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Studying the Benefits of Hybrid Wi-Fi/LiFi Networks for Indoor WLANs
No full textInternational audienceLight Fidelity (LiFi) is a recent wireless technology that offers high data rates, low power consumption, and does not interfere with other radio technologies, such as Wi-Fi. However, its short range and need for a direct line of sight require integration with other wireless technologies for effective use in a wireless local area network (WLAN). In this paper, we study the feasibility and efficiency of Hybrid LiFi/Wi-Fi Networks (HLWNet). Our study aims to determine whether HLWNet is a viable solution for WLANs in terms of throughput and power consumption. We propose an approach to evaluate HLWNet deployments, specifying the optimal number and placement of access points (APs) for each technology to ensure throughput satisfaction for stations (STAs) while minimizing overall network power consumption. Our numerical results indicate that the use of LiFi is not advantageous in all scenarios.</div
A Survey on Transistor-Level Electrical Rule Checking of Integrated Circuits
No full textInternational audienceHardware verification is crucial to ensure the quality of Integrated Circuits, and prevent costly bugs down the manufacturing flow. Electrical Rule Checking (ERC) is a verification step used to assert that a circuit complies with some electrical rules, from the absence of short-circuits to dedicated constructor rules. In this survey, we provide a global overview of existing ERC techniques at transistor-level, where voltage values are explicit. We propose a new classification method to compare the existing approaches based on their semantic modeling of circuits. This survey precisely describes transistor-level ERC research challenges and existing solutions. We believe it will help structure this research domain by positioning existing approaches with respect to each other. Obviously, a survey should also facilitate technological transfer and this one should help CAD vendors identify the most relevant approaches to integrate in their tools. Finally, we highlight several promising directions to improve the existing solutions
Mapd’O - Un nouvel outil pour la visualisation et l’analyse hydromorphologique des réseaux fluviaux à l’échelle nationale
No full textInternational audienceThe hydro-ecological functioning of river systems is influenced by the physical conditions within their corridors (e.g. topography, land use, geology). A systematic description of the physical functioning has so far been limited due to a lack of data on aspects such as lateral dynamics and floodplain connectivity. The Mapd'O project addresses this by providing datasets and a web interface that allow operators and scientists to analyze these conditions for the entire French river corridor network. Novel datasets such as a national land use map with a resolution of 1 m and the first national valley bottom and lateral continuity maps were created using the Fluvial Corridor Toolbox (FCT), a geographic information system toolbox for network-scale hydromorphic characterisation. Using the Mapd'O app, these datasets can be visualized, analyzed and interpreted to enable hydromorphological diagnosis of river systems at reach to network scales: the entire watershed, but also their sub-catchments and individual river axis level.Le fonctionnement hydro-écologique des systèmes fluviaux est influencé par les conditions physiques au sein de leurs corridors (par exemple, la topographie, l'utilisation des sols, la géologie). Une description systématique du fonctionnement physique a jusqu'à présent été limitée en raison d'un manque de données sur des aspects tels que la dynamique latérale et la connectivité des plaines alluviales. Le projet Mapd'O répond à cette problématique en fournissant des ensembles de données et une interface web qui permettent aux opérateurs et aux scientifiques d'analyser ces conditions pour l'ensemble du réseau fluvial français. De nouveaux jeux des données tels qu'une carte nationale d'occupation des sols avec une résolution de 1 m et les premières cartes nationales de fond de vallée et de continuité latérale ont été créés à l'aide de la Fluvial Corridor Toolbox (FCT), une boîte à outils de système d'information géographique pour l'hydromorphologie à grande échelle. En utilisant l'application Mapd'O, ces données peuvent être visualisées, analysées et interprétées pour faciliter un diagnostic hydromorphologique des rivières à différentes échelles : l'ensemble du bassin versant, mais aussi leur sous-bassin versant et l'échelle de l'axe individuel de la rivière
Icy Moons as Probes of Carbon-Rich Conditions During Giant Planet Formation
No full textInternational audienceThe densities and moments of inertia of Jovian and Saturnian icy moons, dwarf planets, and other trans-Neptunian objects (TNOs) suggest the presence of a significant low-density carbonaceous component in their rocky cores. In a homogeneous accretion scenario, where these components are mixed in solar proportions, ices differentiate from the carbon-rich refractory core, while silicate hydration may occur. Thermal models that account for the presence of carbonaceous matter indicate that originally hydrated silicates are now largely dehydrated in the refractory cores of large moons and dwarf planets, due to interactions with volatiles released by the metamorphism of carbonaceous matter.Progressive gas release from the slowly warming, carbonaceous matter-rich cores may sustain, up to the present day, the replenishment of ice-ocean layers with organics and volatiles, as well as outgassing to the surface. This process accounts for the observation of nitrogen, light hydrocarbons, and complex organic molecules at the surface, in the atmospheres, or in the plumes emanating from moons and dwarf planets. The formation of large carbon-rich icy bodies in the outer solar system suggests that a carbon-rich environment prevailed during ice giant planet formation—a scenario that could also lead to the formation of carbon-rich planets at the outskirts of extrasolar systems.In the Neptunian system, Triton—presumed to be a captured TNO—shares density and surface composition characteristics with other large TNOs, including Pluto, Eris, Makemake, Gonggong, Quaoar, and others. Notably, the carbon-bearing molecules at the icy surfaces of TNOs shift from CO₂-dominated compositions in smaller objects (Pinilla-Alonso et al., 2024) to CH₄-rich compositions in the largest TNOs, including Triton (Brown, 2012; Emery et al., 2024; Grundy et al., 2024).In the Uranian system, the latest estimates of regular satellite masses (Jacobson, 2014) reveal a power-law relationship between size and density, reflecting varying rock/ice ratios caused by fractionation processes (Reynard and Sotin, 2025). This relationship is explained by mild enrichment of rock relative to ice in the solids that aggregated to form the moons, following Rayleigh's law of distillation (Rayleigh, 1896). In the outer solar nebula, Rayleigh fractionation may account for the separation of a rock-dominated reservoir and an ice-carbon-dominated reservoir, now represented by CI carbonaceous chondrites/type-C asteroids and comets, respectively. Potential consequences for the composition of Uranus’s moons and targets for future exploration are discussed. Acknowledgement. This work was supported by Institut National des Sciences de l’Univers through Programme National de Planétologie, by the Agence Nationale de la Recherche (ANR, project OSSO BUCO, ANR-23-CE49-0003) and by the European Union (ERC, PROMISES, project #101054470). Views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them
