• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.273-274
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• 1998

We construct a volume whose boundary is a tetrahedron with triangular faces intersecting the cutting planes along the given contours. This volume is obtained by calculating the Delaunay triangulation slice by slice, mapping 2D to 3D as tetrahedron. Also, eliminate extra-voronoi skeleton and non-solid tetrahedron. In this paper, we propose new method to eliminate non-solid tetrahedron based on the modified extra-voronoi skeleton path. This method enable us to do a compact tetrahedrisation and to reconstruct complex shapes.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.181-188
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• 2000

The objective of this research is to develop an efficient reverse engineering method of 3-dimensional compound surfaces for raped prototyping process. As a first step, several image processing techniques were applied to the measured data obtained using laser scanner. And the boundary information of the compound surface were extracted to divide the surface into several separate regions. As a next step, the Delaunay triangulation method were applied to reconstruct the surface based on the measured data and the boundary information. Finally, the STL file were created for the rapid prototyping process. Required simulations and experiments were performed and the results were analyzed to show the effectiveness of the proposed methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.2
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• pp.88-94
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• 2003

In this paper, we propose a hierarchical triangular mesh generation method based on the motion information and a fast rude convergence method. From the variance of Image difference we decide the region that subdivision is required and perform the adequate triangulation method that is possible to yield a successive hierarchical triangulation. For fast node convergence, in initial search, we use the refinement method that separate the backgroung and object region and maintain the mesh connection by using the bilinear interpolation. The simulation result demonstrate that proposed triangulation method have performance in PSNR than the conventional BMA or order mesh based method and refinement is appropriate for the case of the mesh size is small.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.378-385
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• 2011

The three-dimensional triangulation algorithm that the beacon nodes can be allocated to dynamically in not the experimental region but the practical region is suggested, and the performance of the localization system adapting the suggested algorithm is analyzed. The suggested algorithm adapts the computation method of the three dimensional point that the surfaces of three spheres overlapped, while the traditional triangulation algorithm adapts the computation method of the two dimensional point that three circles are overlapped in order to compute the distance between beacon nodes and mobile node that means a radius. In addition to this, to analyze the performance of the localization system adapting the suggested algorithm, first of all, the allocation layout of beacon nodes is made, and the allocation layout is modeled by selection of ten random distance values between mobile node and beacon nodes for computer simulation of the practical model. Next, the two dimensional coordinator of mobile node that is calculated by the suggested algorithm and the traditional triangulation algorithm is compared with each other. The localization measuring performance about three dimensional coordinator(z axis) of the suggested algorithm is also obtained by comparing with that of the practical model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.4
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• pp.859-865
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• 1999

Many sensors such as a laser, and CCD camera to obtain 3D information have been used, but most of algorithms for laser calibration are inefficient since a huge memory and experiment data are required. This method saves a memory and an experimental data since the 3D information are obtained simply triangulation method. In this paper, the calibration algorithm of a slit km laser based on triangulation method is introduced to calculate 3D information in the real world. The laser beam orthogonally mounted on the XY table is projected on the floor. A CCD camera observes the intersection plane of a light and an object plane. The 3D information is calculated using observed and calibration data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.168-173
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• 1999

Many sensors such as a laser, CCD camera to obtain 3D information have been used, but most of calibration algorithms are inefficient since a huge memory and an experiment data for laser calibration are required. In this paper, the calibration algorithm of a slit beam laser based on triangulation method is introduced to calculate 3D information in the real world. The laser beam orthogonally mounted on the XY table is projected on the floor. A Cm camera observes the intersection plane of a light and an object plane. The 3D information is calculated using observed and calibration data. This method saves a memory and an experimental data since the 3D information are obtained simply triangulation method.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.505-513
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• 2017

Recently, numerous small area estimation studies have been conducted to obtain more detailed and accurate estimation results. Most of these studies have employed spatial regression models, which require a clear definition of spatial neighborhoods. In this study, we introduce the Delaunay triangulation as a method to define spatial neighborhood, and compare this method with the k-nearest neighbor method. A simulation was conducted to determine which of the two methods is more efficient in defining spatial neighborhood, and we demonstrate the performance of the proposed method using a land price data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4B
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• pp.309-316
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• 2012

The compensation algorithm for localization using the least-squires method in NLOS(Non Line of Sight) environment is suggested and the performance of the algorithm is analyzed in this paper. In order to improve the localization correction rate of the moving node, 1) the distance value of the moving node that is moving as an constant speed is measured by SDS-TWR(Symmetric Double-Sided Two-Way Ranging); 2) the location of the moving node is measured using the triangulation scheme; 3) the location of the moving node measured in 2) is compensated using the least-squares method. By the experiments in NLOS environment, it is confirmed that the average localization error rates are measured to ${\pm}1m$, ${\pm}0.2m$ and ${\pm}0.1m$ by the triangulation scheme, the Kalman filter and the least-squires method respectively. As a result, we can see that the localization error rate of the suggested algorithm is higher than that of the triangulation as average 86.0% and the Kalman filter as average 16.0% respectively.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.705-711
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• 2000

This paper presents a fast 3D mesh generation method using a surface based method with a stitching algorithm. This method uses the surface based method since the volume based method that uses 3D Delaunay triangulation can hardly deal with a large scale of scanned points. To reduce the processing time, this method also uses a stitching algorithm: after dividing the whole point data into several sections and performing mesh generation on individual sections, the meshes from several sections are stitched into one mesh. Stitching method prevents the surface based method from increasing the processing time exponentially as the number of the points increases. This method works well with different types of scanned points: a scattered type points from a conventional 3D scanner and a cross-sectional type from CT or MRI.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.407-410
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• 2002

Triangulation method, conoscopic holography method and interferometry method are analyzed for effective measurement of micro burr geometry, which is formed in micro drilling. To select proper sensor, cylinder with 0.5mm diameter is measured and the result shows that conoscopic holography method is effective for measuring highly inclined surface. Burr with 1.0mm height and 30$\mu\textrm{m}$ height are measured by all methods. The conoscopic holography method is probed to be most proper method for measuring micro burr. A Program for 3D display of measured burr is developed.