Tesis sobre el tema "Linear estimation problems"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 42 mejores tesis para su investigación sobre el tema "Linear estimation problems".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Edlund, Ove. "Solution of linear programming and non-linear regression problems using linear M-estimation methods /". Luleå, 1999. http://epubl.luth.se/1402-1544/1999/17/index.html.
Texto completoPIEROPAN, MIRKO. "Expectation Propagation Methods for Approximate Inference in Linear Estimation Problems". Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2918002.
Texto completoKaperick, Bryan James. "Diagonal Estimation with Probing Methods". Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90402.
Texto completoMaster of Science
In the past several decades, as computational resources increase, a recurring problem is that of estimating certain properties very large linear systems (matrices containing real or complex entries). One particularly important quantity is the trace of a matrix, defined as the sum of the entries along its diagonal. In this thesis, we explore a problem that has only recently been studied, in estimating the diagonal entries of a particular matrix explicitly. For these methods to be computationally more efficient than existing methods, and with favorable convergence properties, we require the matrix in question to have a majority of its entries be zero (the matrix is sparse), with the largest-magnitude entries clustered near and on its diagonal, and very large in size. In fact, this thesis focuses on a class of methods called probing methods, which are of particular efficiency when the matrix is not known explicitly, but rather can only be accessed through matrix vector multiplications with arbitrary vectors. Our contribution is new analysis of these diagonal probing methods which extends the heavily-studied trace estimation problem, new applications for which probing methods are a natural choice for diagonal estimation, and a new class of deterministic probing methods which have favorable properties for large parallel computing architectures which are becoming ever-more-necessary as problem sizes continue to increase beyond the scope of single processor architectures.
Schülke, Christophe. "Statistical physics of linear and bilinear inference problems". Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC058.
Texto completoThe recent development of compressed sensing has led to spectacular advances in the under standing of sparse linear estimation problems as well as in algorithms to solve them. It has also triggered anew wave of developments in the related fields of generalized linear and bilinear inference problems. These problems have in common that they combine a linear mixing step and a nonlinear, probabilistic sensing step, producing indirect measurements of a signal of interest. Such a setting arises in problems such as medical or astronomical Imaging. The aim of this thesis is to propose efficient algorithms for this class of problems and to perform their theoretical analysis. To this end, it uses belief propagation, thanks to which high-dimensional distributions can be sampled efficiently, thus making a bayesian approach to inference tractable. The resulting algorithms undergo phase transitions that can be analyzed using the replica method, initially developed in statistical physics of disordered systems. The analysis reveals phases in which inference is easy, hard or impossible, corresponding to different energy landscapes of the problem. The main contributions of this thesis can be divided into three categories. First, the application of known algorithms to concrete problems : community detection, superposition codes and an innovative imaging system. Second, a new, efficient message-passing algorithm for blind sensor calibration, that could be used in signal processing for a large class of measurement systems. Third, a theoretical analysis of achievable performances in matrix compressed sensing and of instabilities in bayesian bilinear inference algorithms
Mattavelli, Marco Mattavelli Marco Mattavelli Marco. "Motion analysis and estimation : from III-posed discrete linear inverse problems to MPEG-2 coding /". Lausanne, 1997. http://library.epfl.ch/theses/?nr=1596.
Texto completoBarbier, Jean. "Statistical physics and approximate message-passing algorithms for sparse linear estimation problems in signal processing and coding theory". Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC130.
