Дисертації з теми "Monte Carlo propagation"
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Wyant, Timothy Joseph. "Numerical study of error propagation in Monte Carlo depletion simulations." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44809.
Повний текст джерелаAl-Barwani, Hamdi. "Propagation of fronts with gradient and curvature dependent velocities." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/10341.
Повний текст джерелаTinet, Eric. "Mise au point de méthodes de Monte Carlo performantes pour la simulation de la propagation des faisceaux lasers dans les milieux diffusants homogènes ou inhomomgènes : application à des problèmes liés aux méthodes de diagnostic biomedical." Paris 13, 1992. http://www.theses.fr/1992PA132032.
Повний текст джерелаPrat, Jérome. "Mesure des propriétés optiques de milieux diffusants stratifiés par l'analyse de la rétrodiffusion d'impulsions infrarouges sub-picosecondes." Paris 13, 2002. http://www.theses.fr/2002PA132012.
Повний текст джерелаBruns, Morgan Chase. "Propagation of Imprecise Probabilities through Black Box Models." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10553.
Повний текст джерелаBriton, Jean-Philippe. "Simulations numériques de la diffusion multiple de la lumière par une méthode de Monte-Carlo et applications." Rouen, 1989. http://www.theses.fr/1989ROUES040.
Повний текст джерелаRousseau, Marie. "Propagation d'incertitudes et analyse de sensibilité pour la modélisation de l'infiltration et de l'érosion." Phd thesis, Université Paris-Est, 2012. http://pastel.archives-ouvertes.fr/pastel-00788360.
Повний текст джерелаNezvanov, Aleksandr. "Particularités de l'interaction et de la propagation de neutrons à basse énergie dans des milieux nano-dispersés (l'exemple de la nano-poudre de diamant)." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY069/document.
Повний текст джерелаThe aim of the present study is to develop a quantitative model for the interaction and propagation of low-energy neutrons in nanodispersed media (using the diamond nanopowder as an example), which takes into account the influence of the nanodispersed medium density on the processes of propagation and scattering of low-energy neutrons, and the information about the structure of a diamond nanopowder.The urgency of the problem being solved is due to the lack of information about the completeness of the concepts of the systems under study, about the mechanisms of interaction of low energy neutrons with nanostructured materials, about the features of the properties of the structure of nanodispersed media, about the evolution of nanodispersed systems under the influence of radiation. The development of the proposed quantitative model is necessary for qualitative evaluation and interpretation of various experimental data. The development of a quantitative model and methods for the quantitative calculation of the interaction and propagation of low-energy neutrons in nanodispersed media will allow to interpret independent experimental data within the frames of unified concepts, and will significantly reduce the amount of empirical parameters in the quantitative interpretation of experimental results.The author recommends using the proposed quantitative model and the designed set of computer programs for qualitative and quantitative estimates and interpretation of various experimental results, and for preliminary quantitative calculations at the stage of experiment planning.The thesis consists of an introduction, four chapters, a bibliography and conclusions.The first chapter presents the results of the research into the level of current global technical development of nuclear nanotechnologies. It is noted that at present, the nuclear nanotechnologies are at the stage of fundamental and exploratory academic research, predominantly focused on the extraction and accumulation of new knowledge.The second chapter suggests a model for the propagation of low-energy neutrons in a nanodispersed medium. An expression is obtained for the neutron transfer equation in the diffusion form, i.e. Boltzmann type equation. The boundary conditions are analyzed and established for the neutron transfer equation in the diffusion approximation, accounting for coherent and incoherent processes of neutron interaction with the material. The variational method enables an analytical solution of the transfer equation for the neutron distribution function in the approximation of small angle neutron scattering by nanoparticles in the powder. The experimental data allows to develop a model of diamond nanopowder, which is to be used in calculations.The third chapter describes the design of an algorithm for numerical simulation of neutron transfer in a diamond nanopowder. Model calculations of the cross section for elastic coherent scattering of neutrons by spherical nanoparticles are carried out: 1) precise quantum-mechanical calculations by the phase-function method; 2) calculations in the Born approximation. For reference, we briefly describe standard methods for simulating random values of scattering angles and transformations of coordinate systems in computer Monte Carlo method simulation of neutron propagation in nanopowder.The fourth chapter presents the results of numerical calculations carried out after the suggested quantitative model. The results of numerical calculations are analyzed and compared with experimental data. The comparison shows a satisfactory agreement of calculations with the data of independent experiments
ARBEY, RAZATOVO MARIE-EMMA. "Filiere cmos 0,1 m sur substrat soi : etude du temps de propagation de l'inverseur par simulation particulaire monte carlo." Paris 11, 1998. http://www.theses.fr/1998PA112341.