On deciding transcendence of power series
No full textIt is well known that algebraic power series are differentially finite (D-finite): they satisfy linear differential equations with polynomial coefficients. The converse problem, whether a given D-finite power series is algebraic or transcendental, is notoriously difficult. We prove that this problem is decidable: we give two theoretical algorithms and a transcendence test that is efficient in practice
AbriCoCoDA: A Novel Approach to Urban Heat Mitigation Through Bio-Analogous Climate Shelters
No full textInternational audienc
Démanteler des ouvrages latéraux en rivière pour restaurer la biodiversité : effets à court terme sur les communautés de plantes riveraines
No full textInternational audienceOn the Rhône, dismantling of lateral structures is being carried out to reactivate river dynamics and restore riparian plant communities on riverbanks. The effects of this work were monitored at 5 sites over three years and compared with reference and control sites. The taxonomic and functional response of plant communities was studied at site and quadrat spatial scales. The results show that restoration works have created topographic profiles that were higher relative to the waterline and with greater proportions of fine sediment than at the reference and control sites. In response, riparian communities at restored sites were closer to those at reference sites in the first year, but rapidly diverged towards those at control sites after three years. In addition, at the quadrat scale, the response of plant communities to the work was studied by comparison with quadrats from reference and control sites positioned under similar environmental conditions. Here too, the results showed rapid convergence of the plant communities in the restored quadrats towards those in the control quadrats. This illustrates not only the difficulty of restoring abiotic conditions close to those of reference and control sites, but also that the action of dismantling dykes alone cannot restore riparian plant communities characteristic of mobile sedimentary bars.Sur le Rhône, des travaux de démantèlement d’ouvrages latéraux sont menés pour réactiver la dynamique fluviale et restaurer les communautés végétales riveraines des marges. Les effets de ces travaux ont été suivis sur 5 sites pendant 3 ans et comparés à des sites de références et de contrôle. Les réponses taxonomique et fonctionnelle des communautés ont été étudiées aux échelles spatiales du site et du quadrat. Les résultats montrent que les travaux ont créé des profils topographiques plus élevés par rapport à la ligne d’eau, et avec des proportions plus importantes de sédiments fins, que sur les sites de référence et de contrôle. En réponse, les communautés riveraines des sites restaurés étaient plus proches de celles des sites de référence la première année, mais ont rapidement convergé vers celles des sites de contrôle après trois ans. Aussi, à l’échelle du quadrat, la réponse des communautés aux travaux a été étudiée par comparaison avec les quadrats des sites de référence et de contrôle positionnés dans des conditions environnementales similaires. Là aussi, les résultats ont mis en évidence des convergences rapides des communautés de plantes des quadrats restaurées vers celles des quadrats de contrôle. Ceci illustre non seulement la difficulté de restaurer des conditions abiotiques proches de celles des sites de référence et de contrôle, mais aussi que l'action de démantèlement des ouvrages latéraux ne peut à elle seule restaurer les communautés végétales riveraines caractéristiques des bancs sédimentaires mobiles
Lü bi qinshu: Da Ming lü zhong de nubi “律比亲属”《大明律》中的奴婢
No full textChevaleyre, Claude, “Insiders by Analogy: Slaves in the Great Ming Code,” Slavery & Abolition 3 (2022): 460-481: https://doi.org/10.1080/0144039X.2021.200872
L’aide à la décision pour les transitions énergétiques et environnementales des territoires et organisations
No full textEn effet, face aux enjeux environnementaux majeurs — crise climatique, raréfaction des ressources, érosion de la biodiversité — les transitions énergétiques et environnementales imposent une transformation des pratiques et appellent à repenser les processus de décision.Deux axes de recherche principaux structurent ces travaux de recherche :Les Meilleures Techniques Disponibles (MTD) : évaluation et amélioration des méthodes d’analyse des performances environnementales des sites industriels, avec une portée locale et internationale.La rénovation énergétique des bâtiments : développement d’outils, notamment l’Observatoire National des Bâtiments, pour mieux connaître le parc immobilier et identifier les gisements d’économie d’énergie à l’échelle territoriale.L’ensemble de ces recherches vise à outiller la décision pour accompagner les transitions, en tenant compte de la complexité des enjeux et de la diversité des acteurs impliqués
Adapting to game trees in zero-sum imperfect information games
No full textImperfect information games (IIG) are games in which each player only partially observes the current game state. We study how to learn -optimal strategies in a zero-sum IIG through self-play with trajectory feedback. We give a problem-independent lower bound on the required number of realizations to learn these strategies with high probability, where is the length of the game, and are the total number of actions for the two players. We also propose two Follow the Regularize leader (FTRL) algorithms for this setting: Balanced-FTRL which matches this lower bound, but requires the knowledge of the information set structure beforehand to define the regularization; and Adaptive-FTRL which needs plays without this requirement by progressively adapting the regularization to the observations