Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 77-82). Also available in electronic version.

Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Xu-Feng Niu, Florida State University, College of Arts and Sciences, Dept. of Statistics. Title and description from dissertation home page (viewed Sept. 18, 2006). Document formatted into pages; contains ix, 116 pages. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Notre Dame, 2006. / Thesis directed by Scott E. Maxwell and Steven M. Boker for the Department of Psychology. "July 2006." Includes bibliographical references (leaves 105-119).

Statistics / M. Sc. (Statistics)

A violÃncia tem se tornado um problema de saÃde pÃblica no Brasil, vindo a ser a terceira principal causa de mortes. No grupo das violÃncias, os homicÃdios sÃo as principais causas de Ãbito. O principal objetivo deste estudo foi analisar a distribuiÃÃo espacial dos homicÃdios de Fortaleza no triÃnio 2004 à 2006 relacionados a fatores socioeconÃmicos. Foi utilizada a tÃcnica de linkage para resgate do local de ocorrÃncia dos contidos nos registros do IML para o banco de dados do Sistema de InformaÃÃo sobre Mortalidade (SIM). Foi criado um modelo de anÃlise de regressÃo linear multivariada que permitisse a identificaÃÃo de uma relaÃÃo estatÃstica linear entre homicÃdios e indicadores socioeconÃmicos. Foram registrados 35.266 mil Ãbitos de pessoas residentes em Fortaleza, destes 1.815 foram vÃtimas de homicÃdios. O uso do procedimento do linkage possibilitou uma melhoria das informaÃÃes contidas no SIM, com 93,6% recuperaÃÃo das informaÃÃes dos locais de ocorrÃncia do Ãbito do local de ocorrÃncia do evento violento. Para efeito da anÃlise espacial foram somente considerados 1.699 Ãbitos com bairro de ocorrÃncia identificado. O principal grupo de risco de morte por homicÃdio à o de jovens do sexo masculino entre 15 e 29 anos, em que o risco à 15,5 vezes maior que o sexo feminino, cor parda, solteiros e com baixa escolaridade. A anÃlise estatÃstica espacial foi realizada atravÃs da suavizaÃÃo das variaÃÃes das taxas utilizando-se o mÃtodo Bayesiano empÃrico e da observaÃÃo de autocorrelaÃÃo espacial atravÃs do I de Moran local. Quanto à distribuiÃÃo espacial dos homicÃdios, percebem-se contrastes relevantes entre Ãreas de piores e melhores condiÃÃes de vida, aonde 9,65% dos bairros possuem baixo IDH, tambÃm possuem altas taxas de homicÃdio. A distribuiÃÃo espacial teve um padrÃo irregular, foi realizada a suavizaÃÃo da taxa de homicÃdios que passou a se comportar de forma menos fragmentada. NÃo foi detectada autocorrelaÃÃo espacial, sendo avaliada atravÃs do Ãndice global de Moran (I= 0,0425). O modelo de regressÃo proposto com cinco variÃveis mostrou-se apropriado Ãs pretensÃes deste trabalho obtendo um coeficiente de determinaÃÃo significativo (RÂ=0, 4567). / The violence has become a public health problem in Brazil, is the third leading cause of deaths. In the Group of the violence, murders are the main causes of death. The main objective of this study was to analyze the spatial distribution of the homicides in the triennium 2004 fortress to 2006 related to socioeconomic factors. The technique was used for linkage to rescue the place of occurrence of the contained in the records of the IML to the database of Mortality Information System (SIM). Was created a model of multivariate linear regression analysis that allowed the identification of a statistical relationship between homicides and socioeconomic indicators. We recorded 35,266 thousand deaths in residents in Fortaleza, this 1,815 were victims of homicide. The use of the linkage procedure allowed an improvement of the information contained on the SIM, with 93.6% recovery of information places of occurrence of death at the place of occurrence of the violent event. For effect of spatial analysis were only considered 1,699 deaths with neighborhood of occurrence identified. The main risk group to death for murder is that of young males between 15 and 29 years, in which the risk is 15.5 times greater than the drab female, unmarried and with low schooling. Spatial statistical analysis was performed by smoothing the rate variations using the Bayesian method and empirical observation of Spatial autocorrelation through I of Moran. As for the spatial distribution of the homicide, understand-if relevant contrasts between worst areas and better living conditions, where 9.65% of districts have low IDH, also have high rates of homicide. The spatial distribution had an irregular pattern, was held anti-aliasing of the homicide rate that began to behave less fragmented. Spatial autocorrelation was not detected, being evaluated through the global index of Moran (I=0.0425). The proposed regression model with five variables proved to be appropriate to the claims of this work by obtaining a significant coefficient of determination (R = 0.4567).

