School of Computer Engineering, Nanyang Technological University, Singapore. tim.oliver@pmail.ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. tim.oliver@pmail.ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. tim.oliver@pmail.ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. tim.oliver@pmail.ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. tim.oliver@pmail.ntu.edu.sg