HAL Portal UPHF (Université Polytechnique Hauts-de-France)
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Enjeux et perspectives de la préservation du patrimoine et traçabilité numérique des oeuvres d'art africaines
No full textInternational audienceA poster outlining the main lines of my research as part of my thesis entitled: Enjeux et perspectives de la préservation du patrimoine et traçabilité numérique des œuvres d'art africaines (Issues and prospects for heritage preservation and digital traceability of African works of art).Un poster qui explicite les axes de mes recherches dans le cadre de ma thèse intitulée : Enjeux et perspectives de la préservation du patrimoine et traçabilité numérique des œuvres d'art africaines
Modeling of Surface-Emitting Terahertz Quantum Cascade Laser Based on Difference Frequency Generation
No full textInternational audienceIn this paper, we propose a simple method to calculate the THz field and THz power generated via intracavity difference frequency generation in a dual-wavelength mid-infrared quantum cascade laser. The approach is based on using a surface emission scheme in the nonlinear waveguide. The results show that the THz output power varies linearly with the product of the tow mid-infrared pump powers, and strongly depends on the cover refractive index for the THz waves. Specifically, a higher refractive index leads to a significant increase in THz power, while a low product of the pump powers levels result in weak output power. Additionally, the effect of nonlinear film thickness on optical efficiency is considered. The efficiency decreases as the film thickness increases. This is due to the dependence of the THz field amplitude in the cover region on the film-substrate and film-cover interfaces, which is significantly affected by the film thickness. Our model generates output power through surface emission, in agreement with existing experimental results, highlighting the importance of optimizing the cover material and film thickness to improve output power and THz efficiency
Le parent détenu prévenu de faits de violences conjugales : quelle protection pour l'enfant mineur ?
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Matthias Boeckl: Artistes autrichiens en France (XXe siècle). Traduction d'une notice de dictionnaire en ligne. In: DECAF - Dictionnaire des Echanges Culturels entre l'Autriche et la France / Projet-ANR-22-CE91-0001
No full textMatthias Boeckl. Österreichische bildende Künstler:innen in Frankreich (20. Jh.). Notice de dictionnaire en ligne. In: DECAF - Dictionnaire des Echanges Culturels entre l'Autriche et la France / Projet-ANR-22-CE91-0001Au cours du XIXe siècle, l’industrialisation ainsi que la croissance démographique et économique confèrent à Paris le statut de métropole mondiale. La demande du plus vaste marché de l’art du monde et les nombreuses opportunités de présentations d’œuvres inédites constituent des facteurs essentiels de l’émergence de l’art moderne vers 1900. Paris, « capitale de la modernité », exerce ainsi une attraction considérable sur de nombreux artistes, designers et architectes originaires du monde entier, y compris d’Autriche. Ces derniers effectuent des séjours d’étude et de travail prolongés à Paris, en Provence ou sur les rives de l’Atlantique et de la Méditerranée, où les pionniers français de la modernité ont exercé leur art. Certains d’entre eux ont réussi à s’établir dans le milieu artistique parisien et à y acquérir une certaine notoriété
Estimating weak Markov-switching AR(1) models
No full textIn this paper, we present the asymptotic properties of the moment estimator for autoregressive (AR for short) models subject to Markovian changes in regime under the assumption that the errors are uncorrelated but not necessarily independent. We relax the standard independence assumption on the innovation process to extend considerably the range of application of the Markov-switching AR models. We provide necessary conditions to prove the consistency and asymptotic normality of the moment estimator in a specific case. Particular attention is paid to the estimation of the asymptotic covariance matrix. Finally, some simulation studies and an application to the hourly meteorological data are presented to corroborate theoretical work
Forfait de post-stationnement : le recours peut être formé par mandataire
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Guaranteed State Estimation for H−/L∞ Fault Detection of Uncertain Takagi-Sugeno Fuzzy Systems With Unmeasured Nonlinear Consequents
No full textInternational audienceWe investigate the problem of guaranteed state estimation and robust fault detection of uncertain Takagi-Sugeno (TS) fuzzy systems with unmeasured nonlinearities. The effects of both unknown-but-bounded disturbances and faults are taken into account in the state bounding observer design via zonotopic representation of sets, which aims to reduce set operations to simple matrix calculations. Based on the P -radius criterion, the size of the state bounding observers can be minimized via L∞ performance to mitigate the effect of unknown-but-bounded disturbances. Moreover, for fault detection purposes, Hperformance is taken into account to increase the fault sensibility. The proposed multiobjective H-/L∞ state bounding observer design is reformulated as an optimization problem under linear matrix inequalities (LMIs). As a result, the tradeoff between robustness with respect to uncertainties and fault sensibility can be effectively achieved using standard solvers for LMI constraints. Numerical experiments and suitable comparative studies are performed with a nonlinear autonomous vehicle system to demonstrate the effectiveness and the practical interests of the proposed state bounding TS fuzzy observer design method
The 2024 phononic crystals roadmap
No full textInternational audienceOver the past 3 decades, phononic crystals experienced revolutionary development for understanding and utilizing mechanical waves by exploring interaction between mechanical waves and structures. With the significant advances in manufacture technologies from nanoscale to macroscale, phononic crystals attract researchers from diverse disciplines to study abundant directions such as bandgaps, dispersion engineering, novel modes, reconfigurable control, efficient design algorithms and so on. The aim of this roadmap is to present the current state of the art, an overview of properties, functions and applications of phononic crystals, opinions on the challenges and opportunities. The various perspectives cover wide topics on basic property, homogenization, machine learning assisted design, topological, non-Hermitian, nonreciprocal, nanoscale, chiral, nonlocal, active, spatiotemporal, hyperuniform properties of phononic crystals, and applications in underwater acoustics, seismic wave protection, vibration and noise control, thermal transport, sensing, acoustic tweezers, written by over 40 renown experts. It is also intended to guide researchers, funding agencies and industry in identifying new prospects for phononic crystals in the upcoming years
