Browsing Theses and Dissertations (Statistics) by Type "Thesis"

Browsing Theses and Dissertations (Statistics) by Type "Thesis"

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  • Advances and considerations of Dirichlet with an emphasis on entropy 
    Botha, Tanita (University of Pretoria, 2022)
    The Dirichlet distribution is a cornerstone probabilistic consideration when working with data on the unit simplex. This thesis studies advances of several Dirichlet generalizations such as the Dirichlet generator, noncentral ...
  • Advances in statistical distribution theory inspired by communications systems 
    Ferreira, Johannes T. (University of Pretoria, 2017)
    This thesis contributes to statistical distribution theory by developing bivariate- and matrix variate distributions with their origins in the complex elliptical class. These contributions are inspired by the communications ...
  • Asymmetric generalizations of symmetric univariate probability distributions obtained through quantile splicing 
    Mac'Oduol, Brenda Vuguza (University of Pretoria, 2020)
    This thesis develops a skewing methodology for the formulation of two-piece families of distri- butions that can be defined through their cumulative distribution functions (CDFs), probability density functions (PDFs) or ...
  • Bilevel factor analysis models 
    Pietersen, Jacobus Johannes (University of Pretoria, 2007-12-20)
    The theory of ordinary factor analysis and its application by means of software packages do not make provision for data sampled from populations with hierarchical structures. Since data are often obtained from such populations ...
  • Bimatrix variate distributions of Wishart ratios with application 
    Ehlers, Rene (University of Pretoria, 2011-09-23)
    The focus of this study is the development of a group of bimatrix variate beta distributions with bounded domain for the central and noncentral cases. They are constructed from different dependent Wishart ratios. Exact ...
  • 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 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 ...
  • 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 ...
  • Furtherance of modeling frameworks for multivariate directional statistics 
    Nagar, Priyanka (University of Pretoria, 2022)
    In this thesis, we propose multivariate directional models that serve to fill the gaps in literature and aim to develop innovative theoretical modeling frameworks for contemporary applications where either certain manifolds ...
  • A Gamma-Poisson topic model for short text 
    Mazarura, Jocelyn Rangarirai (University of Pretoria, 2020)
    Most topic models are constructed under the assumption that documents follow a multinomial distribution. The Poisson distribution is an alternative distribution to describe the probability of count data. For topic modelling, ...
  • Generalised beta type II distributions - emanating from a sequential process 
    Adamski, Karien (University of Pretoria, 2013)
    This study focuses on the development of a generalised multivariate beta type II distribution as well as the noncentral and bimatrix counterparts with positive domain. These models emanate from a sequential quality ...
  • A generic probabilistic model for natural hazard assessment 
    Smit, Ansie (University of Pretoria, 2019)
    A generic methodology for probabilistic natural hazard assessment is presented. Three area-characteristic recurrence parameters are defined by combining a Poisson process with the relevant natural-hazard-frequency–event-size ...
  • Modeling of generalized families of probability distribution in the quantile statistical universe 
    Van Staden, Paul Jacobus (University of Pretoria, 2013)
    This thesis develops a methodology for the construction of generalized families of probability distributions in the quantile statistical universe, that is, distributions specified in terms of their quantile functions. ...
  • On weighted Poisson distributions and processes, with associated inference and applications 
    Mijburgh, Philip Albert (University of Pretoria, 2020)
    In this thesis, weighted Poisson distributions and processes are investigated, as alternatives to Poisson distributions and processes, for the modelling of discrete data. In order to determine whether the use of a weighted ...
  • Optimization and estimation study of manpower planning models 
    Setlhare, Keamogetse (University of Pretoria, 2007-06-18)
    An attempt is made in this thesis to study the optimization and estimation of stochastic models of manpower systems incorporating one or more of the following aspects: (i) recruitment, (ii) promotion, (iii) training and ...
  • Parameter structures in the exponential class 
    Strydom, H.F. (Hendrina Fredrika) (University of Pretoria, 2011)
    Maximum likelihood estimation of parameter structures in the exponential class is considered by using a procedure for maximum likelihood estimation under constraints. This procedure does not require maximization of the ...
  • The performance of the preliminary test estimator under different loss functions 
    Kleyn, Judith (University of Pretoria, 2014)
    In this thesis different situations are considered in which the preliminary test estimator is applied and the performance of the preliminary test estimator under different proposed loss functions, namely the reflected ...
  • Statistical analysis of grouped data 
    Crafford, Gretel (University of Pretoria, 2007)
    The maximum likelihood (ML) estimation procedure of Matthews and Crowther (1995: A maximum likelihood estimation procedure when modelling in terms of constraints. South African Statistical Journal, 29, 29-51) is utilized ...
  • Stochastic analysis of AIDS epidemiology 
    Labeodan, Moremi Morire OreOluwapo (University of Pretoria, 2009-10-29)
    In this thesis, some issues about the human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) have been addressed by concentrating on the stochastic modelling of the dynamics of the viruses. The ...
  • Univariate parametric and nonparametric double generally weighted moving average control charts 
    Masoumi Karakani, Hossein (University of Pretoria, 2020)
    Statistical process control (SPC) is a collection of scientific tools developed and engineered to diagnose unnecessary variation in the output of a production process and eliminate it or perhaps accommodate it by adjusting ...