1. Faculty of Computer Science and Cybernetics; T.Shevchenko National University of Kyiv; Volodymyrska 64 Kyiv 01030 Ukraine
2. CIRAD, UMR CBGP; Montpellier F-34398 France
3. CNLAA, BP125; Inezgane 86343 Morocco
4. University Ibn Zohr; Agadir Morocco