1. Department of Mathematics and General Sciences, Prince Sultan University, P. O. Box 66833, Riyadh 11586, Saudi Arabia
2. Department of Medical Research, China Medical University, Taichung 40402, Taiwan
3. Department of Computer Sciences and Information Engineering, Asia University, Taichung, Taiwan
4. Department of Mathematics, University of Science and Technology, Bannu, 28100 Khyber Pakhtunkhwa, Pakistan
5. Institute of Research and Development of Processes, University of the Basque Country, Campus of Leioa (Bizkaia), P.O. Box 644 Bilbao, Barrio Sarriena, 48940 Leioa, Spain