Division of Software and Information Systems, School of Computer Engineering, Nanyang Technological University, Singapore-MIT Alliance, Nanyang Technological University, Singapore 639798 and Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Division of Software and Information Systems, School of Computer Engineering, Nanyang Technological University, Singapore-MIT Alliance, Nanyang Technological University, Singapore 639798 and Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.|Division of Software and Information Systems, School of Computer Engineering, Nanyang Technological University, Singapore-MIT Alliance, Nanyang Technological University, Singapore 639798 and Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Division of Software and Information Systems, School of Computer Engineering, Nanyang Technological University, Singapore-MIT Alliance, Nanyang Technological University, Singapore 639798 and Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.|Division of Software and Information Systems, School of Computer Engineering, Nanyang Technological University, Singapore-MIT Alliance, Nanyang Technological University, Singapore 639798 and Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Division of Software and Information Systems, School of Computer Engineering, Nanyang Technological University, Singapore-MIT Alliance, Nanyang Technological University, Singapore 639798 and Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.