1. Department Mechanical Engineering; Centre for Mechanical Technology and Automation; University of Aveiro; 3810-193 Aveiro Portugal
2. School of Mechanical and Automotive Engineering; South China University of Technology; Tianhe Dist. Guangzhou 510640 China
3. Materials Mechanics Laboratory; Graduate Institute of Ferrous Technology; Pohang University of Science and Technology; San31 Hyoja-Dong, Nam-Ku Pohang 790-784 South Korea