HAL-INSA Toulouse
Not a member yet
34325 research outputs found
Sort by
Fluorescence Modulation through the Inverted Energy Gap Law in Triply N−B←N‐Containing Windmill‐Shaped Triazines
No full textInternational audienceA series of windmill‐shape heterocyclic molecules containing three N−B←N units, TBN and its derivatives, with quasi‐planar C 3 symmetric backbone, are synthesized. The parent TBN exhibits a strongly allowed, doubly degenerate lowest excited state but suffers from very low fluorescence, due to very fast nonradiative decay rate through a conical intersection (CI) as revealed by femtosecond transient absorption spectroscopy and quantum‐chemical calculations. Introducing peripheral phenyl‐ or thienyl‐groups (Ph‐TBN or Th‐TBN) induces pronounced bathochromic shifts and enhances fluorescence, which is beneficial from inhibited nonradiative pathway by the increased energy barriers to access the CI at excited state. The understanding of this rather uncommon behaviour may open routes for the design of novel fluorescence materials
The Topology of the Normalization of Complex Surface Germs
No full textMathematics Subject Classification 2020: 32S50, 32S45, 32S05, 57K30Let (X, p) be a reduced complex surface germ and let LX be its link. If (X, p) is normal at p, DavidMumford [7] shows that (X, p) is smooth if and only if LX is simply connected. Moreover, if p is an isolatedsingular point, LX is a three dimensional Waldhausen graph manifold. Then, the Plumbing Calculusof Walter Neumann [8] shows that the homeomorphism class of LX determines a unique plumbing innormal form and consequently, determines the topology of the good minimal resolution of (X, p).Here, we do not assume that X is normal at p, and so, the singular locus (Σ, p) of (X, p) can be onedimensional. We describe the topology of the singular link LX and we show that the homeomorphismclass of LX (Theorem 4.1) determines the homeomorphism class of the normalization and consequentlythe plumbing of the minimal good resolution of (X, p).In Proposition 5.1, we obtain the following generalization of the above quoted theorem of Mumford:Let ν : (X′, p′) → (X, p) be the normalization of an irreducible germ of complex surface (X, p). Ifthe link LX of (X, p) is simply connected then ν is a homeomorphism and (X′, p′) is a smooth germ ofsurface
Stellar flybies within 1 ly from the Sun and stars passing through the Hills cloud
No full textWe reexamine the SIMBAD database with incorporated Gaia DR3 parallaxes and proper motions. Appropriate query searches allow us to find several nearby stars with measured radial velocities having flybies within 1 ly from the Sun (in linear approximation). The closest past flyby kyr ago at pc is attributed to the star UCAC4 323-037188, currently located at 21.74 pc from the Sun. If the radial velocity of a star is unknown, we attribute to it an ``advantageous'' value of km/s. It allows us to create an additional list of ``Nemesis candidates'' for the perforation of the inner Oort cloud. The closest potential flyby at pc ( 0.050 ly 3147 AU) from the Sun is attributed to GALEX J013712.5-012958 (Gaia DR3 2508809660245711360). It is currently located at the distance of about 111.1 pc and belongs to the Pisces-Eridanus stream. Also, close flybies of some massive bright stars (Algol, A-giant HD 107914, A-subgiant HD 2733 and B-subgiant HD 165704) are analyzed. Finally, we notice that B1-star BD+60 596, whose proper motions and radial velocity are both small, can be considered as the Sun's pseudo-stream companion
PD Operads and Explicit Partition Lie Algebras
No full textTo appear: https://www.ams.org/cgi-bin/mstrack/accepted_papers/memoInternational audienceInfinitesimal deformations are governed by partition Lie algebras. In characteristic , these higher categorical structures are modelled by differential graded Lie algebras, but in characteristic , they are more subtle. We give explicit models for partition Lie algebras over general coherent rings, both in the setting of spectral and derived algebraic geometry. For the spectral case, we refine operadic Koszul duality to a functor from operads to divided power operads, by taking refined linear duals of -representations. The derived case requires a further refinement of Koszul duality to a more genuine setting
Modulated Ligand–Ligand Exchange Coupling and Elusive Spinmerism in a Bis(verdazyl)iron(II) Complex
No full textInternational audienc
Banc de caractérisation multi-canaux de sources de photons uniques pour les télécommunications fibrées quantiques
