength cluster experiments will detect more and more objects at high redshifts, it is crucial to quantify this systematic effect. In this work, we use high-resolution observations of the NIKA2 camera3,4,5,6 to integrate the morphological characteristics of the cluster in our modelling. This is achieved by fitting a two-halo model to the SZ image and then by reconstruction of the resulting projected pressure profile. We then compare these results with the spherical assumption
Les enceintes urbaines en Gaule. Défendre et définir la ville
No full textDossier. Les enceintes urbaines en Gaule. Défendre et définir la ville De nombreuses villes de Gaule romaine se sont dotées de remparts afin d'assurer leur protection ou manifester leur puissance. S'il est difficile de les dater avec précision, les vestiges qui sont parvenus jusqu'à nous, souvent englobés dans des constructions plus récentes, permettent d'en savoir plus sur les conditions de leur réalisation. Archéologia vous propose un vaste panorama de ces majestueuses construction. Par Vivien Barrière, maître de conférences en histoire et archéologie, CY Cergy Paris Université, UMR 9022 HERITAGE
EBP-GEXIT Charts for M-ary AWGN Channel for Generalized LDPC and Turbo Codes
No full textInternational audienceThe maximum a posteriori (MAP) threshold corresponds to the fundamental limit that one can hope to achieve with the given channel code ensemble. Apart from theoretical interests, finding this limit is also desirable since spatial-coupled code ensembles approach this MAP threshold due to phenomenon termed as threshold saturation. However finding this MAP threshold, in general, is known to be computationally prohibitive. This work proposes a tractable method for estimating the MAP threshold for various families of sparse-graph code ensembles over non-binary complexinput additive white Gaussian noise (AWGN) channel. Towards this, we provide a method to approximate the extended belief propagation generalized extrinsic information transfer (EBP-GEXIT) chart and estimate the MAP threshold by applying the Maxwell construction to it. To illustrate the validity of our method, we study spatial coupling for serially-concatenated turbo-codes and numerically observe threshold saturation of these codes to the MAP thresholds estimated via our method
Current and future chemical treatments to fight biodeterioration of outdoor building materials and associated biofilms: moving away from ecotoxic and towards efficient, sustainable solutions
No full textInternational audienceAll types of building materials are rapidly colonized by microorganisms, initially through an invisible and then later a visible biofilm that leads to their biodeterioration. Over centuries, this natural phenomenon has been managed using mechanical procedures, oils, or even wax. In modern history, many treatments such as high-pressure cleaners, biocides (mainly isothiazolinones and quaternary ammonium compounds) are commercially available, as well as preventive ones, such as the use of water-repellent coatings in the fabrication process. While all these cleaning techniques offer excellent cost-benefit ratios, their limitations are numerous. Indeed, building materials are often quickly recolonized after application, and microorganisms are increasingly reported as resistant to chemical treatments. Furthermore, many antifouling compounds are ecotoxic, harmful to human health and the environment, and new regulations tend to limit their use and constrain their commercialization. The current state-of-the-art highlights an urgent need to develop innovative antifouling strategies and the widespread use of safe and eco-friendly solutions to biodeterioration. Interestingly, innovative approaches and compounds have recently been identified, including the use of photocatalysts or natural compounds such as essential oils or quorum sensing inhibitors. Most of these solutions developed in laboratory settings appear very promising, although their efficiency and ecotoxicological features remain to be further tested before being widely marketed. This review highlights the complexity of choosing the adequate antifouling compounds when fighting biodeterioration and proposes developing case-to-case innovative strategies to raise this challenge, relying on integrative and multidisciplinary approaches
Breast imaging by convolutional neural networks from joint microwave and ultrasonic data
No full textInternational audienceConvolutional neural networks to achieve joint in- version of microwave and ultrasonic data for breast imaging are investigated. The estimated contrast current and scattered field inside the domain of interest are used as inputs. A multi- stream structure is employed to input the data from different modalities. The network outputs the distribution maps of electric and acoustic parameters directly so as to achieve real-time imaging. Apart from the regression task, a multi-task learning strategy is used with a classifier which associates each pixel to a tissue type to yield a segmentation image. Weighted loss is used to assign a higher penalty to pixels in tumors when they are wrongly classified. Comparisons have been carried out between different network structures with the same datasets. The prediction results of the networks are evaluated by Intersection- over-Union for segmentation results and by relative error for reconstructions. The simulations on breast phantoms extracted from a dedicated repository show that with both microwave and ultrasonic data, the network can get a better estimate of the breast structure and small tumors detected. Meanwhile, multi- task learning has improved the regression results and multi- stream input has helped to exploit data from different modalities
