scholarly journals Three-Dimensional Diagnosis and Visualization Supports in Orthodontics Based on Reverse Engineering and Solid Free-Form Fabrication Techniques

10.5772/7682 ◽  
2010 ◽  
Author(s):  
Alida Mazzoli ◽  
Michele Germani ◽  
Roberto Raffaeli ◽  
Antonio Gracco
Keyword(s):  
Reverse Engineering ◽  
Three Dimensional ◽  
Free Form ◽  
Dimensional Diagnosis ◽  
Solid Free Form Fabrication

scholarly journals An Integrated Reverse Engineering Approach for Accuracy Control of Free-Form Objects

2016 ◽  
Vol 63 (4) ◽  
pp. 647-663
Author(s):  
Vimal Kumar Pathak ◽  
Chitresh Nayak ◽  
Amit Kumar Singh ◽  
Himanshu Chaudhary
Keyword(s):  
Reverse Engineering ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Point Clouds ◽  
3D Models ◽  
Digital Model ◽  
Surface Generation ◽  
Free Form ◽  
Accuracy Control ◽  
Prosthetic Socket

Abstract Computer-aided tools help in shortening and eradicating numerous repetitive tasks that reduces the gap between digital model and actual product. Use of these tools assists in realizing free-form objects such as custom fit products as described by a stringent interaction with the human body. Development of such a model presents a challenging situation for reverse engineering (RE) which is not analogous with the requirement for generating simple geometric models. Hence, an alternating way of producing more accurate three-dimensional models is proposed. For creating accurate 3D models, point clouds are processed through filtering, segmentation, mesh smoothing and surface generation. These processes help in converting the initial unorganized point data into a 3D digital model and simultaneously influence the quality of model. This study provides an optimum balance for the best accuracy obtainable with maximum allowable deviation to lessen computer handling and processing time. A realistic non trivial case study of free-form prosthetic socket is considered. The accuracy obtained for the developed model is acceptable for the use in medical applications and FEM analysis.

Reverse engineering and rapid prototyping for solid free-form fabrication

1995 ◽  
Author(s):  
James H. Stanley ◽  
Robert N. Yancey ◽  
Qizhi Cao ◽  
Nicolas J. Dusaussoy
Keyword(s):  
Rapid Prototyping ◽  
Reverse Engineering ◽  
Free Form ◽  
Solid Free Form Fabrication

Reverse Engineering of Quadric Surfaces Employing Three-Dimensional Laser Scanning

1994 ◽  
Vol 208 (1) ◽  
pp. 21-28 ◽  
Author(s):  
C Bradley ◽  
G W Vickers ◽  
M Milroy
Keyword(s):  
Reverse Engineering ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Coordinate Measuring Machine ◽  
Complex Surface ◽  
Free Form ◽  
Surface Patches ◽  
Measuring Machine ◽  
Free Form Surfaces

A software package for the reverse engineering of surface forms commonly found in manufactured objects is presented. An object's surface is digitized using a three-dimensional, laser-based scanner that produces accurate and copious data files. Complex surface forms are reconstructed by interactively segmenting the multiple-surface patches, invoking the appropriate surface modelling routine and transferring the resulting surfaces to a CAD package via a standard IGES entity. Examples of the accuracy of the laser scanner data, and software algorithms for modelling planes, cylinders, cones and spheres, are presented by performing comparisons with results generated by a coordinate measuring machine. The paper concentrates on the novel software process to model the principal quadric forms; however, the program's capabilities do extend to free-form surfaces.

scholarly journals Two view NURBS reconstruction based on GACO model

2021 ◽  
Author(s):  
Deepika Saini ◽  
Sanoj Kumar ◽  
Manoj K. Singh ◽  
Musrrat Ali
Keyword(s):  
Optimization Algorithms ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Least Square ◽  
Ant Colony ◽  
Free Form ◽  
Reconstruction Process ◽  
Nurbs Curve ◽  
Data Points ◽  
Ant Colony Optimization Algorithms

AbstractThe key job here in the presented work is to investigate the performance of Generalized Ant Colony Optimizer (GACO) model in order to evolve the shape of three dimensional free-form Non Uniform Rational B-Spline (NURBS) curve using stereo (two) views. GACO model is a blend of two well known meta-heuristic optimization algorithms known as Simple Ant Colony and Global Ant Colony Optimization algorithms. Basically, the work talks about the solution of NURBS-fitting based reconstruction process. Therefore, GACO model is used to optimize the NURBS parameters (control points and weights) by minimizing the weighted least-square errors between the data points and the fitted NURBS curve. The algorithm is applied by first assuming some pre-fixed values of NURBS parameters. The experiments clearly show that the optimization procedure is a better option in a case where good initial locations of parameters are selected. A detailed experimental analysis is given in support of our algorithm. The implemented error analysis shows that the proposed methodology perform better as compared to the conventional methods.

scholarly journals Deciphering the Role of Residues Involved in Disorder-To-Order Transition Regions in Archaeal tRNA Methyltransferase 5

