scholarly journals Geodesic Distance Computation via Virtual Source Propagation

2021 ◽  
Vol 40 (5) ◽  
pp. 247-260
Author(s):  
P. Trettner ◽  
D. Bommes ◽  
L. Kobbelt
Keyword(s):  
Geodesic Distance ◽  
Virtual Source ◽  
Distance Computation

Curvature-based anisotropic geodesic distance computation for  parametric and implicit surfaces

2009 ◽  
Vol 25 (8) ◽  
pp. 743-755 ◽  
Author(s):  
Joon-Kyung Seong ◽  
Won-Ki Jeong ◽  
Elaine Cohen
Keyword(s):  
Geodesic Distance ◽  
Implicit Surfaces ◽  
Distance Computation

Circle Approximations on Spheroids

2011 ◽  
Vol 64 (4) ◽  
pp. 739-749 ◽  
Author(s):  
Young Joon Ahn ◽  
Jian Cui ◽  
Christoph Hoffmann
Keyword(s):  
Approximation Method ◽  
Hausdorff Distance ◽  
Geodesic Distance ◽  
Approximation Error ◽  
The Other ◽  
Distance Computation ◽  
The Earth

We present an approximation method for geodesic circles on a spheroid. Our ap­proximation curve is the intersection of two spheroids whose axes are parallel, and it interpolates four points of the geodesic circle. Our approximation method has two merits. One is that the approximation curve can be obtained algebraically, and the other is that the approximation error is very small. For example, our approximation of a circle of radius 1000 km on the Earth has error 1·13 cm or less. We analyze the error of our approximation using the Hausdorff distance and confirm it by a geodesic distance computation.

scholarly journals Parallel and Scalable Heat Methods for Geodesic Distance Computation

2021 ◽  
Vol 43 (2) ◽  
pp. 579-594 ◽  
Author(s):  
Jiong Tao ◽  
Juyong Zhang ◽  
Bailin Deng ◽  
Zheng Fang ◽  
Yue Peng ◽  
...  
Keyword(s):  
Geodesic Distance ◽  
Distance Computation

Development of a conical anode Fe-gun for low voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 978-979
Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Low Voltage ◽  
Irradiation Damage ◽  
Cold Cathode ◽  
Virtual Source ◽  
Source Position ◽  
Electrostatic Lens ◽  
Electrostatic Lenses ◽  
Wide Range

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.

Novel geodesic distance Fourier shape descriptor

2010 ◽  
Vol 30 (2) ◽  
pp. 362-363
Author(s):  
Sheng CHEN ◽  
Xun LIU
Keyword(s):  
Geodesic Distance ◽  
Shape Descriptor
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