Dialogue entre TSD et TAD pour l’élaboration d’un projet collaboratif d’enseignement des mathématiques
No full textInternational audienc
Gender Differences in Burnout Syndrome and Perceptions of Gender Equality in Research Organisations
No full textInternational audienceWe present the results of a survey which was distributed to six research performing organisations in Albania, France, Germany, Italy, Serbia, and Spain. We found that both academic and non-academic women perceive 1) a greater degree of work pressure than men; and, 2) a greater degree of gender inequality than men. These results are consistent across countries. The fact that women occupy a lower percentage of senior positions than men and do not share the same perception of inequality, may be critical to the resolution of the leaky pipeline phenomenon. These results have provided incentives to the six organisations to implement measures that address gender biases to ensure a balanced gender representation at decision-making levels, and that improve work-life balance to reduce burnout syndrome and positively affect career satisfaction
Les facteurs déterminants de l'adoption des réseaux sociaux en formation à distance par les étudiants au Niger : la leçon de la pandémie de COVID-19
No full textInternational audienceThe present study reports on factors determining the adoption of social networks in distance education (DE) in a health context. An online questionnaire, based on the acceptance and use of technology model (UTAUT) was administered to 93 students from Niger universities and colleges who used social networks to ensure educational continuity. The Partial Least-Squares (PLS) method was used to predict the factors influencing the adoption of social networks in DE. The results showed that performance expectation, effort expectation, social influence and intention to use are determining factors in the adoption of social networks, with a moderating effect of gender.Cette étude rend compte des facteurs déterminants de l'adoption des réseaux sociaux en formation à distance (FAD) dans un contexte sanitaire. Un questionnaire en ligne, basé sur le modèle d'acceptation et d'utilisation des technologies (UTAUT) a été administré à 93 étudiants des universités et des grandes écoles du Niger ayant utilisé les réseaux sociaux numériques (RSN) pour apprendre. La méthode des moindres carrés partiels (PLS) a été utilisée pour prédire les facteurs influençant l'adoption des réseaux sociaux numériques en FAD. Les résultats ont montré que l'attente de performance, l'attente d'effort, l'influence sociale et l'intention de continuer l'utilisation sont des facteurs déterminants dans l'adoption des réseaux sociaux avec un effet modérateur du genre
Déterminants de l’acceptation des réseaux sociaux pour apprendre à l’université virtuelle du Sénégal
No full textInternational audienceThis study addresses the factors that determine student acceptance of digital social networks for learning. Would the learning outcome expectations of students who use social networks be related to an expected added value in learning, or would they only be the result of a social ripple effect? This research is based on the UTAUT (Unified Theory of Acceptance and Use of Technology) model. The data comes from an online survey, to which 520 students from the Virtual University of Senegal (UVS) responded. A structural partial least squares model establishes that students’ behavioral intention and social network use behavior are impacted by effort expectancy and social influence. No significant effect of performance expectancy on behavioral intention was found overall, although a significant difference related to gender and education level was noted.Cette étude se penche sur la question des facteurs qui déterminent l’acceptation, par les étudiants, des réseaux sociaux numériques pour apprendre. Les attentes d’usage des réseaux sociaux pour apprendre seraient-elles en lien avec une valeur ajoutée escomptée dans l’apprentissage ou uniquement le résultat d’un effet d’entraînement social? Cette recherche s’appuie sur le modèle UTAUT (unified theory of acceptance and use of technology). Les données proviennent d’un questionnaire en ligne auquel 520 étudiants de l’Université virtuelle du Sénégal (UVS) ont répondu. Un modèle structurel à moindres carrés partiels permet d’établir que l’intention d’usage et l’attente d’usage des réseaux sociaux pour apprendre sont affectées par l’attente d’effort et l’influence sociale. Aucun effet significatif de l’attente de performance sur l’intention d’usage n’a été globalement mis en évidence, bien qu’une différence significative liée au sexe et au niveau d’études soit notée de ce point de vue