Fuzzy B-spline for three-dimensional urban slum reconstruction from ENVISAT ASAR data

2015 ◽  
Author(s):  
Maged Marghany
Keyword(s):  
Three Dimensional ◽  
Urban Slum ◽  
B Spline ◽  
Envisat Asar

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

scholarly journals Modeling technology of curved surface development for puffer fish

2020 ◽  
Vol 12 (4) ◽  
pp. 168781402091602
Author(s):  
Honggen Zhou ◽  
Jie Cui ◽  
Guizhong Tian ◽  
Yesheng Zhu ◽  
Changfeng Jia
Keyword(s):  
Three Dimensional ◽  
Least Square ◽  
Curved Surface ◽  
B Spline ◽  
Implicit Equation ◽  
Moving Least Square ◽  
Average Value ◽  
Modeling Technology ◽  
Surface Development ◽  
Puffer Fish

The drag reduction mechanism of puffer epidermis was closely related to its real geometry. In order to solve the modeling problem of epidermal spines on the puffer surface, a modeling method for the expansion of puffer shape was proposed. The three-dimensional scanning and non-uniform rational B-spline surface modeling technology was used to reconstruct the puffer model. According to the curvature characteristics, the surface mathematical equations including exponential, logarithmic, and sinusoidal functions were established based on the multinomial function. The surface was generated by a mathematical equation, and the surface was divided into several non-uniform rational B-spline patches according to curvature. After discretization, the point cloud Gaussian curvature and average value were calculated based on the implicit equation of moving least square surface, and whether the surface is approximately extensible or not was judged. Finally, the puffer surface was divided into 46 curved patches. In this article, the surface expansion algorithm gave priority to ensure the area unchanged, and four feature surfaces were selected according to the epidermal spines arrangement of the puffer surface. The results showed that the technique can simply and efficiently unfold the curved surface of the puffer fish, thus the mapping relationship between the epidermal spines on the surface and the plane was determined, which established a foundation for the accurate arrangement and modeling of the epidermal spines on the surface.

Reverse Engineering Physical Models Employing Wrap-Around B-Spline Surfaces and Quadrics

1996 ◽  
Vol 210 (2) ◽  
pp. 147-157 ◽  
Author(s):  
D J Weir ◽  
M J Milroy ◽  
C Bradley ◽  
G W Vickers
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Surface Fitting ◽  
Physical Models ◽  
Scanning System ◽  
Cad Model ◽  
Three Dimensional Model ◽  
B Spline

Reverse engineering involves digitizing a three-dimensional model or part, by means of a tactile or non-contact optical sensor, converting the data to a CAD (computer aided design) database description and manufacturing by CNC (computer numerical controlled) machines. This paper demonstrates an effective approach to the reverse engineering of physical models by employing a three-dimensional laser scanning system in conjunction with surface-fitting software developed by the authors. Accurate surface data are collected by the laser scanner and then input to the surface-fitting software. Surface entities such as B-spline and quadric functions are employed to build the CAD model. The CAD model is compatible with popular design and manufacturing software packages. A telephone receiver is used to illustrate the efficiency of the process.

scholarly journals Optimization of modular and helical coils applying genetic algorithm and fully-three-dimensional B-spline curves

2021 ◽  
Author(s):  
Hiroyuki Yamaguchi ◽  
Shinsuke Satake ◽  
Motoki Nakata ◽  
Akihiro Shimizu ◽  
Yasuhiro Suzuki
Keyword(s):  
Genetic Algorithm ◽  
Three Dimensional ◽  
B Spline ◽  
Spline Curves ◽  
Helical Coils

scholarly journals Simulation of Three-Dimensional of coastal erosion using differential interferometric synthetic aperture radar

2013 ◽  
Vol 16 (1) ◽  
pp. 80-86
Keyword(s):  
Synthetic Aperture Radar ◽  
Three Dimensional ◽  
Shoreline Change ◽  
Synthetic Aperture ◽  
Interferometric Synthetic Aperture Radar ◽  
Envisat Asar ◽  
Digital Elevation ◽  
Elevation Model ◽  
Dimensional Object ◽  
Aperture Radar

<p>This study aims at modelling three-dimensional shoreline change rates using differential interferometric synthetic aperture radar (DInSAR) techinuqe. Neverthless, decorrelation plays significant role to control the accuracy of three dimensional object reconstruction using DInSAR. To solve this problem, multichannel MAP height estimator algorithm is implemented with in ENVISAT ASAR data. Therefore, the proposed method has been applied to coastaline of Johor, Malaysia. The study shows the critical erosion of -3.5 m y-1 with accuracy (RMSE) of &plusmn;0.05 m. In addition, the volume rate of shoreline changes of -2343.42 m3 y-1 corresponds to the lowest digital elevation model (DEM) of 7.4 m. It can be said that accurate rate of shoreline change can be achieved with root mean square error (RMSE) of &plusmn;0.05 m using multichannel MAP height estimator algorithm.</p>

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