1. Department of Electrical Engineering, College of Engineering, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan
2. Department of Electronic Engineering, College of Engineering, National Changhua University of Education, Chunghua 50007, Taiwan
3. Graduate Institute of Business Administration, College of Management, Fu Jen Catholic University, New Taipei City 24205, Taiwan
4. Universal Microwave Technology, Inc., Keelung 20647, Taiwan
5. Wistron Corporation, Taipei 11469, Taiwan