Повний текст джерелаLavigne, Claire. "Étude théorique et expérimentale de la propagation du rayonnement UV dans la basse atmosphère." Rouen, 2001. http://www.theses.fr/2001ROUES042.
Повний текст джерелаMaughan, Nichole Millward. "Simulation of 810 nm Light Propagation Through the Human Finger for Non-Invasive Blood Analysis." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3707.
Повний текст джерелаSahlberg, Arne. "Ensemble for Deterministic Sampling with positive weights : Uncertainty quantification with deterministically chosen samples." Thesis, Uppsala universitet, Tillämpad kärnfysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-297314.
Повний текст джерелаFlorent, Jean-Jacques. "Contribution à l'étude du mode SQS : développement d'un prototype de chambre à localisation : mécanisme de propagation du streamer." Paris 11, 1989. http://www.theses.fr/1989PA112295.
Повний текст джерелаThis work is a study of the Self-Quenching Streamer mode in gaseous detectors. The set-up of a prototype devoted to the localization of light particles in the focal plane of a spectrometer and the experimental results are presented in the first part. The prototype is a cathode read-out multiwire chamber with an Argon-Ethane mixture. The cathode charge distribution is studied. We confirm that the SQS mode is not saturated, but for an adequate choice of the high voltage, we find that the dynamics of the pulses is sufficiently limited to allow 100% efficiency with Z = 1 or 2 particles. The intrinsic spatial resolution is about 200 micrometers. We evaluate the factors contributing to the differential linearity. In the second part, we discuss the streamer propagation mechanisms. Several numeric computation programs were written for this purpose, the most important being:- A Monte-Carlo program simulates the evolution of an electron population in a constant field or during an avalanche taking into account the collisions inside the plasma. - A program is based on a phenomenological model describing the space charge field which governs the streamer propagation starting with experimental or calculated parameters. The first allows the interpretation of the very large dependence of drift velocities on the composition of the gas mixture, and an estimation of the production rates of UV photons in the primary avalanche. With the second we propose a criterion for the transition to SQS mode. A dynamical description of the behavior of the streamer during the first twenty nanoseconds explains some of the experimental observations. A microscopie mode for the streamer propagation is proposed
Bendenia, Mohamed. "Étude de la propagation des ondes électromagnétiques, millimétriques et sub-millimétriques, dans un milieu turbulent et conditions de réception." Toulouse, ENSAE, 1990. http://www.theses.fr/1990ESAE0009.
Повний текст джерелаVaret, Suzanne. "Développement de méthodes statistiques pour la prédiction d'un gabarit de signature infrarouge." Phd thesis, Université Paul Sabatier - Toulouse III, 2010. http://tel.archives-ouvertes.fr/tel-00511385.
Повний текст джерелаBrizard, Matthieu. "Développement et étude d'un viscosimètre absolu à chute de bille." Phd thesis, Université Joseph Fourier (Grenoble), 2005. http://tel.archives-ouvertes.fr/tel-00009440.
Повний текст джерелаAlhassan, Erwin. "Nuclear data uncertainty quantification and data assimilation for a lead-cooled fast reactor : Using integral experiments for improved accuracy." Doctoral thesis, Uppsala universitet, Tillämpad kärnfysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-265502.
Повний текст джерелаClimaco, de Melo Lara. "La Propagation des erreurs dans les modèles de croissance forestière dans un contexte de prévision à l'échelle régional." Thesis, Paris, AgroParisTech, 2018. http://www.theses.fr/2018AGPT0006.
