Dissertationen zum Thema „Simulation réflexive“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-34 Dissertationen für die Forschung zum Thema "Simulation réflexive" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Dissertationen für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
Bailly, Myriam. „Les compétences collaboratives interprofessionnelles au service de l'apprentissage des étudiants infirmiers : optimisation des scénarisations pour penser autrement la formation initiale“. Electronic Thesis or Diss., Université Côte d'Azur, 2023. http://www.theses.fr/2023COAZ6000.
Der volle Inhalt der QuelleThis thesis focuses on the interprofessional collaboration of future health professionals. It has three objectives. The first is to explore the development of interprofessional collaborative skills of student nurses at the end of their initial training. For nursing education, interprofessionality is a transversal declination of other competences but its teaching is not supported by an explicit reference framework of interprofessional collaborative competences. As a result, interprofessional education formats are rarely used. Interprofessional education, which has been widely advocated in the literature, can be used to optimise collaborative work. The second objective of this work is rooted in our preliminary results. It aims to support the development of interprofessional collaborative skills through an interprofessional learning approach that combines reflexive and developmental dimensions. The organising framework of the research is the the clinical approach of activity. Developed by Clot, the clinical approach of activity gives a central place to work collectives, likely to ensure a mediating function between the subject and his activity. Clinical approach of activity aims to develop existing resources, to bring out new psychological instruments and to give students the capacity to act in the exercise of their activity. The research device is part of the health simulation which brings into play the interprofessional collaboration through a simulated collective care activity between nursing students and massage physiotherapists students. The filmic traces of the simulation, mediated by the researcher, are individual and then collective supports for the students' reflection. Finally, the last objective of this thesis pursues an epistemic aim. The research plans to use the discourses of student nurses and kinésithérapists gathered in a work group to support the design of interprofessional education models in the health sciences and to re-interrogate the training curricula
Sillion, François X. „Simulation de l'éclairage pour la synthèse d'images : réalisme et interactivité“. Paris 11, 1989. http://www.theses.fr/1989PA112208.
Der volle Inhalt der QuelleThis work is dealing with lighting models for image synthesis. We first review the physical laws governing the interaction of light with the objects, from which the lighting calculation algorithms are derived, using various approximations. The classical models allowing a global treatment of the illumination, namely by considering the interreflection of light between objects, are then presented. We propose a new calculation algorithm for the radiosity method, which proves especially useful when a high precision is seeked. We then present a new lighting model which combines the strengths of the two main previous methods, and allows a greater realism for the pictures produced, as it models simultaneously specular and diffuse reflection. The algorithms presented in the past few years to simulate light reflection are discussed and compared to our method, so as to allow a motivated choice of the algorithm best suited to one's goals and possibilities. Finally, a set of interaction techniques are proposed, which make the light simulation process easier to use. The organisation of an interactive lighting simulation system is presented, and possible applications are discussed
Moreaux, David. „Localisation de cavités souterraines par réflexion sismique haute résolution : étude numérique, étude de terrain“. Lille 1, 1997. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1997/50376-1997-35.pdf.
Der volle Inhalt der QuelleGuyon, Hervé. „Variables latentes et processus mentaux : une réflexion épistémologique et méthodologique“. Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB015/document.
Der volle Inhalt der QuelleMy thesis considers that experimental psychology must clarify its epistemological position to clarify the formal validation of its approach, without necessarily having to refer to the framework of Science Physics. From a critical reflection, I propose to shift the epistemological framework in psychology and clearly pose a pragmatic-realistic framework. The main thesis of this work is: 1 / mental properties must be understood as emerging phenomena, which implies that their analysis can not be done nor at the neuronal level, nor at the internal dynamics of cognitive processes, but necessarily at these emerging phenomena; 2 / to analyze the mental properties as emerging forms, psychometrics need to use concepts that are in permanent tension between objectivity and intersubjectivity; accordingly, psychometrics must assert a pragmatic-realist approach, breaking with classical empiricism-realistic; 3 / a pragmatist-realistic approach, based among other things on the abduction, can overcome the contradictions pointed in the academic literature on mental properties and their measurements; 4 / a framework for measuring mental properties by latent variables becomes possible if the framework is also understood as a pragmatic-realist; 5 / but use realistic-pragmatic returns accordingly critical of both models with latent variables developed in the academic literature and the social uses of these models. The second part of my thesis focuses on a specific part of formalization of latent variables: the formative model. I develop Monte Carlo simulations to check the range of parameters for efficient formative measure as part of a realistic-empirical positioning
Calandra, Henri. „Etude numérique du problème inverse en sismique réflexion“. Pau, 1987. http://www.theses.fr/1987PAUU3023.
