1. Department of Convergence IT Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyungbuk, Korea
2. School of Electronic Engineering, Kumoh National Institute of Technology, Gumi, Gyungbuk, Korea
3. Department of Electrical Engineering, POSTECH, Pohang, Gyungbuk, Korea
4. Faculty of Engineering of the University of Porto, Porto, Portugal