Повний текст джерелаIn forestry, tree-level growth models provide predictions of forest dynamics andthereby, they support decision-making. Although they are widely used, the uncertainty of their predictions is rarely assessed. Understanding the sources of uncertainty and estimating their impact is an essential step forward in a period where large-scale forecasts are becoming more popular. This thesis addresses the issue of uncertainty estimation in regional growth forecasts. The effects of large-scale disturbances were also studied.The growth model ARTEMIS-2009, which applies to most forest types in Quebec,Canada, was taken as a case study. A bootstrap hybrid estimator was used toestimate the model- and the sampling-related variances. The total variance wasthen decomposed to determine which model component induced the greatest shareof variance in the forecasts. Then, the survival analysis approach was used to develop a harvest model based on plot and regional variables. This model was integrated into ARTEMIS so that harvesting combined with spruce budworm (SBW) outbreaks were accounted in the simulations. Then, their contributions in terms of uncertainty were estimated. The results revealed that the sampling accounted for most of the variance in short-term forecasts. In long-term forecasts, the model contribution turned out to be as important as that of the sampling. The variance decomposition per model component indicated that the mortality sub-model induced the highest variability in the forecasts. A great deal of uncertainty was induced by the natural disturbances when they were accounted for in the projections. In particular, SBW showed to be the most important source of uncertainty compared to harvest activities and sampling. In the light of these results, our recommendations are that the effort to reduce uncertainty should focus on the sampling in short-term forecasts, and on the mortality sub-model and SBW occurrence in mid- and long-term forecasts
Bykov, A. (Alexander). "Experimental investigation and numerical simulation of laser light propagation in strongly scattering media with structural and dynamic inhomogeneities." Doctoral thesis, University of Oulu, 2010. http://urn.fi/urn:isbn:9789514261558.
Повний текст джерелаMagnin, Vincent. "Contribution à l'étude et à l'optimisation de composants optoélectroniques." Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-327.PDF.
Повний текст джерелаDrissi, Mohamed. "Un modèle de propagation de feux de végétation à grande échelle." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4704.
Повний текст джерелаThe present work is devoted to the development of a hybrid model for predicting the rate of spread of wildland fires at a large scale, taking into account the local heterogeneities related to vegetation, topography, and meteorological conditions. Some methods for generating amorphous network, representative of real vegetation landscapes, are proposed. Mechanisms of heat transfer from the flame front to the virgin fuel are modeled: radiative preheating from the flame and embers, convective preheating from hot gases, radiative heat losses and piloted ignition of the receptive vegetation item. Flame radiation is calculated by combining the solid flame model with the Monte Carlo method and by taking into account its attenuation by the atmospheric layer between the flame and the receptive vegetation. The model is applied to simple configurations where the fire spreads on a flat or inclined terrain, with or without a constant wind. Model results are in good agreement with literature data. A sensitivity study is conducted to identify the most influential parameters of the model. Eventually, the model is validated by comparing predicted fire patterns with those obtained from a prescribed burning in Australia and from a historical fire that occurred in Corsica in 2009, showing a very good agreement in terms of fire patterns, rate of spread, and burned area
Boripatkosol, Siriwan. "Contribution à l'étalonnage d'une machine à mesurer de très haute précision : mesure de rectitude et de planéité à un niveau d'incertitudes nanométriques." Phd thesis, Paris, ENSAM, 2010. http://pastel.archives-ouvertes.fr/pastel-00527789.
Повний текст джерелаLacombe, Céline. "Propagation des ondes élastiques dans la lithosphère hétérogène : modélisations et applications." Phd thesis, Grenoble 1, 2001. http://tel.archives-ouvertes.fr/tel-00759982.
Повний текст джерелаMesserly, Richard Alma. "How a Systematic Approach to Uncertainty Quantification Renders Molecular Simulation a Quantitative Tool in Predicting the Critical Constants for Large n-Alkanes." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6598.
Повний текст джерелаMossberg, Eva. "Some numerical and analytical methods for equations of wave propagation and kinetic theory." Doctoral thesis, Karlstad : Fakulty of Technology and Science, Mathematics, Karlstads universitet, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1848.
Повний текст джерелаUng, Philippe. "Simulation numérique du transport sédimentaire : aspects déterministes et stochastiques." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2019/document.
