Mohammad Bagher Ghaemi is an associate professor of mathematics at the Iran University of Science and Technology, Tehran. His research interests include operator theory, nonlinear analysis, approximation theory, functional analysis, functional equations, inequalities and applications. Professor Ghaemi received his PhD in mathematics from Glasgow University, Scotland, in 2000; his PhD advisor was P.G. Spain. He has published more than 60 papers. Nahid Gharakhanlu received her PhD in pure mathematics from the Iran University of Science and Technology, Tehran in 2017.  Her PhD advisor was Mohammad Bagher Ghaemi. Her research interests include matrix analysis, functional analysis, operator theory, linear algebra, inequalities and their applications. Themistocles M. Rassias is professor of mathematics at the National Technical University of Athens. His research interests include nonlinear analysis, global analysis, approximation theory, functional analysis, functional equations, inequalities and their applications. Professor Rassias received his PhD in mathematics from the University of California, Berkeley in 1976; his thesis advisor was Stephen Smale and his academic advisor was Shiing-Shen Chern. In addition to his extensive list of journal publications, Professor Rassias has published as author or volume editor several books published with Springer. Th. M. Rassias has received several awards and is an active editorial board member of an array of journals in mathematical analysis and optimization. His publications have received a large number of citations, with h-index 46. Reza Saadati is a member of the mathematics department of the Iran University of Science and Technology, Tehran. His research interests include nonlinear analysis and applications. Professor Saadati received his PhD in mathematics from Amirkabir University of Technology, in 2010; his PhD advisor was S. M. Vaezpour. He has published several books with Springer.