• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.357-359
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• 1998

무선 통신 환경에서 기지국 안테나를 떠난 전파가 수신안테나에 도달하는 과정 중에 발생하는 전파 손실은 매우 복잡한 비선형 함수이다. 본 논문에서는 신경회로망을 사용한 전파 손실 모델을 제안하고, 3차원 지형 데이터를 이용하여 전파 환경을 반영할 수 있는 특징을 추출하여 이를 신경회로망에 적용함으로써 전파손실 예측모델을 생성하는 방법을 소개한다. 각 필드 측정 데이터에 대한 특징 값을 이용하여 신경회로망을 학습하여 예측모델을 완성한다. 또한, 서울 도심 지역의 실제 PCS 서비스 환경에 대한 실험결과를 통해 제안하는 모델의 우수성을 보인다.

• Korean Journal of Remote Sensing
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• v.7 no.1
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• pp.13-27
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• 1991

DEM(digital elevation map) is a very useful information in various applications. In this paper, we have studied on the terrain matching algorithm using the DEM, which was proposed by Rodriguez and Aggarwal(1990) for an aircraft navigation system. We evaluated its performance using syntactic images. Cliff maps and critical points are used for the reduction of computation time and information size to be processed. The computer simulation shows that though the computational complexity is high, the technique is efficient even to noisy images.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.254-259
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• 2008

지형의 표고값물 격자간격으로 표현하는 수치표고모델(DEM)은 지형분석을 위한 GIS데이터 활용과 휴대전화 중계안테나의 영향권 분석, 정밀지오이드 계산을 위한 지형효과계산 등 여러 가지 분야에 활용되고 있다. 본 연구에서는 이렇게 활용성이 증가하고 있는 수치표고모델을 수집하고 또 진주시 지역을 대상으로 LiDAR촬영을 통한 LiDAR 수치표고모델을 구축하여 그 정확도를 분석하고자 하였다. 연구에 활용된 수치표고모델은 GTOPO30, SRTM-3, 지형도(1/50,000) 독취 DEM, 환경부 DEM, 항공사진에 의해 생성된 DEM, 그리고 LiDAR DEM의 6가지이며, 정확도 분석을 위해 GPS측량과 수준측량이 동시에 실시된 409점의 진주시 3차원 도시기준점 성과를 이용하였다.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.168-182
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• 2014

Several Sungsi Gardens were built up in Old West Village during the period of the Joseon Dynasty. Most of them were painted as True-View landscape painting. This study aims at examining original locations of representative gardens of the Old West Village by empirical investigation of related True-View landscape paintings. It seeks to demonstrate the garden landscape in True-View landscape painting by utilizing ArcGIS, 3D topographic modeling to observe geographical locations and landscape more realistically. After forming 3D topographic modeling of estimated locations of the gardens, location of objects at composition of 3D modeling similar to True-View landscape painting was found by shifting viewpoints. And by overlapping the cadastral map on the modeling, we could verify the current lot number of the garden sites. The interpretation of processes and results are as follows. In the early stage, Chungpunggye garden was built at the very end of Mt. InWang valley. The site is hidden from the outside, and appeared as 'Enclosed Landscape'. In the middle stage, Chunghuigak garden was built between Okryu-dong valley and the surrounding ridge. It appeared as 'Semi-Opened Landscape'. In the late stage, Seowon garden was built at the highest level of the ridge among the research areas. It appeared as 'Prospective Landscape'. In the last period, Songsukwon garden, was built at a point of contact of the ridge end and surrounding residential area. So it appeared as 'Opened Landscape' to the town. In other words, the location, landscape and social function of the gardens in Old West Village had been gradually opened in Joseon Dynasty.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1519-1522
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• 2003

본 논문에서는 지리정보서비스 개념을 사이버 박물관 정보 서비스와 접목하여 구현하였다. 입체적인 지리정보를 활용하기 위해서 유물과, 유적에 대한 정보를 3D모델링 하였으며, 3D모델의 랜더링 최적화를 위해서 LOD(level of detial)를 적용하여 범용 PC의 유저(user) 누구나 쉽게 이용할 수 있다. 또한 사용자로 하여금 실시간 인터렉티브 기능을 부여하여 네비게이션(navigation)을 쉽게 구현하였다. 일반적으로 종래의 사이버 정보서비스의 멀티미디어매체가 수동적이고, 실감적인 효과가 떨어지는 단점을 보완하는 실시간 3차원 인터렉티브 컨텐츠를 제작 방법을 구현하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.63-68
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• 2010

