• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.322-325
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• 2004

Recently the domestic technologies to manage forest and to control all related information were developed very rapidly by integrating FGIS (Forest Geographic Information System) and IT (Information technology). However, there still exists a mapping problem for example when overlaying a topography maps scaled in 1/5,000 to a forest type map scaled in 1/25.000. Moreover, there is a greater need to introduce the advanced spatial technologies such as high-resolution satellite image such as IKONOS and GIS to forest. In this study, 3D high-resolution forest mapping system was developed to possibly overlay with all kinds of scale maps and provide the all detailed information by using high-resolution satellite image and GIS. Through this system, all related forest officials could have and maintain the data consistency for their job and share the standard forest database with other post.

• 대한토목학회논문집
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• 제28권6D호
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• pp.923-929
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• 2008

3차원 공간데이터에 대한 요구가 증가하면서 지형뿐만 아니라 건물에 대한 모형화는 아주 중요한 부분을 차지하고 있다. 본 연구에서는 라이다자료만을 이용하여 계산량과 사용자의 개입을 최소화한 건물의 경계를 추출하는 방법론을 제시하였다. 그 특징은 점기반처리와 영상기반처리의 장점을 융합하여 1차 건물의 경계를 개략적으로 검색한 후 다시 원 라이다 자료를 분석하여 제약조건이 부가된 불규칙삼각망을 형성하여 건물의 경계를 정하였다. 그 후 건물의 면적과 한 변의 길이 등을 고려하여 건물의 형상을 갖도록 처리하였다. 제안한 방법론은 실제 라이다자료를 이용하여 검증하였으며 수치지도와 비교를 통해서 효용성을 입증하였다.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3709-3715
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• 2023

It is an important work to measure the dimensions of underwater spent fuel assemblies in the nuclear power industry during the overhaul, to judging whether the spent fuel assemblies can continue to be used. In this paper, a three dimensional reconstruction method for underwater spent fuel assemblies of nuclear reactor based on linear structured light is proposed, and the topography and size measurement was carried out based on the reconstructed 3D model. Multiple linear structured light sensors are used to obtain contour size data, and the shape data of the whole spent fuel assembly can be collected by one-dimensional scanning motion. In this paper, we also presented a corrected model to correct the measurement error introduced by lead-glass and water is corrected. Then, we set up an underwater measurement system for spent fuel assembly based on this method. Finally, an underwater measurement experiment is carried out to verify the 3D reconstruction ability and measurement ability of the system, and the measurement error is less than ±0.05 mm.

• 한국해안해양공학회지
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• 제19권1호
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• pp.57-65
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• 2007

천해파랑을 산정하기 위하여 천수, 굴절, 회절, 반사 및 쇄파 등의 파랑변형요소를 고려하는 대부분의 수치모델은 천해역에서의 바람장을 수치모델과 결합하여 천해파랑을 산정하고 있다. 그리고, 일반적으로 천해역에서 바람장을 산정하는 경우에 태풍모델로부터 얻어진 바람장을 해상풍으로 변환하여 사용하고 있다. 그러나, 이러한 해상풍 산정법은 해상풍의 평가에 중요한 요소로 작용될 수 있는 육상지형의 영향에 대해서는 고려하고 있지 않다. 본 연구는 천해역에서의 해상풍 산정에 대하여 육상지형의 영향을 고려함으로써, 결과적으로 정도 높은 천해파랑산정을 목적으로 한다. 먼저 지역적으로 차폐 및 개방되어 있는 해역을 대상으로 태풍모델로부터 얻어진 해상풍과 본 연구에서 적용하는 육상지형의 영향을 고려할 수 있는 MASCON모델로 산정된 해상풍의 결과를 상호 비교 검토한다. 그리고, 각 모델로부터 얻어진 해상풍을 SWAN모델에 적용하여 천해파랑을 산정하며, 이의 결과를 상호 비교 검토한다. 검토된 결과로부터 정도 높은 천해파랑산정을 위한 MASCON모델의 필요성을 논의한다.

• 한국정밀공학회지
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• 제12권3호
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• pp.119-129
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• 1995

In this paper, the inclined endmilling process with a 3-axis machining center using inclined jigs is introduced for the purpose of reducing overall Dies/Molds machining time and improving the machining accuracies. In order to analyze the cutting mechanism of a given endmill more accurately, the unification of the cutting mechanism model of 3-different- kind endmills is carried out by using a nose radius as a parameter. By adding radial runouts as a parameter which influences on surface roughness, the superposition method which defines the effective cusp height superposing the cutter mark height and the conventional cusp height is advanced. And 3-D suface topography predicted in this paper looks like the surface normally observed in practice. Through machining experiments, the adequacy of the superposition method was confirmed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.962-965
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• 2005

