1. a Institute of Industrial Engineering, National Taiwan University , 1, Section 4, Roosevelt Rd , Taipei , 106 , Taiwan
2. b Department of Computing and Software , McMaster University , 1280 Main Street West, Hamilton , Ontario , Canada , L8S 4L7
3. c School of Operations Research and Information Engineering , Cornell University , 226 Rhodes Hall, Ithaca , NY , 14853 , USA