Recent Submissions

  • HIV-exposure, early life feeding practices and delivery mode impacts on faecal bacterial profiles in a South African birth cohort 

    Claassen-Weitz, Shantelle; Gardner-Lubbe, Sugnet; Nicol, Paul; Botha, Gerrit; Mounaud, Stephanie; Shankar, Jyoti; Nierman, William C.; Mulder, Nicola; Budree, Shrish; Zar, Heather J.; Nicol, Mark P.; Kaba, Mamadou (Nature Research, 2018)
    There are limited data on meconium and faecal bacterial profiles from African infants and their mothers. We characterized faecal bacterial communities of infants and mothers participating in a South African birth cohort. ...
  • Sorting in combination with quality scoring : a tool for industry professionals to identify drivers of wine quality rapidly 

    Brand, J.; Kidd, M.; Van Antwerpen, L.; Valentin, D.; Naes, T.; Nieuwoudt, H. H. (South African Society for Enology and Viticulture, 2018)
    Quality plays an important role in the criteria directing wine product development. The evaluation of sensory characteristics associated with wine quality, as perceived by industry professionals, is therefore important. ...
  • Interpreting decision boundaries of deep neural networks 

    Wessels, Zander (Stellenbosch : Stellenbosch University, 2019-12)
    ENGLISH ABSTRACT: As deep learning methods are becoming the front runner among machine learning techniques, the importance of interpreting and understanding these methods grows. Deep neural networks are known for their ...
  • Recommender systems 

    Dumbleton, Bronwyn Catherine (Stellenbosch : Stellenbosch University, 2019-12)
    ENGLISH ABSTRACT: A Recommender System (RS) is a particular type of information filtering system used to propose relevant items to users. Their successful application in online retail is reflected in increased customer ...
  • The bells of the Stellenbosch Moederkerk 

    De Wet, Tertius; Teugels, Jef L.; Van Deventer, Pieta (Church History Society of Southern Africa, 2018)
    The Dutch Reformed Moederkerk of Stellenbosch has a long history, being the second oldest congregation of the Dutch Reformed Church in South Africa. The history of the church has been well documented, including the ...
  • Biplot methodology for analysing and evaluating missing multivariate nominal scaled data 

    Nienkemper-Swanepoel, Johane (Stellenbosch : Stellenbosch University, 2019-12)
    ENGLISH ABSTRACT: This research aims at developing exploratory techniques that are specifically suitable for missing data applications. Categorical data analysis, missing data analysis and biplot visualisation are the ...
  • Simulation of a coal stacking process using an online X-Ray Fluorescence analyser 

    Rossouw, R. F.; Coetzer, R. L. J.; Le Roux, N. J. (Operations Research Society of South Africa (ORSSA), 2018)
    The Sasol Coal Value Chain is a complex system consisting of blending, stacking and reclaiming of no fewer than six different coal sources with vastly different coal qualities. The amount and quality of the gas produced ...
  • Value at risk and extreme value theory : application to the Johannesburg Securities Exchange 

    Williams, R.; Van Heerden, J. D.; Conradie, W. J. (Bureau for Economic Research, 2018)
    Value at Risk (VaR) has been established as one of the most important and commonly used financial risk management tools. Nevertheless, the attractive features and wide-spread use of VaR could not help to avoid a number of ...
  • Interpretable multi-label classification by means of multivariate linear regression 

    Bierman, Surette (South African Statistical Association, 2019)
    In this paper, the potential of using a multivariate regression approach in order to obtain interpretable output in a multi-label classification problem is investigated. We focus in our analysis on extensions of ordinary ...
  • Improving hyperplane based density clustering solutions with applications in image processing 

    Kenyon, Jacob Bradley (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : Minimum Density Hyperplane (MDH) clustering is a recently proposed method that seeks the location of an optimal low-density separator by directly minimising the integral of the empirical density function ...
  • Deep learning for tabular data : an exploratory study 

    Marais, Jan Andre (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : From about 2006, deep learning has proven to be very successul in application areas such as computer vision, natural language processing, speech and audio recognition, machine translation, bioinformatics, ...
  • Preconditioning for feature selection in classification 

    Pretorius, Jani (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : Increased dimensionality of data is a clear trend that has been observed over the past few decades. However, analysing high-dimensional data in order to predict an outcome can be problematic. In certain ...
  • Predicting equity movements using structural models of debt pricing and statistical learning 

    Singh, Kiran Ryan (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : Valuation is not an interesting problem in corporate finance, it is the only problem. Price and value are assumed to be the same number in economic theories of equilibrium and perfect capital markets. The ...
  • Investigation into the appropriateness of the South African microinsurance solvency capital regulation 

    Melville, William George (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH ABSTRACT : In South Africa, there are two different regulatory capital requirement options for insurers selling microinsurance products. The first is the capital requirement for traditional insurers under the ...
  • Markov modelling of disease progression in the presence of missing covariates 

    Kotze, Loamie (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : Breast cancer is a very prevalent cancer amongst women. The stages of breast cancer are influenced by characteristics such as age, hormone receptor statuses, HER2 status and staging information (TNM ...
  • Application of statistics and machine learning in healthcare 

    Van der Merwe, Schalk Gerhardus (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : Clinical performance and cost efficiency are key focus areas in the healthcare industry, since providing quality and affordable healthcare is a continuing challenge. The goal of this research is to use ...
  • Classification in high dimensional data using sparse techniques 

    Stulumani, Agrippa (Stellenbosch : Stellenbosch University, 2019-04)
    ENGLISH SUMMARY : Traditional classification techniques fail in the analysis of high-dimensional data. In response, new classification techniques and accompanying theory have recently emerged. These techniques are natural ...
  • Regularised Gaussian belief propagation 

    Kamper, Francois (Stellenbosch : Stellenbosch University, 2018-12)
    ENGLISH SUMMARY : Belief propagation (BP) has been applied as an approximation tool in a variety of inference problems. BP does not necessarily converge in loopy graphs and, even if it does, is not guaranteed to provide ...
  • Ensemble methods in multi-label classification 

    Muller, Annegret (Stellenbosch : Stellenbosch University, 2018-12)
  • An application of copulas to improve PCA biplots for multivariate extremes 

    Perrang, Justin (Stellenbosch : Stellenbosch University, 2018-12)
    ENGLISH SUMMARY : Principal Component Analysis (PCA) biplots is a valuable means of visualising high dimensional data. The application of PCA biplots over a wide variety of research areas containing multivariate data is ...

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