• 한국측량학회지
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• 제17권1호
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• pp.61-67
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• 1999

하천과 유역을 연구하는데 있어서, 유역에 대한 지형인자는 매우 중요한 부분을 차지한다. 이러한 지형인자를 구하기 위해서, 기존에서는 지형도상에서 직접 구하거나 지형도를 수치화하여 사용하였다. 그러나 이러한 방법은 매우 번거롭거나 비경제적이다. 본 연구에서는 미국의 DMA에서 제공하는 DTED를 사용하여, 하천과 유역을 생성하고, 지형인자를 추출하였다. 지형도를 수치화하여 구한 지형인자와 DTED에서 구한 지형인자들을 서로 비교함으로써 DTED의 활용여부에 대해서 알아보고자 하였다.

• 산업기술연구
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• 제18권
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• pp.35-41
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• 1998

A watershed terrain factor is known to the very important in studies of a stream and a watershed. We have obtained the terrain factor in map directly or we have generated it in a digitalized map. In this study, DTED(Digital Terrain Elevation Data) offering in DMA(Defense Mapping Agency) was used to create a stream and a watershed and to extract the terrain factor. As comparison of the factors gererated in digitalized map the terrain factors extracted in DTED, DTED could be used to extract a terrain factor for a watershed management.

• Wind and Structures
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• 제17권2호
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• pp.135-162
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• 2013

The majority of experiments to characterize the turbulence in the surface layer have been performed in flat, open expanses. In order to characterize the turbulence in built-up terrain, two mobile towers were deployed during Hurricane Ike (2008) in close proximity, but downwind of different terrain conditions: suburban and open. Due to the significant non-stationarity of the data primarily caused by changes in wind direction, empirical mode decomposition was employed to de-trend the signal. Analysis of the data showed that the along-wind mean turbulence intensity of the suburban terrain was 37% higher than that of the open terrain. For the mean vertical turbulence intensity, the increase for the suburban terrain was as high as 74%, which may have important implications in structural engineering. The gust factor of the suburban terrain was also 16% higher than that of the open terrain. Compared to non-hurricane spectral models, the obtained spectra showed significantly higher energy in low frequencies especially for the open terrain.

• 한국측량학회지
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• 제24권5호
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• pp.389-397
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• 2006

본 논문은 라이다 데이터를 활용하여 지형에 대한 3차원 해석을 보여 주는 것이다. 일반적으로, 라이다 측량은 항공레이저스캐너를 이용하여 지표의 정량 및 정성적 정보를 얻을 수 있는 방법이다 획득된 라이다 데이터를 사용해 불규칙 삼각망, 수치표면모형 및 수치표고모형 등의 지형 데이터를 만들어 지형의 가시성, 음영기복, 경사방향 및 경사도와 같은 요소들을 조사했다. 각 항목으로부터 얻은 해석 결과들은 지형해석에 있어서 주요한 요소로 사용되어지며, 라이다 측량이 지형해석을 위한 새로운 방법으로 이용되기를 기대한다.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권5호
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• pp.226-232
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• 2001

The ability to efficiently and robustly recover accurate 3D terrain models from sets of stereoscopic images is important to many civilian and military applications. To develop an effective and practical terrain modeling system, we propose a new multi-image stereo method which detect unreliable elevations in DEM(Digital Elevation Map), and fuse several DEMs from multiple sources into an accurate and reliable results. This paper focuses on two key factors for generating robust 3D terrain models: the ability to detect unreliable elevation estimates and the ability to fuse the reliable elevations into a single optimal terrain model. We apply the self-consistency methodology to reconstruct accurate DEM from multi-image and show the method is more effective than the conventional stereo image 3D reconstruction method. Using photo-realistic simulator, four synthetic image are generated from ground truth DEM and orthoimage to evaluate the accuracy of the proposed method quantitatively.

