A multimodal method for defect characterization of large-aperture optics

2021 ◽  
Author(s):  
Jian Chen ◽  
Weiyang Yu ◽  
Haifeng Zhou ◽  
Jian Zhang ◽  
Xi Wang ◽  
...  
2007 ◽  
Vol 4 (10) ◽  
pp. 3659-3663 ◽  
Author(s):  
S. Neretina ◽  
D. Grebennikov ◽  
R. A. Hughes ◽  
M. Weber ◽  
K. G. Lynn ◽  
...  

2013 ◽  
Vol 330 ◽  
pp. 504-509
Author(s):  
Yang Zheng ◽  
Jin Jie Zhou ◽  
Hui Zheng

Although many imaging algorithms such as ellipse and hyperbola algorithm can roughly locate defects in large plate-like structures with sparse guided wave arrays, quantitative characterization of them is still a challenging problem, especially for those small defects known as subwavelength defects. Scattering signals of defects contain abundant information so that can be used to evaluate defects. A defects recognition method using the S-matrix (scattering matrix) was presented. S-matrices of hole and crack with S0 mode incident were experimentally measured. The results show that defects can be recognized from the morphology of 2D S-matrix chart. This method has great potential to achieve more specific parameters of small defects with sparse guided wave arrays.


1997 ◽  
Vol 36 (Part 1, No. 2) ◽  
pp. 633-637
Author(s):  
Stewart A. Goodman ◽  
F. D. Auret

2013 ◽  
Vol 443 ◽  
pp. 012033 ◽  
Author(s):  
Werner Puff ◽  
Xiang Zhou ◽  
Bernd Oberdorfer ◽  
Boris Scherwitzl ◽  
Peter Parz ◽  
...  

2018 ◽  
Vol 68 (329) ◽  
pp. 149 ◽  
Author(s):  
A. Delgado ◽  
C. Pereira ◽  
J. De Brito ◽  
J. D. Silvestre

A statistical characterization of defects in 35 buildings and 98 wood floorings (softwood and hardwood floors, and laminated and engineered wood floors), their diagnostic methods and repair solutions is presented. An expert system for inspecting wood flooring, comprising the classification of defects, their most probable causes, diagnostic methods and repair techniques, was used. Results include age, affected area, severity and frequency of defects and their main causes, as well as appropriate diagnostic methods, preventive and curative repair solutions most prescribed and the most significant correlations. Scratches were detected in more than five sixths of the sample, highly associated with exterior mechanical actions, and with an inadequate finishing layer. Wearing of the finishing layer was detected in a quarter of the inspected floorings. Accordingly, the application of a suitable finishing layer and, alternatively, its replacement are the most prescribed repair techniques.


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