George Athanasopoulos Aphrodite Tsalgatidou Michael Pantazoglou 174-181 2006 conf/IEEEscc/2006 IEEE SCC http://doi.ieeecomputersociety.org/10.1109/SCC.2006.59 db/conf/IEEEscc/scc2006.html#AthanasopoulosTP06