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Almost cohomology of finite-dimensional Lie rings
No full textWe introduce almost cohomology groups for Lie rings definable in finite-dimensional theory. In particular, we define the 0th and 1st almost cohomology groups of a Lie ring module. Moreover, we prove that the 1st almost cohomology group of a finite-dimensional definable Lie ring module is finite if the 0th almost cohomology group is finite
Experimental study on triaxial fatigue properties of mudstone interlayers in CAES under synergistic effects of stress amplitude and time interval
No full textInternational audienc
Alignement d'ontologies frugal pour servients WoT
No full textInternational audienceIn distributed and constrained Web of Things (WoT) infrastructures, servients exchange RDF messages that can rely on compact formats to reduce both bandwidth and memory footprint. To this end, in the context of the CoSWoT project, we adapted the CBOR-LD specification. As servients can connect or appear in these infrastructures, each using a different dialect, there is a need for off-the-shelf interoperability during message exchanges at runtime. This paper presents a frugal workflow to detect semantic similarity among messages encoded in CBOR-LD using heterogeneous vocabularies. We experimented different ML-based approaches: a lightweight neural network, a decision tree-based model and a transformer-based architecture. We present a end-to-end pipeline able to integrate each of these algorithms and provide alignment predictions. We ran our experiments on a catalogue of more than 700 production payloads curated to train the models. Our results show various levels of prediction accuracy regarding approaches and model sizes, leading to appropriate choices depending on available resources on targeted platforms.Dans une infrastructure Web des Objets (WoT) distribuée et contrainte, des servients échangent des messages RDF pouvant s’appuyer sur des formats compacts afin de réduire à la fois la bande passante et l’empreinte mémoire. À cette fin, dans le cadre du projet CoSWoT, nous avons adapté la spécification CBOR-LD. Comme les servients peuvent se connecter ou apparaître au sein de ces infrastructures, chacun utilisant un dialecte différent, il est nécessaire d’assurer à l'exécution et de manière automatique une interopérabilité entre les servients à partir des messages qu'ils échangent. Cet article présente une méthodologie permettant de détecter de manière frugale la similarité sémantique entre des messages encodés en CBOR-LD utilisant des vocabulaires hétérogènes. Nous avons expérimenté différentes approches basée sur l’apprentissage automatique : un réseau de neurones léger, un modèle basé sur des arbres de décision et une architecture transformeur. Nous présentons un pipeline capable d’intégrer chacun de ces algorithmes et de fournir des prédictions d’alignement. Nous avons mené nos expériences sur un catalogue de plus de 700 messages produits par des servients, sélectionnés pour entraîner les modèles. Nos résultats montrent divers niveaux de précision des prédictions selon les approches et la taille des modèles, permettant de choisir une approche en fonction des ressources disponibles sur les plateformes visées
A mesoscale Eulerian numerical method for short-range repulsion in interfacial dynamics
No full textInternational audienceThe dynamics of bubble and droplet coalescence and repulsion are critical in a variety of natural and industrial multiphase systems. Their direct numerical simulation (DNS) remains challenging due to the multiscale nature of interfacial interactions. This study presents a mesoscale numerical approach that incorporates a repulsive disjoining pressure into an Eulerian framework to model near-contact interactions without explicitly resolving nanoscale forces. The method computes interfacial distances through a transport equation, enabling efficient and scalable implementation across parallel computing architectures. Unlike traditional marker-based or interface-tracking methods, the approach is independant of the number of bubbles or droplets in the domain. The method is validated on representative test cases, including droplet collisions and static foam networks, and is shown to accurately capture both dynamic inertial effects and quasi-static configurations. Notably, it enables DNS of wet foams with reduced liquid fractions compared to conventional level-set methods where repulsive interactions are not accounted for. This approach lays the foundation for simulating more realistic foam structures and analyzing destabilization phenomena such as drainage and coarsening, thus contributing to the predictive modeling of complex gas-liquid systems
Corrosion fatigue mechanisms of high-strength steel wires in the presence of various aggressive ions
