1. Department of Computer Science and Electronics, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
2. Faculty of Informatics, Institut Teknologi Telkom Purwokerto, Purwokerto 53147, Indonesia
3. School of Computing, Telkom University, Bandung 40257, Indonesia
4. Department of Electrical Engineering, University of Ulsan, Ulsan 680749, Republic of Korea