1. Deggendorf Institute of Technology,Faculty of European Campus Rottal-Inn,Deggendorf,Germany
2. Institute for High Performance Computing and Networking,National Research Council of Italy,Palermo,italy
3. University of L’Aquila,Department of Information Engineering Computer Science and Mathematics,L’Aquila,italy
4. Free University of Bozen-Bolzano,Faculty of Computer Science,Bozen-Bolzano,italy