No full textInternational audienceThis work focuses on the corrosion fatigue of high-strength steel wires with diameters of 200 μm. The fatigue load consists of a bending rotation with a stress amplitude between 1300 MPa and 700 MPa. Various solutions at pH 6 containing either sulfate, a mixture of citrate and either phosphate or hydroxyl are selected to evaluate the role of each ion or their combinations in accelerating the breakdown of the wires. For the higher stress amplitude applied, the lifetime is almost independent of the solution, showing mechanically controlled damage. For the lowest stress amplitude, the corrosion-fatigue limit significantly evolves depending on the solution. Sulfate leads to the shortest lifetimes, whereas experiments performed in deionized water show the longest lifetimes. A combination of citrate with either phosphate or hydroxyl leads to intermediate lifetime. The effect of each ion on the stability of the iron hydroxide oxide and the iron dissolution mechanisms is discussed. The results highlight the role of the chemical affinity of these ions with the iron surface and their consequences in corrosion fatigue crack generation
Congruences for hook lengths of partitions
No full text14 pages, all comments are welcome ! arXiv admin note: text overlap with arXiv:2107.06793International audienceRecently, Amdeberhan et al. proved congruences for the number of hooks of fixed even length among the set of self-conjugate partitions of an integer , therefore answering positively a conjecture raised by Ballantine et al.. In this paper, we show how these congruences can be immediately derived and generalized from an addition theorem for self-conjugate partitions proved by the second author. We also recall how the addition theorem proved before by Han and Ji can be used to derive similar congruences for the whole set of partitions, which are originally due to Bessenrodt, and Bacher and Manivel. Finally, we extend such congruences to the set of -asymmetric partitions defined by Ayyer and Kumari, by proving an addition-multiplication theorem for these partitions. Among other things, this contains as special cases the congruences for the number of hook lengths for the self-conjugate and the so-called doubled distinct partitions
Associations indépendantes de la pollution de l’air et des conditions météorologiques avec les hospitalisations pour maladies circulatoires et respiratoires dans la métropole de Lyon, France (2012–2019) : une analyse à retards distribués non linéaire.
No full textInternational audienceThe impact of air pollution on respiratory and circulatory diseases is a major public health topic. The present study examines the impact of air pollution and weather on hospital admissions for circulatory and respiratory diseases in adults in the Lyon metropolitan area, France. A quasi-Poisson generalized linear model, along with a distributed lag nonlinear model (DLNM), was used to investigate the nonlinear exposure-response relationships of air pollutants and weather variables on daily adult hospital admissions from 2012 to 2019. Subgroup analyses by age, French deprivation index (FDep), and Charlson comorbidity index (CCI) were performed. Based on cumulative effects over the entire lag range, results showed that for respiratory admissions, CO at the 99th percentile was positively associated with overall admissions, and admissions of patients aged ≥ 65 years, FDep>1, and CCI = {0, 1} . PM10>75th percentile was negatively associated with overall admissions and admissions of patients aged ≥ 65, FDep=1 or >1, and CCI = {0, 1} . Ox below the median was positively associated with admissions in patients aged ≥ 65, and negatively associated at the 75th percentile. Temperature at the 99th percentile was negatively associated with overall admissions, and admissions in patients categorized as FDep=1 and CCI>1. Rainfall at the 99th percentile was negatively associated with admissions in patients categorized as CCI = {0, 1} . For circulatory admissions, only wind speed above the median was positively associated with overall admissions and admissions of patients categorized as FDep=1. Lag-specific associations revealed heterogeneous temporal patterns across exposures and subgroups
SYSTÈME DE TRAITEMENT DE SIGNAL DE DENTS D'ENGRENAGE PAR FENÊTRAGE ET TRANSFORMÉE DE FOURIER, PROCÉDÉ ET PROGRAMME SUR LA BASE D'UN TEL SYSTÈME
No full textThe invention relates to a system for processing measured signals in relation to teeth of a gear mechanism, the processing system comprising means for: - selecting data corresponding to the intermediate zone of the teeth; - putting the data into the same angular base; - weighting the data; - windowing the data; - calculating a Fourier transform of the data; - identifying phantom orders in the transformed data spectrum. The invention also relates to a method and a program based on such a system.L'invention concerne un système de traitement de signal de mesure relatif à des dents d'un mécanisme d'engrenage, le système de traitement comprenant des moyens pour : - sélectionner les données correspondant à la zone intermédiaire des dents; - mettre les données dans une même base angulaire; - pondérer les données; - réaliser un fenêtrage des données; - calculer une transformée de Fourier des données; - identifier des ordres fantômes dans le spectre de données transformées. L'invention concerne également un procédé et un programme sur la base d'un tel système
