Department of Computer Science and Communication Engineering, Providence University, 200, Sec, 7, Taiwan Boulevard, 43301 Shalu Dist,, Taichung, Taiwan. fang@pu.edu.tw.|Department of Computer Science and Communication Engineering, Providence University, 200, Sec, 7, Taiwan Boulevard, 43301 Shalu Dist,, Taichung, Taiwan. fang@pu.edu.tw.|Department of Computer Science and Communication Engineering, Providence University, 200, Sec, 7, Taiwan Boulevard, 43301 Shalu Dist,, Taichung, Taiwan. fang@pu.edu.tw.|Department of Computer Science and Communication Engineering, Providence University, 200, Sec, 7, Taiwan Boulevard, 43301 Shalu Dist,, Taichung, Taiwan. fang@pu.edu.tw.|Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India. ns@mbu.iisc.ernet.in.|Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India. ns@mbu.iisc.ernet.in.