Browsing Research Articles (Statistics) by Title

Browsing Research Articles (Statistics) by Title

Sort by: Order: Results:

  • Efficient response-surface designs with unknown block sizes 
    Debusho, Legesse Kassa; Chibayambuya, Gamu (South African Statistical Association, 2013)
    This paper focuses on the construction of D- and Ds-optimal designs for a secondorder response surface model when the block sizes are not fixed. Overviews of the Procedure OPTEX in SAS for the construction of these designs ...
  • Electricity load forecasting with artificial neural networks 
    Boraine, H.; Yadavalli, Venkata S. Sarma (Southern African Institute for Industrial Engineering, 2003)
    Artificial neural networks are powerful tools for time series forecasting. The problem addressed in this article is to do multi-step prediction of a stationary time series, and to find the associated prediction limits. ...
  • Email communication in project management : a bane or a blessing? 
    Smit, Marius C.; Bond-Barnard, Taryn Jane; Steyn, Herman; Fabris-Rotelli, Inger Nicolette (AOSIS, 2017-08-11)
    BACKGROUND : Project success used to be measured solely in terms of efficiency metrics such as scope, cost and time; however, there are proposals that more attention should be paid to process-related performance factors ...
  • An endometrial histomorphometric study of CD56+ natural killer cells in women with unexplained infertility 
    Muller, M.; Kalmeier, G.; Eyal, P.; De Bruin, A.; Pool, Roger; Du Rant, C.; Ehlers, Rene; Stander, Andre; Van Schoor, Albert-Neels; Nortje, Evangeline; Du Toit, Peet J. (Health and Medical Publishing Group, 2017-09)
    BACKGROUND. The number of peripheral blood and endometrial natural killer cells varies greatly during implantation and the first trimester of pregnancy and is thought to play a role in the maintenance of a healthy pregnancy. ...
  • An enriched α − μ model as fading candidate 
    Ferreira, Johannes Theodorus; Bekker, Andriette, 1958-; Marques, F.; Laidlaw, M. (Hindawi Publishing, 2020-04-25)
    This paper introduces an enriched α − μ distribution which may act as fading model with its origins via the scale mixture construction. The distribution’s characteristics are visited and its feasibility as a fading candidate ...
  • Epidemiology and time-loss shoulder injuries in professional South African rugby players : a prospective study that focuses on real-time collision data during a tackle 
    Louwrens, Jan Gerhardus; Jansen van Rensburg, Audrey; Viljoen, Carel T.; Hendricks, Sharief; Botha, Tanita; Janse van Rensburg, Dina Christina (MDPI, 2023-10-03)
    BACKGROUND : In rugby, the shoulder contributes to attack/defence during collisions, tackling, falling, scrummaging, and mauling. We investigated the frequency, tissue, and pathology type of shoulder injuries per player ...
  • The epidemiology of injury and illness at the Vitality Netball World Cup 2019 : an observational study 
    Janse van Rensburg, Dina Christina; Bryant, Grace; Kearney, Sharon; Singh, Praimanand; Devos, Arnold; Jansen van Rensburg, Audrey; Schwellnus, Martin Peter; Botha, Tanita (Taylor and Francis, 2022)
    BACKGROUND : Netball is a physical game with sudden direction changes, decelerations, jumping and landing, stop/start maneuvers and restrictive footwork rules exposing players to injury. Close contact play and shared ...
  • An ERA-Interim HAILCAST hail climatology for southern Africa 
    Dyson, Liesl L.; Pienaar, Nita; Smit, Ansie; Kijko, Andrzej (Wiley, 2021-01)
    Understanding the character of hail is an important part of mitigating its impact on life and property. Climatologies of hail over South Africa are rare and based on observed data with a coarse spatial and temporal resolution. ...
  • Establishing the safety of the lateral femoral cutaneous nerve when using the bridging infix for anterior pelvic fixation 
    Van Schalkwyk, Jerolize; Keough, Natalie; Strydom, Sven; Snyckers, Christian H; Masenge, Andries; Mogale, Nkhensani (MedPharm Publications, 2023-11)
    BACKGROUND Established subcutaneous internal fixation techniques have shown a better quality of life with reduced pain. However, complications still arise, with the most significant being injury of the lateral femoral ...
  • Estimate time-to-infection (TTI) vaccination effect when TTI for unvaccinated group is unknown 
    Chen, Ding-Geng (Din); Chung, Yunro; Beyene, Kassu Mehari (Springer, 2024-02)