Der volle Inhalt der QuelleGérard, Odile. „Propagation acoustique dans un milieu diphasique : eau-bulles d'air. Facteurs de réflexion et de transmission d'un rideau de bulles“. Aix-Marseille 2, 1991. http://www.theses.fr/1991AIX22009.
Der volle Inhalt der QuelleSartoretti, Mathieu. „Inversion interactive, et caractérisation des incertitudes structurales en milieux géologiques complexes, à partir de données de sismique réflexion“. Pau, 2003. http://www.theses.fr/2003PAUU3020.
Der volle Inhalt der QuelleComplex medium bring up limitations in seismic processing and imaging techniques. These can bias the determination of a structural representation of the subsurface. We propose an interactive methodology to determine a structural representation, quantitatively validated by the seismic data, and constrained by interpretative considerations coming from the operator's knowledge. The data are used as reference. We use forward operators of seismic simulation to generate synthetic data from prior structural representation. The efficiency of our operators allows to perform this operation systematically, and to explore interactively the model space, selecting model representations that are consistent with the data. We have the possibility to validate model representations, quantify their uncertainties, and refine prior structural representations in an interactive structural inversion process. The presented tools and methodologies are illustrated with real data examples in complex contexts
Jiang-Levesque, Bei-Feng. „Étude du problème inverse linéarisé dans l'équation des ondes acoustiques à deux dimensionsÉtude mathématique d'un problème inverse de l'équation des ondes à une dimension dans un cas particulier“. Paris 11, 1989. http://www.theses.fr/1989PA112029.
Der volle Inhalt der QuelleOne of the advantages of seismic inversion methods for petroleum exploration is the potential quantitative evaluation of the distributed parameters (propagation velocity, acoustic impedance) characterizing subsurface formations. Such methods are particularly attractive for detecting stratigraphic traps, which can be recognized by a lateral variation in these parameters. In this way, such methods yield a substantial improvement in conventional prestack migrations which only provide images of heterogeneities. Among inversion methods, linearized inversion is arousing great interest because of the simplifications it brings to computing. The disadvantage of this approach stems from the difficulty in finding of a so-called reference medium that is sufficiently close to the actual unknown medium to justify the linearization. The first chapter of this work aims at a better understanding of the linearized forward problem and attempts to answer the following question: In what way must the reference medium be close to the exact medium for the linearization to be justified? Which of the parameters for the linearization are tolerant with regard to defects in the reference medium? The second chapter of the work examines numerically the 2-D linearized inverse problem and analyses how errors resulting from the linearization can influence the solution of the problem. Numerical experiments show the effectiveness of the linearized inversion; more specifically it allows a quantitative identification of the heterogeneities, as well as nonlinear inversion, when the reference medium approximates accurately the velocity of the actual medium. With a cruder reference medium the quantitative identification of the heterogeneities is no more possible, but the linearized inversion yields a better imaging as compared to prestack migration
Cazier, Dorothée. „Modélisation et simulation des propriétés radiatives des surfaces : implantation et expérimentation“. Nancy 1, 1996. http://www.theses.fr/1996NAN10116.
Der volle Inhalt der QuelleIn the light transfer equation, we have to take into account the physical features of the material reflection. This have led many researchers to elaborate various models. These models are more or less physically valid; they are also more or less easy to use. In fact, on one hand they have to be processed by an algorithm of global lighting transfer between all surfaces of the geometrical environment to be simulated, and in the other hand they have to permit to determine parameters for the complex photometrical behavior of these surfaces. Our study concerns the modelisation of the radiative properties of surfaces. We focus more precisely on the properties measurement for real cases of surfaces, by taking into account these properties in the illumination simulation process and on the experimentation of a number of models, in the perspective of lighting engineering applications
Reversat, Bernard. „La réflexion éthique au service de l'analyse des pratiques professionnelles sur un territoire de santé“. Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0621/document.
