Institute of Statistics, National Tsing Hua University, Hsin-Chu City, 300, Taiwan. wphsieh@stat.nthu.edu.tw|Institute of Statistics, National Tsing Hua University, Hsin-Chu City, 300, Taiwan. wphsieh@stat.nthu.edu.tw|Institute of Statistics, National Tsing Hua University, Hsin-Chu City, 300, Taiwan. wphsieh@stat.nthu.edu.tw|Institute of Statistics, National Tsing Hua University, Hsin-Chu City, 300, Taiwan. wphsieh@stat.nthu.edu.tw