[1] Univ Limerick, Dept Engn, Limerick V94 T9PX, Ireland
[2] Univ Galway, Coll Sci & Engn, Galway H91 TK33, Ireland
[3] Univ LUM Jean Monnet, Dept Management Studies, I-70010 Casamassima, Italy
[4] Univ Witwatersrand, Wits Business Sch, ZA-2193 Johannesburg, South Africa