• Wind and Structures
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• 제19권5호
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• pp.541-563
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• 2014

This paper investigates the topographic effects on wind characteristics over hilly terrain, based on wind data recorded at a number of meteorological stations in or near complex terrain. The multiply data sources allow a more detailed investigation of the flow field than is normally possible. Vertical profiles of mean and turbulent wind components from a Sodar profiler were presented and then modeled as functions of height and wind speed. The correlations between longitudinal and vertical wind components were discussed. The phenomena of flow separation and generation of vortices were observed. The distance-dependence of the topographic effects on gust factors was revealed subsequently. Furthermore, the canyon effect was identified and discussed based on the observations of wind at a saddle point between two mountain peaks. This study aims to further understanding of the characteristics of surface wind over rugged terrain. The presented results are expected to be useful for structural design, prevention of pollutant dispersion, and validation of CFD (computational fluid dynamics) models or techniques over complex terrains.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.385-388
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• 2004

Many environmental destruction factors are accompanied in the mining development work and the secondary environmental disaster and the induction factors are inhered. We aquired digital data using aerial photogrammetry to analyze the terrain current situation according to the development situation of the mining restoration plan. We made the object area to 3D model and conducted terrian change monitoring. Then, we presented the decision-making information to improve rational management according to the original state plan.

• Wind and Structures
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• 제35권6호
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• pp.419-430
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• 2022

In wind-resistant designs, wind velocity is assumed to be a Gaussian process; however, local complex topography may result in strong non-Gaussian wind features. This study investigates the non-Gaussian wind features over complex terrain under atmospheric turbulent boundary layers by the large eddy simulation (LES) model, and the turbulent inlet of LES is generated by the consistent discretizing random flow generation (CDRFG) method. The performance of LES is validated by two different complex terrains in Changsha and Mianyang, China, and the results are compared with wind tunnel tests and onsite measurements, respectively. Furthermore, the non-Gaussian parameters, such as skewness, kurtosis, probability curves, and gust factors, are analyzed in-depth. The results show that the LES method is in good agreement with both mean and turbulent wind fields from wind tunnel tests and onsite measurements. Wind fields in complex terrain mostly exhibit a left-skewed Gaussian process, and it changes from a softening Gaussian process to a hardening Gaussian process as the height increases. A reduction in the gust factors of about 2.0%-15.0% can be found by taking into account the non-Gaussian features, except for a 4.4% increase near the ground in steep terrain. This study can provide a reference for the assessment of extreme wind loads on structures in complex terrain.

• Structural Engineering and Mechanics
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• 제63권4호
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• pp.509-519
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• 2017

Wind field in mountainous regions demonstrates unique distribution characteristic as compared with the wind field of the flat area, wind load and wind effect are the key considerations in structural design of television towers situated in mountainous regions. The television tower to be constructed is located at the top of Xiushan Mountain in Nanjing, China. In order to investigate the impact of terrain factors of hilltops on wind loads, firstly a wind tunnel test was performed for the mountainous area within 800m from the television tower. Then the tower basal forces such as bending moments and shear strength were obtained based on high frequency force balance (HFFB) test. Based on the experiments, the improved method for determining the load combinations was applied to extract the response distribution patterns of foundation internal force and peak acceleration of the tower top, then the equivalent static wind loads were computed under different wind angles, load conditions and equivalent goals. The impact of terrain factors, damping ratio and equivalent goals on the wind load distribution of a television tower was discussed. Finally the equivalent static wind loads of the television tower under the 5 most adverse wind angles and 5 most adverse load conditions were computed. The experimental method, computations and research findings provide important references for the anti-wind design of high-rise structure built on hilltops.

• 디지털융복합연구
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• 제12권11호
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• pp.1-12
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• 2014

오늘날 각종 재난발생 유형이 다양해지고 다기능화 된 도시 구조로 예측 불허의 재난 발생이 우려되고 있다. 또한 지구 온난화 등으로 재난이 한번 발생했다 하면 대형화되고 있고, 재난 수습을 위하여 가용한 자원을 최대한 동원하여야 하며, 재난현장이 실시간대 언론 등 미디어를 통해 생중계되는 상황이기에 재난현장 지휘자는 그 모든 요소를 고려하여 재난현장을 지휘해야 한다. 그러나 재난현장 지휘에 영향을 미치는 요소는 그 중요성에도 불구하고, 여기에 관련된 사전 연구가 거의 없는 실정이다. 이에 따라 본 연구에서는 국방 분야에서 전투현장 지휘에 적용되고 있는 요소인 METT-TC(Mission, Enemy, Troops, Terrain and weather, Time available, and Civilian considerations)를 기반으로, 일반 재난현장을 효과적으로 지휘하는데 영향을 미치는 요소로 MORT-TEC(Mission, Object, Resources available, Terrain and weather, Time available, Exercise, and Civilian considerations)를 제안한다. 이러한 요소를 세월호 구조 상황에 적용해 봄으로써, 향후 연구 및 재난현장의 지휘자들에게 도움이 될 수 있는 정책적인 의미를 제시한다.