1. Mechanical Engineering DepartmentAnkara Yıldırım Beyazıt University 06010 Ankara Turkey
2. Railway Research and Technology Centre Turkish State Railways, 06105 Ankara Turkey
3. Graduate School of Sciences and Technology for InnovationYamaguchi University Ube 755‐8611 Japan
4. Mechanical Engineering DepartmentYamaguchi University Ube 755‐8611 Japan