Der volle Inhalt der QuelleThe meaning of the nursing exercise is based on the notion of “living together” and feeds on an important need for ethical reflection both from students and healthcare professionals. However, the reflection exercise and the development of training in the field of ethics have been scarce in initial training and in the career path of most of professionals in service. The individual reflexive position is not sufficient and must be completed by a collective approach of ethical reflection in which the patient, his/her family or his/her close relations are associated with interdisciplinary dialogue. The “Ethics and Health Professions” committee (as per the A Cordier report in 2003) pointed out a lack of locations and time for the nursing staff, which could allow them to “formalize” their ethical reflection. This thesis suggests identifying the systems to be created in order, for example of the sequences of simulation in health, to accompany nursing players in this questioning approach a priori but also exposit. Questionnaires will be used to enhance and consolidate the main assumption. Another research focus will attempt to objectify changes in the level of relevance of ethical principles involved, according to contexts and through observations conducted during multidisciplinary meetings between health professionals. This approach will attempt to validate another hypothesis. Finally, to answer the initial question, it appears that a Continuous Professional Development program (DPC), designed as a “new area for reflection” seems to be an opportunity that must be seized, to help care providers to clarify situations et build their practice purpose in a collegial manner
Ait, Ali Lahcen. „Etude théorique et expérimentale des non linéarites ultrasonores : intérêt du second harmonique en imagerie par réflexion“. Nancy 1, 2001. http://www.theses.fr/2001NAN10010.
Der volle Inhalt der QuelleMaftei, Radu. „Analyse stochastique pour la simulation de particules lagrangiennes : application aux collisions de particules colloïdes“. Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4130/document.
Der volle Inhalt der QuelleThis thesis broadly concerns colloidal particle simulation which plays an important role in understanding two-phase flows. More specifically, we track the particles inside a turbulent flow and model their dynamics as a stochastic process, their interactions as perfectly elastic collisions where the influence of the flow is modelled by a drift on the velocity term. By coupling each particle and considering their relative position and velocity, the perfectly elastic collision becomes a specular reflection condition. We put forward a time discretisation scheme for the resulting Lagrange system with specular boundary conditions and prove that the convergence rate of the weak error decreases at most linearly in the time discretisation step. The evidence is based on regularity results of the Feynman-Kac PDE and requires some regularity on the drift. We numerically experiment a series of conjectures, amongst which the weak error linearly decreasing for drifts that do not comply with the theorem conditions. We test the weak error convergence rate for a Richardson Romberg extrapolation. We finally deal with Lagrangian/Brownian approximations by considering a Lagrangian system where the velocity component behaves as a fast process. We control the weak error between the position of the Lagrangian system and an appropriately chosen uniformly elliptic diffusion process and subsequently prove a similar control by introducing a specular reflecting boundary on the Lagrangian and an appropriate reflection on the elliptic diffusion
Torres, Andrés. „Décantation des eaux pluviales dans un ouvrage réel de grande taille : éléments de réflexion pour le suivi et la modélisation“. Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0013/these.pdf.
Der volle Inhalt der QuelleRetention and settling basins represent important elements in management of urban stormwater rejections. These deviees, used for settling of stormwater, were already the subject of in situ experimentations and laboratory experimentations cou pied with hydrodynamic modellings. The results obtained in laboratory conditions remain hardly transposable to real systems because of many reasons : complexity of geometries, in let and hydrodynamic features variabilities, heterogeneity of sediment characteristics, etc. This PhD work was thus focused on both metrology and modelling of stormwater settling problem in full-scale sedimentation systems. Il was supported by the retention and settling basin experimental site Django Reinhardt at Chassieu. Three main aspects have been treated in terms of metrology: the applicability of VI CAS protocol for the assessment of settling velocities sediments settled on the bottom of the device, the physico-chemical characterisation of settled sediments and the processing of the online data in order to estimate the pollutant loads at basin in let and out let. The Rubar 20 CFD software has been applied to modelling the settling of the retention and settling basin. The results obtained suggest a good capacity of the model to predict the settling efficiency and similarities between settling preferential areas predicted and observed in situ. The results obtained confirm the relevance of coupling metrology and modelling in order to improve the design, sizing, modelling and management of urban stormwater retention and settling basins
Zhao, Su. „Étude et intégration de capteurs ultrasonores dans un système de contrôle hiérarchisé : application à un organe de sécurité "réflexe" pour un robot mobile“. Compiègne, 1994. http://www.theses.fr/1994COMPD687.
Der volle Inhalt der QuelleBen, Abdessalem Khaled. „Etude de l'écoulement pulsatile d'un fluide visqueux dans un milieu viscoélastique non linéaire et présentant deux sites de réflexion : application à l'écoulement du sang dans les artères“. Paris 7, 2008. http://www.theses.fr/2008PA077212.