Texto completoThis thesis is interested in the application of statistical physics methods and inference to signal processing and coding theory, more precisely, to sparse linear estimation problems. The main tools are essentially the graphical models and the approximate message-passing algorithm together with the cavity method (referred as the state evolution analysis in the signal processing context) for its theoretical analysis. We will also use the replica method of statistical physics of disordered systems which allows to associate to the studied problems a cost function referred as the potential of free entropy in physics. It allows to predict the different phases of typical complexity of the problem as a function of external parameters such as the noise level or the number of measurements one has about the signal: the inference can be typically easy, hard or impossible. We will see that the hard phase corresponds to a regime of coexistence of the actual solution together with another unwanted solution of the message passing equations. In this phase, it represents a metastable state which is not the true equilibrium solution. This phenomenon can be linked to supercooled water blocked in the liquid state below its freezing critical temperature. Thanks to this understanding of blocking phenomenon of the algorithm, we will use a method that allows to overcome the metastability mimicing the strategy adopted by nature itself for supercooled water: the nucleation and spatial coupling. In supercooled water, a weak localized perturbation is enough to create a crystal nucleus that will propagate in all the medium thanks to the physical couplings between closeby atoms. The same process will help the algorithm to find the signal, thanks to the introduction of a nucleus containing local information about the signal. It will then spread as a "reconstruction wave" similar to the crystal in the water. After an introduction to statistical inference and sparse linear estimation, we will introduce the necessary tools. Then we will move to applications of these notions. They will be divided into two parts. The signal processing part will focus essentially on the compressed sensing problem where we seek to infer a sparse signal from a small number of linear projections of it that can be noisy. We will study in details the influence of structured operators instead of purely random ones used originally in compressed sensing. These allow a substantial gain in computational complexity and necessary memory allocation, which are necessary conditions in order to work with very large signals. We will see that the combined use of such operators with spatial coupling allows the implementation of an highly optimized algorithm able to reach near to optimal performances. We will also study the algorithm behavior for reconstruction of approximately sparse signals, a fundamental question for the application of compressed sensing to real life problems. A direct application will be studied via the reconstruction of images measured by fluorescence microscopy. The reconstruction of "natural" images will be considered as well. In coding theory, we will look at the message-passing decoding performances for two distincts real noisy channel models. A first scheme where the signal to infer will be the noise itself will be presented. The second one, the sparse superposition codes for the additive white Gaussian noise channel is the first example of error correction scheme directly interpreted as a structured compressed sensing problem. Here we will apply all the tools developed in this thesis for finally obtaining a very promising decoder that allows to decode at very high transmission rates, very close of the fundamental channel limit
Krishnan, Rajet. "Problems in distributed signal processing in wireless sensor networks". Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1351.
Texto completoKontak, Max [Verfasser]. "Novel algorithms of greedy-type for probability density estimation as well as linear and nonlinear inverse problems / Max Kontak". Siegen : Universitätsbibliothek der Universität Siegen, 2018. http://d-nb.info/1157094554/34.
Texto completoPester, Cornelia. "A posteriori error estimation for non-linear eigenvalue problems for differential operators of second order with focus on 3D vertex singularities". Doctoral thesis, Berlin Logos-Verl, 2006. http://deposit.ddb.de/cgi-bin/dokserv?id=2806614&prov=M&dok_var=1&dok_ext=htm.
Texto completoPester, Cornelia. "A posteriori error estimation for non-linear eigenvalue problems for differential operators of second order with focus on 3D vertex singularities". Doctoral thesis, Logos Verlag Berlin, 2005. https://monarch.qucosa.de/id/qucosa%3A18520.
Texto completoXiong, Jun. "Set-membership state estimation and application on fault detection". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2013. http://tel.archives-ouvertes.fr/tel-01068054.
Texto completoHavet, Antoine. "Estimation de la loi du milieu d'une marche aléatoire en milieu aléatoire". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX033/document.
Texto completoIntroduced in the 1960s, the model of random walk in i.i.d. environment on integers (or RWRE) raised only recently interest in the statistical community. Various works have in particular focused on the estimation of the environment distribution from a single trajectory of the RWRE.This thesis extends the advances made in those works and offers new approaches to the problem.First, we consider the estimation problem from a frequentist point of view. When the RWRE is transient to the right or recurrent, we build the first non-parametric estimator of the density of the environment distribution and obtain an upper-bound of the associated risk in infinite norm.Then, we consider the estimation problem from a Bayesian perspective. When the RWRE is transient to the right, we prove the posterior consistency of the Bayesian estimator of the environment distribution.The main difficulty of the thesis was to develop the tools necessary to the proof of Bayesian consistency.For this purpose, we demonstrate a quantitative version of a Mac Diarmid's type concentration inequality for Markov chains.We also study the return time to 0 of a branching process with immigration in random environment (or BPIRE). We show the existence of a finite exponential moment uniformly valid on a class of BPIRE. The BPIRE being a Markov chain, this result enables then to make explicit the dependence of the constants of the concentration inequality with respect to the characteristics of the BPIRE
Omar, Oumayma. "Sur la résolution des problèmes inverses pour les systèmes dynamiques non linéaires. Application à l’électrolocation, à l’estimation d’état et au diagnostic des éoliennes". Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENT083/document.
