1. Agro-Food Economics and Development (CREDA-UPC-IRTA), Parc Mediterrani de la Tecnologia, Edifici ESAB, 08860 Castelldefels, Spain
2. Department of Electrical Engineering, University of Engineering and Technology, Taxila 47050, Pakistan
3. Department of Civil and Environmental Engineering, Brunel University London, Uxbridge UB8 3PH, UK
4. School of Economics and Management, North China Electric Power University, Beijing 102206, China