1. Department of Healthcare Engineering, The Graduate School, Jeonbuk National University, 567 Baekje-daero, Jeonju 54896, Republic of Korea
2. Division of Biomedical Engineering, College of Engineering, Jeonbuk National University, 567 Baekje-daero, Jeonju 54896, Republic of Korea
3. Research Center for Healthcare and Welfare Instrument for the Elderly, Jeonbuk National University, 567 Baekje-daero, Jeonju 54896, Republic of Korea