Texto completoThis thesis mainly concerns the resolution of dynamic inverse problems involvingnonlinear dynamical systems. A set of techniques based on the use of trains of pastmeasurements saved on a sliding window was developed. First, the measurements areused to generate a family of graphical signatures, which is a classification tool, in orderto discriminate between different values of variables to be estimated for a given nonlinearsystem. This technique was applied to solve two problems : the electrolocationproblem of a robot with electrical sense and the problem of state estimation in nonlineardynamical systems. Besides these two applications, receding horizon inversion techniquesdedicated to the fault diagnosis problem of a wind turbine proposed as an internationalbenchmark were developed. These techniques are based on the minimization of quadraticcriteria based on knowledge-based models
Cioaca, Alexandru George. "A Computational Framework for Assessing and Optimizing the Performance of Observational Networks in 4D-Var Data Assimilation". Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51795.
Texto completoPh. D.
Gaspar, Jonathan. "Fluxmétrie et caractérisation thermiques instationnaires des dépôts des composants face au plasma du Tokamak JET par techniques inverses". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4739/document.
Texto completoThis work deals with the successive resolution of two inverse heat transfer problems: the estimation of surface heat flux on a material and equivalent thermal conductivity of a surface layer on that material. The direct formulation is bidimensional, orthotropic (real geometry of a composite material), unsteady, non-linear and solved by finite elements. The studied materials are plasma facing components (carbon-carbon composite tiles) from Tokamak JET. The searched heat flux density varies with time and one dimension in space. The surface layers conductivity varies spatially and can vary with time during the experiment (the other thermophysical properties are temperature dependent). The two inverse problems are solved by the conjugate gradient method with the adjoint state method for the exact gradient calculation. The experimental data used for the first inverse problem resolution (surface heat flux estimation) is the thermogram provided by an embedded thermocouple. The second inverse problem uses the space and time variations of the surface temperature of the unknown surface layer (infrared thermography) for the conductivity identification. The confidence calculations associated to the estimated values are done by the Monte Carlo approach. The method developed during this thesis helps to the understanding of the plasma-wall interaction dynamic, as well as the kinetic of the surface carbon layer formation on the plasma facing components, and will be helpful to the design of the components of the future machines (WEST, ITER)
Martins, André Christóvão Pio. "Estimativa do conjunto atrator e da área de atração para o problema de Lure estendido utilizando LMI". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-03022016-161753/.
Texto completoThe stability analysis of nonlinear systems is present in several engineering fields. Usually, the concern is the determination of stable attractor sets and their associated attraction areas. Methods based on the Lyapunov method provide estimates of these sets. However, these methods involve a nonsystematic search for auxiliary functions called Lyapunov functions. This work presents a systematic procedure, based on Lyapunov method, to estimate attractor sets and their associated attraction areas of a class of nonlinear systems, called in this work extended Lure problem. The extended Lure problem consists of nonlinear systems like those of Lure problem where the nonlinear functions can violate the sector conditions around the origin. The developed procedure is based on the extension of invariance LaSalle principle and uses the general Lyapunov functions of Lure problem to estimate the attractor set and their associated attraction area. The parameters of the Lyapunov functions are obtained solving an optimization problem write like a linear matrix inequality (LMI).
Wikström, Gunilla. "Computation of Parameters in some Mathematical Models". Doctoral thesis, Umeå University, Computing Science, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-565.
