• ETRI Journal
• /
• 제27권2호
• /
• pp.235-238
• /
• 2005

A new mesh reconstruction scheme for approximating a surface from a set of unorganized 3D points is proposed. The proposed method, called a shrink-wrapped boundary face (SWBF) algorithm, produces the final surface by iteratively shrinking the initial mesh generated from the definition of the boundary faces. SWBF surmounts the genus-0 spherical topology restriction of previous shrink-wrapping-based mesh generation techniques and can be applied to any type of surface topology. Furthermore, SWBF is significantly faster than a related algorithm of Jeong and others, as SWBF requires only a local nearest-point-search in the shrinking process. Our experiments show that SWBF is very robust and efficient for surface reconstruction from an unorganized point cloud.

• 대한두경부종양학회지
• /
• 제27권1호
• /
• pp.27-31
• /
• 2011

Purpose : Anterolateral thigh and radial forearm flap is the most important fasciocutaneous flap widely used for reconstruction of tongue. One important purpose of flap is replacing the volume of tongue but still there is no data about the surface area and volume to be reconstructed after glossectomy. In this paper, surface area and volume is estimated from the 3-dimensionally reconstructed MRI images to see which flap is more ideal and to give the reference value for reconstruction. Materials and Methods : With coronal MRI image, tongue including only the intrinsic muscle is delineated in every section and reconstructed 3-dimensionally and calculated the volume and surface area to be reconstructed according to the degree of glossectomy. This volume and surface area was compared with the volume of anterolateral thigh and radial forearm flap. Results : The volume and surface area to be reconstructed in hemiglossectomy was $39.0{\pm}4.0cm^3$ and $31.8{\pm}2.7cm^2$ respectively. The average thickness of anterolateral thigh flap is $9.4{\pm}2.8mm$ and that of radial forearm is $3.8{\pm}1.0mm$. Comparing the curve of tongue surface area and volume with the volume of flap, the anterolateral thigh flap has more ideal volume to replace the defect. Conclusions : The surface area and volume requested for reconstruction could be suggested and the anterolateral thigh flap has more ideal volume for reconstruction of glossectomy defect.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
• /
• pp.83-86
• /
• 2005

This paper presents a method for point-based 3D building reconstruction using LiDAR data and digital map. The proposed method consists of three processes: extraction of building roof points, identification of roof types, and 3D building reconstruction. After extracting points inside the polygon of building, the ground surface, wall and tree points among the extracted points are removed through the filtering process. The filtered points are then fitted into the flat plane using ODR(Orthogonal Distance Regression). If the fitting error is within the predefined threshold, the surface is classified as a flat roof. Otherwise, the surface is fitted and classified into a gable or arch roof through RMSE analysis. Based on the roof types identified in automated fashion, the 3D building reconstruction is performed. Experimental results showed that the proposed method classified successfully three different types of roof and that the fusion of LiDAR data and digital map could be a feasible method of modelling 3D building reconstruction.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.268-273
• /
• 1998

This study applies an on-line system, which employes an adaptive reconstruction technique to monitor and forecast ocean surface changes. The system adaptively generates an appropriate synthetic time series with recovering missing measurements for sequential images. The reconstruction method incorporates temporal variation according to physical properties of targets and anisotropic spatial optical properties into image processing techniques. This adaptive approach allows successive refinement of the structure of objects that are barely detectable in the observed series. The system sequentially collects the estimated results from the adaptive reconstruction and then statistically analyzes them to monitor and forecast the change in surface characteristics.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
• /
• pp.151-151
• /
• 2000

We have studied the atomic structure of Si(100)-c(4$\times$4) reconstruction using scanning tunneling microscopy(STM). The c(4$\times$4) reconstruction can be formed by annealing the hydrogen exposured surface at temperatures between 850 and 960 K. At this temperature ranges, adsorbed hydrogen atoms are all desorbed. Therefore, the c(4$\times$4) reconstruction is due to the Si dimers on surface. The filled and empty state images of the STM were interpreted in terms of Si dimers in c(4$\times$4) primitive cell forming the reconstruction. Based on the STM images and hydrogen adsorption experiment on c(4$\times$40 surface, we suggest that Si dimers in c(4$\times$40 unit cell are perpendicular ad-dimer to the underlying Si dimer rows.

