Using 3D Geometry Systems to Find Theorems of Billiard Trajectories in Polyhedra

2019 ◽  
pp. 255-273
Author(s):  
Heinz Schumann
Keyword(s):  
3D Geometry

Use of Magnetic Resonance Imaging (MRI) to Determine the 3D Geometry in the Human Rectum

Endoscopy ◽  
2004 ◽  
Vol 36 (10) ◽  
Author(s):  
BP McMahon ◽  
JB Frøkjær ◽  
A Bergmann ◽  
DH Liao ◽  
E Steffensen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
3D Geometry ◽  
Human Rectum ◽  
Magnetic Resonance Imaging Mri

A Study on Utilization of Three-Dimensional Sensor Lip Image for Developing a Pronunciation Recognition System

2019 ◽  
Vol 63 (5) ◽  
pp. 50402-1-50402-9 ◽  
Author(s):  
Ing-Jr Ding ◽  
Chong-Min Ruan
Keyword(s):  
Principal Component Analysis ◽  
Automatic Speech Recognition ◽  
Feature Fusion ◽  
Three Dimensional ◽  
Principal Component ◽  
Recognition System ◽  
Geometrical Characteristics ◽  
3D Geometry ◽  
Different Types ◽  
The Disabled

Abstract The acoustic-based automatic speech recognition (ASR) technique has been a matured technique and widely seen to be used in numerous applications. However, acoustic-based ASR will not maintain a standard performance for the disabled group with an abnormal face, that is atypical eye or mouth geometrical characteristics. For governing this problem, this article develops a three-dimensional (3D) sensor lip image based pronunciation recognition system where the 3D sensor is efficiently used to acquire the action variations of the lip shapes of the pronunciation action from a speaker. In this work, two different types of 3D lip features for pronunciation recognition are presented, 3D-(x, y, z) coordinate lip feature and 3D geometry lip feature parameters. For the 3D-(x, y, z) coordinate lip feature design, 18 location points, each of which has 3D-sized coordinates, around the outer and inner lips are properly defined. In the design of 3D geometry lip features, eight types of features considering the geometrical space characteristics of the inner lip are developed. In addition, feature fusion to combine both 3D-(x, y, z) coordinate and 3D geometry lip features is further considered. The presented 3D sensor lip image based feature evaluated the performance and effectiveness using the principal component analysis based classification calculation approach. Experimental results on pronunciation recognition of two different datasets, Mandarin syllables and Mandarin phrases, demonstrate the competitive performance of the presented 3D sensor lip image based pronunciation recognition system.

scholarly journals Numerical Analysis of the Bond Strength between Two Methacrylic Polymers by Surface Modification

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3927
Author(s):  
Joanna Taczała ◽  
Katarzyna Rak ◽  
Jacek Sawicki ◽  
Michał Krasowski
Keyword(s):  
Numerical Analysis ◽  
Bond Strength ◽  
Angular Position ◽  
Fem Analysis ◽  
Groove Depth ◽  
Chemical Reagent ◽  
Shear Process ◽  
3D Geometry ◽  
The Right ◽  
Artificial Teeth

The creation of acrylic dentures involves many stages. One of them is to prepare the surfaces of artificial teeth for connection with the denture plates. The teeth could be rubbed with a chemical reagent, the surface could be developed, or retention hooks could be created. Preparation of the surface is used to improve the bond between the teeth and the plate. Choosing the right combination affects the length of denture use. This work focuses on a numerical analysis of grooving. The purpose of this article is to select the shape and size of the grooves that would most affect the quality of the bond strength. Two types of grooves in different dimensional configurations were analyzed. The variables were groove depth and width, and the distance between the grooves. Finally, 24 configurations were obtained. Models were analyzed in terms of their angular position to the loading force. Finite element method (FEM) analysis was performed on the 3D geometry created, which consisted of two polymer bodies under the shear process. The smallest values of the stresses and strains were characterized by a sample with parallel grooves with the grooving dimensions width 0.20 mm, thickness 0.10 mm, and distance between the grooves 5.00 mm, placed at an angle of 90°. The best dimensions from the parallel (III) and cross (#) grooves were compared experimentally. Specimens with grooving III were not damaged in the shear test. The research shows that the shape of the groove affects the distribution of stresses and strains. Combining the selected method with an adequately selected chemical reagent can significantly increase the strength of the connection.

scholarly journals Extensive Analyses of Superconducting Cables 3D Geometry With Advanced Tomographic Examinations

