Departmentof Computing, University of Western Sydney, Nepean, P.O. Box 10, Kingswood NSW 2474, Australia;Centre for Parallel Processing and industrial Control, Charles Sturt University, Mitchell, Bathurst, NSW 2795, Australia;Centre for Parallel Processing and industrial Control, Charles Sturt University, Mitchell, Bathurst, NSW 2795, Australia;Centre for Parallel Processing and industrial Control, Charles Sturt University, Mitchell, Bathurst, NSW 2795, Australia;Centre for Parallel Processing and industrial Control, Charles Sturt University, Mitchell, Bathurst, NSW 2795, Australia