1. Associate Professor, Dept. of Civil Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan Univ., P.O. Box 1915, Kathmandu, Nepal.
2. Assistant Professor, Dept. of Civil Engineering, Univ. of Aveiro, 3810-193 Aveiro, Portugal.
3. Assistant Professor, Dept. of Economics, Management and Industrial Engineering, Univ. of Aveiro, 3810-193 Aveiro, Portugal (corresponding author).
4. Associate Professor, Dept. of Economics, Management and Industrial Engineering, Univ. of Aveiro, 3810-193 Aveiro, Portugal.