In this study, subject areas with different topographic feature were selected for the purpose of measuring the slope terrain by setting Terrestrial LiDAR in different places. And the slope terrain was analyzed based on three-dimensional raw data obtained through the measurement of slope terrain. With DEM data obtained from five measurement instances with 5mm of scan interval by setting Terrestrial LiDAR on the site 30m away straight from the slope terrain consisting of asphalt, rock, soil, and plants, the slope terrain was analyzed according to topographic feature. In addition, in consideration of changes in setting location that might affect the measured result, this study reviewed the accuracy of measured data obtained from different measurement areas.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.301-306
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• 2010

Recently GIS is not only displaying and servicing data on the 2D, but also is changing rapidly to display and service 3D data. Also 3D related technology is developing actively. For display of 3D data, terrain DTM has become a basis. Generally, to acquire DTM, users are using LIDAR data or digital map's contour line. However, if using these data for producing DTM, users need to additional cost and data lead time. And hard to update terrain data. For possibility of solving these problem, this study did DTM extraction with automatic matching for aerial photograph, and analysed the result with measurement of Orthometric height and excuted accuracy through DTM(which extracted from digital photogrammetric technique). As a result, we can get a high accuracy of RMSE (0.215m).

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.379-386
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• 2007

In this paper, topographic factors over 3-dimensional hills were estimated through wind tunnel tests. Topographic models having five different slopes of $5.71^{\circ}, \;11.31^{\circ},\;16.70^{\circ},\;21.80^{\circ}$, and $26.57^{\circ}$ which were based on Korean Building Code(KBC(2005), were made for wind tunnel tests. From the result of wind tunnel tests, topographic factors over 3-dimensional hills were obtained at various locations, and the ranges of topographic effects were decided. The ranges of topographic effects was whole area of the hills in the horizontal ranges and heights of 3.5 times of the hills in the vortical ranges. Topographic effects was large at the top of hills, and wind velocity was increased 57% over hill of $5.71^{\circ}$, 75% over hill of $11.31^{\circ}$, 79% over hill of $16.70^{\circ}$, 81% over hill of $21.80^{\circ}$, and 61% over hill of $26.57^{\circ}$. Wind velocity was bigger over surface of across-wind direction of hills than one over surface of wind direction of hills, and wind velocity was increased $10{\sim}30%$ at locations of across-wind direction.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.12-14
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• 2000

최근 들어 컴퓨터그래픽, 가상현실, 3차원 위상기하학, 그리고 3차원 공간 데이터 저장 관리 기술 등의 발달로 3차원 지리정보시스템 또는 가상 지리정보시스템의 구현가능성에 대한 활발한 연구가 세계적으로 진행 중이다. 특히 인터넷의 쉽고 광범위한 접근 용이성을 이용하여 인터넷 환경에서 운용되는 가상 지리정보시스템의 개발에 대한 연구가 주목을 받고 있다. 본 논문에서는 인터넷 기반 가상 지리정보시스템의 설계와 구현을 개발 사례를 중심으로 간단히 언급한다. 본 논문에서 제안한 시스템은 인터넷 환경 하에서 3차원 지형 및 시설물 등의 대용량 3차원 공간정보를 빠르고 효율적으로 저장, 관리, 편집 분석, 가시화 할 수 있는 장점이 있으므로 일반인 및 전문가들에게 고급의 의사결정 수단을 제공할 수 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.4
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• pp.437-444
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• 2020

A lunar rover's optical camera is used to provide navigation and terrain information in an exploration zone. However, due to the scant presence of atmosphere, the Moon has homogeneous terrain with dark soil. Also, in extreme environments, the rover has limited data storage with low computation capability. Thus, for successful exploration, it is required to examine feature detection and matching methods which are robust to lunar terrain and environmental characteristics. In this research, SIFT, SURF, BRISK, ORB, and AKAZE are comparatively analyzed with lunar terrain images from a lunar rover. Experimental results show that SIFT and AKAZE are most robust for lunar terrain characteristics. AKAZE detects less quantity of feature points than SIFT, but feature points are detected and matched with high precision and the least computational cost. AKAZE is adequate for fast and accurate navigation information. Although SIFT has the highest computational cost, the largest quantity of feature points are stably detected and matched. The rover periodically sends terrain images to Earth. Thus, SIFT is suitable for global 3D terrain map construction in that a large amount of terrain images can be processed on Earth. Study results are expected to provide a guideline to utilize feature detection and matching methods for future lunar exploration rovers.