1. INTI International University, Faculty of Engineering and Quantity Surveying, Nilai 71800, Negeri Sembilan, Malaysia
2. Engineering Faculty, University of Mataram, Mataram, West Nusa Tenggara, Indonesia
3. Universitas Islam Kalimantan Muhammad Arsyad Al Banjari Banjarmasin, Banjarmasin, Indonesia
4. Student of Mechanical Engineering, UMP, Pekan, Malaysia