2021 ◽  
Vol 31 (5) ◽  
pp. 1-5
Author(s):  
L. Zani ◽  
I. Tiseanu ◽  
M. Chiletti ◽  
D. Dumitru ◽  
M. Lungu ◽  
...  
Keyword(s):  
3D Geometry ◽  
Superconducting Cables

scholarly journals Numerical Homogenization of Multi-Layered Corrugated Cardboard with Creasing or Perforation

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3786
Author(s):  
Tomasz Garbowski ◽  
Anna Knitter-Piątkowska ◽  
Damian Mrówczyński
Keyword(s):  
Computational Models ◽  
Load Capacity ◽  
Torsional Stiffness ◽  
Numerical Homogenization ◽  
Corrugated Board ◽  
3D Geometry ◽  
Corrugated Cardboard ◽  
Numerical Tools ◽  
Packaging Industry ◽  
Theoretical Considerations

The corrugated board packaging industry is increasingly using advanced numerical tools to design and estimate the load capacity of its products. This is why numerical analyses are becoming a common standard in this branch of manufacturing. Such trends cause either the use of advanced computational models that take into account the full 3D geometry of the flat and wavy layers of corrugated board, or the use of homogenization techniques to simplify the numerical model. The article presents theoretical considerations that extend the numerical homogenization technique already presented in our previous work. The proposed here homogenization procedure also takes into account the creasing and/or perforation of corrugated board (i.e., processes that undoubtedly weaken the stiffness and strength of the corrugated board locally). However, it is not always easy to estimate how exactly these processes affect the bending or torsional stiffness. What is known for sure is that the degradation of stiffness depends, among other things, on the type of cut, its shape, the depth of creasing as well as their position or direction in relation to the corrugation direction. The method proposed here can be successfully applied to model smeared degradation in a finite element or to define degraded interface stiffnesses on a crease line or a perforation line.

Urban scene recognition by graphical model and 3D geometry

2011 ◽  
Vol 18 (3) ◽  
pp. 110-119 ◽  
Author(s):  
Ke-yan REN ◽  
Han-xu SUN ◽  
Qing-xuan JIA ◽  
Yao-hong WU ◽  
Wei-yu ZHANG ◽  
...  
Keyword(s):  
Graphical Model ◽  
Scene Recognition ◽  
3D Geometry ◽  
Urban Scene

Dataset Construction to Explore Chemical Space with 3D Geometry and Deep Learning

2021 ◽  
Vol 61 (3) ◽  
pp. 1095-1104
Author(s):  
Jianing Lu ◽  
Song Xia ◽  
Jieyu Lu ◽  
Yingkai Zhang
Keyword(s):  
Deep Learning ◽  
Chemical Space ◽  
3D Geometry

Coordinate-Free Analysis of Mitral Valve Dynamics in Normal and Ischemic Hearts

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Paul Dagum ◽  
Tomasz A. Timek ◽  
G. Randall Green ◽  
David Lai ◽  
George T. Daughters ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Color Doppler ◽  
Mitral Annulus ◽  
Left Ventricular ◽  
Free System ◽  
Ring Annuloplasty ◽  
3D Geometry ◽  
Valve Function ◽  
Valve Dynamics ◽  
Radiopaque Markers

Background —The purpose of this investigation was to study mitral valve 3D geometry and dynamics by using a coordinate-free system in normal and ischemic hearts to gain mechanistic insight into normal valve function, valve dysfunction during ischemic mitral regurgitation (IMR), and the treatment effects of ring annuloplasty. Methods and Results —Radiopaque markers were implanted in sheep: 9 in the ventricle, 1 on each papillary tip, 8 around the mitral annulus, and 1 on each leaflet edge midpoint. One group served as a control (n=7); all others underwent flexible Tailor partial (n=5) or Duran complete (n=6) ring annuloplasty. After an 8±2-day recovery, 3D marker coordinates were measured with biplane videofluoroscopy before and during posterolateral left ventricular ischemia, and MR was assessed by color Doppler echocardiography. Papillary to annular distances remained constant throughout the cardiac cycle in normal hearts, during ischemia, and after ring annuloplasty with either type of ring. Papillary to leaflet edge distances similarly remained constant throughout ejection. During ischemia, however, the absolute distances from the papillary tips to the annulus changed in a manner consistent with leaflet tethering, and IMR was observed. In contrast, during ischemia in either ring group, those distances did not change from preischemia, and no IMR was observed. Conclusions —This analysis uncovered a simple pattern of relatively constant intracardiac distances that describes the 3D geometry and dynamics of the papillary tips and leaflet edges from the dynamic mitral annulus. Ischemia perturbed the papillary-annular distances, and IMR occurred. Either type of ring annuloplasty prevented such changes, preserved papillary-annular distances, and prevented IMR.

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