Der volle Inhalt der QuelleThe knowledge of hemodynamic quantities of the cardiovascular System in relation to pathological or physiological data h£ been the subject of much research in recent decades. The aim of this thesis was to study the possibility of non-intrusive investigation of the arterial System, which is based on the use of ultrasound measurement. We have developed seven methods for non-invasive quantification of hemodynamic quantities of clinical interest. We presented in a first time a method for determining the propagation coefficient, based on simultaneous measurement of the velocity or radius into three section of an arterial trunk. In a second time, we presented a new method of measuring this quantity, based on non-invasive measurement of the velocity and radius at only two sections of a tube or an arterial tree. These methods have been validate by numerical simulation for various geometrical and physical conditions in the presence of noise. In the second part of the work, we developed a method that allows estimation of wave speed through the measurement of velocity and the section in single site. The results of experiments on hydrodynamics banc were compared with classic models of literature. We the presented two methods for the assessment of the distance from the reflection site. Finally we have developed a model the takes into account the presence of two reflections sites. The model allows Computing the flow, the unsteady pressure and the impedance
Jin, Guanghai. „Nouvelles techniques de modélisation optique : application à quelques composants d'optique intégrée“. Lille 1, 1997. http://www.theses.fr/1997LIL10212.
Der volle Inhalt der QuelleClarke, Richard William Barnes. „Modélisation et inversion de données cinématiques complexes en 3D“. Pau, 1997. http://www.theses.fr/1997PAUU3010.
Der volle Inhalt der QuelleAgudelo, William. „Imagerie sismique quantitative de la marge convergente d'Equateur-Colombie : Application des mèthodes tomographiques aux données de sismique réflexion multitrace et réfraction-réflexion grand-angle des campagnes SISTEUR et SALIERI“. Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/tel-00010415.
Der volle Inhalt der QuelleSoyer, Martin. „Improvement of the sensory stimuli restitution on driving simulator“. Electronic Thesis or Diss., université Paris-Saclay, 2022. http://www.theses.fr/2022UPAST103.
Der volle Inhalt der QuelleHigh performance driving simulators reproduce vehicle acceleration based on adequate motion systems. The driver is immersed in a multisensorial (visual, haptic, vestibular and sound stimulation) environment of synthesis. The performance of driving simulator outside of its mechanical capacity (the visual latency, the delay of restitution of movement, etc...) and of the temporal coherence of the different stimuli are factors that can condition the validity of the perception. The present thesis aims at to develop a motion restitution algorithm that minimizes the calculation time and corrects the simulator delay while maintaining the performance of motion restitution. This restitution algorithm receives a specific interest from the driving simulation community through the denomination MCA (Motion Cueing Algorithm). This thesis work deals with optimal control and particularly on the recent use of Model Predictive Control (MPC) as a base of the algorithm. The different ways for improving concern the set invariance use in the control design for the trajectory tracking. Thus, a delay compensation algorithm is proposed with a less computational burden. A non predictive algorithm is also designed based on the interpolation-based control technique adapted to the dynamic trajectory tracking. Finally, new set theoretic notions relaxing set invariance notions are proposed in order to minimize the complexity of optimization problems in the MPC procedure
Brahmi, Nassim. „Etude numérique de la propagation et l’atténuation des ondes de choc en milieux confinés Turbulent structures of shock-wave diffraction over 90° convex corner Analysis of shock-wave diffraction over double concave cylindrical wedges. Part I: Shock dynamics Analysis of shock-wave diffraction over double cylindrical wedges. Part II: Vorticity generation Achieving an optimal shock-wave mitigation inside open channels with cavities for weak shock waves: a computational study“. Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR09.
Der volle Inhalt der QuelleThe propagation of shock waves involves complex interactions between waves and surrounding media, which gives rise to several phenomena such as reflection, diffraction, etc. To shed more light into the fundamental physics associated with these phenomena, high resolution numerical simulations were carried out. In particular, analysis of shock diffraction over double concave cylindrical wedges revealed that the transition angles, from regular to Mach reflection, increase with the Mach number, whereas they are found to be almost the same over the two concave surfaces for the transonic Mach regimes and relatively larger on the second surface for high ones showing that the flow is capable of retaining the memory of the past events over the entire process for the high Mach numbers. The analysis of the vorticity equation balance showed, for the first time, that the diffusion of the vorticity due to the viscous effects is quite important compared to the baroclinic term for low Mach numbers, while this trend is inverted for higher Mach numbers. The study also showed that the stretching of the vorticity due to the compressibility effects plays an important role in the vorticity production. On the basis of these numerical simulations, an approximate universal relation is proposed, allowing to predict the incident-shock trajectory and velocity as a function of the incident-shock Mach number, the radius of curvature of the geometry, and the gas properties. Afterward, the study of shock-waves propagation and their attenuation in channel flow having different heights and exhibiting a hollow circular cavities with different depths has been clone. The results also showed the importance of reducing the height of the channel and changing the position of the reduced section in addition to the diffraction angle and the cavity depth for better shock-waves attenuation. A subtle arrangement of channel position/height and a cavity location/depht was found
Patriarche, Manolis. „Mesure et modélisation de la lumière naturelle dans les canyons urbains“. Thesis, Vaulx-en-Velin, Ecole nationale des travaux publics, 2014. http://www.theses.fr/2014ENTP0009/document.
