Affiliation: | (1) School of Computing Science, Middlesex University, Trent Park, Bramley Road, London, N14 4YZ, UK;(2) Department of Computer Science and Information Systems, University of Jyväskylä, P.O. Box 35 (Agora), FIN 40014 Jyväskylä, Finland;(3) Faculty of Science, Higher Technical School of Computer Engineering, Department of Informatics, Valladolid University, Valladolid, Spain;(4) Faculty of Systems Engineering, Southampton Institute, East Park Terrace, Southampton, Hampshire, SO14 0YN, UK |