1. a Department of Industrial Engineering , Rutgers University , P.O. Box 909, Piscataway, NJ, 08855-0909, USA.
2. b Programa de Pós-Granduaçã Engenharia de Produgao, Universidade Federal do Rio Grande do Sul , 90210 Porto Alegre RS, Piscataway, NJ, 08855-0909, Brasil.
3. c Department of Industrial Engineering , Keimyung University , Taegu 704–701, Korea.