The document appears to be a technical report or paper containing 20 figures labeled Fig. 1 through Fig. 20 grouped into 13 numbered sections, with some sections containing single figures and other sections containing multiple figures. The document focuses on presenting and discussing the 20 labeled figures but provides no other contextual information.

1. 1

2. 2
Fig.1 Fig.2
Fig.3 Fig.4

3. 3
Fig.5 Fig.6
Fig.7 Fig.8

4. Fig.9

5. 5
Fig.10

6. 6
Fig.11

7. 7
Fig.12 Fig.13
Fig.14

8. 8
Fig.15
Fig.12

9. 9
Fig.16

10. 10
Fig.17

11. 11
Fig.18

12. 12
Fig.19

13. 13
Fig.20