• Explainable Bayesian networks : taxonomy, properties and approximation methods 

  Derks, Iena Petronella (University of Pretoria, 2024-07-22)

  Technological advances have integrated artificial intelligence (AI) into various scientific fields, necessitating understanding AI-derived decisions. The field of explainable artificial intelligence (XAI) has emerged to ...
• Hypersphere candidates emanating from the Dirichlet and its extension 

  Leshilo, Ramadimetje Lethabo (University of Pretoria, 2024-07)

  Compositional datasets consist of observations that are proportional and are subject to non-negativity and unit-sum constraints. These datasets arise naturally in a multiplicity of fields such as agriculture, archaeology, ...
• Essays on estimation strategies addressing label-switching in Gaussian mixtures of semi- and non-parametric regressions 

  Skhosana, Sphiwe Bonakele (University of Pretoria, 2024-04-30)

  Gaussian mixtures of non-parametric regressions (GMNRs) are a flexible class of Gaussian mixtures of regressions (GMRs). These models assume that some or all of the parameters of GMRs are non-parametric functions of the ...
• Multiscale decomposition of spatial lattice data for hotspot prediction 

  Stander, René (University of Pretoria, 2023-11-27)

  Being able to identify areas with potential risk of becoming a hotspot of disease cases is important for decision makers. This is especially true in the case such as the recent COVID-19 pandemic where it was needed to ...
• Enhancing spatial image analysis : modelling perspectives on the usefulness of level-sets 

  Stander, Jean-Pierre (University of Pretoria, 2024-03)

  This thesis presents a comprehensive exploration of level-sets applied to various stages of image analysis, aiming to enhance understanding, modelling, and interpretability of image data. The research focuses on three ...
• New characterisations of spatial linear networks for geographical accessibility 

  Thiede, Renate Nicole (University of Pretoria, 2024-02-13)

  Target 9.1 of the United Nations Sustainable Development Goals specifies the need for affordable, equitable access for all. In South Africa, where most travel occurs via the road network, apartheid policies designed the ...
• Spatial-temporal topic modelling of COVID-19 tweets in South Africa 

  Jafta, Papama Hlumela Gandhi (University of Pretoria, 2023-12-07)

  In the era of social media, the analysis of Twitter data has become increasingly important for understanding the dynamics of online discourse. This research introduces a novel approach for tracking the spatial and temporal ...
• A robust simulation to compare meaningful batting averages in cricket 

  Vorster, Johannes S. (University of Pretoria, 2023-11-17)

  In cricket, the traditional batting average is the most common measure of a cricket player’s batting performance. However, the batting average can easily be inflated by a high number of not-out innings. Therefore, in this ...
• A mixture model approach to extreme value analysis of heavy tailed processes 

  Sanqela, Lizo (University of Pretoria, 2023-12-07)

  Extreme value theory (EVT) encompasses statistical tools for modelling extreme events, which are defined in the peaks-over-threshold methodology as excesses over a certain high threshold. The estimation of this threshold ...
• An interactive R shiny application for learning multivariate data analysis and time series modelling 

  Frances, Motala Charles (University of Pretoria, 2024-02-07)

  Multivariate analysis and time series modelling are essential data analysis techniques that provide a comprehensive approach for understanding complex datasets and supporting data-driven decision-making. Multivariate ...
• Breaking the norm : approaches for symmetric, positive, and skewed data 

  Wagener, Matthias (University of Pretoria, 2023-11-06)

  This research contributes to the advancement of flexible and interpretable models within distribution theory, which is a fundamental aspect of numerous academic disciplines. This study investigates and presents the ...
• Bayesian learning of regularized Gaussian graphical networks 

  Smith, Jarod Mark (University of Pretoria, 2024)

  The advancement of digitisation in various scientific disciplines has generated data with numerous variables. Gaussian graphical models (GGMs) offer a convenient framework for analysing and interpreting the conditional ...
• The theory and application of bootstrap control charts for statistical process control 

  Coetzee, Evert Johan (University of Pretoria, 2017-05)

  Chapter 1 of this mini-dissertation gives an introduction to Statistical Process Control (SPC) and provides some background on the Shewhart, CUSUM and the EWMA control charts. The bootstrap by [9] Efron (1979) is discussed ...
• 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 ...
• Lower quantile estimation within an artificially censored framework 

  Smith, Jarod (University of Pretoria, 2020)

  Quantile estimation is a vital aspect of statistical analyses in a variety of fields. For example, lower quantile estimation is crucial to ensure the safety and reliability of wood-built structures. Various statistical ...
• A functional approach to distribution modelling : the spliced generalised normal distribution 

  Wagener, Matthias (University of Pretoria, 2019)

  A new body and tail generalisation of the normal distribution is introduced, the spliced generalised normal (SGN). A special case of the SGN, the tail-adjusted normal distribution, is further generalised with two-piece ...
• Distributional properties of ratios of gamma random variables in the context of quality control 

  Mijburgh, Philip Albert (University of Pretoria, 2016)

  This study emanates from a practical problem in the statistical process control (SPC) environment where the quality of a process is monitored. Speci cally, where the variance of a process is being assessed to be the same ...
• 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 ...
• Product of independent generalised gamma random variables 

  Bilankulu, Vusi Raphael (University of Pretoria, 2016-10)

  The generalised gamma distribution has received much attention due to its exibility and also for having some well-known distributions as special cases. This study originates from a statistic de ned as the ratio of ...
• Contributions to k-u models in wireless systems 

  Nagar, Priyanka (University of Pretoria, 2017-06)

  Please read abstract in the document

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