Повний текст джерелаIn this thesis, we are interested on the study of a sediment transport model through two different approaches. One of them concerns the numerical modelling of the problem and proposes a numerical problem-solving method based on an approximate Riemann solver for the Saint-Venant-Exner system which is one of the most common model to deal with sedimentary bed-load transport. This last one is based on a coupling between the hydraulic model of Saint-Venant and the morphodynamic model of Exner. The key point of the proposed method is the treatment of the coupling issue. Indeed, there exists two strategies; the first one consists on decoupling the resolution of the fluid part from the solid part and making them interact at fixed times whereas the second one considers a coupled approach to solve the system by jointly updating the hydraulic and solid quantities at same times. We then raise the issue of the choice of the strategy for which we suggest answers by comparing both approaches. The other one focuses on the development of a methodology to study the uncertainties related to the model previously mentioned. To this end, we propose a stochastic formulation of the Saint-Venant-Exner system and we look for characterizing the variabilities of the outputs in relation to the naturally random input parameters. This first study reveals the need for a return to the Saint-Venant system with a perturbed bed to understand the sensitivity of the hydraulic quantities on the topographical perturbations
Boutahar, Jaouad. "Méthodes de réduction et de propagation d'incertitudes : application à un mùodèle de Chimie-Transport pour la modélisation et la stimulation des impacts." Marne-la-vallée, ENPC, 2004. https://pastel.archives-ouvertes.fr/tel-00007557.
Повний текст джерелаTian, Jingduo. "Quantitative performance evaluation of autonomous visual navigation." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/quantitative-performance-evaluation-of-autonomous-visual-navigation(be6349b5-3b38-4ac5-aba2-fc64597fd98a).html.
Повний текст джерелаCzerwinski, Marek. "Modélisation de la turbidité spectrale d'un milieu multidiffusif et son application au problème inverse." Rouen, 1998. http://www.theses.fr/1998ROUES067.
Повний текст джерелаKébir, Hocine. "Approches déterministe et probabiliste de la prévision de la durée de vie de structures aéronautiques à l'aide de la méthode des équations intégrales duales." Compiègne, 1998. http://www.theses.fr/1998COMP1157.
Повний текст джерелаHauseux, Paul. "Propagation d’incertitudes paramétriques dans les modèles numériques en mécanique non linéaire : applications à des problèmes d’excavation." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10116/document.
Повний текст джерелаA 3D numerical modelling using the Enhanced Finite Element Method (E-FEM) is developped to address induced fracture networks around drifts after an excavation in Callovo-Oxfordian claystone (COx). A transversely isotropic behaviour is considered for the host rock and two failure criteria are proposed and implemented to characterize shear and tensile fractures: an anisotropic/isotropic Mohr Coulomb criterion with sliding (mode II) and an anisotropic principal strain criterion with mode I opening. Numerical simulations of underground excavations are presented and the results are discussed compared to in situ observations. The influence of the anisotropy of rock properties and in situ stress field on the induced fractures and the convergence of drifts are also studied. The geological origin of the COx as well as the large size of drifts lead to a large uncertainty related to hydro-mechanical properties of this material. Stochastic problems for linear and non linear systems are more and more of interest because it is an important issue to quantify uncertainties when parameters (loading, material properties) are modelled by correlated random fields. Despite a slow convergence, Monte Carlo methods are the most often used to solve these problems thanks to its easy implementation (non intrusive computation). Probabilistic Finite Element methods like Galerkin formulations which produce a coupled system are often viewed as intrusive. Here, we want to show that is possible to compute them in a non intrusive way and with the same accuracy as Monte Carlo methods which are considered as a reference. These methods are applied to take into account and to propagate parametric uncertainties related to claystone's behavior. 3D Numerical results are presented and discussed concerning the induced fracture networks around drifts and the anisotropic convergence of walls
Wang, Xiaofeng. "Computational technology for damage and failure analysis of quasi-brittle materials." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/computational-technology-for-damage-and-failure-analysis-of-quasibrittle-materials(a7c91eb6-5058-4e73-95de-b2f3efd645d2).html.
Повний текст джерелаMoffitt, Blake Almy. "A methodology for the validated design space exploration of fuel cell powered unmanned aerial vehicles." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33877.
Повний текст джерелаPutze, Antje. "Phénoménologie et détection du rayonnement cosmique nucléaire." Phd thesis, Université Joseph Fourier (Grenoble), 2009. http://tel.archives-ouvertes.fr/tel-00433301.
Повний текст джерелаBoutahar, Jaouad. "Méthodes de réduction et de propagation d'incertitudes : application à un modèle de chimie-transport pour la modélisation et la simulation des impacts." Phd thesis, Ecole des Ponts ParisTech, 2004. http://tel.archives-ouvertes.fr/tel-00007557.