Texto completoIn computational science it is common to describe dynamic systems by mathematical models in forms of differential or integral equations. These models may contain parameters that have to be computed for the model to be complete. For the special type of ordinary differential equations studied in this thesis, the resulting parameter estimation problem is a separable nonlinear least squares problem with equality constraints. This problem can be solved by iteration, but due to complicated computations of derivatives and the existence of several local minima, so called short-cut methods may be an alternative. These methods are based on simplified versions of the original problem. An algorithm, called the modified Kaufman algorithm, is proposed and it takes the separability into account. Moreover, different kinds of discretizations and formulations of the optimization problem are discussed as well as the effect of ill-conditioning.
Computation of parameters often includes as a part solution of linear system of equations Ax = b. The corresponding pseudoinverse solution depends on the properties of the matrix A and vector b. The singular value decomposition of A can then be used to construct error propagation matrices and by use of these it is possible to investigate how changes in the input data affect the solution x. Theoretical error bounds based on condition numbers indicate the worst case but the use of experimental error analysis makes it possible to also have information about the effect of a more limited amount of perturbations and in that sense be more realistic. It is shown how the effect of perturbations can be analyzed by a semi-experimental analysis. The analysis combines the theory of the error propagation matrices with an experimental error analysis based on randomly generated perturbations that takes the structure of A into account
Schinzinger, Edo [Verfasser]. "Credibility estimation in insurance data: generalized linear models and evolutionary modeling / Edo Schinzinger". Ulm : Universität Ulm. Fakultät für Mathematik und Wirtschaftswissenschaften, 2015. http://d-nb.info/1074196236/34.
Texto completoIossaqui, Juliano Gonçalves 1982. "Técnicas não lineares de controle e filtragem aplicadas ao problema de rastreamento de trajetórias de robôs móveis com deslizamento longitudinal das rodas". [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/262930.
Texto completoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-22T20:54:00Z (GMT). No. of bitstreams: 1 Iossaqui_JulianoGoncalves_D.pdf: 6240978 bytes, checksum: 597b8a76b18670b60a9c6b9804b7b692 (MD5) Previous issue date: 2013
Resumo: Esta tese trata do problema de controle de trajetórias de robôs móveis não holonômicos com deslizamento longitudinal das rodas. As estratégias de controle propostas são projetadas usando dois modelos, um cinemático e um dinâmico, que consideram os deslizamentos longitudinais das rodas como parâmetros desconhecidos. A primeira estratégia de controle consiste em um controlador adaptativo projetado com base em um modelo cinemático que utiliza como entrada de controle, as velocidades angulares das rodas. Essas velocidades angulares são fornecidas por uma lei de controle cinemática que utiliza estimativa dos parâmetros de deslizamento desconhecidos, obtidas por meio de uma lei de adaptação. A segunda estratégia de controle consiste em um controlador adaptativo projetado com base em um modelo dinâmico simplificado que utilizam como entrada de controle, forças de propulsão aplicadas no centro das rodas. A lei de controle, que fornece essas forças, é projetada aplicando-se a técnica backstepping ao modelo dinâmico reduzido, que foi obtido com a utilização do método da dinâmica inversa. Os parâmetros de deslizamento longitudinal desconhecidos, necessários para a utilização do método da dinâmica inversa, são estimados por uma lei de adaptação. O filtro de Kalman unscented também é utilizado para estimar os parâmetros de deslizamento desconhecidos. Essas estimativas são utilizadas, da mesma forma que as estimativas obtidas pela lei de adaptação, nas leis que fornecem as velocidades angulares e as forças de propulsão das rodas. As estratégias propostas, baseadas na teoria de controle adaptativo e na teoria de filtragem, diferenciam-se basicamente pela técnica que utilizam para estimar os parâmetros de deslizamento. No caso das estratégias adaptativas, a estabilidade do sistema em malha fechada é garantida pela teoria de Lyapunov. Simulações numéricas são realizadas para apresentar o desempenho das estratégias de controle propostas em termos do erro de postura do robô para diferentes perfis de deslizamento
