• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.10
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• pp.901-906
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• 2010

A three-dimensional flow simulation was performed to investigate the flow field in a wind farm on a complex terrain. The present study aims to examine the effects of mountainous terrain and turbine arrangement on the performance of wind power generation. A total of 49 wind turbines was modeled in the computational domain; detailed blade shape of the turbines was considered. Frozen rotor method was used to simulate the rotating operation. The torque acting on the turbine blades was calculated to evaluate the performance of the wind turbines. The numerical results showed details of the flow structure in the wind farm including the velocity deficit in the separated flow regions; this velocity deficit was due to the topographical effect. The effect of the wake induced by the upstream turbine on the performance of the downstream wind turbine could also be observed from the results. The methodology of the present study can be used for selecting future wind-farm sites and wind-turbine locations in a selected site to ensure maximum power generation.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.312-312
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• 2022

우리나라는 하천법 및 소하천정비법에 의거하여 하천기본계획 수립 또는 하천의 지정 및 변경고시 시 하천구역을 지정하고 있다. 하천구역은 일반적으로 제방부지 및 제방하심측 토지경계를 기준으로 지정하나, 제방이 존재하지 않는 무제부 구간의 경우 명확한 제방경계가 없는관계로 하천법 제 10조 3항에서 5항까지 별도의 기준을 통해 하천구역 지정을 권장하고 있는 실정이다. 하천구역 설정 시 기준으로 삼는 횡단측점 자료의 경우 그 특성상 하천의 종단방향으로 불연속적인 특징을 갖고 있어 평면상 정확한 경계의 파악이 어려우며, 도로·철도 등 선형시설경계를 하천구역으로 설정 시 편입용지의 보상기준이 모호하여 다량의 민원이 발생하고 있다. 본 연구에서는 하천정비 시 기본계획이 수립되어 각 횡단측점별 결정된 계획홍수위를 기반으로 인접 지형의 홍수위 영향범위를 자동으로 추출하여 하천구역을 정밀하게 결정할 수 있는 방법론을 정립하고자 한다. 첫째로, 하천중심선의 각 측점의 위치정보와 하천의 지형을 위상정보체계로 구성하여 DB를 구축하였다. 둘째로, 측선과 측선사이 절점에 계획홍수위를 선형보간하여 부여하고 이를 지형도의 최단거리에 위치한 지형의 격자표고와 비교해 침수여부를 판단한다. 셋째, 최단거리 지형격자가 침수로 판단될 시 인접한 8개 지형격자의 지형표고와 홍수위를 비교하여 반복적으로 위 과정 수행을 통해 계획홍수위 기반 침수범위를 추출한다. 마지막으로, 이를 수치지형도에 중첩시켜 최종 정밀 하천구역을 결정할 수 있다. 이를 이용하여 산정된 정밀한 하천구역 경계설정을 통해 하천 내사유지 편입을 최소화함과 동시에 명확한 하천구역 구획기준을 정립하여 토지소유주와 담당부처 간 논의 시 기반자료로 활용될 수 있고, 하천구역의 신속하고 정확한 구역설정을 통해 하천인근의 토지이용 고도화 및 효율적인 이용이 가능할 것으로 기대된다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.532-534
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• 2004

본 논문은 분석가들에게 Naive Geography에 기반 한 형상 추출기술과 상식적 공간추론 기술을 제공하는 문제 해결 환경인 NG Analyst의 개발 사례에 대해 다뤘다. 지형과 각각의 객체에 대한 구성 정보는 분산된 지형공간의 지식을 사실적으로 묘사하는 추론집합에 의해 표현되며 사용자가 형상정보를 인지적으로 이해할 수 있도록 3차원으로 표현한다. 여러 그래픽 적인 요소들로 표현된 Naive Geography 정보들은 분석가들에게 실세계의 공간과 객체들을 유사하게 구성하여 제공함으로서 직관적으로 이해하고 상호작용 할 수 있는 문제 해결 환경을 제공한다.

• Journal of the Korean Geographical Society
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• v.47 no.2
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• pp.159-178
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• 2012

Since the suggestions on the paleo-glacial landforms in and around the northern high mountains of Korean Peninsula by some western and Japanese scientists in the early 1900s, the likelihood of the glacier existence in the Baekdusan over the Quaternary glacial period has been had in common among most of the Korean geomorphologists. In the other meaning, some have cast doubt on the likelihood the paleo-glacier in the Baekdusan because there has been no unequivocal evidences for the glacier such as striation, moraines, except morphologic characteristic landforms possibly related to glacier. Here we show some evidences for the existence of the glacier in the Baekdusan and their cosmogenic $^{36}Cl$ exposure ages over the late Quaternary and would put forward a model on the Quaternary landscape evolution of the Baekdusan, with a focus on the relationship of 1000 AD explosive eruption and the glacial landforms. The exposure ages constrained by cosmogenic $^{36}Cl$ abundances of the col surface of the western slope located below the glacier yield 46~26 ka, which is inphase with the last glacial period. Given all the evidences above, we can draw a conclusion that the glacier existed on the Baekdusan over the late Quaternary and the style of glaciation changed from extensive ice cap through valley glacier to restricted cirque.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.355-367
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• 2005

