1. Center for Nonlinear Dynamics, Defense University, Ethiopia
2. Department of Mechanical, Petroleum and Gas Engineering, Faculty of Mines and Petroleum Industries, University of Maroua, P.O. Box 46, Maroua, Cameroon
3. Department of Physics, Higher Teacher Training College, The University of Bamenda, P.O. Box 39 Bamenda, Cameroon
4. Laboratory of Electronics and Signal Processing (LETS), Department of Physics, Faculty of Science, University of Dschang, P. O. Box 67, Dschang, Cameroon
5. School of Electronics and Telecommunications, Hanoi University of Science and Technology, 01 Dai Co Viet, Hanoi, Vietnam