[1] Addis Ababa Inst Technol, Sch Multidisciplinary Engn, Ctr Mat Engn, Addis Ababa 1000, Ethiopia
[2] Natl Metrol Inst Ethiopia, Ctr Dimens Metrol Dept, Sci Metrol Directorate, Addis Ababa 5722, Ethiopia
[3] North West Univ, HySA Infrastruct Ctr Competence, South Africa NWU, Fac Engn, ZA-2531 Potchefstroom, South Africa
[4] Natl Inst Theoret & Computat Sci, ZA-2000 Johannesburg, South Africa