Abstract: This thesis deals with the trajectory tracking control problem of nonholonomic mobile robots with longitudinal slip of the wheels. The proposed control strategies are designed using a kinematic model and a dynamic model which consider the longitudinal slip of the wheels as unknown parameters. The first proposed control strategy consists in an adaptive controller based on a kinematic model that uses the wheel angular velocities as control input. These angular velocities are provided by a kinematic control law which uses the unknown slip parameters estimated by an adaptive rule. The second proposed control strategy consists in an adaptive controller based on a simplified dynamic model that uses the thrust forces applied on the center of the wheels as control input. The control law that provides these thrust forces is designed using the backstepping technique applied to a reduced dynamic model obtained using the inverse dynamic method. The unknown longitudinal slip parameters necessary to use the inverse dynamic method are estimated by an adaptation rule. The unscented Kalman filter is also used to estimate the unknown slip parameters. These estimates are used, in the same way as the estimates obtained by the adaptation rule, by the control laws that provide the angular velocities and the thrust forces. The main difference between the proposed control strategies, based on the adaptive control theory and on the filtering theory, is given by the technique used to estimate the slip parameters. In the case of the adaptive strategies, the stability of the closed-loop system is ensured by the Lyapunov theory. Numerical simulations show the performance of the proposed control strategies in terms of the posture error of the robot with different wheels slip profiles
Doutorado
EUVRARD, GUILLAUME. "Estimation d'une regression non lineaire par reseaux de neurones; application a un probleme de robotique mobile". Paris 6, 1993. http://www.theses.fr/1993PA066087.
Texto completoIwaza, Lana. "Joint Source-Network Coding & Decoding". Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112048/document.
Texto completoWhile network data transmission was traditionally accomplished via routing, network coding (NC) broke this rule by allowing network nodes to perform linear combinations of the upcoming data packets. Network operations are performed in a specific Galois field of fixed size q. Decoding only involves a Gaussian elimination with the received network-coded packets. However, in practical wireless environments, NC might be susceptible to transmission errors caused by noise, fading, or interference. This drawback is quite problematic for real-time applications, such as multimediacontent delivery, where timing constraints may lead to the reception of an insufficient number of packets and consequently to difficulties in decoding the transmitted sources. At best, some packets can be recovered, while in the worst case, the receiver is unable to recover any of the transmitted packets.In this thesis, we propose joint source-network coding and decoding schemes in the purpose of providing an approximate reconstruction of the source in situations where perfect decoding is not possible. The main motivation comes from the fact that source redundancy can be exploited at the decoder in order to estimate the transmitted packets, even when some of them are missing. The redundancy can be either natural, i.e, already existing, or artificial, i.e, externally introduced.Regarding artificial redundancy, we choose multiple description coding (MDC) as a way of introducing structured correlation among uncorrelated packets. By combining MDC and NC, we aim to ensure a reconstruction quality that improves gradually with the number of received network-coded packets. We consider two different approaches for generating descriptions. The first technique consists in generating multiple descriptions via a real-valued frame expansion applied at the source before quantization. Data recovery is then achieved via the solution of a mixed integerlinear problem. The second technique uses a correlating transform in some Galois field in order to generate descriptions, and decoding involves a simple Gaussian elimination. Such schemes are particularly interesting for multimedia contents delivery, such as video streaming, where quality increases with the number of received descriptions.Another application of such schemes would be multicasting or broadcasting data towards mobile terminals experiencing different channel conditions. The channel is modeled as a binary symmetric channel (BSC) and we study the effect on the decoding quality for both proposed schemes. Performance comparison with a traditional NC scheme is also provided.Concerning natural redundancy, a typical scenario would be a wireless sensor network, where geographically distributed sources capture spatially correlated measures. We propose a scheme that aims at exploiting this spatial redundancy, and provide an estimation of the transmitted measurement samples via the solution of an integer quadratic problem. The obtained reconstruction quality is compared with the one provided by a classical NC scheme
SOUHAIL, Hicham. "Schema volumes finis : Estimation d'erreur a posteriori hierarchique par elements finis mixtes. Resolution de problemes d'elasticite non-linearie". Phd thesis, Ecole Centrale de Lyon, 2004. http://tel.archives-ouvertes.fr/tel-00005418.
