Abrasive Surfaces Measured by Digital Optical Stereopsis

2009 ◽  
Vol 76-78 ◽  
pp. 465-470
Author(s):  
Dennis V. de Pellegrin ◽  
Andrew Torrance

The principle of stereopsis involves measuring an object’s geometry from a pair of images taken at slightly different viewing positions. This technique is frequently used for geographical mapping in satellite-based reconnaissance, however, the same practice has not been reliably applied at the other end of the scale spectrum: i.e. optical microscope imaging. The impediments have been identified and addressed in this work, concluding that optical stereopsis can be applied to microscopical surface examinations, and that the resulting digital elevation models can be of particular use in tribological investigations for performance and failure analysis.

2020 ◽  
Vol 12 (20) ◽  
pp. 3429
Author(s):  
Ziyang Xing ◽  
Zhaohui Chi ◽  
Ying Yang ◽  
Shiyi Chen ◽  
Huabing Huang ◽  
...  

Digital Elevation Models (DEMs) of Greenland provide the basic data for studying the Greenland ice sheet (GrIS), but little research quantitatively evaluates and compares the accuracy of various Greenland DEMs. This study uses IceBridge elevation data to evaluate the accuracies of the the Greenland Ice Map Project (GIMP)1 DEM, GIMP2 DEM, TanDEM-X, and ArcticDEM in their corresponding time ranges. This study also analyzes the impact of DEM accuracy and resolution on the accuracy of river network extraction. The results show that (1) within the time range covered by each DEM, TanDEM-X with an RMSE of 5.60 m has higher accuracy than the other DEMs in terms of absolute height accuracy, while GIMP1 has the lowest accuracy among the four Greenland DEMs, with an RMSE of 14.34 m. (2) Greenland DEMs are affected by regional errors and interannual changes. The accuracy in areas with elevations above 2000 m is higher than that in areas with elevations below 2000 m, and better accuracy is observed in the north than in the south. The stability of the ArcticDEM product is higher than those of the other three DEM products, and its RMSE standard deviation over multiple years is only 0.14 m. Therefore, the errors caused by the applications of DEMs with longer time spans are smaller. GIMP1 performs in an opposite manner, with a standard deviation of 2.39 m. (3) The river network extracted from TanDEM-X is close to the real river network digitized from remote sensing images, with an accuracy of 50.78%. The river network extracted from GIMP1 exhibits the largest errors, with an accuracy of only 8.83%. This study calculates and compares the accuracy of four Greenland DEMs and indicates that TanDEM-X has the highest accuracy, adding quantitative studies on the accuracy evaluation of various Greenland DEMs. This study also compares the results of different DEM river network extractions, verifies the impact of DEM accuracy on the accuracy of the river network extraction results, and provides an explorable direction for the hydrological analysis of Greenland as a whole.


10.1596/34445 ◽  
2020 ◽  
Author(s):  
Louise Croneborg ◽  
Keiko Saito ◽  
Michel Matera ◽  
Don McKeown ◽  
Jan van Aardt

Author(s):  
Oliver D. Patterson ◽  
Deborah A. Ryan ◽  
Xiaohu Tang ◽  
Shuen Cheng Lei

Abstract In-line E-beam inspection may be used for rapid generation of failure analysis (FA) results for low yielding test structures. This approach provides a number of advantages: 1) It is much earlier than traditional FA, 2) de-processing isn’t required, and 3) a high volume of sites can be processed with the additional support of an in-line FIB. Both physical defect detection and voltage contrast inspection modes are useful for this application. Voltage contrast mode is necessary for isolation of buried defects and is the preferred approach for opens, because it is faster. Physical defect detection mode is generally necessary to locate shorts. The considerations in applying these inspection modes for rapid failure analysis are discussed in the context of two examples: one that lends itself to physical defect inspection and the other, more appropriately addressed with voltage contrast inspection.


Author(s):  
P. Egger ◽  
C. Burmer

Abstract The area of embedded SRAMs in advanced logic ICs is increasing more and more. On the other hand smaller structure sizes and an increasing number of metal layers make conventional failure localization by using emission microscopy or liquid crystal inefficient. In this paper a SRAM failure analysis strategy will be presented independent on layout and technology.


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