[1] University of Johannesburg, School of Electrical Engineering, Auckland Park, 2000, South Africa
[2] Johannesburg Machine Intelligence Laboratory, Auckland Park, 2006, South Africa
[3] University of Witwatersrand, School of Statistics and Actuarial Science, Johannesburg,2006, South Africa
[4] Queen Mary University of London, School of Electronic Engineering and Computer Science, London,E1 4NS, United Kingdom