• 한국정보과학회논문지:시스템및이론
• /
• 제32권8호
• /
• pp.411-417
• /
• 2005

본 논문에서는 입력으로 주어진 점집차 (point cloud)으로부터 캐널곡면을 복원 (reconstruction)하는 알고리즘을 제시한다. 캐널곡면은 반경이 변화하며 중심점이 기준곡선(spine curve)을 따라 이동하는 구(moving sphere)의 스웹트곡면(swept surface)이다. 이 논문에서는 수축기법(shrinking method)과 moving least-square 방법을 이용하여 주어진 점집합을 세곡선(thin-curve)형태의 점집합으로 수축시킴으로써 캐널곡면의 기준곡선을 근사한다. 근사된 기준곡선과 입력으로 주어진 점집합에 포함된 점들 사이의 거리를 이용하여, 캐널곡면을 구성하는 이동 구의 반경을 계산한다.

• 한국진공학회지
• /
• 제1권1호
• /
• pp.83-87
• /
• 1992

최근 Angle Resolved Ultraviolet Photoemission Spectroscopy(ARUPS)를 통하여 Mo(011)과 W(011)의 surface Fermi contour에 관한 연구가 발표되었다. Hydrogen 흡착시 W(011)의 electron contour는 팽창하였다. 이것은 electron contour를 이루는 surface state가 hydrogen 흡착시 higher binding energy로 이동한 결과이다. Surface state의 higher binding energy로의 이동은 결국 band flattening으로 이해되며, 이 band flattening 에 S.E.Trullinger의 long range dipole dipole force와 Kohn anomaly 현상을 부합시켜 W(011) surface에 수소 흡착시 일어나는 reconstruction 현상에 대한 설명을 시도해 보았다.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제9권2호
• /
• pp.29-43
• /
• 2005

We consider a surface reconstruction problem from geometrical points (i.e., points given without any order) distributed on a series of smooth parallel cross sections in ${\mathbb{R}}^3$. To solve the problem, we utilize the natural points ordering method in ${\mathbb{R}}^2$, described in [18], which is a method of reconstructing a curve from a set of sample points and is based on the concept of diffusion motions of a small object from one point to the other point. With only the information of the positions of these geometrical points, we construct an acceptable surface consisting of triangular facets using a heuristic algorithm to link a pair of parallel cross-sections constructed via the natural points ordering method. We show numerical simulations for the proposed algorithm with some sets of sample points.

• 한국해양공학회지
• /
• 제27권6호
• /
• pp.100-105
• /
• 2013

This paper presents a sea surface reconstruction method that uses measured radar images by applying filtering techniques and identifying wave characteristics of the surrounding the Ieodo ocean research station using WaveFinder (X-band wave measurement radar), which is installed in the station. In addition, the results obtained from real radar images are used to verify the reconstructed sea surface. WaveFinder is a marine system that was developed to measure wave information in real time. The WaveFinder installed in the station could acquire sequent images for the sea surface at constant time intervals to obtain real time information (Wave height, mean wave period, wave directionality, etc.) for the wave by getting a three-dimensional spectrum by applying an FFT algorithm to the acquired sequent images and wave dispersion relation. In particular, we found the wave height using the SNR (Signal to noise ratio) of the acquired images. The wave information measured by WaveFinder could be verified by comparing and analyzing the results measured using the wave measurement instrument (Sea level monitor) in the station. Additionally, the wave field around the station could be reconstructed through the three-dimensional spectrum and the inverse FFT filtering from the analyzed results for the measured radar images. We verified the applicability of the sea surface reconstruction method by comparing the measured and simulated sea surfaces.

• 전자공학회논문지S
• /
• 제34S권6호
• /
• pp.58-66
• /
• 1997

This paper proposes a multiresolution surface parameter estimation method for range images. Based on robust estimation of surface parameters, it approximates a patch to a planar surface in the locally adaptive window. Selection of resolution is made pixelwise by comparing a locally computed homogeneity measure with th eglobal threshold determined by te distribution of the approximation error. The proposed multiresolution surface parameter estimation method is applied to range image reconstruction. Computer simulation results with noisy rnag eimages contaminated by additive gaussian noise and impulse noise show that the proposed multiresolution reconstruction method well preserves step and roof edges compared with the conventional methods. Also the segmentation method based on the estimated surface parameters is shown to be robust to noise.