1. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, R.O.C.
2. Department of Engineering and System Science, National Tsing Hwa University, Hsinchu, Taiwan, R.O.C.
3. Center for General Education, Chung Chou Institute of Technology, Changhua County 510, Taiwan, R.O.C.
4. Department of Applied Science, National Hsinchu University of Education, Hsinchu 30014, Taiwan, R.O.C.