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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Statistická klasifikace pomocí zobecněných lineárních modelů. / Statistical Classification by means of generalized linear models

Sladká, Vladimíra January 2010 (has links)
The goal of this thesis is introduce the theory of generalized linear models, namely probit and logit model. This models are especially used for medical data processing. In our concrete case these mentioned models are applied to data file obtained in teaching hospital Brno. The aim is statically analyzed immune response of child patients in dependence of twelve selected types of genes and find out which combinations of these genes influence septic state of patients.
42

Inference in Generalized Linear Models with Applications

Byrne, Evan 29 August 2019 (has links)
No description available.
43

Tests pour la dépendance entre les sections dans un modèle de Poisson

Roussel, Arnaud 05 1900 (has links)
Les simulations et figures ont été réalisées avec le logiciel R. / Pour des données de panel, les mesures répétées dans le temps peuvent remettre en cause l’hypothèse d’indépendance entre les individus. Des tests ont été développés pour pouvoir vérifier s’il reste de la dépendance entre les résidus d’un modèle. Les trois tests que nous présentons dans ce mémoire sont ceux de Pesaran (2004), Friedman (1937) et Frees (1995). Ces trois tests se basent sur les résidus (et leurs corrélations) et ont été construits pour des modèles linéaires. Nous voulons étudier dans ce mémoire les performances de ces trois tests dans le cadre d’un modèle linéaire généralisé de Poisson. Dans ce but, on compare tout d’abord leurs performances (niveaux et puissances) pour deux modèles linéaires, l’un ayant un terme autorégressif et l’autre non. Par la suite, nous nous intéressons à leurs performances pour un modèle linéaire généralisé de Poisson en s’inspirant de Hsiao, Pesaran et Pick (2007) qui adaptent le test de Pesaran (2004) pour un modèle linéaire généralisé. Toutes nos comparaisons de performances se feront à l’aide de simulations dans lesquelles nous ferons varier un certain nombre de paramètres (nombre d’observations, force de la dépendance, etc.). Nous verrons que lorsque les corrélations sont toutes du même signe, le test de Pesaran donne en général de meilleurs résultats, à la fois dans les cas linéaires et pour le modèle linéaire généralisé. Le test de Frees présentera de bonnes propriétés dans le cas où le signe des corrélations entre les résidus alterne. / For panel data, repeated measures over time can challenge the hypothesis of dependence between subjects. Tests were developped in order to assess if some dependence remains among residuals. The three tests we present in this master thesis are from Pesaran (2004), Friedman (1937) and Frees (1995). These three tests, constructed specifically for linear models, are based on the residuals generated from models (and their correlations). We wish to study in this master thesis the performances of these three tests in the case of generalized linear Poisson models. For that goal, we compare them between each other (level, power, etc.) using two linear models, one with an autoregressive term and the other without. Next, inspired by Hsiao, Pesaran and Pick (2007) who adapt the test from Pesaran (2004), we will study their performances in a generalized Poisson model. All of our comparisons are done with simulations by modifying some variables (number of observations, strength of the dependence). We will observe that when the correlation is always of the same sign, Pesaran’s test is the best in most cases, for the linear models and the generalized linear model. Frees’ test will show good performances when the sign of the correlations alternates.
44

Spotřební chování / Consumer Behaviour

Babáková, Andrea January 2010 (has links)
The thesis focuses on investigating and searching for differences between consumer behavior of Czech and Slovak households depending on chosen socioeconomic factors. For the purpose of this thesis source materials are taken mainly from researches realized by Czech and Slovak Statistical Office, specifically from survey sampling Household Budget Study 2009. Data are analyzed through the use of comprehensive characteristics of location, variability and box diagrams. Generalized linear models are used for modeling dependence of consumer behavior on chosen quantitative and qualitative factors. Household consumer behavior is expressed through economic index - propensity to consume - which is determined by the share of total monthly income and expenditures.
45

Relação entre poluição do ar e internações de adultos por doenças cardiovasculares totais em São Paulo entre 2000 e 2013

