1. Division of Bioinformatics & Biostatistics, National Center for Toxicological Research, US Food & Drug Administration, Jefferson, AR 72079, USA
2. Graduate Institute of Biostatistics, China Medical University, Taichung, Taiwan.
3. Department of Public Health, Institute of Epidemiology & Preventive Medicine, National Taiwan University, Taipei, Taiwan
4. Department of Applied Mathematics, Feng Chia University, Taichung, Taiwan