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Estruturas unidimensionais e bidimensionais utilizando P-splines nos modelos mistos aditivos generalizados com aplicação na produção de cana-de-açúcar / Unidimensional and bidimensional structures using P-splines in generalized additive mixed models with application in the production of sugarcaneRondinel Mendoza, Natalie Veronika 29 November 2017 (has links)
Os P-splines de Eilers e Marx (1996) são métodos de suavização que é uma combinação de bases B-splines e uma penalização discreta sobre os coeficientes das bases utilizados para suavizar dados normais e não normais em uma ou mais dimensões, no caso de várias dimensões utiliza-se como suavização o produto tensor dos P-splines. Também os P-splines são utilizados como representação de modelos mistos Currie et al. (2006) pela presença de características tais como: efeitos fixos, efeitos aleatórios, correlação espacial ou temporal e utilizados em modelos mais generalizados tais como os modelos mistos lineares generalizados e modelos mistos aditivos generalizados. Neste trabalho apresentou-se toda a abordagem, metodologia e descrição dos P-splines como modelos mistos e como componentes das estruturas suavizadoras de variáveis unidimensionais e bidimensionais dos modelos mistos aditivos generalizados, mostrando essa abordagem e propondo seu uso em uma aplicação no comportamento dos níveis médios da produção de cana-de-açúcar sob a influência das alterações das variáveis climáticas como temperatura e precipitação, que foram medidos ao longo de 10 anos em cada mesorregião do Estado de São Paulo. O motivo de usar essa abordagem como método de suavização é que muitas vezes não é conhecido a tendência dessas covariáveis climáticas mas sabe-se que elas influenciam diretamente sobre a variável resposta. Além de permitir essa abordagem inclusão de efeitos fixos e aleatórios nos modelos a serem propostos, permitirá a inclusão do processo autoregressivo AR(1) como estrutura de correlação nos resíduos. / P-splines of Eilers e Marx (1996) are methods of smoothing that is a combination of B-splines bases and penalty the coefficients of the bases used to smooth normal and non-normal data in one or more dimensions; in the case of several dimensions it is used as smoothing the tensor product of the P-splines. Also the P-splines are used as representation of mixed models Currie et al. (2006) by the presence of characteristics such as: fixed effects, random effects, spatial or temporal correlation and used in more generalized models such as generalized linear mixed models and generalized additive mixed models. In this work the whole approach, methodology and description of the P-splines as mixed models and as components of the smoothing structures of one-dimensional and two-dimensional variables of generalized additive mixed models were presented, showing this approach and proposing its application in the behavior of the average levels of sugarcane production, which is influenced by changes in climatic variables such as temperature and precipitation , which were measured over 10 years in each mesoregion of the state of São Paulo. The reason for using this approach as a smoothing method is that the tendency of these climate covariables is not know for the most part, but is known that they influence directly the response variable, besides allowing this approach to include fixed and random effects in the models to be proposed, will allow the inclusion of the autoregressive process AR(1) as a correlation structure in the residuos.
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Deconvolution of variable rate reservoir performance data using B-splinesIlk, Dilhan 25 April 2007 (has links)
This work presents the development, validation and application of a novel deconvolution method based on
B-splines for analyzing variable-rate reservoir performance data. Variable-rate deconvolution is a
mathematically unstable problem which has been under investigation by many researchers over the last 35
years. While many deconvolution methods have been developed, few of these methods perform well in
practice - and the importance of variable-rate deconvolution is increasing due to applications of
permanent downhole gauges and large-scale processing/analysis of production data. Under these
circumstances, our objective is to create a robust and practical tool which can tolerate reasonable
variability and relatively large errors in rate and pressure data without generating instability in the
deconvolution process.
We propose representing the derivative of unknown unit rate drawdown pressure as a weighted sum of Bsplines
(with logarithmically distributed knots). We then apply the convolution theorem in the Laplace
domain with the input rate and obtain the sensitivities of the pressure response with respect to individual
B-splines after numerical inversion of the Laplace transform. The sensitivity matrix is then used in a
regularized least-squares procedure to obtain the unknown coefficients of the B-spline representation of
the unit rate response or the well testing pressure derivative function. We have also implemented a
physically sound regularization scheme into our deconvolution procedure for handling higher levels of
noise and systematic errors.
We validate our method with synthetic examples generated with and without errors. The new method can
recover the unit rate drawdown pressure response and its derivative to a considerable extent, even when
high levels of noise are present in both the rate and pressure observations. We also demonstrate the use of
regularization and provide examples of under and over-regularization, and we discuss procedures for
ensuring proper regularization. Upon validation, we then demonstrate our deconvolution method using a variety of field cases.
Ultimately, the results of our new variable-rate deconvolution technique suggest that this technique has a
broad applicability in pressure transient/production data analysis. The goal of this thesis is to demonstrate
that the combined approach of B-splines, Laplace domain convolution, least-squares error reduction, and
regularization are innovative and robust; therefore, the proposed technique has potential utility in the
analysis and interpretation of reservoir performance data.
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Représentation d'objets flexibles avec contact et frictionDegila, Gbetondji Jules Richard. January 1999 (has links)
Thèses (M.Sc.)--Université de Sherbrooke (Canada), 1999. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.
