1. Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
2. Functional Materials and Nanotechnology Center of Excellence, School of Science, Walailak University, Nakhon Si Thammarat 80160, Thailand
3. Department of Statistics, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
4. Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand