1. Department of Industrial Engineering,University of A Coruña, Avda. 19 de febrero s/n, 15405 Ferrol, A Coruña, Spain
2. Department of Construction and Manufacturing Engineering, University of Oviedo, Campus de Viesques, 33204 Gijón, Spain
3. Universidad Nacional de Colombia, Facultad de Minas, Sede Medellín, Carrera 80 No 65-223, 050034 Medellín, Colombia
4. Department of Mining Exploitation,University of Oviedo, Calle San Francisco, 1, 33004 Oviedo, Spain
5. Department of Computer Science,Yonsei University, Seoul 03722, South Korea