Der volle Inhalt der QuelleAs the world population and the urbanization increase, cities become denser, thus reducing access to daylight and sunlight for city dwellers. This access is linked to some issues such as energy consumption, health and comfort; it can be limited by several urban fabric features such as street width, building height, façade and road coating. We have evaluated the influence of the most important features of an urban canyon regarding daylight availability inside the canyon under real sky conditions.To that end, we have built a scale model of an urban canyon, the simplest representation of a street. This scale model can be modified: the aspect ratio H/W (Height/Width) can be changed as well as the type of façade. During one year, outdoor illuminances have been measured every minute on the ground and at different heights of the façades. Hence, we created a database containing twelve combinations of an urban canyon with the following parameters: three aspect ratios (H/W=2, 1 and 0.5) and four types of façades with different reflection factors. The different coatings of the façades are: black, white, roughcast and roughcast with windows. We evaluate the influence of these parameters for each type of sky defined according to the CIE for a north/south orientated canyon.We also use this database in order to evaluate the ease of use, performance and precision of three software tools for the estimation of solar radiation in urban context: Citysim, Daysim and Heliodon, each having different simplification levels.Finally, we have carried a measuring campaign in the streets of the French city of Lyons. This campaign allowed us to realize the difficulty of collecting data in the field and modelling solar radiation of a real street. We have also assessed a new method for measuring illuminances of a whole façade. This method is based on a luminance map generated from a calibrated digital camera equipped with a fisheye lens. A comparison between these illuminances with illuminances measured on the scale model with regular sensors allows us to estimate the bias of using a simplified coating.Based on illuminances measured on the scale model, a canyon with an aspect ratio H/W=1 has a better access to daylight, it represents a good compromise between contributions of the sky and the opposing façade. Every city has an optimal canyon shape according to its local climate that could be defined as the frequency of occurrence of the CIE types of sky. We have evaluated the ability of the selected software tools to take into account the climate. For clear skies, Heliodon is able to produce illuminances close to those measured on the scale model. Because the weather changes throughout the year, one would rather take into account the 15 CIE types of sky instead of using either a clear sky or an overcast sky as many studies do. Citysim and Daysim are able to take into account the climate and correlate well with scale model measurements for each type of sky. The method for measuring illuminances using a fisheye lens camera has been validated based on the measurements in real streets of Lyons. This method could produce more accurate values using a reflection factor map of the façade. Illuminances measured on the scale models didn’t correlate well with illuminances measured in real streets because of the complexity of the streets compared to the simplicity of the idealized canyon of the scale model. The use of simplified models of streets can lead to bad results, for instance, with studies estimating the energy consumption of buildings for lighting at district or urban scale. The density of urban areas must decrease in order to improve access to daylight. That would provide other advantages such as the reduction of exposure to vehicles pollution or reduction of the urban heat island. The calculation of an ideal aspect ratio could be achieved using tools evaluated in this thesis
Buob, Marc-Olivier. „Routage intradomaine et interdomaine dans les réseaux de coeur“. Phd thesis, Université d'Angers, 2008. http://tel.archives-ouvertes.fr/tel-00450680.
Der volle Inhalt der QuelleBehlouli, Abdeslam. „Simulation du canal optique sans fil. Application aux télécommunications optique sans fil“. Thesis, Poitiers, 2016. http://www.theses.fr/2016POIT2308/document.
Der volle Inhalt der QuelleThe context of this PhD thesis falls within the scope of optical wireless communications for applications in indoor environments. To discuss the performance of an optical wireless link, it is necessary to establish a characteristic study of the behavior of the optical wave propagation channel. This study can be realized by measurement or by the simulation of the channel impulse response. After describing the composition of an optical wireless link and reviewing existing simulation methods, we present our new simulation algorithms channel in realistic environments by focusing on their performances in terms of accuracy and their complexity in terms of computation time. These methods are based on solving the light transport equations by ray-tracing techniques associated with stochastic Monte Carlo integration methods. The classical version of these methods is the basis of three proposed simulation algorithms. By applying an optimization using Markov Chain, we present two new algorithms. A performance assessment of our simulation algorithms is established in mono and multi-antenna scenarios of our simulation algorithms. Finally, we present the application of these algorithms for characterizing the impact of the simulation environment on the performances of a visible light communication link. We particularly focus on the transmitter models, surface coating materials, obstruction of the user's body and its mobility, and the geometry of the simulation scene
Abdoulatuf, Antoisse. „Modélisation et simulation de la propagation d'ondes guidées dans des milieux élastiques en présence d'incertitudes : Application à la caractérisation ultrasonore“. Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1011/document.
