Browsing Theses and Dissertations (Statistics) by Title

Browsing Theses and Dissertations (Statistics) by Title

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  • Causal Inference : controlling for bias in observational studies using propensity score methods 
    Msibi, Mxolisi (University of Pretoria, 2020)
    Adjusting for baseline pre-intervention characteristics between treatment groups, through the use of propensity score matching methods, is an important step that enables researchers to do causal inference with confidence. ...
  • Clustering time-course data using P-splines and mixed effects mixture models 
    Bredenkamp, Deidre (University of Pretoria, 2022)
    In the field of biology, gene expressions are evaluated over time to study complicated biological processes and genetic supervisory networks. Because the process is continuous, time-course gene-expression data may ...
  • Comparing logistic regression methods for completely separated and quasi-separated data 
    Botes, Michelle (University of Pretoria, 2013)
    An occurrence which is sometimes observed in a model based on dichotomous dependent variables is separation in the data. Separation in the data is when one or more of the independent variables can perfectly predict some ...
  • The compounding method for finding bivariate noncentral distributions 
    Ferreira, Johannes Theodorus (University of Pretoria, 2014-04)
    The univariate and bivariate central chi-square- and F distributions have received a decent amount of attention in the literature during the past few decades; the noncentral counterparts of these distributions have been ...
  • Computational aspects of differential networks 
    Marques Salgado, Ricardo Daniel (University of Pretoria, 2021)
    The need for statistical tools capable of addressing high-dimensional data is ever-growing. One such tool is that of differential networks, which have become increasing popular within various branches of science. The ...
  • Computational aspects of hierarchical mixture models for geological data 
    Laidlaw, Michaela (University of Pretoria, 2021)
    Buidling off a foundation of knowledge from studies into modelling wind speed, models are fitted to multimodal datasets of geological nature. Mixtures of distributions are derived with parameter updates done via ...
  • Construction and parameter estimation of wrapped normal models 
    Roux, Hannaline (University of Pretoria, 2019)
    If a known distribution on a real line is given, it can be wrapped on the circumference of a unit circle. This research entails the study of a univariate skew-normal distribution where the skew-normal distribution is ...
  • Construction and parameter estimation of wrapped normal models 
    Roux, Hannaline (University of Pretoria, 2019-08)
    If a known distribution on a real line is given, it can be wrapped on the circumference of a unit circle. This research entails the study of a univariate skew-normal distribution where the skew-normal distribution is ...
  • Contemplating Statistics : estimation and regression according to arc lengths 
    Loots, Mattheus Theodor (University of Pretoria, 2017)
    Advances in computing has undoubtfully been one of the main catalysts in the formation of the discipline always known as Statistics. A fundamental question addressed here is whether computing facilities, such as parallel ...
  • Contributions to control charts for attributes data 
    Shongwe, Sandile Charles (University of Pretoria, 2014)
    No abstract
  • Contributions to k-u models in wireless systems 
    Nagar, Priyanka (University of Pretoria, 2017-06)
    Please read abstract in the document
  • Contributions to the theory and applications of univariate distribution-free Shewhart, CUSUM and EWMA control charts 
    Graham, Marien Alet (University of Pretoria, 2013)
    Distribution-free (nonparametric) control charts can be useful to the quality practitioner when the underlying distribution is not known. The term nonparametric is not intended to imply that there are no parameters ...
  • Customer Value Management Using the Cox Additive Regression Model 
    van Wyk de Vries, Jan (University of Pretoria, 2013)
    The Cox-Proportional Hazards model is introduced as a potential tool to understand customer behavior relating to churn or disconnections in the telecommunications space. An overview of Survival Analysis is provided along ...
  • Data Compression and Quantization 
    Du Toit, Benjamin David (University of Pretoria, 2014)
    Data Compression Due to limitations in data storage and bandwidth, data of all types has often required compression. This need has spawned many different methods of compressing data. In certain situations the fidelity of ...
  • Dependence structures in multidimensional arrays 
    Lau, Kwok-Ho (University of Pretoria, 2016)
    In the process of data acquisition the information obtained are more than often contaminated by noise. To purify the data smoothers are designed to remove the noise. The LULU operators are such smoothers, more speci ...
  • Deriving trajectory embeddings from global positioning system movement data 
    Graaff, Armand (University of Pretoria, 2022-12-07)
    Analysing unstructured data with minimal contextual information is a challenge faced in spatial applications such as movement data. Movement data are sequences of time-stamped locations of a moving entity analogous to text ...
  • Describing heterogeneity in spatial point processes 
    Kraamwinkel, Christine (University of Pretoria, 2017)
    In this mini-dissertation we briefly describe the context and development of spatial statistics, spatial sampling and point patterns. Thereafter spatial homogeneity is considered in detail. Before selecting an appropriate ...
  • The development of the quaternion normal distribution 
    Loots, Mattheus Theodor (University of Pretoria, 2010-12-28)
    In this dissertation an overview on the real representation of quaternions in distribution theory is given. The density functions of the p-variate and matrix-variate quaternion normal distributions are derived from first ...
  • Developments in Wishart ensemble and Bayesian application 
    Van Niekerk, Janet (University of Pretoria, 2017)
    The increased complexity and dimensionality of data necessitates the development of new models that can adequately model the data. Advances in computational approaches have pathed the way for consideration and implementation ...
  • Diffusion processes and applications to financial time series 
    Van der Berg, Jacobus Marthinus (University of Pretoria, 2021-10)
    Diffusion processes are effective tools for modeling financial and economic phenomena. Diffusion models have been implemented with great success in financial markets where stochastic calculus based on such models allow ...