scholarly journals Coarse Fingerprint Registration Using Orientation Fields

2005 ◽  
Vol 2005 (13) ◽  
Author(s):  
Neil Yager ◽  
Adnan Amin
Keyword(s):  
Orientation Fields

scholarly journals Anisotropic x-ray scattering and orientation fields in cardiac tissue cells

2017 ◽  
Vol 19 (1) ◽  
pp. 013012 ◽  
Author(s):  
M Bernhardt ◽  
J-D Nicolas ◽  
M Eckermann ◽  
B Eltzner ◽  
F Rehfeldt ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientation Fields ◽  
Tissue Cells ◽  
Ray Scattering

Investigation of Parameter Spaces for Topology Optimization With Three-Dimensional Orientation Fields for Multi-Axis Additive Manufacturing

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Joseph R. Kubalak ◽  
Alfred L. Wicks ◽  
Christopher B. Williams
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Design Space ◽  
Mechanical Performance ◽  
Unit Length ◽  
Three Dimensions ◽  
Layer By Layer ◽  
Material Distribution ◽  
Orientation Fields ◽  
Material Orientation

Abstract The layer-by-layer deposition process used in material extrusion (ME) additive manufacturing results in inter- and intra-layer bonds that reduce the mechanical performance of printed parts. Multi-axis (MA) ME techniques have shown potential for mitigating this issue by enabling tailored deposition directions based on loading conditions in three dimensions (3D). Planning deposition paths leveraging this capability remains a challenge, as an intelligent method for assigning these directions does not exist. Existing literature has introduced topology optimization (TO) methods that assign material orientations to discrete regions of a part by simultaneously optimizing material distribution and orientation. These methods are insufficient for MA–ME, as the process offers additional freedom in varying material orientation that is not accounted for in the orientation parameterizations used in those methods. Additionally, optimizing orientation design spaces is challenging due to their non-convexity, and this issue is amplified with increased flexibility; the chosen orientation parameterization heavily impacts the algorithm’s performance. Therefore, the authors (i) present a TO method to simultaneously optimize material distribution and orientation with considerations for 3D material orientation variation and (ii) establish a suitable parameterization of the orientation design space. Three parameterizations are explored in this work: Euler angles, explicit quaternions, and natural quaternions. The parameterizations are compared using two benchmark minimum compliance problems, a 2.5D Messerschmitt–Bölkow–Blohm beam and a 3D Wheel, and a multi-loaded structure undergoing (i) pure tension and (ii) three-point bending. For the Wheel, the presented algorithm demonstrated a 38% improvement in compliance over an algorithm that only allowed planar orientation variation. Additionally, natural quaternions maintain the well-shaped design space of explicit quaternions without the need for unit length constraints, which lowers computational costs. Finally, the authors present a path toward integrating optimized geometries and material orientation fields resulting from the presented algorithm with MA–ME processes.

scholarly journals Orientation Fields Filtering by Derivates of a Gaussian

2003 ◽  
pp. 19-27
Author(s):  
Josef Bigun ◽  
Tomas Bigun ◽  
Kenneth Nilsson
Keyword(s):  
Orientation Fields

Möbius Moduli for Fingerprint Orientation Fields

2017 ◽  
Vol 60 (5) ◽  
pp. 651-660 ◽  
Author(s):  
Christina Imdahl ◽  
Carsten Gottschlich ◽  
Stephan Huckemann ◽  
Ken’ichi Ohshika
Keyword(s):  
Orientation Fields

Microstructure Evolution in Sintering of Alumina-Zirconia Ceramics Simulated by a Modified Phase Field Method

2012 ◽  
Vol 715-716 ◽  
pp. 788-793
Author(s):  
Cheng Yang Wei ◽  
Sai Yi Li
Keyword(s):  
Grain Size ◽  
Phase Field ◽  
Volume Fraction ◽  
Field Method ◽  
Density Field ◽  
Phase Field Method ◽  
Green Density ◽  
Zirconia Ceramics ◽  
Final Density ◽  
Orientation Fields

The densification and grain growth during sintering of alumina-zirconia (Al2O3ZrO2) ceramics were simulated using a modified phase field method, which considered simultaneously a density field, a composition filed and orientation fields. The results indicate that the model can capture the main microstructure features in the different stages of sintering. A higher relative green density leads to a higher final density and a larger final grain size in the sintered ceramics. A higher volume fraction of the ZrO2 phase results in a lower relative density and a smaller final grain size.

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