Bezerra, Yuri Charllub Pereira 30 January 2017 (has links)
Submitted by Rosina Valeria Lanzellotti Mattiussi Teixeira (rosina.teixeira@unisantos.br) on 2017-04-10T12:24:50Z No. of bitstreams: 1 Yuri C. Pereira Bezerra.pdf: 1511197 bytes, checksum: 07b7896685114a1850da4781cd9b97e8 (MD5) / Made available in DSpace on 2017-04-10T12:24:50Z (GMT). No. of bitstreams: 1 Yuri C. Pereira Bezerra.pdf: 1511197 bytes, checksum: 07b7896685114a1850da4781cd9b97e8 (MD5) Previous issue date: 2017-01-30 / This observational, ecological time series study aims to verify the relationship between adult hospitalizations for total cardiovascular diseases (CVDD) and air pollution stratified by sex in residents of the city of São Paulo from 2000 to 2013, observing their Structure of lag. Analyzes were stratified by age group and sex and included hospitalizations for Total Cardiovascular Diseases (ICD10: Chapter IX - I00-I99). The pollutant and meteorological data were provided by the Environmental Sanitation Technology Company of the State of São Paulo. The relationship between air pollutants and climatic factors in hospitalizations for Total Cardiovascular Diseases was analyzed by means of a polynomial distribution lag model for both temperature and air pollutants with a lag structure of up to 6 days after exhibition. Generalized linear models of Poisson regression were used, controlling for long-term seasonality, days of the week, and holidays. The following was calculated the increase in the number of hospitalizations for the interquartile difference of the pollutants significant in the regression model, as well as for the meteorological factors. For all hospital admissions for Total Cardiovascular Diseases, acute short-term effects were observed. The O3 was the only pollutant that did not have any relation to any of the analyzed results and NO2 had the greater effect, for an increase of interquartile 50.22 ¿g / m 3 of NO2, an increase of 13.09% (IC95 %: 4.74% - 21.45%), among the total admissions from 30 to 44 years. Stratifying the analysis by age group, a greater effect was found for hospitalizations from 45 to 60 years. Regarding gender, between the age group 30 and 44, the men stood out, and for the 45-60 age group, the women were more affected than the men. / Este estudo observacional, ecológico de series temporais tem por objetivo de verificar a relação entre internações de adultos por doenças cardiovasculares totais (DCVT) e poluição do ar estratificado por sexo, em residentes do município de São Paulo no período de 2000 a 2013, observando sua estrutura de defasagem. As analises foram estratificadas por faixa etária e sexo e incluíram internações por Doenças Cardiovasculares Totais (CID10: capítulo IX - I00-I99). Os dados de poluentes e meteorológicos foram fornecidos pela Companhia de Tecnologia de Saneamento Ambiental do Estado de São Paulo. A relação entre poluentes do ar e fatores climáticos nas internações por Doenças Cardiovasculares Totais, foram analisadas por meio de um modelo de defasagem de distribuição polinomial tanto para a temperatura como para os poluentes do ar, com uma estrutura de defasagem de até 6 dias após a exposição. Foram utilizados modelos lineares generalizados de regressão de Poisson, controlando-se para sazonalidade de longa duração, dias da semana e feriados. A seguir foi calculado o aumento no número de internações para a diferença interquartil dos poluentes significativos no modelo de regressão, bem como para os fatores meteorológicos. Para todas as admissões hospitalares por Doenças Cardiovasculares Totais, foram observados efeitos agudos de curta duração. O O3 foi o único poluente que não teve relação a nenhum dos desfechos analisados e o NO2 foi o que teve o efeito maior, para um aumento de interquartil 50,22 µg/m³ de NO2, revelou um aumento de 13,09% (IC95%: 4,74% - 21,45%), entre as internações totais de 30 a 44 anos. Estratificando a análise por faixa etária, encontrou-se um maior efeito para as internações de 45 a 60 anos. No que diz respeito ao sexo, entre a faixa etária 30 a 44, sobressaíram os homens, e para a faixa etária de 45 a 60 anos, as mulheres foram mais afetadas que os homens.
46

Novel Statistical Methods in Quantitative Genetics : Modeling Genetic Variance for Quantitative Trait Loci Mapping and Genomic Evaluation