Texto completoLa partie 2 introduit, d'abord un maillage rectangulaire, puis un maillage structure, une famille de schemas volumes finis de type differences finies. Des essais numeriques sur des problemes modeles montrent que l'ordre prevu par l'analyse peut etre atteint.
La partie 3 presente l'application de ces schemas volumes finis a la simulation numerique du comportement d'un bloc de gomme en presence d'une fissure finie. Il s'agit d'un materiau hyperelastique compressible en grandes deformations et differents tenseurs de contraintes, avec tests en quasi-incompressible et des simulations d'endommagement.
Marnitz, Philipp [Verfasser], Axel [Akademischer Betreuer] Munk, Russell [Akademischer Betreuer] Luke y Thorsten [Akademischer Betreuer] Hohage. "Statistical multiresolution estimatiors in linear inverse problems - foundations and algorithmic aspects / Philipp Marnitz. Gutachter: Axel Munk ; Russell Luke ; Thorsten Hohage. Betreuer: Axel Munk". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2010. http://d-nb.info/1043515356/34.
Texto completoMarnitz, Philipp Verfasser], Axel [Akademischer Betreuer] [Munk, Russell [Akademischer Betreuer] Luke y Thorsten [Akademischer Betreuer] Hohage. "Statistical multiresolution estimatiors in linear inverse problems - foundations and algorithmic aspects / Philipp Marnitz. Gutachter: Axel Munk ; Russell Luke ; Thorsten Hohage. Betreuer: Axel Munk". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2010. http://d-nb.info/1043515356/34.
Texto completoCherfils, Laurence. "Méthode de cheminement adaptative pour les problèmes semi-linéaires dépendant d'un paramètre". Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10105.
Texto completoShikhar. "COMPRESSIVE IMAGING FOR DIFFERENCE IMAGE FORMATION AND WIDE-FIELD-OF-VIEW TARGET TRACKING". Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194741.
Texto completoMarushkevych, Dmytro. "Asymptotic study of covariance operator of fractional processes : analytic approach with applications". Thesis, Le Mans, 2019. http://www.theses.fr/2019LEMA1010/document.
Texto completoEigenproblems frequently arise in theory and applications of stochastic processes, but only a few have explicit solutions. Those which do are usually solved by reduction to the generalized Sturm-Liouville theory for differential operators.The more general eigenproblems are not solvable in closed form and the subject of this thesis is the asymptotic spectral analysis of the fractional Gaussian processes and its applications.In the first part, we develop methodology for the spectral analysis of the fractional type covariance operators, corresponding to an important family of processes that includes the fractional Ornstein-Uhlenbeck process, the integrated fractional Brownian motion and the mixed fractional Brownian motion. We obtain accurate second order asymptotic approximations for both the eigenvalues and the eigenfunctions. In Chapter 2 we consider the covariance eigenproblem for Gaussian bridges. We show how the spectral asymptotics of a bridge can bederived from that of its base process, considering, as an example, the case of the fractional Brownian bridge. In the final part we consider three representative applications of the developed theory: filtering problem of fractional Gaussian signals in white noise, large deviation properties of the maximum likelihood drift parameter estimator for the Ornstein-Uhlenbeck process driven by mixed fractional Brownian motion and small ball probabilities for the fractional Gaussian processes
Corrêa, Eduardo Dias. "Estimativas a priori para problemas não lineares de condução de calor, com o uso da transformada de Kirchhoff". Universidade do Estado do Rio de Janeiro, 2014. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=7693.