No full textNational audienceLa caractérisation de paires de photons, voire de peignes quantiques, est une problématique essentielle du domaine des télécommunications quantiques fibrées. Un banc faible coût a été développé autour de 1550 nm à partir de composants SPADs refroidis, d'un laser pulsé et de différentes solutions de filtrage. Une première application à la caractérisation de la génération de paires de photons par un résonateur fibré non-linéaire est présentée
Efficiency of the Coriolis µ Air Sampling Device for Fungal Contamination Analysis of Indoor Air: A Case Study
No full textInternational audienceMolds are frequent indoor contaminants, where they can colonize many materials. The subsequent aerosolization of fungal spores from moldy surfaces can strongly impact indoor air quality and the health of occupants. The investigation of fungal contamination of habitations is a key point in evaluating sanitary risks and understanding the relationship that may exist between the fungal presence on surfaces and air contamination. However, to date there is no “gold standard” of sampling indoor air for such investigations. Among various air sampling methods, impingement can be used for capturing fungal spores, as it enables real-time sampling and preserves analytical follow-up. Its efficiency varies depending on several factors, such as spore hydrophobicity, sampling conditions, etc. Sampling devices may also impact the results, with recovery rates sometimes lower than filtration-based methods. The Coriolis µ air sampler, an impingement-based device, utilizes centrifugal force to concentrate airborne particles into a liquid medium, offering flexibility for molecular analysis. Several studies have used this device for air sampling, demonstrating its application in detecting pollen, fungal spores, bacteria, and viruses, but it is most often used in laboratory conditions. The present case study, conducted in a moldy house, aims to investigate the efficiency of this device in sampling fungal spores for DNA analysis in indoor environments. The results obtained suggest that the use of this device requires an optimized methodology to enhance its efficiency and reliability in bioaerosol research
Vers une approche collaborative pour l'orchestration de services dans les réseaux multi-domaines interalliés
No full textNational audienceNetwork softwarisation has reshaped the design and operation of modern communication systems and how communication services are managed, from fulfilment, control and quality assurance to decommissioning. Service orchestration is now a reality in the context of a network under one single administrative authority. However, it faces many challenges when it comes to multi-administrative multi-domain networks, as domains restrict the information and collaboration capabilities they disclose to other domains. This is especially the case of military coalition networks, where ally nations connect and share some of their network infrastructure to support the communications services required by military missions. This work investigates the opportunities brought by network softwarisation to enable end-to-end service orchestration and devise novel end-to-end services for future federated military networks. The following contributions are proposed in this thesis. A flexible domain-level computing and network resource abstraction framework is defined. Compared to existing abstractions, it enables an enriched collaboration between domains while respecting their respective confidentiality constraints. Two novel end-to-end multi-domain service models are also proposed and prototyped on a physical network platform. Their corresponding resource embedding methods, which compute the optimal placement of their components with respect to network resource utilisation, are defined and then extensively evaluated.La softwarisation des réseaux a transformé la conception et l'exploitation des systèmes de communication modernes, ainsi que la gestion des services de communication, allant de leur mise en œuvre, leur contrôle, et assurant leur qualité jusqu'à leur décommissionnement. Dans le cadre d'un réseau placé sous une seule autorité administrative, l'orchestration des services est désormais une réalité. Cependant, elle fait face à de nombreux défis lorsqu'il s'agit de réseaux multi-domaines et multi-administratifs, où chaque domaine restreint les informations et les capacités de collaboration qu'il divulgue aux autres domaines. Cela est particulièrement vrai pour les réseaux