Shen, Xia January 2012 (has links)
This thesis develops and evaluates statistical methods for different types of genetic analyses, including quantitative trait loci (QTL) analysis, genome-wide association study (GWAS), and genomic evaluation. The main contribution of the thesis is to provide novel insights in modeling genetic variance, especially via random effects models. In variance component QTL analysis, a full likelihood model accounting for uncertainty in the identity-by-descent (IBD) matrix was developed. It was found to be able to correctly adjust the bias in genetic variance component estimation and gain power in QTL mapping in terms of precision.  Double hierarchical generalized linear models, and a non-iterative simplified version, were implemented and applied to fit data of an entire genome. These whole genome models were shown to have good performance in both QTL mapping and genomic prediction. A re-analysis of a publicly available GWAS data set identified significant loci in Arabidopsis that control phenotypic variance instead of mean, which validated the idea of variance-controlling genes.  The works in the thesis are accompanied by R packages available online, including a general statistical tool for fitting random effects models (hglm), an efficient generalized ridge regression for high-dimensional data (bigRR), a double-layer mixed model for genomic data analysis (iQTL), a stochastic IBD matrix calculator (MCIBD), a computational interface for QTL mapping (qtl.outbred), and a GWAS analysis tool for mapping variance-controlling loci (vGWAS).
47

Novel Statistical Methods in Quantitative Genetics : Modeling Genetic Variance for Quantitative Trait Loci Mapping and Genomic Evaluation

Shen, Xia January 2012 (has links)
This thesis develops and evaluates statistical methods for different types of genetic analyses, including quantitative trait loci (QTL) analysis, genome-wide association study (GWAS), and genomic evaluation. The main contribution of the thesis is to provide novel insights in modeling genetic variance, especially via random effects models. In variance component QTL analysis, a full likelihood model accounting for uncertainty in the identity-by-descent (IBD) matrix was developed. It was found to be able to correctly adjust the bias in genetic variance component estimation and gain power in QTL mapping in terms of precision.  Double hierarchical generalized linear models, and a non-iterative simplified version, were implemented and applied to fit data of an entire genome. These whole genome models were shown to have good performance in both QTL mapping and genomic prediction. A re-analysis of a publicly available GWAS data set identified significant loci in Arabidopsis that control phenotypic variance instead of mean, which validated the idea of variance-controlling genes.  The works in the thesis are accompanied by R packages available online, including a general statistical tool for fitting random effects models (hglm), an efficient generalized ridge regression for high-dimensional data (bigRR), a double-layer mixed model for genomic data analysis (iQTL), a stochastic IBD matrix calculator (MCIBD), a computational interface for QTL mapping (qtl.outbred), and a GWAS analysis tool for mapping variance-controlling loci (vGWAS).
48

Crescimento de espécies florestais madeiráveis como subsídio para o manejo florestal na Amazônia ocidental / Growth of forest timber species as improvements to the forest management in western Amazon

