1. School of Informatics, Computing, and Cyber Systems|Northern Arizona University, 1295 S. Knoles Dr., Building 90, Room 320, Flagstaff, AZ 86011, USA
2. Department of Physic, Faculty of Sciences, University of Yaounde 1, Yaounde 812, Cameroon
3. Department of Marine Engineering, University of A Coruña, Paseo de Ronda 51, 15011 A Coruña, Spain