1. Department of Industrial Engineering, Yildiz Technical University, Istanbul 34349 Turkey, and also with the Graduate School of Science and Engineering, Istanbul 34220 Turkey.
2. Department of Industrial Engineering, Yildiz Technical University, Istanbul 34349 Turkey.
3. Royal School of Mines, Imperial College London SW7 2AZ, London U.K., and also with the Department of Industrial Engineering, Turkish Naval Academy, National Defence University, Istanbul 34940 Turkey.