468 research outputs found

    Colobome cristallinien unilatéral : À propos d’un cas

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    3-D Human Action Recognition by Shape Analysis of Motion Trajectories on Riemannian Manifold

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    International audienceRecognizing human actions in 3D video sequences is an important open problem that is currently at the heart of many research domains including surveillance, natural interfaces and rehabilitation. However, the design and development of models for action recognition that are both accurate and efficient is a challenging task due to the variability of the human pose, clothing and appearance. In this paper, we propose a new framework to extract a compact representation of a human action captured through a depth sensor, and enable accurate action recognition. The proposed solution develops on fitting a human skeleton model to acquired data so as to represent the 3D coordinates of the joints and their change over time as a trajectory in a suitable action space. Thanks to such a 3D joint-based framework, the proposed solution is capable to capture both the shape and the dynamics of the human body simultaneously. The action recognition problem is then formulated as the problem of computing the similarity between the shape of trajectories in a Riemannian manifold. Classification using kNN is finally performed on this manifold taking advantage of Riemannian geometry in the open curve shape space. Experiments are carried out on four representative benchmarks to demonstrate the potential of the proposed solution in terms of accuracy/latency for a low-latency action recognition. Comparative results with state-of-the-art methods are reported

    Proton conductivity in Al-stevensite pillared clays

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    Fine stevensite mineral fraction (< 2 m) has been extracted from natural Moroccan ghassoulite clay. Thereafter, it has been pillared by Al13 polycations species. Physico-chemical characterization, performed using X-ray diffraction (XRD), thermal analysis (TG-TDA) and Scanning Electron Microscopy (SEM) equipped with X-ray Energy Dispersion (XED) analysis, has proved that stevensite pillaring has been successfully achieved. Electrical impedance measurements, carried out onto samples before and after pillaring operation, have shown an increase in proton conductivity for pillared with respect to pristine stevensite clay mineral.Fine stevensite mineral fraction (< 2 m) has been extracted from natural Moroccan ghassoulite clay. Thereafter, it has been pillared by Al13 polycations species. Physico-chemical characterization, performed using X-ray diffraction (XRD), thermal analysis (TG-TDA) and Scanning Electron Microscopy (SEM) equipped with X-ray Energy Dispersion (XED) analysis, has proved that stevensite pillaring has been successfully achieved. Electrical impedance measurements, carried out onto samples before and after pillaring operation, have shown an increase in proton conductivity for pillared with respect to pristine stevensite clay mineral

    Diagnostic et traitement de la Maladie du charbon à localisation palpébrale: à propos d’un cas et revue de littérature

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    L´anthrax est une zoonose causée par le Bacillus anthracis. les humains contractent généralement cette maladie dans des régions endémiques, par contact direct avec des animaux infectés ou avec leurs produits contaminés. Les localisations palpébrales sont rares dans la pratique clinique et posent des problèmes de diagnostic différentiel. Les auteurs rapportent l'observation d'un patient admis dans un tableau de cellulite préseptale, avec escarre noirâtre étendue de la paupière supérieure et oedème extensif de l´hémiface, faisant suspecter une localisation palpébrale de la maladie du charbon. L'examen bactériologique a permis de confirmer le diagnostic. Le patient a bénéficié d´une antibiothérapie à base de pénicilline G avec une bonne évolution.Key words: Maladie du charbon, oeil, oedème, blépharoplasti

    Elucidating the crystal-chemistry of Jbel Rhassoul stevensite (Morocco) by advanced analytical techniques

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    The composition of Rhassoul clay is controversial regarding the nature of the puremineral clay fraction which is claimed to be stevensite rather than saponite. In this study, the raw and mineral fractions were characterized using various techniques including Fourier transform infrared spectroscopy and magic angle spinning nuclear magnetic resonance (MAS NMR). The isolated fine clay mineral fraction contained a larger amount of Al (>1 wt.%) than that reported for other stevensite occurrences. The 27Al MAS NMR technique confirmed that the mineral is stevensite in which the Al is equally split between the tetrahedral and octahedral coordination sites. The 29Si NMR spectrum showed a single unresolved resonance indicating little or no short-range ordering of silicon. The chemical composition of the stevensite from Jbel Rhassoul was determined to be ((Na0.25K0.20 (Mg5.04Al0.37Fe0.20&0.21)5.61(Si7.76Al0.24)8O20(OH)4). This formula differs from previous compositions described from this locality and shows it to be an Al-bearing lacustrine clay mineral

    Explorations électrophysiologiques visuelles : principes et indications.

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    Les explorations électrophysiologiques visuelles sont des examens fonctionnels qui explorent le fonctionnement de la rétine et des voies visuelles. Leurs indications sont très variées et doivent être connues par les médecins généralistes. Le but de ce travail est d’expliquer de façon claire et concise les principes de ces examens et de souligner leurs principales indications

    Elastic Shape Models for Face Analysis Using Curvilinear Coordinates

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    International audienceThis paper studies the problem of analyzing variability in shapes of facial surfaces using a Rie- mannian framework, a fundamental approach that allows for joint matchings, comparisons, and deformations of faces under a chosen metric. The starting point is to impose a curvilinear coordinate system, named the Darcyan coordinate system, on facial surfaces; it is based on the level curves of the surface distance function measured from the tip of the nose. Each facial surface is now represented as an indexed collection of these level curves. The task of finding optimal deformations, or geodesic paths, between facial surfaces reduces to that of finding geodesics between level curves, which is accomplished using the theory of elastic shape analy- sis of 3D curves. Elastic framework allows for nonlinear matching between curves and between points across curves. The resulting geodesics provide optimal elastic deformations between faces and an elastic metric for comparing facial shapes. We demonstrate this idea using examples from FSU face databas

    VMD description of τ→(ω, ϕ)π−ντ\tau \to (\omega,\ \phi) \pi^- \nu_{\tau} decays and the ω−ϕ\omega-\phi mixing angle

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    Using the vector meson dominance model we get predictions for the Cabibbo-favored \tom and \tphi decays. We show how the measurements of these two decays can provide information on the nature of the violation of the OZI rule.Comment: A misprint in Eqs. (14) has been correcte
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