Повний текст джерелаLa seconde est relative à la réduction du nombre de simulations demandé par la méthode Monte-Carlo classique de propagation d'incertitude. La technique utilisée ici est basée sur une représentation d'une sortie de modèle incertaine comme un développement de polynômes orthonormaux de variables d'entrées. Un autre point clé dans la modélisation intégrée d'impacts est de développer des stratégies de réduction des émissions en calculant des matrices de transfert sur plusieurs années de simulation. Une méthode efficace de calcul de ces matrices a été ainsi développée, notamment en définissant des scénarios "chimiquement" représentatifs.
L'ensemble de ces méthodes a été appliqué au modèle POLAIR3D, modèle de Chimie-Transport développé dans le cadre de cette thèse.
Mohamed, Drissi. "Un modèle de propagation de feux de végétation à grande échelle." Phd thesis, Université de Provence - Aix-Marseille I, 2013. http://tel.archives-ouvertes.fr/tel-00931806.
Повний текст джерелаMartinez, Alexandre Souto. "Statistique de polarisation et effet Faraday en diffusion multiple de la lumière." Grenoble 1, 1993. http://www.theses.fr/1993GRE10082.
Повний текст джерелаTaktak, Mohamed. "Mesure de la matrice de diffusion d'un tronçon traité cylindrique : applications à la mesure de son efficacité et à la détermination de son impédance homogénéisée." Compiègne, 2008. http://www.theses.fr/2008COMP1788.
Повний текст джерелаIn this work, two applications based on the measurement and the compute of the multimodal scattering matrix of a cylindrical lined duct were developed and presented. The first is related to the measurement of the liner efficiency in function of the incoming pressures and or powers. The second is related to the determination of this wall duct by determining its homogenized acoustic impedance by an indirect method in association with the numerical compute of this matrix. The scattering matrix measurement technique is based on the multi sources method with , the use of an anechoic termination and the conservation of the transmitted and retrograde pressures separation. The numerical computation of the scattering matrix, using the finite elements method, assumes that the duct is axisymetric and covered by a locally reacting liner were developed. The proposed evaluation of the lined duct section efficiency is based on the compute of its acoustic power dissipation and attenuation deduced from the scattering matrix using an incoming pressure vector. Also, the indirect method to determine the homogenized acoustic impedance of the duct is presented ; it is based on the minimisation of the difference between theorical and experimental dissipations computed from the scattering matrix and an incoming pressures vector from only one side. The precision of these techniques was estimated through a simulation of the experiment coupled with the Monte Carlo technique leading to determine the confidence intervals of several output experimental data measured parameters. Finally, different techniques presented in this work were tested with two lined ducts which the wall is covered with industrial locally reacting materials made of a honeycomb and a perforated sheet. In this part of work, Experimental and theoretical results of the scattering matrix coefficients and of the acoustic power dissipated and attenuated by the silencer are compared and pointed out, as already found in the litterature, the effect of the vibration of the rigid part of the wall near the higher order mode resonance frequencies. A comparison between theorical and experimental results is made and acoustic power dissipation and attenuation were determined. Then, it is shown that to determine the homogenized acoustic impedance of the liner, the indirect method has to be based on a cost function defined by the difference between the acoustic power dissipated by the actual lined duct section and the reference duct section avoiding the effect of the wall vibration
Marinelli, Marco Antonio. "Modelling and communicating the effects of spatial data uncertainty on spatially based decision-making." Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/1842.
Повний текст джерелаHouret, Thomas. "Méthode d’estimation des valeurs extrêmes des distributions de contraintes induites et de seuils de susceptibilité dans le cadre des études de durcissement et de vulnérabilité aux menaces électromagnétiques intentionnelles." Thesis, Rennes, INSA, 2019. http://www.theses.fr/2019ISAR0011.
