1. Ph.D. Scholar, Dept. of Mathematics, Quaid-i-Azam Univ., Islamabad 45320, Pakistan (corresponding author).
2. Assistant Professor, Dept. of Mathematics, Comsats Institute of Information Technology, Park Rd., Chak Shahzad, Islamabad 44000, Pakistan.
3. Professor, Dept. of Mathematics, Faculty of Science, King Abdulaziz Univ., Jeddah, Saudi Arabia 21589.
4. Professor, Dept. of Mathematics, Quaid-i-Azam Univ., Islamabad 45320, Pakistan; and Assistant Professor, Dept. of Mathematics, Faculty of Science, King Abdulaziz Univ., Jeddah, Saudi Arabia 21589.
5. Dept. of Electrical and Computer Engineering, Faculty of Engineering, King Abdulaziz Univ., Jeddah, Saudi Arabia 21589.