Dr. Emil Krén is a retired scientist in solid state physics, presently a consultant in information technology at KFKI System Integration Ltd., Budapest, Hungary.

You can contact him at kren@sunserv.kfki.hu

Dr. Dániel Marx is a researcher at the Department of Computer Science and Information Theory, Budapest University of Technology and Economics, Budapest, Hungary.

You can contact him at marx@inf.bme.hu