0000000001249714

AUTHOR

Christophe Guillet

showing 4 related works from this author

Frontal Electroencephalogram Alpha Asymmetry during Mental Stress Related to Workplace Noise

2021

This study aims to investigate the effects of workplace noise on neural activity and alpha asymmetries of the prefrontal cortex (PFC) during mental stress conditions. Workplace noise exposure is a pervasive environmental pollutant and is negatively linked to cognitive effects and selective attention. Generally, the stress theory is assumed to underlie the impact of noise on health. Evidence for the impacts of workplace noise on mental stress is lacking. Fifteen healthy volunteer subjects performed the Montreal imaging stress task in quiet and noisy workplaces while their brain activity was recorded using electroencephalography. The salivary alpha-amylase (sAA) was measured before and immedi…

medicine.medical_specialtyBrain activity and meditationAlpha (ethology)ElectroencephalographyAudiologylcsh:Chemical technologyBiochemistryPrefrontal cortexArticle050105 experimental psychologyNoise stressAnalytical ChemistryTraitement du signal et de l'image [Informatique]Salivary alpha-amylase03 medical and health sciences0302 clinical medicine[INFO.INFO-TS]Computer Science [cs]/Signal and Image ProcessingStress (linguistics)medicine[INFO.INFO-IM]Computer Science [cs]/Medical ImagingHumansImagerie médicale [Informatique]lcsh:TP1-1185Attention0501 psychology and cognitive sciencesElectrical and Electronic EngineeringWorkplacePrefrontal cortexEEG alpha-asymmetryInstrumentationmedicine.diagnostic_test05 social sciencesElectroencephalographyCognitionAtomic and Molecular Physics and OpticsElectroencephalogram (EEG)Frontal LobeAlpha RhythmNoiseQUIETPsychologyStress Psychological030217 neurology & neurosurgery
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Application of a non linear local analysis method for the problem of mixed convection instability

2007

Abstract We consider the problem of laminar mixed convection flow between parallel, vertical and uniformly heated plates where the governing dimensionless parameters are the Prandtl, Rayleigh and Reynolds numbers. Using the method based on the centre manifold theorem which was derived from the general theory of dynamical systems, we reduce a three-dimensional simplified model of ordinary differential amplitude equations emanating from the original Navier-Stokes system of the problem in the vicinity of a trivial stationary solution. We have found that when the forcing parameter, the Rayleigh number, increases beyond the critical value Ra s , the stationary solution is a pitchfork bifurcation…

Dynamical systems theoryApplied MathematicsMechanical EngineeringMathematical analysisPrandtl numberReynolds numberLaminar flowRayleigh numberPhysics::Fluid DynamicsNonlinear systemsymbols.namesakePitchfork bifurcationMechanics of MaterialsCombined forced and natural convectionPhysical SciencessymbolsComputingMilieux_MISCELLANEOUSMathematics
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INSTABILITY OF HAMILTONIAN SYSTEMS IN THE SENSE OF CHIRIKOV AND BIFURCATION IN A NON LINEAR EVOLUTION PROBLEM EMANATING FROM PHYSICS

2004

We prove the existence of a minimal geometrico-dynamical condition to create hyperbolicity in section in the vicinity of a transversal homoclinic partially hyperbolic torus in a near integrable Hamiltonian system with three degrees of freedom. We deduce in this context a generalization of the Easton's theorem of symbolic dynamics. Then we give the optimal estimation of the Arnold diffusion time along a transition chain in the initially hyperbolic Hamiltonian systems with three degrees of freedom with a surrounding chain of hyperbolic periodic orbits .In a second part, we describe geometrically a mechanism of diffusion studied by Chirikov in a near integrable Hamiltonian system with three de…

[ MATH ] Mathematics [math]dynamique symboliquehyperbolicitymodulational instabilityNavier Stokespartially hyperbolic tori[MATH] Mathematics [math]amplitude equationschevauchement de résonancescenter manifoldconvection mixte –hyperbolicitéoverlapping resonancessymbolic dynamicséquations d'amplitudesystèmes Hamiltoniensbifurcationinstabilité modulationnellevariété centraleHamiltonian systems[MATH]Mathematics [math]tores partiellement hyperboliquesmixed convection
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A predictive approach for a real-time remote visualization of large meshes

2012

Déjà sur HAL; Remote access to large meshes is the subject of studies since several years. We propose in this paper a contribution to the problem of remote mesh viewing. We work on triangular meshes. After a study of existing methods of remote viewing, we propose a visualization approach based on a client-server architecture, in which almost all operations are performed on the server. Our approach includes three main steps: a first step of partitioning the original mesh, generating several fragments of the original mesh that can be supported by the supposed smaller Transfer Control Protocol (TCP) window size of the network, a second step called pre-simplification of the mesh partitioned, ge…

[ MATH.MATH-GT ] Mathematics [math]/Geometric Topology [math.GT]geometrytopologyComputer scienceSynthèse d'image et réalité virtuelle [Informatique]Distributed computingSewingContext (language use)02 engineering and technologySolid modeling[INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG]SimplificationvisualisationData visualizationtopology.[MATH.MATH-GT]Mathematics [math]/Geometric Topology [math.GT]Serverpartitioning0202 electrical engineering electronic engineering information engineeringPolygon meshVisualization[MATH.MATH-GT] Mathematics [math]/Geometric Topology [math.GT]Meshbusiness.industryProcess (computing)simplification020207 software engineering[ INFO.INFO-GR ] Computer Science [cs]/Graphics [cs.GR][INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]VisualizationIEEEmesh[INFO.INFO-CG] Computer Science [cs]/Computational Geometry [cs.CG]Mesh generation[ INFO.INFO-CG ] Computer Science [cs]/Computational Geometry [cs.CG]020201 artificial intelligence & image processingbusinesssewingPartitioning
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