Reza Tavakkoli-Moghaddam*, Mehdi Alinaghian, Alireza Salamat-Bakhsh and Narges Norouzi
* Corresponding author: Reza Tavakkoli-Moghaddam tavakoli@ut.ac.ir
Journal of Industrial Engineering International 2012, 8:4 doi:10.1186/2251-712X-8-4