1. Type I configuration | ||
IA | 1 ring and 1 linear element. | |
IB | 1 ring and 2 linear elements. | |
IC | 1 ring and 3 or more linear elements. | |
2. Type II configuration | ||
IIA | 2 rings and 1 linear element. | |
IIB | 2 rings and 2 linear elements. | |
IIC | 2 rings and 3 linear elements | |
IID | 2 rings and 4 linear elements. | |
3. Type III configuration | ||
IIIA: 3 or more rings and 1 linear element. | ||
IIIB : 3 or more rings and 2 linear elements. | ||
IIIC : 3 or more rings and 3 linear elements. | ||
IIID : 3 or more rings and 4 or more linear elements. |