Themistocles M. Rassias is professor of mathematics at the National Technical University of Athens. Rassias’ work has received a number of honors and awards and is credited in mathematical terminology, as Hyers–Ulam–Rassias stability for functional equations & the Aleksandrov–Rassias problem for isometric mappings. He has published as author or editor several books and volumes by Springer as well as serves as an editorial board member of several journals. His research interests include nonlinear analysis, global analysis, approximation theory, functional analysis, functional equations, analytic inequalities, metric geometry and their applications. Rassias received his PhD in mathematics from the University of California, Berkeley in 1976; his thesis advisor was Stephen Smale and his academic advisory was Shiing-Shen Chern.  Panos M. Pardalos serves as distinguished professor of industrial and systems engineering at the Universityof Florida. Additionally, he is the Paul and Heidi Brown Preeminent Professor of industrial and systems engineering. Pardalos is also an affiliated faculty member of the computer and information science department, the Hellenic Studies Center, and the biomedical engineering program. Additionally, he serves as the director of the Center for Applied Optimization. Pardalos is a world leading expert in global and combinatorial optimization. His recent research interests include network design problems, optimization in telecommunications, e-commerce, data mining, biomedical applications, and massive computing. Pardalos is a prolific author who lectures all over the world. He is the recipient of a multitude of fellowships and awards, the most recent of which is the Humboldt Research Award (2018).