    The COVID-19 pandemic has caused significant morbidity and mortality, as well as social and economic disruption worldwide in general and USA in particular. In order to reduce these effects, a global effort to develop ...
  • Estimating unhealthy food effects on childhood overweight in Malawi using an observational study 
    Twabi, Halima S.; Manda, S.O.M. (Samuel); Small, Dylan S. (Springer, 2022-11)
    INTRODUCTION : Consumption of unhealthy foods in children contributes to high levels of childhood obesity globally. In developing countries there is paucity of empirical studies on the association. This study employed ...
  • Estimation of the inequality indices based on the well-known rank-based sampling schemes 
    Rad, Najmeh Nakhaei; Salehi, Mahdi; Mehrali, Yaser (Taylor and Francis, 2022)
    Using the simple random sampling (SRS) for collecting the income data may results poor estimators specially when the sample size is not enough large. Since under this circumstance, it may be difficult to obtain a representative ...
  • Estimation under the matrix variate elliptical model 
    Van Niekerk, Janet; Bekker, Andriette, 1958-; Arashi, Mohammad; De Waal, Duan J.31cca2cb-0f0b-4ea7-a9c1-9711569804a7 (South African Statistical Association, 2016)
    The problem of estimation within the matrix variate elliptical model is addressed. In this paper a subjective Bayesian approach is followed to derive new estimators for the parameters of the matrix variate elliptical ...
  • Evaluation of a pure-strategy Stackelberg game for wildlife security in a geospatial framework 
    Kirkland, Lisa-Ann; De Waal, Alta; De Villiers, Johan Pieter (Springer, 2020-12)
    Current research on wildlife security games has minimal focus on performance evaluation. The performance of the rangers is evaluated by assessing their game utility, sometimes in comparison with their maximin utility, and ...
  • Evaluation of noise removal in signals by LULU operators 
    Fabris-Rotelli, Inger Nicolette; Van Oldenmark, K.; Van Staden, Paul Jacobus (South African Statistical Association, 2010-11)
    The LULU smoothers are effective nonlinear smoothers for signals. We investigate their ability to remove different noise types, namely symmetrical and skewed, as well as heavy- and light-tailed, thereby uncovering the true ...
  • Evaluation of predictive CYP2C19 genotyping assays relative to measured phenotype in a South African cohort 
    Dodgen, Tyren Mark; Drögemöller, Britt I.; Wright, Galen E.B.; Warnich, Louise; Steffens, Francois E.; Cromarty, Allan Duncan; Alessandrini, Marco; Pepper, Michael Sean (Future Medicine, 2015-08)
    AIM : To align predicted and measured CYP2C19 phenotype in a South African cohort. MATERIALS AND METHODS : Genotyping of CYP2C19*2, *3, *9, *15, *17, *27 and *28 was performed using PCR-RFLP, and an Activity Score (AS) ...
  • Evaluation of radiation awareness among oral health care providers in South Africa 
    Vilborn, Piret; Uys, Andre; Yakoob, Zarah; Cronje, Tanita (South African Dental Association, 2021-04)
    AIMS AND OBJECTIVES : The aim of this study was to assess the awareness of oral health care providers and dental students regarding radiation safety, protection and legislation pertaining to dental radiography in South ...
  • Evolutionary support vector regression for monitoring Poisson profiles 
    Yeganeh, Ali; Abbasi, Saddam Akber; Shongwe, Sandile Charles; Malela-Majika, Jean-Claude; Shadman, Ali Reza (Springer, 2024-03)
    Many researchers have shown interest in profile monitoring; however, most of the applications in this field of research are developed under the assumption of normal response variable. Little attention has been given to ...
  • Exact nonnull distribution of Wilks' statistic : the ratio and product of independent components 
    Bekker, Andriette, 1958-; Roux, Jacobus J.J.; Arashi, Mohammad (Elsevier, 2011-03)
    The study of the noncentral matrix variate beta type distributions has been sidelined because the final expressions for the densities depend on an integral that has not been resolved in an explicit way. We derive an exact ...
  • An expert-driven causal model of the rhino poaching problem 
    Koen, Hildegarde; De Villiers, Johan Pieter; Roodt, Henk; De Waal, Alta (Elsevier, 2017-03)
    A significant challenge in ecological modelling is the lack of complete sets of high-quality data. This is especially true in the rhino poaching problem where data is incomplete. Although there are many poaching attacks, ...