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 399
Author(s):  
Ambuj Srivastava ◽  
Dhanusha Yesudhas ◽  
Shandar Ahmad ◽  
M. Michael Gromiha
Keyword(s):  
Three Dimensional ◽  
Md Simulations ◽  
Order Transition ◽  
Free Form ◽  
Wild Type ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Type Complex ◽  
In The Wild ◽  
Trna Methyltransferase

tRNA methyltransferase 5 (Trm5) enzyme is an S-adenosyl methionine (AdoMet)-dependent methyltransferase which methylates the G37 nucleotide at the N1 atom of the tRNA. The free form of Trm5 enzyme has three intrinsically disordered regions, which are highly flexible and lack stable three-dimensional structures. These regions gain ordered structures upon the complex formation with tRNA, also called disorder-to-order transition (DOT) regions. In this study, we performed molecular dynamics (MD) simulations of archaeal Trm5 in free and complex forms and observed that the DOT residues are highly flexible in free proteins and become stable in complex structures. The energetic contributions show that DOT residues are important for stabilising the complex. The DOT1 and DOT2 are mainly observed to be important for stabilising the complex, while DOT3 is present near the active site to coordinate the interactions between methyl-donating ligands and G37 nucleotides. In addition, mutational studies on the Trm5 complex showed that the wild type is more stable than the G37A tRNA mutant complex. The loss of productive interactions upon G37A mutation drives the AdoMet ligand away from the 37th nucleotide, and Arg145 in DOT3 plays a crucial role in stabilising the ligand, as well as the G37 nucleotide, in the wild-type complex. Further, the overall energetic contribution calculated using MMPBSA corroborates that the wild-type complex has a better affinity between Trm5 and tRNA. Overall, our study reveals that targeting DOT regions for binding could improve the inhibition of Trm5.

An Equivalent-Plane Cross-Coupling Position Control for Contour-Accuracy Improvement in Three-Axis Free-Form Contour Following Tasks

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Jian-Wei Ma ◽  
De-Ning Song ◽  
Zhen-Yuan Jia ◽  
Wen-Wen Jiang ◽  
Fu-Ji Wang ◽  
...  
Keyword(s):  
Error Control ◽  
Position Control ◽  
Three Dimensional ◽  
Cross Coupling ◽  
Experimental Tests ◽  
Numerical Control ◽  
Free Form ◽  
Contouring Error ◽  
Contour Following ◽  
Better Than

To reduce the contouring errors in computer-numerical-control (CNC) contour-following tasks, the cross-coupling controller (CCC) is widely researched and used. However, most existing CCCs are well-designed for two-axis contouring and can hardly be generalized to compensate three-axis curved contour following errors. This paper proposes an equivalent-plane CCC scheme so that most of the two-axis CCCs or flexibly designed algorithms can be utilized for equal control of the three-axis contouring errors. An initial-value regeneration-based Newton method is first proposed to compute the foot point from the actual motion position to the desired contour with a high accuracy, so as to establish the equivalent plane where the estimated three-dimensional contouring-error vector is included. After that, the signed contouring error is computed in the equivalent plane, thus a typical two-axis proportional-integral-differential (PID)-based CCC is utilized for its control. Finally, the two-axis control commands generated by the typical CCC are coupled to three-axis control commands according to the geometry of the established equivalent plane. Experimental tests are conducted to verify the effectiveness of the presented method. The testing results illustrate that the proposed equivalent-plane CCC performs much better than conventional method in both error estimation and error control.

Kinesthetically Augmented Mid-Air Sketching of Multi-Planar 3D Curve-Soups

2018 ◽  
Author(s):  
Ronak R. Mohanty ◽  
Umema H. Bohari ◽  
Vinayak ◽  
Eric Ragan
Keyword(s):  
Force Feedback ◽  
Three Dimensional ◽  
Free Form ◽  
Manual Labor ◽  
3D Design ◽  
Planar Curves ◽  
Kinesthetic Feedback ◽  
Curve Modeling

We present haptics-enabled mid-air interactions for sketching collections of three-dimensional planar curves — 3D curve-soups — as a means for 3D design conceptualization. Haptics-based mid-air interactions have been extensively studied for modeling of surfaces and solids. The same is not true for modeling curves; there is little work that explores spatiality, tangibility, and kinesthetics for curve modeling, as seen from the perspective of 3D sketching for conceptualization. We study pen-based mid air interactions for free-form curve input from the perspective of manual labor, controllability, and kinesthetic feedback. For this, we implemented a simple haptics-enabled workflow for users to draw and compose collections of planar curves on a force-enabled virtual canvas. We introduce a novel force-feedback metaphor for curve drawing, and investigate three novel rotation techniques within our workflow for both controlled and free-form sketching tasks.

Solid free-form fabrication of drug delivery devices

1996 ◽  
Vol 40 (1-2) ◽  
pp. 77-87 ◽  
Author(s):  
Benjamin M. Wu ◽  
Scott W. Borland ◽  
Russell A. Giordano ◽  
Linda G. Cima ◽  
Emanuel M. Sachs ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Free Form ◽  
Solid Free Form Fabrication ◽  
Drug Delivery Devices

Preoperative Three-Dimensional Diagnosis of Neurovascular Relationships at the Root Exit Zones During Microvascular Decompression for Hemifacial Spasm

2016 ◽  
Vol 92 ◽  
pp. 171-178 ◽  
Author(s):  
Keisuke Ohtani ◽  
Toshihiro Mashiko ◽  
Keiji Oguro ◽  
Atsuhito Takemura ◽  
Toru Hatayama ◽  
...  
Keyword(s):  
Hemifacial Spasm ◽  
Microvascular Decompression ◽  
Three Dimensional ◽  
Dimensional Diagnosis
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