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Spatially adaptive priors for regression and spatial modelingYue, Yu, January 2008 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 3, 2009) Vita. Includes bibliographical references.
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Estruturas unidimensionais e bidimensionais utilizando P-splines nos modelos mistos aditivos generalizados com aplicação na produção de cana-de-açúcar / Unidimensional and bidimensional structures using P-splines in generalized additive mixed models with application in the production of sugarcaneNatalie Veronika Rondinel Mendoza 29 November 2017 (has links)
Os P-splines de Eilers e Marx (1996) são métodos de suavização que é uma combinação de bases B-splines e uma penalização discreta sobre os coeficientes das bases utilizados para suavizar dados normais e não normais em uma ou mais dimensões, no caso de várias dimensões utiliza-se como suavização o produto tensor dos P-splines. Também os P-splines são utilizados como representação de modelos mistos Currie et al. (2006) pela presença de características tais como: efeitos fixos, efeitos aleatórios, correlação espacial ou temporal e utilizados em modelos mais generalizados tais como os modelos mistos lineares generalizados e modelos mistos aditivos generalizados. Neste trabalho apresentou-se toda a abordagem, metodologia e descrição dos P-splines como modelos mistos e como componentes das estruturas suavizadoras de variáveis unidimensionais e bidimensionais dos modelos mistos aditivos generalizados, mostrando essa abordagem e propondo seu uso em uma aplicação no comportamento dos níveis médios da produção de cana-de-açúcar sob a influência das alterações das variáveis climáticas como temperatura e precipitação, que foram medidos ao longo de 10 anos em cada mesorregião do Estado de São Paulo. O motivo de usar essa abordagem como método de suavização é que muitas vezes não é conhecido a tendência dessas covariáveis climáticas mas sabe-se que elas influenciam diretamente sobre a variável resposta. Além de permitir essa abordagem inclusão de efeitos fixos e aleatórios nos modelos a serem propostos, permitirá a inclusão do processo autoregressivo AR(1) como estrutura de correlação nos resíduos. / P-splines of Eilers e Marx (1996) are methods of smoothing that is a combination of B-splines bases and penalty the coefficients of the bases used to smooth normal and non-normal data in one or more dimensions; in the case of several dimensions it is used as smoothing the tensor product of the P-splines. Also the P-splines are used as representation of mixed models Currie et al. (2006) by the presence of characteristics such as: fixed effects, random effects, spatial or temporal correlation and used in more generalized models such as generalized linear mixed models and generalized additive mixed models. In this work the whole approach, methodology and description of the P-splines as mixed models and as components of the smoothing structures of one-dimensional and two-dimensional variables of generalized additive mixed models were presented, showing this approach and proposing its application in the behavior of the average levels of sugarcane production, which is influenced by changes in climatic variables such as temperature and precipitation , which were measured over 10 years in each mesoregion of the state of São Paulo. The reason for using this approach as a smoothing method is that the tendency of these climate covariables is not know for the most part, but is known that they influence directly the response variable, besides allowing this approach to include fixed and random effects in the models to be proposed, will allow the inclusion of the autoregressive process AR(1) as a correlation structure in the residuos.
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Tools for the simulation and analysis of aerodynamic modelsAndrew, Steven Paul January 1999 (has links)
No description available.
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Utilisation de la méthode de validation croisée pour le lissage par fonctions Spline à une ou deux variablesUtreras, Florencio 11 May 1979 (has links) (PDF)
Lissage à une variable : les methodes de choix du paramètre d'ajustement, réalisation pratique de la méthode de validation croisée, expériences numériques, optimalité à asymptotique de la méthode de validation croisée, un procédé de lissage pour un grand nombre de nœuds. le lissage à 2 variables : étude des valeurs propres associées aux fonctions splines bidimensionnelles, les fonctions spline bicubiques, expérience numérique à 2 variables
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Modeling Stokes Flow Using Hierarchical Structure-Preserving B-SplinesShepherd, Kendrick Monroe 01 March 2015 (has links) (PDF)
A new spline space, the hierarchical structure-preserving B-spline space, is introduced and implemented in the analysis of Stokes flow. The space, when properly constrained, is shown to be stable and to have at least optimal convergence rates in the velocity field and suboptimal convergence rates in the pressure field. However, results show that superoptimal convergence can often be expected in the pressure field, likely due to error reduction in the velocity field. Like other hierarchical spline spaces, these splines are shown to greatly increase accuracy and to drastically lower computation times for analyses on domains whose solution fields have singularities or could otherwise benefit from local refinement. With the advent of this adaptive, locally-refineable, high-fidelity technology, isogeometric methods can become more feasible for use in fluid analyses.
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Chaînes de Markov régulées et approximation de Poisson pour l'analyse de séquences biologiquesVergne, Nicolas Prum, Bernard. January 2008 (has links) (PDF)
Thèse de doctorat : Mathématiques appliquées : Evry-Val d'Essonne : 2008. / Titre provenant de l'écran-titre.
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Application des techniques mathématique [sic] à la gestion des mélangesSlaoui Hasnaoui, Khalid Laurent, Pierre Jean January 2008 (has links)
Reproduction de : Thèse de docteur-ingénieur : mathématiques appliquées : Grenoble INPG : 1986. / Titre provenant de l'écran-titre. Bibliogr. p.xxx-xxx. Index.
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