1. Laboratory of Engineering Civil and Mechanic, National Advanced School of Engineering of Yaounde, University of Yaounde I, Yaounde, Cameroon
2. Department of Industrial and Mechanical Engineering, National Advanced School of Engineering of Yaounde, University of Yaounde I, Yaounde, Cameroon
3. Advanced Teacher’s Training School for Technical Education, Laboratory of Mechanical Engineering, University of Douala, Douala, Cameroon