Повний текст джерелаIntentional ElectroMagnetic Interference (IEMI) can cause equipment failure. The study of the effects of an IEMI begins with an assessment of the risk of equipment failure in order to implement appropriate protections, if required. Unfortunately, a deterministic prediction of a failure is impossible because both characteristics of equipment and of the aggression are very uncertain. The proposed strategy consists of modelling the stress generated by the aggression, as well as the susceptibility of the equipment, as random variables. Then, three steps are necessary: The first step deals with the estimation of the probability distribution of the random susceptibility variable. The second step deals with the similar estimation for the constraint / stress then that of the stress. Eventually, the third step concerns the calculation of the probability of failure. For the first step, we use statistical inference methods on a small sample of measured susceptibility thresholds. We compare two types of parametric inference: bayesian and maximum likelihood. We conclude that a relevant approach for a risk analysis is to use the confidence or credibility intervals of parameter estimates to frame the probability of failure, regardless of the inference method chosen. For the second step we explore extreme value exploration techniques while reducing the number of simulations required. In particular, we propose the technique of Controlled Stratification by Kriging. We show that this technique drastically improves performance compared to the classic approach (Monte Carlo simulation). In addition, we propose a particular implementation of this technique in order to control the calculation effort. Finally, the third step is the simplest once the first two steps have been completed since, by definition, a failure occurs when the stress is greater than the susceptibility. With the help of a final test case comprising the simulation of an electromagnetic aggression on a piece of equipment, we use the method developed in our work to estimate the frame of the probability of failure, More specifically, we show that the combined use of controlled stratification by kriging and inference of susceptibility distribution, allows to frame the estimated true value of the probability of failure
Deaconu, Madalina. "Processus stochastiques associés aux équations d'évolution linéaires ou non-linéaires et méthodes numériques probabilistes." Habilitation à diriger des recherches, Université Henri Poincaré - Nancy I, 2008. http://tel.archives-ouvertes.fr/tel-00590778.
Повний текст джерелаFabík, Jiří. "Realistická vizualizace alkoholických nápojů pomocí distribuovaného raytracingu." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236392.
Повний текст джерелаBuot, de l’Épine Yorick. "Identification de l’impédance d’un traitement en présence d’un écoulement." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2369/document.
Повний текст джерелаLocally reactive acoustic liners such as honeycomb structures with perforated panels can be modeled with a surface impedance in standard numerical models. However, the characterization of this impedance is not always straightforward. Empirical models or standing wave tube measurements are generally used to get the behavior of these acoustic treatments. Unfortunately, these methods provide only an evaluation of the impedance under specific conditions. Moreover, the conditions of use can change significantly the acoustic liners behavior as grazing flow conditions or oblique incident waves. A characterization of locally reactive acoustic liners is presented here. Starting from a set of parameters and represents a surface impedance using empirical model, an inverse method based on Bayesian approach is used to return the surface impedance taking in consideration the real conditions of use. A rectangular duct treated by a liner on its upper face is considered and these conditions are similar to the experiment present at the Université de Technologie de Compiègne. This inverse method requires a direct model to predict the pressure at some microphone positions with any surface impedance. The model used in the following is based on the Mode-Matching method. From the direct analytical model, the Bayes'rule is then used to get the posterior probability density function of the estimated impedance. An Evolutionary Monte Carlo by Markov chain (EMCMC) method is used to sample this posterior probability density. This method provides not only the best set of parameters but also some statistical information for each parameter
Savin, Eric. "Influence de la variabilité spatiale en interaction sismique sol-structure." Phd thesis, Ecole Centrale Paris, 1999. http://tel.archives-ouvertes.fr/tel-00006636.
Повний текст джерелаSabouri, Pouya. "Application of perturbation theory methods to nuclear data uncertainty propagation using the collision probability method." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENI071/document.
Повний текст джерелаThis dissertation presents a comprehensive study of sensitivity/uncertainty analysis for reactor performance parameters (e.g. the k-effective) to the base nuclear data from which they are computed. The analysis starts at the fundamental step, the Evaluated Nuclear Data File and the uncertainties inherently associated with the data they contain, available in the form of variance/covariance matrices. We show that when a methodical and consistent computation of sensitivity is performed, conventional deterministic formalisms can be sufficient to propagate nuclear data uncertainties with the level of accuracy obtained by the most advanced tools, such as state-of-the-art Monte Carlo codes. By applying our developed methodology to three exercises proposed by the OECD (UACSA Benchmarks), we provide insights of the underlying physical phenomena associated with the used formalisms
Volat, Ludovic. "Développement d’une méthode stochastique de propagation des incertitudes neutroniques associées aux grands coeurs de centrales nucléaires : application aux réacteurs de génération III." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0330/document.