Der volle Inhalt der QuelleIn this thesis, we are interested in the modeling and simulation of the propagation of ultrasonic waves in the cortical bone. Precisely, we have studied and analyzed the Quantitative Ultrasound (QUS) technique for the evaluation of the quality of bone tissue. It is an emerging technique those the application to bone tissue arouses particular interest in the scientific community. Since bone tissue is a living tissue, it is subject to aging and various pathologies, such osteoporosis, osteomalacia, osteoporomalacia, or the so-called Paget disease. To assist in therapeutic follow-up of the bone, monitoring of quality of bone tissue is essential. In this context, methods based on QUS technique are deemed to be interesting, due of their non-invasive, inexpensive, portable and non-ionizing characteristics. However, use the ultrasound in the context of characterization of bone tissue, requires a deep understanding of the different physical phenomena involved in their propagation. In this perspective, our work is developed in the modeling theme dedicated to the propagation of ultrasonic waves in multidimensional, heterogeneous, anisotropic waveguides, constituted of materials whose heterogeneity can be qualified as random. One of the originalities of this thesis concerns the study of the reflection and transmission coefficients and the dispersion curves in the presence of uncertainties in the material properties. In a first part, we study the reflection/transmission phenomena via a two-dimensional tri-layer model taking into account the soft tissues and the random heterogeneity of the bone tissue. We analyzed the impact of these characteristics on the reflection and transmission coefficients. A gradient of material properties is introduced, and its effect on the coefficients of interest is examined. The modal aspect of the waves is explored, by studying the dispersion of Lamb waves. The results obtained in a two-dimensional geometrical configuration made it possible to discuss the influence of the various parameters, in terms of mechanical and/or geometric properties, on the propagation of the ultrasonic waves in the cortical tissue. In a second part, the proposed model is extended for a cylindrical geometric configuration. The discussion is carried out in order to analyze the influence of the three-dimensional geometry of the bone on the phenomena of propagation
Boukongo, Sotaine Marie Aimé. „Etude des hydrates de gaz sur la marge active de Nankai (Japon) : analyse de données de sismique réflexion 3D et inversion des formes d'onde“. Paris, Institut de physique du globe, 2007. http://www.theses.fr/2007GLOB0002.
Der volle Inhalt der QuelleThe analysis of 3D seismic reflection data on the Nankai (Japan) active margin showed evidenceof a BSR (bottom simulating reflector) and a double BSR. The BSR is an acoustic impedance contrastat the interface separating sediments rich in gas hydrate, having a high velocity above, and sedimentsrich in free gas, having a low velocity below. The double BSR can be considered as a fossil BSR orcan result from a mixture of gases of different compositions within the sediments. The BSR depth isused to constrain the thermal regime in the 3D box (5 km x 42. 5 km) of the Nankai margin. The heatflow calculated from BSR depths gives values between 20-68 mW/m2. Strong BSR amplitudes arelocalized in the zone where the heat flow is relatively low, and weak BSR amplitudes are localized inthe zone where the heat flow is relatively high. The circulation of warm fluids would perturb theamplitude of BSR. The BSR is absent around the Tokai fault in the slope basin zone, and issometimes discontinuous or absent around the Kodaiba fault in the forearc basin zone. In the forearcbasin where the distribution of the BSR is more important, full waveform inversion results allowed toconfirm the presence of a zone with high velocity above the BSR, which could be due to the presenceof gas hydrate in sediments. Just below the BSR, we find a low velocity zone, which could be due tothe presence of the free gas in sediments. Strong BSR amplitude could be correlated with the presenceof underlaying free gas. The estimated concentration of gas hydrate is lower than 25 %. The meanvolume of gas hydrate calculated is about 85 x 107 m3. The estimated concentration of free gas variesbetween 0. 7 and 8 %. The mean volume of free gas calculated is about 6 x 107 m3. In the study area,we conclude that these concentrations/volumes are enormous but, they cannot constitute aneconomically exploitable reservoir, because gas hydrates are disseminated in the sediments
Laouini, Mariem. „Conception, simulation et mesures de différents circuits reconfigurables utilisant des commutateurs MEMS RF et des commutateurs à matériaux à changement de phase (PCM)“. Electronic Thesis or Diss., Limoges, 2023. https://aurore.unilim.fr/theses/nxfile/default/15037a69-5484-4258-a2c0-9a2beb9183c1/blobholder:0/2023LIMO0020.pdf.