Texto completoEste trabalho apresenta uma estimativa a priori para o limite superior da distribuição de temperatura considerando um problema em regime permanente em um corpo com uma condutividade térmica dependente da temperatura. A discussão é realizada supondo que as condições de contorno são lineares (lei de Newton do resfriamento) e que a condutividade térmica é constante por partes (quando considerada como uma função da temperatura). Estas estimativas consistem em uma ferramenta poderosa que pode prescindir da necessidade de uma simulação numérica cara de um problema de transferência de calor não linear, sempre que for suficiente conhecer o valor mais alto de temperatura. Nestes casos, a metodologia proposta neste trabalho é mais eficaz do que as aproximações usuais que assumem tanto a condutividade térmica quanto as fontes de calor como constantes.
This article presents an a priori upper bound estimate for the steady-state temperature distribution in a body with a temperature-dependent thermal conductivity. The discussion is carried out assuming linear boundary conditions (Newton law of cooling) and a piecewise constant thermal conductivity (when regarded as a function of the temperature). These estimates consist of a powerful tool that may circumvent an expensive numerical simulation of a nonlinear heat transfer problem, whenever it suffices to know the highest temperature value. In these cases the methodology proposed in this work is more effective than the usual approximations that assume thermal conductivities and heat sources as constants.
Iwaza, Lana y Lana Iwaza. "Joint Source-Network Coding & Decoding". Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00855787.
Texto completoPřibyl, Bronislav. "Odhad pózy kamery z přímek pomocí přímé lineární transformace". Doctoral thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2018. http://www.nusl.cz/ntk/nusl-412595.
Texto completoBraga, Josà Ederson Melo. "Problemas variacionais de fronteira livre com duas fases e resultados do tipo PhragmÃn-Lindelof regidos por equaÃÃes elÃpticas nÃo lineares singulares/degeneradas". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15623.
Texto completoNeste trabalho de tese discutimos resultados recentes sobre a regularidade e propriedades geomÃtricas de soluÃÃes variacionais de problemas de fronteira livre de duas fases regidos por equaÃÃes elÃpticas nÃo lineares degeneradas/singulares. Discutimos tambÃm resultados do tipo PhragmÃm-Lindelof para tais equaÃÃes classificando essas soluÃÃes em semi-espaÃos.
In this work of thesis we discuss recents results on the regularity and geometric properties of variational solutions of two phase free boundary problems governed by singular/degenerate nonlinear elliptic equations. We also discuss PhragmÃn-Lindelof type results for such equations classifying those solutions in half spaces.
In this work of thesis we discuss recents results on the regularity and geometric properties of variational solutions of two phase free boundary problems governed by singular/degenerate nonlinear elliptic equations. We also discuss PhragmÃn-Lindelof type results for such equations classifying those solutions in half spaces.
Schorsch, Julien. "Contributions à l'estimation paramétrique des modèles décrits par les équations aux dérivées partielles". Phd thesis, Université de Lorraine, 2013. http://tel.archives-ouvertes.fr/tel-00913579.
Texto completoBringmann, Philipp. "Adaptive least-squares finite element method with optimal convergence rates". Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22350.
Texto completoThe least-squares finite element methods (LSFEMs) base on the minimisation of the least-squares functional consisting of the squared norms of the residuals of first-order systems of partial differential equations. This functional provides a reliable and efficient built-in a posteriori error estimator and allows for adaptive mesh-refinement. The established convergence analysis with rates for adaptive algorithms, as summarised in the axiomatic framework by Carstensen, Feischl, Page, and Praetorius (Comp. Math. Appl., 67(6), 2014), fails for two reasons. First, the least-squares estimator lacks prefactors in terms of the mesh-size, what seemingly prevents a reduction under mesh-refinement. Second, the first-order divergence LSFEMs measure the flux or stress errors in the H(div) norm and, thus, involve a data resolution error of the right-hand side f. These difficulties led to a twofold paradigm shift in the convergence analysis with rates for adaptive LSFEMs in Carstensen and Park (SIAM J. Numer. Anal., 53(1), 2015) for the lowest-order discretisation of the 2D Poisson model problem with homogeneous Dirichlet boundary conditions. Accordingly, some novel explicit residual-based a posteriori error estimator accomplishes the reduction property. Furthermore, a separate marking strategy in the adaptive algorithm ensures the sufficient data resolution. This thesis presents the generalisation of these techniques to three linear model problems, namely, the Poisson problem, the Stokes equations, and the linear elasticity problem. It verifies the axioms of adaptivity with separate marking by Carstensen and Rabus (SIAM J. Numer. Anal., 55(6), 2017) in three spatial dimensions. The analysis covers discretisations with arbitrary polynomial degree and inhomogeneous Dirichlet and Neumann boundary conditions. Numerical experiments confirm the theoretically proven optimal convergence rates of the h-adaptive algorithm.
