School of Computer Engineering, Nanyang Technological University, Singapore. wumi0002@ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. wumi0002@ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. wumi0002@ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. wumi0002@ntu.edu.sg|School of Computer Engineering, Nanyang Technological University, Singapore. wumi0002@ntu.edu.sg