• Journal of the Korea Society of Computer and Information
• /
• v.19 no.11
• /
• pp.81-90
• /
• 2014

For necessary information sharing or operation control via wire-wireless/mobile network connecting of devices at disaster area in greatest need of attention, an emergency network efficient construction method quickly connecting nodes within specific range using Delaunay triangulation is proposed. The emergency network constructed by proposed method shows the same aggregate network length, but does more excellent performance in term of network construction time the more long max length connectable to adjacent node as compared with the network by naive method. In experiment of 1000 input terminal nodes, 5 max length connectable to adjacent node, our proposed method enhances 89.1% in execution time without network length increase compared to naive method. So our method can go well to many useful applications as shift construction of communication network of adjacent devices, internet of things and efficient routing in the sensor network in continuous improvement of communication capability.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.889-893
• /
• 1995

This paper verified error of STL file and presented a new application of reformed division method for reducing to appeared error by using Delaunay triangulation method that used to modify error of verified data. First, it is analyzed each vertices in hole error and classified follow case that is 1. case of plan or slope, 2. case of edge, 3. case of apex and 4. case of rapid curve, and reduced volume tolerance between original model and converted model after convert STL file.

• Journal of Korean Society for Quality Management
• /
• v.22 no.2
• /
• pp.154-165
• /
• 1994

A new criterion, the solid angle, is introduced to measure the Quality of tetrahedral mesh. This criterion is compared with the existing Delaunay triangulation criterion. The properties of solid angles have been studied and are proposed for utilization in 3-D meshing algorithms. Furthermore, difficulties of developing a 3-D algorithm that provides a lower bound on the smallest angle have been discussed.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.10b
• /
• pp.202-205
• /
• 2007

본 논문에서는 3D 점집합으로부터 3D 메쉬를 생성하는 효율적인 기법을 소개한다. 대표적인 3D 삼각화 방법으로 3D Delaunay 삼각화 기법이 있으나 물체의 표면만을 고려한 메쉬 생성을 위한 방법으로 비효율적인 측면이 있다. 본 논문에서는 적은 계산량으로 물체의 표면 메쉬를 생성하는 기법을 소개한다. 물체의 각 영역을 분할하고 각 영역에 대해서 2D Delaunay 삼각화를 적용하여 3D 메쉬 구조를 얻는다. 3차원 점 집합에 대해 OBB를 계산하고 이를 기준으로 점집합을 다양한 각도에서 자르고 각 부분 점집합에 대해서 2D Delaunay 삼각화를 실시한다. 절단하는 각도의 간격이나 폭은 원래의 3D 점집합에서의 가장 가까운 이웃점들까지의 평균 거리를 이용하여 결정하도록 하였다. 후처리 과정으로 삼각 분할과정에서 잘못된 에지의 연결을 제거함으로써 객체의 삼각 분할 결과를 향상시킨다. 제안된 메쉬 생성 기법은 다양한 영상 기반 모델링 응용에서 효과적으로 적용될 수 있다.

• Korean Journal of Remote Sensing
• /
• v.30 no.6
• /
• pp.787-795
• /
• 2014

This paper presents an image registration using Triangulation-based Local Transformation (TLT) applied to the remaining matched points after elimination of the matched points with gross error. The corners extracted using geometric mean-based corner detector are matched using Pearson's correlation coefficient and then accepted as initial matched points only when they satisfy the Left-Right Consistency (LRC) check. We finally accept the remaining matched points whose RANdom SAmple Consensus (RANSAC)-based global transformation (RGT) errors are smaller than a predefined outlier threshold. After Delaunay triangulated irregular networks (TINs) are created using the final matched points on reference and sensed images, respectively, affine transformation is applied to every corresponding triangle and then all the inner pixels of the triangles on the sensed image are transformed to the reference image coordinate. The proposed algorithm was tested using KOMPSAT-2 images and the results showed higher image registration accuracy than the RANSAC-based global transformation.

• Journal of Korea Game Society
• /
• v.10 no.6
• /
• pp.137-146
• /
• 2010

According to rapid advent of the smartphone, software technologies which have been used on PCs are being introduced into the smartphone. This paper introduces an implementation of an application software under the Android platform using morphing and warping technology. It composes two face images with morphing technology and also transforms an original face image using warping technology for fun. For this, the image is triangulated by Delaunay Triangulation based on control points which are created by simple LCD touches on the mobile device. The implementation case of this paper will be a good reference for the development of applications like games using morphing and warping technologies over Android platforms.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.18 no.2
• /
• pp.103-111
• /
• 2005

In this paper, a new meshfree technique which improves the numerical integration accuracy is introduced. This new method called thc Petrov-Galerkin natural clement method(PG-NEM) by authors is based on the Voronoi diagram and the Delaunay triangulation which is based on the same concept used lot conventional natural clement method called the Bubnov-Galerkin natural element method(BG-NEM). But, unlike the BG-NEM, the test basis function is differently chosen, based on the concept of Petrov-Galerkin, such that its support coincides exactly with a regular integration region in background mesh. Therefore, it is expected that the proposed technique ensures the remarkably improved numerical integration accuracy in comparison with the BG-NEM.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2002.11a
• /
• pp.163-170
• /
• 2002

Terrain surfaces have to be modeled in very detail and wheel-surface contacting geometry must be well defined in order to obtain proper ground-reaction and friction forces for realistic simulation of off-road vehicles. Delaunay triangulation is one of the most widely used methods in modeling 3-dimensional terrain surfaces, and T-search is a relevant algorithm for searching resulting triangular polygons. The T-search method searches polygons in successive order and may not allow real-time computation of off-road vehicle dynamics if the terrain is modeled with many polygons, depending on the computer performance used in the simulation. In order to accelerate the searching speed of T-search, a terrain database of triangular polygons is modeled in multi-levels by adopting the LOD (Level of Detail) method used in realtime computer graphics. Simulation results show that the new LOD search is effective in shortening the required computing time. The LOD search can be even further accelerated by introducing an NN (Neural Network) algorithm, in the cases where a appropriate range of moving paths can be predicted by cultual information of the simulated terrain, such as lakes, houses, etc.. Numerical tests show that LOD-NN search almost double the speed of the original T-search.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.8 no.2
• /
• pp.1-8
• /
• 1990

A regular grid or a triangulated irregular network is generally used as the data structure of digital terrain models. A Regular grid is simple and easy to manipulate, but it can't describe well terrain surface features and requires vast volumes of data. In the meantime, a triangulated irregular network has complex data structure, but it can describe well terrain surface features and can achieve the accuracy suitable to its application with relatively little data. This paper aims at the construction of efficient digital terrain models by the improvment of a triangulated irregular network based on Delaunay triangulation. Regular and irregular data set are sampled from existing contour maps, and the efficiency and the accuracy of the two data structures are compared.

• Journal of Broadcast Engineering
• /
• v.23 no.2
• /
• pp.227-234
• /
• 2018

Recently, stitching techniques are used for obtaining wide FOV, e.g., panorama contents, from normal cameras. Despite many proposed algorithms, the no objective quality evaluation method is developed, so the comparison of algorithms are performed only in subjective way. The paper proposes a 'Delaunay-triangulation based objective assessment method' for evaluating the geometric and photometric distortions of stitched or warped images. The reference and target images are segmented by Delaunay-triangulation based on matched points between two images, the average Euclidian distance is used for geometric distortion measure, and the average or histogram of PSNR for photometric measure. We shows preliminary results with several test images and stitching methods for demonstrate the benefits and application.