ARS MATHEMATICA CONTEMPORANEA
Norbert Seifter is 60!
Norbert Seifter (left) Participants of the LL2016 Graph Theory Seminar in Judenburg (right).
In 2016, the traditional Ljubljana-Leoben Graph Theory Seminar took place in Judenburg, Austria, the home town of Norbert Seifter. See the page of LL2016: https://www.math.tugraz. at/mathc/ll2016/. Judenburg was chosen in order to honour Norbert's 60-th birthday, with a special session dedicated to Bojan Mohar who also turned 60 this year.
From the first meeting in Ljubljana in 1981, Austrian and Slovenian graph theorists established a sound and fruitful collaboration: frequent research visits, bilateral projects, exchange of students, and organising workshops - all this resulted in numerous joint publications.
Norbert has been an active participant and organizer of many of these events ever since he started, upon completing his PhD in 1981, his professional career at the Department of Applied Mathematics at Montanuniversitaet Leoben, where to this day holds regular courses on programming, optimisation, operations research, numerical analysis, information systems, neural networks, fuzzy-sets and fuzzy-logic. Fields of his research interest include matrix theory, automorphism groups of undirected and directed graphs, highly arc transitive digraphs, growth of graphs and groups, combinatorial group theory, dominating sets in undirected and directed graphs, and several other topics in discrete applied mathematics.
Happy birthday, Norbert! And remain so enthusiastic about the structure of infinite graphs still for many years to come.
Aleksander Malnic Editor
xxii