Comparative study on surface reconstruction accuracy of stereo imaging devices for microsurgery

2015 ◽  
Vol 11 (1) ◽  
pp. 145-156 ◽  
Author(s):  
Andreas Schoob ◽  
Dennis Kundrat ◽  
Lüder A. Kahrs ◽  
Tobias Ortmaier
Keyword(s):  
Comparative Study ◽  
Surface Reconstruction ◽  
Stereo Imaging ◽  
Reconstruction Accuracy

The Design and Application of a New Type of Instrument for Testing the Worn Surface of Casing Wear

2008 ◽  
Author(s):  
Jianchun Fan ◽  
Qiang Chen ◽  
Laibin Zhang ◽  
Dong Wen
Keyword(s):  
Comparative Study ◽  
Surface Reconstruction ◽  
Wear Mechanism ◽  
3D Surface Reconstruction ◽  
3D Surface ◽  
Testing Data ◽  
New Type ◽  
Casing Wear ◽  
The Comparative Study ◽  
Worn Surface

In this paper, a new kind of instrument used specially for testing the worn surface of casing was introduced, its structure and testing principle was further elaborated. Meanwhile, the testing data were also used for the 3D surface reconstruction of the worn area of casing. The comparative study with SEM pictures could tell that the instrument performed very well and is quite helpful in the observation of worn rejoin of casing; the conclusions drawn from the study could be applied in the research of wear mechanism.

Surface Reconstruction of (123) and (111) Ge(Sn) Solid Solutions Induced by Tin Segregation

1998 ◽  
Vol 05 (01) ◽  
pp. 265-268 ◽  
Author(s):  
A. Rolland ◽  
A. Rouabah ◽  
F. Cabané
Keyword(s):  
Phase Diagram ◽  
Comparative Study ◽  
Surface Reconstruction ◽  
Solid Solutions ◽  
Surface Segregation ◽  
Fair Agreement ◽  
Kinetic Curves ◽  
Surface Reconstructions ◽  
Kinetics Of

We present a comparative study of tin segregation onto the (123) and (111) surfaces of a Ge(Sn)- 0.5 at. % bicrystal using the AES technique. Between 350°C and 450°C, the maximum segregated tin amount, about 1.25 monolayer, does not vary with the orientation of the surface or the temperature. This indicates that attractive Sn-Sn forces are involved in the segregated phase which is in fair agreement with the Ge-Sn phase diagram. The shape of the kinetic curves depends on the orientation. On the (111) surface, the formation of various structures in equilibrium with the bulk is correlated with surface reconstructions. First, Sn atoms take the place of Ge adatoms to form a 2D phase; then, Sn segregates in other superficial sites, which leads to the nucleation of denser 2D phases, such as (7 × 7) structure. On the (123) surface, Sn atoms take the place of Ge atoms in quasisubstitutional sites of the superficial layers; the kinetics of surface segregation is not sensitive to sub monolayer structures.

scholarly journals Advanced 3D Photogrammetric Surface Reconstruction of Extensive Objects by UAV Camera Image Acquisition

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2815 ◽  
Author(s):  
Michele Calì ◽  
Rita Ambu
Keyword(s):  
Surface Reconstruction ◽  
Large Scale ◽  
Image Acquisition ◽  
Three Dimensional ◽  
Geometric Parameters ◽  
Reconstruction Accuracy ◽  
Camera Image ◽  
Aerial Vehicle ◽  
Euclidean Distances

This paper proposes a replicable methodology to enhance the accuracy of the photogrammetric reconstruction of large-scale objects based on the optimization of the procedures for Unmanned Aerial Vehicle (UAV) camera image acquisition. The relationships between the acquisition grid shapes, the acquisition grid geometric parameters (pitches, image rates, camera framing, flight heights), and the 3D photogrammetric surface reconstruction accuracy were studied. Ground Sampling Distance (GSD), the necessary number of photos to assure the desired overlapping, and the surface reconstruction accuracy were related to grid shapes, image rate, and camera framing at different flight heights. The established relationships allow to choose the best combination of grid shapes and acquisition grid geometric parameters to obtain the desired accuracy for the required GSD. This outcome was assessed by means of a case study related to the ancient arched brick Bridge of the Saracens in Adrano (Sicily, Italy). The reconstruction of the three-dimensional surfaces of this structure, obtained by the efficient Structure-From-Motion (SfM) algorithms of the commercial software Pix4Mapper, supported the study by validating it with experimental data. A comparison between the surface reconstruction with different acquisition grids at different flight heights and the measurements obtained with a 3D terrestrial laser and total station-theodolites allowed to evaluate the accuracy in terms of Euclidean distances.

A comparative study of surface reconstruction of wurtzite GaN on (0001) sapphire by RF plasma-assisted molecular beam epitaxy

2001 ◽  
Vol 231 (1-2) ◽  
pp. 8-16 ◽  
Author(s):  
Kyeong K. Lee ◽  
William A. Doolittle ◽  
Tong-Ho Kim ◽  
April S. Brown ◽  
Gary S. May ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Comparative Study ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Rf Plasma

MBE Growth of GaN using NH3 and Plasma Sources

2000 ◽  
Vol 639 ◽  
Author(s):  
A.V. Sampath ◽  
A. Bhattacharyya ◽  
I. Sandeep ◽  
H.M. Ng ◽  
E. Iliopoulos ◽  
...  
Keyword(s):  
Comparative Study ◽  
Surface Reconstruction ◽  
Growth Temperature ◽  
Molecular Nitrogen ◽  
Catalytic Decomposition ◽  
Plasma Source ◽  
Mbe Growth ◽  
Plasma Sources ◽  
Plasma Activation ◽  
Aln Buffer

ABSTRACTWe report on a comparative study of the growth of GaN in an arsenic free MBE system using either the method of plasma activation of molecular nitrogen or catalytic decomposition of ammonia on a heated substrate. We find that while growth with a plasma source leads to smooth films only under Ga- rich conditions, growth with ammonia leads to smooth films under ammonia-rich conditions. In both cases we find a 2×2 surface reconstruction when using an AlN buffer, which is evidence that material grown with this buffer layer has the Ga-polarity. In the case of plasma growth we also investigated the use of a GaNbuffer and found that at the growth temperature the surface is unreconstructed, however it undergoes 3×3 reconstruction upon cooling to 300 °C. This observation is evidence that material grown on a GaN buffer has the N-polarity.

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