Document Type Master's Dissertation Author Ackermann, Maria Helena URN etd-08232011-123306 Document Title Mixture models based on power means and generalised Q-fractions Degree MSc Department Chemical Engineering Supervisor
Advisor Name Title Dr R Coetzer Co-Supervisor Prof W W Focke Supervisor Keywords
- Scheffé quadratic polynomial
- mixture experiments
- mixture models
- experimental design
- weighted power mean
- Wohl's Q-fractions
Date 2011-09-14 Availability unrestricted AbstractMixture experiments are widely applied. The Scheffé quadratic polynomial is the most popular mixture model in industry due to its simplicity, but it fails to accurately describe the behaviour of response variables that deviate greatly from linear blending. Higherorder Scheffé polynomials do possess the ability to predict such behaviour but become increasingly more complex to use and the number of estimable parameters grow exponentially . A parameter-parsimonious mixture model, developed from the linear blending rule with weighted power means and Wohl's Q-fractions, is introduced. Bootstrap is employed to analyse the model statistically. The model is proved to be flexible enough to model non-linear deviations from linear blending without losing the simplicity of the linear blending rule.
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Please cite as follows:
Ackermann, MH 2011, Mixture models based on power means and generalised Q-fractions, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-08232011-123306/ >
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