M.Sc. / Please refer to full text to view abstract

The current study evaluated the performance of traditional versus modern MDTs in the estimation of fixed-effects and variance components for data missing at the second level of an hierarchical linear model (HLM) model across 24 different study conditions. Variables manipulated in the analysis included, (a) number of Level-2 variables with missing data, (b) percentage of missing data, and (c) Level-2 sample size. Listwise deletion outperformed all other methods across all study conditions in the estimation of both fixed-effects and variance components. The model-based procedures evaluated, EM and MI, outperformed the other traditional MDTs, mean and group mean substitution, in the estimation of the variance components, outperforming mean substitution in the estimation of the fixed-effects as well. Group mean substitution performed well in the estimation of the fixed-effects, but poorly in the estimation of the variance components. Data in the current study were modeled as missing completely at random (MCAR). Further research is suggested to compare the performance of model-based versus traditional MDTs, specifically listwise deletion, when data are missing at random (MAR), a condition that is more likely to occur in practical research settings.

Body weight is considered an important trait for the selection of replacement animals in both wool and mutton sheep. Knowledge of the genetic variance of each trait and covariances among traits is essential for effective genetic evaluation and improvement programs. It is important that estimated breeding values for performance traits should be estimated as accurately as possible. This could be achieved by fitting the most appropriate statistical model, which accounts for all known non-genetic effects, as well as correctly partitioning the genetic variance into its various sources. The aim of this study was to identify the most appropriate models for estimation of breeding values for body weights recorded at different ages in Merino sheep. Various statistical procedures, including uni- and multivariate linear models employing restricted maximum likelihood methods, random regression and repeatability models were evaluated. The dataset used in this study comprises body weight data recorded at different ages in the Grootfontein Merino stud from 1968 to 2012. The total number of males and females for which birth weight was recorded, were 7794 and 8317 respectively. The univariate direct heritability of body weight increased with an increase in age. Direct heritability estimates were 0.20 ± 0.03 for birth weight, 0.16 ± 0.02 for weaning weight, 0.51 ± 0.04 for 15-month body weight and 0.40 ± 0.05 for 3-year adult body weight. Maternal heritability estimates were 0.11 ± 0.02 for birth weight, 0.04 ± 0.01 for weaning weight and 0.08 ± 0.02 for 15-month body weight. The genetic correlation between direct and maternal effects was negative for all weights where it was included and ranged from -0.95 ± 0.14 for 6-month body weight to -0.28 ± 0.09 for birth weight. The repeatability model including direct and maternal genetic effects, without splines, was the most appropriate repeatability model for estimation of genetic parameters for body weight. The accuracy of the estimated breeding values were determined using Spearman rank correlations and number and proportion of common animals in the Top 10% and Top 1% lists. The comparison of estimated breeding values for body weights obtained with univariate, multivariate and repeatability models revealed that the multivariate model was the most efficient method due to the high accuracies obtained with this procedure. These results will be implemented when estimating breeding values for body weights for the animals in the Merino reference population during the development phase of a suitable SNP key to be used in genomic selection for body weight in South African Merino sheep. / Dissertation (MSc (Agric))--University of Pretoria, 2017. / Animal and Wildlife Sciences / MSc (Agric) / Unrestricted

<div>This thesis is concerned with massive data analysis via robust A-optimally efficient non-uniform subsampling. Motivated by the fact that massive data often contain outliers and that uniform sampling is not efficient, we give numerous sampling distributions by minimizing the sum of the component variances of the subsampling estimate. And these sampling distributions are robust against outliers. Massive data pose two computational bottlenecks. Namely, data exceed a computer’s storage space, and computation requires too long waiting time. The two bottle necks can be simultaneously addressed by selecting a subsample as a surrogate for the full sample and completing the data analysis. We develop our theory in a typical setting for robust linear regression in which the estimating functions are not differentiable. For an arbitrary sampling distribution, we establish consistency for the subsampling estimate for both fixed and growing dimension( as high dimensionality is common in massive data). We prove asymptotic normality for fixed dimension. We discuss the A-optimal scoring method for fast computing. We conduct large simulations to evaluate the numerical performance of our proposed A-optimal sampling distribution. Real data applications are also performed.</div>