1. 1 School of Engineering of University of Minho , Portugal
2. 2 School of Engineering of University of Minho , Portugal
3. 3 School of Engineering of University of Minho , Portugal
4. 4 School of Engineering of University of Minho , Portugal
5. 5 School of Engineering of University of Minho , Portugal
6. 6 School of Engineering of University of Minho , Portugal
7. 7 School of Engineering of University of Minho , Portugal