1. Laboratory of Biophysics, Department of Physics, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
2. African Center of Excellence in Information and Communication Technologies, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
3. International Center for Complex Systems, Faculty of Science, University of Yaound I, P.O. Box 812, Yaounde, Cameroon
4. Complex Systems, Faculty of Science, University of Maroua, P.O. Box 814, Maroua, Cameroon
5. Laboratory of Mechanics, Department of Physics, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon
6. Botswana International University of Science and Technology, Private Bag 16, Palapye, Botswana