Der volle Inhalt der QuelleThis manuscript represents the thesis work that mainly deals with the design of RF MEMS switches for reconfigurable circuits. A solution that solves the problem of trapping phenomenon in the dielectric of the switch has been proposed using Ta/Ta2O5 dielectric. This RF MEMS switch, operating at a frequency of 20 GHz, has showed reliable operation without the occurrence of the dielectric-trapping phenomenon. It also gave a high capacitance value of 350 fF and a high capacitive contrast of seven. These components are then integrated into the design of a reflective type phase shifter using the Lange hybrid coupler. The phase shifter guaranteed a 180° phase shift, low insertion losses as well as good isolation below -23 dB.Other RF MEMS switches, using Au/SiN actuation electrode, are used in the design of a 2-bit and a 3-bit phase shifter. The 2-bit phase shifter demonstrated the ability to have a smooth phase shift of 0°, 96° and 186° with an approximate step size of 90°. The PCM phase change materials switches, designed in our XLIM laboratory, were also tested for the design of a phase shifter. The conceived circuit was able to reach the 180° phase shift with, however, high insertion losses. In the last project, we detailed a design of an LC reconfigurable impedance tuner. This impedance adapter is tested on the WolfSpeed CGH40010F transistor and demonstrated a good matching at the output of the transistor at 5 GH. The design of the tuner and its integration into a PCB card on a FR4 substrate are still, however, a matter of concern
Andreani, Anna. „Conception d’un dispositif de mesure de BSDF pour l’éco-conception de bâtiments“. Thesis, Lyon, 2020. http://www.theses.fr/2020LYSET003.
Der volle Inhalt der QuelleIn a context of increasing scarcity of primary energy, it is necessary to work to reduce energy consumption related to lighting in buildings while ensuring that occupants enjoy good visual comfort. Physical-realistic simulation using light simulation software is a tool for evaluating various variants of a building. It can be used in multi-criteria optimization approaches with a view to deploying decision-support systems designed to identify the best possible trade-offs between energy consumption and user comfort. Insofar as the optical properties of building materials (opaque, transparent, coloured, isotropic, anisotropic and with textures or micro-reliefs) are an input to light simulation software, their characterization is an essential prerequisite for the implementation of this eco-design approach for buildings. The optical properties of materials are described by the mathematical formalism of the BSDF (Bidirectional Scattering Distribution Function) and can be integrated into most light simulation software in the form of analytical models or tabulated measurements. Widely used analytical models can be used to characterize optically simple materials but are difficult to extend to more complex materials. Moreover, no device currently exists that can finely characterise the full range of materials in a building in an operational time frame using tabulated measurements. Therefore, the aim of this thesis work is to design a device for the fast and accurate measurement of the optical characteristics of materials for the physico-realistic simulation of buildings. A first measuring device has been designed and has shown the feasibility of operating an instrument equipped with multi-sensors as a detector. It identified the pitfalls to be avoided as well as the obstacles to be circumvented for the design of a second, more operational measuring device with increased capabilities. Based on an instrument equipped with multi-sensors and a computer-controlled positioning system, it allows the measurement of the optical properties of the building's constituent materials in an operational context. The raw data acquisition and processing phases are supervised by computer. The duration of the measurements ranges from 5 minutes 40 seconds to 3 hours 2 minutes and 30 seconds. Their average repeatability is 97.88%
Appadoo, Owen Kevin. „Recherches et expérimentations artistiques en images numériques à base d'interférences : concevoir des personnages tridimensionnels grâce aux illusions visuelles des franges d'interférence volontairement perturbées“. Phd thesis, Paris 8, 2006. http://octaviana.fr/document/119079542#?c=0&m=0&s=0&cv=0.