Cunha, Thiago Augusto da 25 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Reliable growth data from trees are very important in the context of forest management. Tree-characteristics such as architecture and competition are associated with diameter growth. Previous studies analyzing tree growth changes have indicated that these variables can describe these effects more effectively. However, the precise role of these effects in the growth modeling of tropical trees needs to be studied further to discuss more effectively the actual forest management practices. Here, we reconstructed the periodic annual basal area increment (IPAg) of four long-lived timber species from the Amazon forest: Cedro (Cedrela odorata); Cerejeira (Amburana cearensis); Copaíba (Copaifera paupera) e Mogno (Swietenia macrophylla) aiming to explain the IPAg variation by developing a individua-tree growth model using the following potential predictors: tree size, morphometric data, competition; crown position and liana load. The model was fitted using a Gamma distribution in the context of Generalized Linear Models. The statistics criteria and residual distributions showed that growth model was adequate to adjust the observed IPAg data and revealed some dendrometric variables that were involved into the effects that lead the observed variation in IPAg, presenting a broad range of the observed data in situations were growth is complex and variable between species. Trees sampled in good site conditions - expressed as a good crown exposure to light, and therefore low competition - presented higher growth rates than trees sampled under high competition from neighboring trees. Besides, the variables Liana load, for Cedrela, the crown diameter and the Hegyi competition index was demonstrated to be highly influential predictive variable. Also, trees sampled in densities greater than 25 m2.ha-1 had their IPAg% significantly reduced. In the context of basal area increment yield by the space occupied in the forest (crown efficiency) the species presented mostly efficiency when growth in dominant position with thin and long crown (crown formal). Among the species, Cedrela odorata was the most efficient in growth. This behavior reinforces the importance of release trees to obtain better crown exposure. / Dados confiáveis de crescimento de árvores são muito importantes no contexto do manejo florestal. Características próprias da árvore como a arquitetura e a competição estão associadas diretamente com o crescimento em diâmetro e altura. Estudos anteriores indicaram que essas variáveis podem descrever a variação do incremento. No entanto, o efeito dessas variáveis na modelagem do crescimento de árvores tropicais precisa ser mais bem estudado, para discutir efetivamente as praticas de manejo florestal atuais. Portanto, nessa pesquisa reconstruiu-se o incremento periódico anual em área basal (IPAg) de quatro espécies de árvores madeiráveis de vida longa da Amazônia: Cedro (Cedrela odorata); Cerejeira (Amburana cearensis); Copaíba (Copaifera paupera) e Mogno (Swietenia macrophylla) com o objetivo de explicar a variação de IPAg, propondo um modelo de crescimento tipo de árvore individual utilizando os seguintes preditores potenciais: tamanho e morfometria da árvore; o status competitivo; a posição social e a carga de lianas na copa. O modelo foi ajustado considerando a distribuição de probabilidade Gama no contexto de Modelo Linear Generalizado. Em base a critérios estatísticos e avaliação residual, o modelo de crescimento demonstrou ser adequado para explicar a variação de IPAg e revelou variáveis dendrométricas que englobam grande parte dos efeitos que moldaram a variação observada do IPAg, apresentando boa abrangência dos dados observados em situações onde o crescimento é complexo e variado entre as espécies. As árvores quando amostradas em boas condições de sítio, expressado por boa exposição da copa à luz solar e, portanto, pouca competição, apresentaram as maiores taxas de IPAg, no período avaliado, do que aquelas encontradas sob forte competição por árvores vizinhas. Além disso, as variáveis carga de lianas na copa, para Cedrela, o diâmetro de copa e o status competitivo de Hegyi influenciaram de forma significativa o IPAg. Árvores amostradas em densidade maior do que 25 m2.ha-1 mostraram queda significativa do IPAg%. No contexto de incremento em área basal por área ocupada na floresta (eficiência da copa), todas as quatro espécies mostraram-se mais eficientes quando em melhor posição social e quando com copas estreitas e longas (formal de copa pequeno). Entre as espécies a Cedrela odorata foi a mais eficiente no crescimento, comportamento que reforça a importância da liberação das árvores o que proporcionaria melhor exposição da copa à luz solar.
49

Aspekty kolaborativních nákupů: Centralizace, rozsah a rozdílné tržní struktury / The Aspects of Collaborative Procurement: Centralization, Scope and Different Market Structures

Počarovská, Amália January 2018 (has links)
Procurement centralization is a process that includes policy decisions on the appropriate level of collaboration, aggregation and standardization. We analyse the main aspects of collaborative procurement: centralization, scope and different market structures. We use a unique dataset that combines Czech tender-level data with the manually-collected data on centrally procured tenders and financial firm-level data for the time span 2008 - 2016. We apply vector generalized linear model to the compulsory centralized procurement sectors and assess the market competition and concentration. We find several key aspects of centralized procurement: the centralization has a significant positive impact on the competition in selected sectors. The framework agreement is recognized as a positive setup of public procurement. We identified a strong negative evidence of the heterogeneity of the procured commodity. The design of centralization process and the degree of centralization is always bound by two elementary questions: the flexibility or unification trade-off and the set-up costs or unit costs trade-off. JEL Classification D44, H11, H57 Keywords public procurement, centralization, tender- level data, firm-level data, market structure, concentration index, vector generalized linear model, Herfindahl-Hirschman...
50

