Affiliation: | a Department of Electrical & Electronic Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar 31750 Tronoh, Perak Darul Ridzuan, Malaysia b Department of Electrical Engineering, Universitas Gadjah Mada, Jalan Grafika 2, Kampus UGM, Jogjakarta 55281, Indonesia |