Dr. Gavriil Paltineanu was a professor in the Department of Mathematics and Computer Science, Technical University of Civil Engineering of Bucharest, and he was a member of editorial board in Mathematical Reports of Romanian Academy. His research interests are approximation theory, real analysis, and convexity. And he published 56 research papers, 4 monographs, 13 books, and 5 exercise books for students during his career. Dr. Ileana Gabriela Bucur is Associated Professor in the Department of Mathematics and Computer Science at the Civil Engineering faculty, Bucharest, Romania. She received her P.h.D. degree from University of Bucharest, in 1996. Her research includes knowledge in general topology, topological vector-ordered spaces, functional analysis, real analysis, and approximation theory. Dr. Mariana Zamfir is Assistant Professor in the Department of Mathematics and Computer Science of Technical University of Civil Engineering Bucharest, Romania. She received her Ph.D. degree in Mathematics at University of Bucharest, Romania, in 2012. Her fields of research include knowledge in spectral theory of operators, representations of Hilbert C*-modules and C*-algebras, projective representations, and completely positive linear maps.