1 Railway Track Geometry Defect Modeling: Deterioration, Derailment 1 Risk and Optimal Repair 2 3 Qing He * , Hongfei Li, Debarun Bhattacharjya, Dhaivat P. Parikh, and Arun Hampapur 4 5 6 7 Qing He, Hongfei Li, Debarun Bhattacharjya 8 {qhe, liho, debarunb}@us.ibm.com 9 IBM T J Watson Research Center 1 10 1101 Kitchawan Rd/ Route 134 11 Yorktown Heights, NY 10598 12 13 Dhaivat P. Parikh 14 dhaivat.parikh@us.ibm.com 15 IBM Global Business Service 2 16 1177 S Belt Line Rd 17 Coppell, TX 75019-4642 USA 18 19 Arun Hampapur 20 arunh@us.ibm.com 21 IBM T J Watson Research Center 1 22 1101 Kitchawan Rd/ Route 134 23 Yorktown Heights, NY 10598 24 25 26 27 Revised on October 28 2012 28 29 30 Figures + Table = 10 31 Total words: 4987 + 10*250 = 7487 32 * Corresponding author, currently affiliated with Department of Civil Engineering and Department of Industrial Engineering, University at Buffalo, The State University of New York, Email: qinghe@buffalo.edu, Telephone: 716-645-3470