[1] Norwegian Univ Sci & Technol, Fac Informat Technol & Elect Engn, Dept Comp Sci, Trondheim, Norway
[2] Univ Nottingham, Fac Engn, Dept Mech Mat & Mfg Engn, Human Factors Res Grp, Nottingham, England
[3] Univ Appl Sci Vorarlberg, User Ctr Technol Res Ctr, Dornbirn, Austria