1. School of Computing and Mathematics; Keele University; Keele Staffordshire ST5 5BG U.K
2. Faculty of Computer Science and Management; Wrocław University of Science and Technology; Wyb. Wyspianskiego 27 Wroclaw 50-370 Poland
3. Research Center for Statistics, Geneva School of Economics and Management; University of Geneva; Geneva Switzerland
4. Geneuro SA; Geneva Switzerland