1. Universitas Syiah Kuala Banda Aceh, Indonesia and Universitas Muhammadiyah,Doctoral Program. School of Engineering,Sumatera Utara,Indonesia
2. Universitas Sumatera Utara,Dept. of Electrical Engineering,Medan,Indonesia
3. Universitas Syiah Kuala,Dept. of Electrical and Computer Engineering,Banda Aceh,Indonesia