Повний текст джерелаGeneration III Light Water Reactors undoubtedly follow design guidelines comparable to those of current PWRs. Furthermore, they take advantage of enhanced features in terms of safety, energy efficiency, radiation protection and environment. Then, we talk about an evolutionary approach. Amongst those improvements, the significant size and the use of a heavy reflector translate into a better neutronics efficacy, leading to intrinsic enrichment benefits then to natural uranium profits. They contribute to the core vessel preservation as well.Because of their large dimensions, the neutronic bulge of this kind of reactors is emphasized. Therefore, it is a parameter of interest in the reactor safety studies. Nevertheless, the uncertainty related to the radial power map is hardly reachable by using the numerical methods implemented in the neutronics codes.Given the above, this PhD work aims to develop an innovative stochastic neutronics uncertainties propagation method. By using recent probabilistic results, it makes good use of the growing calculation means in order to explore all the physical states of the reactor statiscally foreseen.After being validated , our method has been applied to a reactor proposed in the framework of a large core OECD/NEA international benchmark with carefully chosen covariances values. Thus, for this system, the uncertainties related to the keff reaches 638~pcm $(1\sigma)$. What is more, the total bulge equals 8.8~\% $(1\sigma)$ and the maximal uncertainty related to the insertion of a group of control rods reaches 11~\% $(1\sigma)$
Hosseinizadeh, Ahmad. "Excited States in U(1)2+1 Lattice Gauge Theory and Level Spacing Statistics in Classical Chaos." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/26815/26815.pdf.
Повний текст джерелаSanchez-Palencia, Laurent. "ETUDE THEORIQUE DE LA DYNAMIQUE NON LINEAIRE D'ATOMES FROIDS DANS UN RESEAU OPTIQUE DISSIPATIF : TRANSPORT SPONTANE ET TRANSPORT STIMULE." Phd thesis, Ecole Polytechnique X, 2003. http://tel.archives-ouvertes.fr/tel-00003425.
Повний текст джерелаNous distinguons deux classes d'atomes, respectivement piégés et non-piégés dans les puits de potentiel, aux comportements très différents. Cette distinction permet de comprendre précisément le comportement des distributions de vitesse ainsi que les propriétés du transport spontané (diffusion spatiale) dans un domaine de paramètres allant du régime sautant au régime oscillant.
Des phénomènes de transport stimulés sont étudiés dans le régime intermédiaire entre les régimes sautant et oscillant où les temps typiques du mouvement hamiltonien et des phénomènes dissipatifs sont comparables. Nous caractérisons les modes de propagation Brillouin ainsi que leurs mécanismes d'excitation. Nous montrons que ceux-ci donnent lieu au phénomène de résonance stochastique qui correspond à la synchronisation du mouvement hamiltonien et des processus dissipatifs. Nous étudions enfin un rochet atomique temporel correspondant à un mouvement dirigé induit par la brisure de la symétrie temporelle.
Santos, Elton Márcio da Silva. "QCD na rede: um estudo não-perturbativo no calibre de Feynman." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-19102011-135900/.
Повний текст джерелаThe infrared behavior of gluon and ghost propagators is of fundamental importance for the understanding of the low-energy limit of quantum chromodynamics (QCD), especially with respect to the problem of the confinement of quarks and gluons. The goal of this thesis is to implement a new method to study the gluon propagator in the linear covariant gauge in lattice QCD. In particular, we analyze in detail the newly proposed implementation and study the algorithms for numerically fixing this gauge. Note that the numerical fixing of the Feynman gauge condition poses several problems that are not present in the Landau and Coulomb cases, which prevented it from being properly studied for a long time. In fact, the definition considered initially, by Giusti et. al., is of difficult numerical implementation and introduces spurious conditions into the gauge fixing. As a consequence, the only studies carried out previously involved gluon and quark propagators on relatively small lattices, hindering a careful analysis of the infrared limit of QCD in this gauge. Obtaining new solutions for the implementation of the Feynman gauge on the lattice is therefore of great importance to enable more systematic numerical studies of propagators and vertices in this gauge and, in general, in the linear covariant gauge.
Davis, Mitchell Alan. "Monte Carlo simulation of fluorescence imaging of microvasculature." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-08-4191.
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