In Korea, it is reported that the study about tourism geology, which is a new branch af applied geology that would support the growth of ecotourism world-wide, is significantly deficient. The objectives of this study include (1) the promotion in geodiversity of tourism geology using the data for type and distribution patterns of geological and geomorphological landscapes resources, and (2) the redoubling of diversity in environmental interpretation programs offerend by National Parks Authority (NPA). According to this research results, 62 geological and geomorphological landscape resources in Naejangsan national park were observed. Weathering topography is the most discovered type followed by river, mountain and tectonic topography in decreasing order. It is thought that the above-mentioned data can be utilized to sort and filter by the discussion through consortium organized by geologist and geomorphologist. Furthermore, in order to promote the activation of developing user-oriented geotourism sites, the monitoring on demographical characteristics of geotourists, behaviora characteristics of geotourists within geotourism site, and the analysis for developing geotourism program and events should be accompanied. And, the support of geological engineering dealing the estimation of weathering degree and development of conservation techniques for the object of geotourism will improve the activation of tourism geology.

• Journal of Korea Spatial Information System Society
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• v.3 no.2 s.6
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• pp.5-19
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• 2001

We are able to construct and utilize DEM(Digital Elevation Model) throughout the NGIS(National Geographic Information System) project. It is important that interpolation methods and appreciate size of grid for the construction of accurate DEM(Digital Elevation Model). There were several references related to the DEM(Digital Elevation Model) construction method, however they couldn't consider various topographical characteristics in the korea. In this study, we recommended that suitable interpolation method for each topographic element. After dividing Poonggi area into mountain, hill, urban, agricultural land, we constructed DEM(Digital Elevation Model) with various interpolation methods and grid size using 1:5,000 digital map. Then evaluated accuracy using elevation data which extracted from air-photo. The interpolation methods were analyzed and compared for various topographical conditions. As a result, Kriging method was superior to TIN method for all the topographical conditions. Another experiment was performed to examine optimal grid space for DEM with each topographical condition. 10m grid space was most suitable for mountain area and hilly districts, while 30m grid space was most suitable for urban area and farm land.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.519-528
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• 2012

It was pointed out that the terrain distortion of SAR image is even worse than that of optical image although SAR imagery has the advantages of being independent of solar illumination and weather conditions. It is thus necessary to correct terrain distortion in SAR image for various application areas to integrate SAR and optical image information. There has to be a clear evaluation of terrain correction of high resolution SAR image according to the quality of DEM because the DEM of study site is generally used in the process of terrain correction. To achieve this issue, this paper compared the effects of quality of Digital Elevation Model(DEM) in the process of terrain correction of high resolution SAR images, using the DEM produced from 1:5000 topographic contour maps, LiDAR DEM, ASTER GDEM, SRTM DEM. We used TerraSAR-X and Cosmo-SkyMed, as the test data set, which are constructed on the same X-band SAR system as KOMPSAT-5. In order to evaluate quantitatively the correction results, we conducted comparative evaluation with the KOMPSAT-2 ortho image of the same region. The evaluation results showed that the DEM produced from 1:5000 topographic contour maps achieved successful results in the terrain correction of SAR image compared with the other DEM data, and the widely used SRTM DEM data in various applications was not suitable for the terrain correction of high resolution SAR images.

• Proceedings of the KSRS Conference
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• 2000.04a
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• pp.166-171
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• 2000

