1. Ph.D. Student and Research Assistant, Dept. of Mathematics, Dokuz Eylul Univ., Tnaztepe Campus, Buca, Izmir 35390, Turkey (corresponding author). ORCID: .
2. Professor, School of Mathematics, Univ. of East Anglia, Norwich, U.K. NR4 7TJ.
3. Professor, Dept. of Mathematics, Izmir Institute of Technology, Urla, Izmir 35430, Turkey.