Department of Applied Mathematics Hong Kong Polytechnic University Hong Kong China;
Department of Mathematics Kano University of Science and Technology Wudil Nigeria;
JC School of Public Health and Primary Care Chinese University of Hong Kong Hong Kong China;
Shenzhen Research Institute of Chinese University of Hong Kong Shenzhen China;
JC School of Public Health and Primary Care Chinese University of Hong Kong Hong Kong China;
Shenzhen Research Institute of Chinese University of Hong Kong Shenzhen China;
Collage of Health Sciences Bayero Unuversity Kano Nigeria;
Department of Mathematics Federal University Dutse Dutse Nigeria;
Department of Applied Mathematics Hong Kong Polytechnic University Hong Kong China;