Ferramentas de seleção para uniformidade de produção em tilápias do Nilo (Oreochromis niloticus) / Selection tools for uniformity of production in Nile tilapia (Oreochromis niloticus) / Herramientas de selección para uniformidad de producción en tilápias del Nilo (Oreochromis niloticus)

Lázaro Velasco, Ángel de Jesús [UNESP] 26 September 2017 (has links)
Submitted by ANGEL DE JESUS LAZARO VELASCO null (angelstrauss26@hotmail.com) on 2017-10-25T17:49:03Z No. of bitstreams: 1 DissertacaoAngel.pdf: 1392488 bytes, checksum: 30d16b1c40935e0572a92a6d9c6dc400 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-31T17:00:42Z (GMT) No. of bitstreams: 1 velasco_ajl_me_jabo.pdf: 1392488 bytes, checksum: 30d16b1c40935e0572a92a6d9c6dc400 (MD5) / Made available in DSpace on 2017-10-31T17:00:42Z (GMT). No. of bitstreams: 1 velasco_ajl_me_jabo.pdf: 1392488 bytes, checksum: 30d16b1c40935e0572a92a6d9c6dc400 (MD5) Previous issue date: 2017-09-26 / Consejo Nacional de Ciencia y Tecnología (CONACYT) / Há evidências na literatura que a uniformidade das características fenotípicas dos peixes, entre outros animais, pode ser afetada por componentes genéticos, além de fatores ambientais. Maior uniformidade na despesca é desejada, a fim de reduzir a competição entre os animais e, assim, ter uma produção mais homogênea, visando maior retorno financeiro da atividade. O objetivo deste estudo foi estimar se as variâncias residuais do peso e comprimento à despesca de tilápias do Nilo (Oreochromis niloticus) são afetadas por componentes genéticos, para avaliar a possibilidade de seleção para uniformidade de produção. Empregou-se o modelo hierárquico linear generalizado duplo (DHGLM) para calcular os componentes de variância, os parâmetros de herdabilidade, coeficientes de variação e correlações genéticas para peso (não transformado e com transformação Box-Cox) e comprimento à despesca. Foi utilizado um total de 8.725 informações fenotípicas de tilápias provenientes de 271 famílias da linhagem GIFT (Malásia), criados na estação experimental de piscicultura da Universidade Estadual de Maringá. Os resultados apoiaram a hipótese de heterogeneidade genética da variância residual para peso e comprimento à despesca, e a oportunidade de seleção medida através do coeficiente genético de variação da variância residual. Além disso, observou-se a necessidade de um grande número de filhos para a obtenção de estimativas precisas do mérito genético para variação residual, conforme indicado pelas estimativas de baixa herdabilidade. A transformação de Box-Cox foi capaz de diminuir a dependência entre a variância e a média do peso à despesca. A transformação reduziu, mas não eliminou toda a heterogeneidade genética da variância residual, destacando sua presença além do efeito da escala. / There is evidence in the literature that the uniformity of phenotypic traits of fish, among other animals, can be affected by genetic components, as well as environmental factors. Greater uniformity is desired in order to reduce competition among animals and thus have a more uniform production, aiming a greater financial return of the activity. The objective of this study was to assess if the residual variance of the weight and harvest length of the Nile tilapia (Oreochromis niloticus) is affected by a genetic component, to evaluate the possibility of selection for uniformity of production. The double hierarchical generalized linear model was used to estimate the components of variance, heritability, coefficients of variation and genetic correlation for weight (untransformed and with Box-Cox transformation) and harvest length. Phenotypic records of 8,725 individuals from 271 families were analyzed. The results supported the existence of genetic heterogeneity of residual variance on harvest weight and length, and the opportunity to select for increasing uniformity. Moreover, the low heritability estimates showed the necessity of high number of progeny for an accurate estimate of the genetic merit for the residual variance. The Box-Cox transformation of harvest weight reduced the dependency among its mean and variance. The transformation reduced but did not eliminate the genetic heterogeneity of residual variance, highlighting its presence beyond the scale effect. / CONACYT: 579742/410471

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