Der volle Inhalt der QuelleThe ability to conceive in total abstraction calls upon the faculty that has our brain to fill what is not visible by the nearest image. That creates a visual illusion and then our imagination bring forward mental images. My research consists in presenting an artistic concept using interferences and illusions to create three-dimensional characters. Also this thesis is composed in two sections. The first section is a general study on the properties of light, optical and the method to create interferences. The second section is based on my practical work. I explain, step by step, how to conceive three-dimensional characters due to visual illusions obtained through interference rings disturbed on purpose
Issiaka, Koné. „Résonateurs à Ondes Acoustiques Guidées sur Miroir de Bragg“. Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2010. http://tel.archives-ouvertes.fr/tel-00540624.
Der volle Inhalt der QuelleMazet, Vincent. „Développement de méthodes de traitement de signaux spectroscopiques : estimation de la ligne de base et du spectre de raies“. Phd thesis, Université Henri Poincaré - Nancy I, 2005. http://tel.archives-ouvertes.fr/tel-00011477.
Der volle Inhalt der QuelleDans un premier temps est proposée une méthode déterministe qui permet d'estimer la ligne de base des spectres par le polynôme qui minimise une fonction-coût non quadratique (fonction de Huber ou parabole tronquée). En particulier, les versions asymétriques sont particulièrement bien adaptées pour les spectres dont les raies sont positives. Pour la minimisation, on utilise l'algorithme de minimisation semi-quadratique LEGEND.
Dans un deuxième temps, on souhaite estimer le spectre de raies : l'approche bayésienne couplée aux techniques MCMC fournit un cadre d'étude très efficace. Une première approche formalise le problème en tant que déconvolution impulsionnelle myope non supervisée. En particulier, le signal impulsionnel est modélisé par un processus Bernoulli-gaussien à support positif ; un algorithme d'acceptation-rejet mixte permet la simulation de lois normales tronquées. Une alternative intéressante à cette approche est de considérer le problème comme une décomposition en motifs élémentaires. Un modèle original est alors introduit ; il a l'intérêt de conserver l'ordre du système fixe. Le problème de permutation d'indices est également étudié et un algorithme de ré-indexage est proposé.
Les algorithmes sont validés sur des spectres simulés puis sur des spectres infrarouge et Raman réels.
Liu, Penghuan. „Statistical and numerical optimization for speckle blind structured illumination microscopy“. Thesis, Ecole centrale de Nantes, 2018. http://www.theses.fr/2018ECDN0008/document.
Der volle Inhalt der QuelleConventional structured illumination microscopy (SIM) can surpass the resolution limit inoptical microscopy caused by the diffraction effect, through illuminating the object with a set of perfectly known harmonic patterns. However, controlling the illumination patterns is a difficult task. Even worse, strongdistortions of the light grid can be induced by the sample within the investigated volume, which may give rise to strong artifacts in SIM reconstructed images. Recently, blind-SIM strategies were proposed, whereimages are acquired through unknown, non-harmonic,speckle illumination patterns, which are much easier to generate in practice. The super-resolution capacity of such approaches was observed, although it was not well understood theoretically. This thesis presents two new reconstruction methods in SIM using unknown speckle patterns (blind-speckle-SIM): one joint reconstruction approach and one marginal reconstruction approach. In the joint reconstruction approach, we estimate the object and the speckle patterns together by considering a basis pursuit denoising (BPDN) model with lp,q-norm regularization, with p=>1 and 0
Mohammad, Mahdizadeh Mahdi. „Propagation et réflexion de la marée interne: une étude numérique et expérimentale“. Phd thesis, 2008. http://tel.archives-ouvertes.fr/tel-00339961.
Der volle Inhalt der QuelleDesjardins, Marc-Antoine. „Construction interactive de BRDFs par simulation 2D de micro-géométries en couches multiples“. Thèse, 2012. http://hdl.handle.net/1866/9201.
Der volle Inhalt der QuelleComplex reflection models, with their many parameters, some of which are not intuitive at all, are difficult to control when trying to achieve a desired appearance. Moreover, even if an artist can more easily understand the shape of the surface micro-geometry, its 3D modeling and 4D simulation remain extremely tedious and expensive in memory. We propose an intermediate solution, where the artist represents a 2D cross section of a material, by drawing a multi-layered surface micro-geometry. An efficient 2D ray tracing simulation captures the light distribution specific to those micro-geometries. Off plane deflection is automatically calculated in a probabilistic way, based on the surface normal at the intersection point and the incident ray direction. This results in complete and complex isotropic BRDFs, simulated at interactive rates, and allowing interactive editing of rich and varied materials.
Lavoie, Patrick. „Contribution d'un débriefing au jugement clinique d'étudiants infirmiers lors de simulations de détérioration du patient“. Thèse, 2016. http://hdl.handle.net/1866/18588.
Der volle Inhalt der Quelle