Richardson, Alice. "Some problems in estimation in mixed linear models". Phd thesis, 1995. http://hdl.handle.net/1885/133644.
Texto completoSuliman, Mohamed Abdalla Elhag. "Regularization Techniques for Linear Least-Squares Problems". Thesis, 2016. http://hdl.handle.net/10754/609160.
Texto completoBALLERINI, VERONICA. "Fisher's noncentral hypergeometric distribution and population size estimation problems". Doctoral thesis, 2021. http://hdl.handle.net/11573/1563206.
Texto completoMatić, Rada. "Estimation Problems Related to Random Matrix Ensembles". Doctoral thesis, 2006. http://hdl.handle.net/11858/00-1735-0000-0006-B406-B.
Texto completoAbarin, Taraneh. "Second-order least squares estimation in regression models with application to measurement error problems". 2009. http://hdl.handle.net/1993/3126.
Texto completoFebruary 2009
Sawlan, Zaid A. "Statistical Analysis and Bayesian Methods for Fatigue Life Prediction and Inverse Problems in Linear Time Dependent PDEs with Uncertainties". Diss., 2018. http://hdl.handle.net/10754/629731.
Texto completoPester, Cornelia [Verfasser]. "A posteriori error estimation for non-linear eigenvalue problems for differential operators of second order with focus on 3D vertex singularities / vorgelegt von Cornelia Pester". 2006. http://d-nb.info/980933056/34.
Texto completoScoleri, Tony. "Fundamental numerical schemes for parameter estimation in computer vision". 2008. http://hdl.handle.net/2440/50726.
Texto completoThesis (Ph.D.) - University of Adelaide, School of Mathemtical Sciences, Discipline of Pure Mathematics, 2008
Liu, Te-Wei y 劉得偉. "An Inverse Vibration Problem of Estimating Coefficients of Stiffness and Damping for the Multiple Degrees of Freedom System with Non-linear External Forces". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/13939892173889638651.
Texto completo國立高雄應用科技大學
模具工程系
99
In this study the Beck’s nonlinear estimation procedure coupled with Runge-Kutta method is applied to solve the reverse of multiple degrees of freedom with nonlinear external force vibration problems. The sensitivity coefficients of Beck’s nonlinear estimation procedure are modified by the fourth-order Runge-Kutta numerical method, improves the accuracy of the program to accelerate the iteration convergence rate, and so reverse forecast multiple unknown stiffness and damping coefficients. Baker's estimate of the original program is a non-linear first-order Taylor series of precision, and this research is an amendment to Baker's non-linear estimation procedures to enhance the accuracy of four-order Taylor series. Beck's nonlinear estimation procedure is applied with Runge-Kutta numerical method, reverse to solve sets of unknown spring and damping factor, is a major innovative features of this study. The convergence rate is better than the original Baker's non-linear estimation procedures, is a major focus of development in this study. The results showed that the inverse algorithm for solving the cases of three non-linear force able to effectively improve the original Beck's nonlinear estimation procedure, the best convergence rate can be increased to 33.3%. From the numerical computation of the elasticity and damping, compare with the exact solutions under the measurement errors on the assumption that 1%, 5% and 10% of the conditions, the real percentage of error are less than 0.9%, 4.5% and 9.2%, and the measurement error is proportional to the percentage of the real error.