This study is an inspection of press forming product and mould using reverse engineering system. The inspection process on production field involves a lot of errors because of the hand-work so we focussed on improving the measured precision through performing the effective inspection using 3D non-contact scanner. By so doing that, we improved the precision of press forming product by analyzing the cause following the inspection result. Through the inspection, we applied it to the reverse engineering and we could improve the inspection process.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.329-329
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• 2017

In this study attempted to evaluate the stability of the protection methods by examining hydraulic characteristics of the area around the point in which marine cable protector is installed such as surf zone occurrence point of shore-end submarine cables suitable for coastal marine environmental conditions, flow rate t the tope of the protector and maximum wave height, and to provide basic data for the selection of the optimal protection method. In performing hydraulic model experiments, the topography of submarine cable installation location was reproduced in 2-D sectional channel, and models appropriate for experimental scale and similitude law were produced and installed for each condition of submarine cables and protectors. Since the topography and submarine cable protectors were reproduced and installed in 2-D sectional channel, the exact reproduction of surf and transformation in shallow water zone was possible, and thus the physical properties could be clearly analyzed. For stability review, an experiment to examine the stability was conducted using a wave maker with 50-year frequency design waves as target, and wave height and cycles were applied based on the approximate lowest low water level(Approx. L.L.W), which is the most dangerous in submarine cable protection methods. As for experimental time, typhoon passing time in summer (about 3 hours) was applied, and wave patterns and deviation ratio of the submarine cable protector were investigated after making irregular waves corresponding to design waves. In addition, current meter and wave height meter were installed at the installation location of the submarine cable protector, and the flow rates and wave height at the top of the protector were measured and analyzed to review hydraulic properties.

• 대기
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• 제29권5호
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• pp.537-550
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• 2019

To analyze the observation environment of solar radiation stations operated by the Korea Meteorological Administration (KMA), we analyzed the skyline, Sky View Factor (SVF), and solar radiation due to the surrounding topography and artificial structures using a Digital Elevation Model (DEM), 3D camera, and solar radiation model. Solar energy shielding of 25 km around the station was analyzed using 10 m resolution DEM data and the skyline elevation and SVF were analyzed by the surrounding environment using the image captured by the 3D camera. The solar radiation model was used to assess the contribution of the environment to solar radiation. Because the skyline elevation retrieved from the DEM is different from the actual environment, it is compared with the results obtained from the 3D camera. From the skyline and SVF calculations, it was observed that some stations were shielded by the surrounding environment at sunrise and sunset. The topographic effect of 3D camera is therefore more than 20 times higher than that of DEM throughout the year for monthly accumulated solar radiation. Due to relatively low solar radiation in winter, the solar radiation shielding is large in winter. Also, for the annual accumulated solar radiation, the difference of the global solar radiation calculated using the 3D camera was 176.70 MJ (solar radiation with 7 days; suppose daily accumulated solar radiation 26 MJ) on an average and a maximum of 439.90 MJ (solar radiation with 17.5 days).

• 한국정보처리학회논문지
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• 제4권2호
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• pp.586-595
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• 1997

본 논문에서는 프렉탈과 신경망을 이용하여 등고선 데이타로부터 3차원 지형을 복원하는 더욱 개선된 알고리즘을 제안한다. 본 알고리즘은 이미 제안한 것[1, 2, 3]을 바탕으로 인접 패치들과의 관계를 고려하여 개선한 것으로, 지형의 특징을 좀더 사실 적으로 반영할 수 있는 더 많은 조건을 부여한 데이타를 기존의 특징 데이타에 부가하여 학습한다. 학습 결과 평균오차가 줄어든 학습 패턴을 이용하여 산악지형과 평탄지형 에 대하여 실험하고 결과 산악지형에 대한 적용이 더 효과적임을 보였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.19.2-19.2
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• 2011

The $(Sr_{0.75},\;La_{0.25})TiO_3$ (SLTO) ultra-thin films with various thicknesses have been grown on Ti-O terminated $SrTiO_3$(100) substrate using Laser-Molecular Beam Epitaxy (Laser MBE). By monitoring the in-situ specular spot intensity oscillation of reflection high energy electron diffraction (RHEED), we controlled the layer-by-layer film growth. The film structure and topography were verified by atomic force microscopy (AFM) and high resolution thin film x-ray diffraction by the synchrotron x-ray radiation. We have also investigated the electronic band structure using x-ray absorption spectroscopy (XAS). The ultra thin SLTO film exhibits thickness driven metal-insulator transition around 8 unit cell thickness when the film thickness progressively reduced to 2 unit cell. The SLTO thin films with an insulating character showed band splitting in Ti $L_3-L_2$ edge XAS spectrum which is attributed to Ti 3d band splitting. This narrow d band splitting could drive the metal-insulator transition along with Anderson Localization. In optical conductivity, we have found the spectral weight transfer from coherent part to incoherent part when the film thickness was reduced. This result indicates the possibility of enhanced electron correlation in ultra thin films.