HAL - La Rochelle Université, Archives Ouvertes
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Aspect en coréen et changement d’état : le cas des adjectifs en -ke toeta
No full textInternational audienc
From Navier-Stokes to Darcy : a Multiscale Lattice Boltzmann Framework for Coupled Free-Porous Flows
No full textInternational audienceFlow through porous media is fundamental to a wide range of applications, from hydrogeology to industrial filtration. When modeling fluid displacement in domains comprising both free-flow and porous regions using methods based on PDE discretization, one typically faces two options. The first is to employ very fine grids and the Navier-Stokes equations within the micropores. However, for most practical applications, the computational cost of this approach is prohibitive. The second option involves coupling at least two PDE models with significantly different structures. This method, however, introduces considerable velocity discontinuities at the fluid-porous interfaces. Furthermore, the coupling condition at the interface between a free fluid and a fluid in a porous medium remains a subject of ongoing debate (e.g., Beavers-Joseph-Saffman type conditions).In this work we propose another approach consisting in forgetting the classical PDEs model and solely using a lattice Boltzmann scheme properly weighted for accounting for all possible fluid regimes. Specifically, we implement a modification to the streaming step, as proposed by Walsh et al. (2009), which enables the extension of LBM to multi-scale porous media. Through asymptotic analysis, we show that this LB-WBS scheme can recover a broad spectrum of governing equations, from Navier-Stokes to Darcy’s law. We present simulation results for geometries containing free-flow, permeable, and impermeable regions, and discuss the stability of the LB-WBS scheme as well as the identification of the associated Beavers and Joseph parameters. Finally, we introduce LBMultiScale, a library that facilitates the automatic construction of LB-WBS models directly from physical descriptions of multi-porous systems
L'oustillement au vilain - Édité d'après le ms. BnF fr. 837
No full textL'oustillement au vilain - Édité d'après le ms. BnF fr. 83
La dame qui se venja du chevalier - Édité et traduit d'après le ms. Berlin Staatsbibliothek 257
No full textLa dame qui se venja du chevalier - Édité et traduit d'après le ms. de Berlin Staatsbibliothek 25
Le chevaler a la corbayle - Édité et traduit d'après le ms. Harley 2253
No full textLe chevaler a la corbayle - Édité et traduit d'après le ms. Harley 225
Elephant seals as sentinels of the ongoing changes affecting the Southern Ocean: Disentangling environmental and maternal effects on pup size and body condition
No full textInternational audienceThe weaning mass of southern elephant seal pups (Mirounga leonina) is a key predictor of their first-year survival probability. However, variations in pup morphometric characteristics (length, mass and body condition i.e. the residual of the allometric relationship between log(mass) and log(length)) are strongly associated with mother's length and body condition. Leveraging a comprehensive long-term dataset (2006–2024) that integrates morphometric, isotopic, and environmental data, we applied a structural equation model to disentangle the direct and indirect drivers of pup phenotype at weaning. This approach reveals that pup length and mass are primarily determined by maternal length, while pup body condition is mainly shaped by the environmental conditions experienced by the mother during her pre-breeding trip. Our long-term dataset highlights a decline in pup weaning mass and length but an increase in their body condition despite an increase in the size of the breeding population. The concurrent decrease in pup blood δ13C and δ15N values, reflecting those of their mother, suggests shifts in southern hemisphere food webs and in the trophic ecology of Kerguelen southern elephant seals. We hypothesize that these changes are mainly linked to shifts in the composition of the phytoplankton community at the base of the trophic chains, which could have downstream effects on intermediate trophic levels and top predators, as well as a southward shift in female at-sea distribution confirmed by the tracking data
Graph Neural Networks for Moving Objects Detection in Videos
No full textInternational audienceDeep learning has been widely applied for the detection of moving objects from static cameras. Recently, many methods using graph neural networks for background subtraction have been reported with very promising performance. This chapter provides a survey of different graph neural for moving object detection. First, a comparison of the transductive and inductive architectures of each method is provided, followed by a discussion of the specific application requirements, such as spatio-temporal and real-time constraints. After analyzing the strategies of each method and showing their limitations, a comparative evaluation of the large-scale CDnet2014 dataset is provided. Finally, we conclude with some potential future research directions
Défis de la restauration du lit et de la plaine inondable de l’Ebre moyen
No full textInternational audienceThe Ebro River is a large Iberian watercourse that develops an extensive floodplain in its middle reach with frequent floods and flooding processes. Fluvial dynamics have been stabilised by regulation and defence works. The flood risk management paradigm has now been changed and some nature-based solutions are being implemented within the framework of the LIFE+ Ebro Resilience strategy and project. With a large interdisciplinary scientific team, the SEDEXCHARE Project evaluates this change in flood risk management from a hydromorphological and river restoration perspective. The achievements so far are scarce in restoration, but important in risk management. It is explained in which line actions should be increased to recover the river dynamics, proposing a territory of freedom for the river. Learning lines are also defined from the current diagnosis for a context of climate emergency and increase in extreme events. The recovered health of the river will provide territorial resilience to the floodable space, which includes population centres, agricultural uses and natural spaces.L'Èbre est un grand fleuve ibérique qui, dans son cours moyen, développe une vaste plaine inondable avec des crues et des processus d'inondation fréquents. La dynamique fluviale a été stabilisée par la régulation et les défenses. Actuellement, le paradigme de gestion des inondations a été modifié et certaines solutions basées sur la nature sont mises en œuvre dans le cadre de la stratégie et du projet LIFE+ Ebro Resilience. Issu d'une large équipe scientifique interdisciplinaire, le projet SEDEXCHARE évalue ce changement dans la gestion des crues dans une perspective hydromorphologique et de restauration des rivières. Les réalisations jusqu’à présent sont peu nombreuses en matière de restauration, mais importantes en matière de gestion des risques. On explique dans quelles directions il convient d'intensifier les actions de récupération de la dynamique fluviale, en proposant un espace de liberté pour le fleuve. Des pistes d’apprentissage sont également définies à partir du diagnostic actuel dans un contexte d’urgence climatique et de multiplication des événements extrêmes. La santé retrouvée du fleuve assurera la résilience territoriale de la zone inondable, qui comprend les centres de population, les utilisations agricoles et les espaces naturels
Les dispositifs numériques de vigilance des firmes multinationales. Une perspective critique à partir de la notion de « voile numérique » d’Andrew Feenberg
No full textThis article focuses on the notion of the « digital veil », inspired by the work of Andrew Feenberg, a philosopher of technology in the tradition of the Frankfurt School. The digital veil designates the world's frame of reference, the technical skeleton that integrates society's fundamental values and helps propagate them. We illustrate the relevance of this concept using the example of the use of digital platforms with artificial intelligence to manage CSR risks (via the Duty of Vigilance Act). This leads us to ask whether it makes sense to use artificial intelligence to deal with CSR issues.L’article est centré autour de la notion de « voile numérique » inspirée des travaux d’Andrew Feenberg, philosophe des techniques dans la lignée de l’École de Francfort. Le voile numérique désigne le cadre de référence du monde, le squelette technique qui intègre les valeurs fondamentales de la société et contribuent à les propager. Nous illustrons la pertinence de ce concept à partir de l’exemple de l’utilisation de plateformes numériques ayant recours à l’intelligence artificielle pour manager les risques RSE (via la loi sur le devoir de vigilance). Cela nous conduit à nous demander s’il est bien raisonnable de passer par une intelligence artificielle pour traiter des problématiques de RSE