de coalition militaire, dans lesquels des nations alliées connectent et partagent une partie de leur infrastructure afin de soutenir les services de communication nécessaires au bon déroulement de missions. Ce travail explore les opportunités offertes par la softwarisation des réseaux pour permettre l'orchestration de services de bout en bout et en concevoir de nouveaux. Les contributions suivantes sont proposées dans cette thèse : un cadre d'abstraction flexible pour les ressources réseau et informatiques au niveau du domaine est défini. Comparé aux abstractions existantes, ce cadre permet une collaboration enrichie entre les domaines tout en respectant leurs contraintes de confidentialité respectives. Deux nouveaux modèles de service multi-domaines de bout en bout sont également proposés et prototypés sur une plateforme réseau physique. Les méthodes d'intégration des ressources correspondantes, qui calculent le placement optimal de leurs composants en fonction de l'utilisation des ressources réseau, sont définies et évaluées de manière approfondie
Wasserstein distance based semi-supervised manifold learning for GNSS multipath detection
No full textNational audienceOne of the main weaknesses of the Global Navigation Satellite System (GNSS) is the sensitivity to multi-path disturbances. A multi-path is a reflection of the signal emitted by a navigation satellite on one or more surfaces surrounding the receiving antenna. These multi-paths degrade the precision and accuracy of the position calculated by the GNSS receiver. This could lead to potential hazard especially in safety of life applications. Aircraft navigation which heavily depends on GNSS nowadays is a typical illustration. Thus, detecting the possible distortion in the input data is of prior importance. Previous studies have shown the interest of supervised Machine Learning (ML) techniques in the purpose of detecting distortion in GNSS signals. However, real labelled data are scarce. This is a genuine difficulty as supervised ML algorithms require in general large amount of labelled data for training.The aim of this research work is to consider semi-supervised learning as a mean to improve the performance of a fully supervised model by means of unlabelled samples added to the training dataset.The underlying principle is that the manifold of the data can also be learned by the network through unlabelled samples if a suitable measure of similarity with labelled samples is provided. The metric chosen in this study is the Wasserstein distance also known as the Earth Mover's Distance (EMD).The implementation of the unsupervised contribution to the training process takes the form of a regularisation term in addition to the classical supervised Binary Cross Entropy (BCE) loss function. This unsupervised term is linear in sample thus it preserves the ability to process large data sets by batches of data and it benefits from stochastic gradient based techniques during training too
Défi du GDR GPL ADaptation DYnamique et ConTinue ADDYCT
No full textL'adaptabilité est un enjeu majeur des systèmes complexes dans des environnements dynamiques. Ces environnements regroupent les architectures distribuées composées de systèmes "component-based" et les infrastructures déployées sur des plateformes hétérogènes à différentes échelles : Cloud, Fog, Edge, ou IoT. Tous ces systèmes doivent être capables d'ajuster leur configuration de manière autonome pour répondre à des évènements exogènes et/ou endogènes.Les systèmes logiciels doivent être considérés dès leur conception comme des systèmes durables en termes de temporalité (Système temps long, Cycle de vie, Couplage), de scalabilité (Granularité, Interfaces, Gestion massive de données) et d'hétérogénéité (Intégration, Interopérabilité).Ces challenges sont d'autant plus importants lorsque la taille du système est grande et couplée avec des artefacts matériels (IoT, CPS, Jumeaux numériques, Cloud...) L'objectif de ce défi est de modéliser, analyser et d'implémenter des moyens et des politiques d'adaptation pour des systèmes logiciels complexes (distribués, componentisés etc.).L'approche adoptée repose sur les boucles de contrôle MAPE-K, un modèle d'auto-adaptation autonome capable de s'ajuster dynamiquement à un environnement permettant de répondre à la nécessité d'intégrer les données collectées et leurs modèles de traitement, le système opérant et sa connexion avec son environnement, l'évolution dynamique et la nécessité de maintenir une représentation fidèle du comportement attendu