Browsing Doctoral Degrees (Statistics) by Issue Date
Now showing items 1-20 of 32
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Analysis of longitudinal binary data : an application to a disease process.
(2008)The analysis of longitudinal binary data can be undertaken using any of the three families of models namely, marginal, random effects and conditional models. Each family of models has its own respective merits and demerits. ... -
D-optimal designs for drug synergy.
(2009)This thesis is focused on the construction of optimal designs for detecting drug interaction using the two-variable binary logistic model. Two specific models are considered: (1) the binary two-variable logistic model ... -
Statistical methods for longitudinal binary data structure with applications to antiretroviral medication adherence.
(2010)Longitudinal data tend to be correlated and hence posing a challenge in the analysis since the correlation has to be accounted for to obtain valid inference. We study various statistical methods for such correlated ... -
Comparative approaches to handling missing data, with particular focus on multiple imputation for both cross-sectional and longitudinal models.
(2012)Much data-based research are characterized by the unavoidable problem of incompleteness as a result of missing or erroneous values. This thesis discusses some of the various strategies and basic issues in statistical ... -
Statistical modelling of availability of major food cereals in Lesotho : application of regression models and diagnostics.
(2012)Oftentimes, application of regression models to analyse cereals data is limited to estimating and predicting crop production or yield. The general approach has been to fit the model without much consideration of the ... -
Likelihood based statistical methods for estimating HIV incidence rate.
(2013)Estimation of current levels of human immunodeficiency virus (HIV) incidence is essential for monitoring the impact of an epidemic, determining public health priorities, assessing the impact of interventions and for ... -
Statistical methods for analysing complex survey data : an application to HIV/AIDS in Ethiopia.
(2013)The HIV/AIDS pandemic is currently the most challenging public health matter that faces third world countries, especially those in Sub-Saharan Africa. Ethiopia, in East Africa, with a generalised and highly heterogeneous ... -
Use of statistical modelling and analyses of malaria rapid diagnostic test outcome in Ethiopia.
(2013)The transmission of malaria is among the leading public health problems in Ethiopia. From the total area of Ethiopia, more than 75% is malarious. Identifying the infectiousness of malaria by socio-economic, demographic ... -
Combining dynamic factor models and artificial neural networks in time series forecasting with applications.
(2014)This study investigates and examines the advantages and forecasting performance of combining the dynamic factor model (DFM) and artificial neural networks (ANNs) leading to new novel models that have capabilities to produce ... -
Nonlinear mixed-effects models for multi-variate longitudinal data with application to HIV disease dynamics.
(2014)The motivation for the study of nonlinear mixed-effects models is due to the growing interest in the estimation of parameters in HIV disease dynamical models using real multivariate longitudinal data with varying degrees ... -
Covariates and latents in growth modelling.
(2014)The growth curve models are the natural models for the increment processes taking place gradually over time. When individuals are observed over time it is often apparent that they grow at different rates, even though ... -
A perspective on incomplete data in longitudinal multi-arm clinical trials, with emphasis on pattern-mixture-model based methodology.
(2014)Missing data are common in longitudinal clinical trials. Rubin described three different missing data mechanisms based on the level of dependence between the missing data process and the measurement process. These are ... -
Numerical study of convective fluid flow in porous and non-porous media.
(2015)Abstract available in PDF file. -
Statistical methods to evaluate disease outcome diagnostic accuracy of multiple biomarkers with application to HIV and TB research.
(2015)One challenge in clinical medicine is that of the correct diagnosis of disease. Medical researchers invest considerable time and effort to improving accurate disease diagnosis and following from this diagnostic tests are ... -
Flexible statistical modelling in food insecurity risk assessment.
(2015)Food insecurity has remained a persistent problem in Sub-Saharan Africa. Conflict and other protracted crisis have rendered a significant proportion of Africa’s populations to suffer the risk of food insecurity, as their ... -
The management of missing categorical data : comparison of multiple imputation and subset correspondence analysis.
(2015)Missing data is a common problem in research and the manner in which this ‘missingness’ is managed, is crucial to the validity of analysis outcomes. This study illustrates the use of two diverse methods to handle, in ... -
Application of mixed model and spatial analysis methods in multi-environmental and agricultural field trials.
(2015)Agricultural experimentation involves selection of experimental materials, selection of experimental units, planning of experiments, and collection of relevant information, analysis and interpretation of the results. An ... -
Bayesian spatial models with application to HIV, TB and STI modeling in Kenya.
(2014)This dissertation is concerned with developing and extending statistical models in the area of spatial modeling with particular interest towards application to HIV, TB and HSV-2 data. Hierarchical spatial modeling is a ... -
A frequentist and a Bayesian approach to estimating HIV prevalence accounting for non-response using population-based survey data.
(2016)Enhanced and novel frequentist and Bayesian approaches to estimating disease measures such as HIV prevalence utilizing the recent advances in statistical computing software are explored and applied making use of ... -
Measuring poverty and child malnutrition with their determinants from household survey data.
(2016)The eradication of poverty and malnutrition is the main objective of most societies and policy makers. But in most cases, developing a perfect or accurate poverty and malnutrition assessment tool to target the poor ...