1. School of Mining Engineering, University of the Witwatersrand, 2nd Floor, ARM Building, 1 Jan Smuts Avenue, Braamfontein, Johannesburg 2017, South Africa
2. School of Electrical and Information Engineering, University of the Witwatersrand, 2nd Floor, ARM Building, 1 Jan Smuts Avenue, Braamfontein, Johannesburg 2017, South Africa