Variance And Covariance Matrices
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Principal Component Analysis and Factor Analysis: differences and similarities in Nutritional Epidemiology application
RESUMO: Introdução: Métodos estatísticos de análise multivariada, tais como Análise de Componentes Principais e Análise Fatorial, têm sido cada vez mais utilizados nos estudos em Epidemiologia Nutricional, no entanto equívocos quanto à escolha e aplicação dos métodos são observados. Objetivos: Os objetivos deste estudo são comparar e apres
Rev. bras. epidemiol.. Publicado em: 29/07/2019
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2. Repeatability of agronomic characters in Brachiaria brizantha cultivars
This experiment was carried out with the objectives of determining repeatability coefficients, the number of harvests necessary to increase accuracy and the genotypic stability of yield characteristics in Brachiaria brizantha cultivars in the northeast region of Brazil in the period from July 2009 to March 2011. The experimental design used was completely ra
R. Bras. Zootec.. Publicado em: 2013-01
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3. Modelos lineares mistos em dados longitudionais com o uso do pacote ASReml-R / Linear Mixed Models with longitudinal data using ASReml-R package
Currently, most part of the experiments installed is designed to be carried out observations over time or at different depths. These experiments usually have a longitudinal factor. One way of analyzing this data set is by using mixed models through means of inclusion of random effect factors, and it is possible to estimate the variance components associated
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/04/2012
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4. Métodos de análise de dados longitudinais no melhoramento genético da pinha (Annona squamosa L.) / Methods of data analysis in longitudinal genetic improvement of custard apple (Annona squamosa L.)
A pinha ou fruta-do-conde (Annona squamosa L.) é uma fruteira importante para o Brasil, especialmente na Região Nordeste. Nessa espécie, os caracteres são avaliados repetidas vezes no decorrer da vida do organismo e são denominados infinitamente dimensionais, no sentido de que, em cada unidade de tempo ou idade, o caráter pode ser avaliado, gerando um
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/08/2010
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5. Evolução da modularidade no crânio de mamíferos / Evolution of modularity in the mammalian skull
Morphological integration refers to the modular structuring of intertrait relationships in an organism, which could bias the direction and rate of morphological change, either constraining or facilitating evolution along certain dimensions of the morphospace. Therefore, the description of morphological integration patterns and its magnitude and the analysis
Publicado em: 2009
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6. Evolução do crânio dos macacos do Velho Mundo: uma abordagem de genética quantitativa / Cranial evolution of Old World monkeys and Apes: a quantitative genetics approach
This is a study on the cranial diversification of the Catarrhini, a large group of primates that includes all Old World monkeys and apes, bringing together two approaches to investigate the evolution of complex characters: quantitative genetics and morphological integration. It has three main goals: 1) to compare magnitudes and patterns of inter-trait relati
Publicado em: 2009
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7. Repeatability and selection of Panicum maximum Jacq. / Repetibilidade e seleção em Panicum maximum Jacq.
The experiment was done with the objective to evaluate the repeatability coefficient of some agronomic characteristics in hybrids of Panicum maximum, and to select superior genotypes in half-sib populations obtained from crosses between sexual plants and apomictic accessions. It was also proposed to compare selection strategies between and within families, c
Publicado em: 2007
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8. Variances and covariances in deconvolution of multichannel spectra: 34S (g, n) cross section
This paper discusses some aspects of deconvolution of one-dimensional spectra in the framework of the Least Squares Method and presents a minimum variance regularization procedure. Covariance matrices are taken into account inevery step. Fluctuation and artifacts, both in the deconvolved and regularized spectra, are related to the structure of the covariance
Brazilian Journal of Physics. Publicado em: 2001-03
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9. Analysis of the Covariance Structure of Digital Ridge Counts in the Offspring of Monozygotic Twins
Improved methods for analysis of covariance structures now permit the rigorous testing of multivariate genetic hypotheses. Using Jöreskog 's Lisrel IV computer program we have conducted a confirmatory factor analysis of dermal ridge counts on the individual fingers of 509 offspring of 107 monozygotic twin pairs. Prior to the initiation of the model-fitting
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10. Nature of Random Variation in the Nutrient Composition of Meals
The mathematical formulation of nutrient variation in meals in presented by means of random vectors. The primary sources of nutrient variation in unit portions of menu items are identified and expressed in terms of random food-nutrient, random portion size and random ingredient composition variations. A secondary source of nutrient variation can be traced to
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11. Multivariate Mutation-Selection Balance with Constrained Pleiotropic Effects
A multivariate quantitative genetic model is analyzed that is based on the assumption that the genetic variation at a locus j primarily influences an underlying physiological variable y(j), while influence on the genotypic values is determined by a kind of ``developmental function'' which is not changed by mutations at this locus. Assuming additivity among l