밀티빔 음향 측심기 (Multibeam Echo Sounder)는 탐사선에 수직방향으로 해저면을 주사(Swath)하여, 한번의 송수신(Ping)으로 다중의 빔자료를 얻을 수 있는 측심기로, 해저면에 반사되어 되돌아오는 음파의 음압을 기록하고, 사이드 스캔 소나 자료도 동시에 취득하는 기능을 가지고 있으므로, 측심된 해저 지형(Bathymetry)과 해저 지형을 덮고 있는 해저면의 퇴적 상황(Sediment Environment)도 동시에 얻을 수 있는 다목적 측심기이다. 본 논문에서는 L3사의 Sea Beam 2100 멀티빔 음향 측심기를 통해 얻은 자료를 처리하여, 3차원 공간 데이터인 DEM(Digital Elevation Model)을 생성하고, VRML을 이용한 웹상에서의 해저 지형 가시화를 통해, 세계 어느 곳에서나 웹을 통하여 쉽게 정보를 공유할 수 있는 3차원 해저 지리 정보 시스템의 구현을 목적으로 한다. 멀티빔 음향 측심기를 통해 얻어진 자료는 항해 자료 보정, 음속 보정, 빔 좌표 계산과 분리, 오측심 자료 제거, 조석 보정 등의 단계를 거쳐 측심자료의 정확도 및 신뢰도를 높이는 과정을 거치게 된다. 보정된 멀티빔 음향 측심자료는 무작위 점 사상(Point Topology)으로 산재 되어 있는 빔 자료를 임의의 단위영역으로 변환하는 과정을 거쳐야 하는데, 이 과정을 격자화라고 한다. 자료의 격자화를 통해 3차원 공강 데이터인 DEM 파일을 제작하고, 이 DEM 파일과 음압 영상을 이용해 웹상에서의 3차원 해저 지형의 가시화를 실현한다. 웹상에서의 3차원 지형 가시화에서 방대한 양의 지형 데이터는 데이터 전송 시간과 렌더링 시간에 치명적인 문제이다. 따라서, 렌더링 시간과 데이터 전송 시간을 단축시키기 위한, 지형 자료의 LOD(Level of Detail)를 통해, VRML을 이용한 보다 효과적인 웹상에서의 3차원 해저 지형의 가시화를 실현한다.면 기업은 고객으로 공간적인 제약으로 인한 불신을 불식시키는 신뢰감을 주게 된다. 이러한 고객서비스 향상과 물류비용 절감은 사이버 쇼핑몰이 전국 어디서나 우리의 안방에서 자연스럽게 점할 수 있는 상황을 만들 것이다.SP가 도입되어, 설계업무를 지원하기위한 기본적인 시스템 구조를 구상하게 된다. 이와 함께 IT Model을 구성하게 되는데, 객체지향적 접근 방법으로 Model을 생성하고 UML(Unified Modeling Language)을 Tool로 사용한다. 단계 4)는 Software Engineering 관점으로 접근한다. 이는 최종산물이라고 볼 수 있는 설계업무 지원 시스템을 Design하는 과정으로, 시스템에 사용될 데이터를 Design하는 과정과, 데이터를 기반으로 한 기능을 Design하는 과정으로 나눈다. 이를 통해 생성된 Model에 따라 최종적으로 Coding을 통하여 실제 시스템을 구축하게 된다.the making. program and policy decision making, The objectives of the study are to develop the methodology of modeling the socioeconomic evaluation, and build up the practical socioeconomic evaluation model of the HAN projects including scientific and technological effects. Since the HAN projects consists of 18 subprograms, it is difficult In evaluate all the subprograms simultaneously. Despite, each program is being performed under the category of HAN projects, so the common soci

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.1-8
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• 2018

Extreme climate phenomena are occurring around the world caused by global climate change. The heavy rains exceeds the previous record of highest rainfall. In particular, as flash floods generate heavy rainfall on the mountains over a relatively a short period of time, the likelihood of landslides increases. Gangwon region is especially suffered by landslide damages, because the most of the part is mountainous, steep, and having shallow soil. Therefore, in this study, is to predict the risk of disasters by applying topographic classification techniques and landslide risk prediction techniques to mountain watersheds. Classify the hazardous area by calculating the topographic position index (TPI) as a topographic classification technique. The SINMAP method, one of the earth rock predictors, was used to predict possible areas of a landslide. Using the SINMAP method, we predicted the area where the mountainous disaster can occur. As a result, the topographic classification technique classified more than 63% of the total watershed into open slope and upper slope. In the SINMAP analysis, about 58% of the total watershed was analyzed as a hazard area. Due to recent developments, measures to reduce mountain disasters are urgently needed. Stability measures should be established for hazard zone.

• Journal of the Korean GEO-environmental Society
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• v.22 no.2
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• pp.35-39
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• 2021

Photogrammetry using drone can produce high-resolution ortho image and acquire high-accuracy 3D information, which is useful. Therefore, this study attempted to determine the possibility of using drone-photogrammetry in park construction by producing a topographic map using drone-photogrammetry and analyzing the problems and accuracy generated during production. For this purpose, we created ortho image and DSM (digital surface model) using drone images and created topographic status map by vectorizing them. Accuracy was compared based on topographic status map by GPS (global positioning system) and TS (total station). The resulting of analyzing mean of the residuals at check points showed that 0.044 m in plane and 0.066 m in elevation, satisfying the tolerance range of 1/1,000 numerical maps, and result of compared lake size showed a difference of about 4.4%. On the other hand, it was difficult to obtain accurate height values for terrain in which existed vegetation when producing the topographic map, and in the case of underground buried objects, it is not possible to confirm it in the image, so direct spatial information acquisition was necessary. Therefore, it is judged that the topographic status map using drone photogrammetry can be efficiently constructed if direct spatial data acquisition is achieved for some terrain.