• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.39-47
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• 2014

In this study, the epipolar images were created by both methods of resolution adjustment and piecewise approach using RPC(Rational Polynomial coefficients) and ancillary data of IKONOS-2 and SPOT-5 satellite images whose resolutions are different from each other. The stereo geometry of these two satellite images was analyzed and the RPC block modelling was accomplished for generating epipolar images. In order to evaluate the accuracy of created epipolar images, the y-parallaxes were analyzed for the specific points which were apparently identified in mountainous, plain and urban area. Also the RMSEs of the specific points were calculated using the coordinates from the epipolar stereo images and the coordinates from the block triangulation. Y-parallaxes were within one pixel and the RMSEs were within two meters for X, Y and Z each.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.37-37
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• 2011

최근 세계적인 지진의 발생과 함께 구조물의 내진성능 평가 및 증진 방법에 대하여 많은 연구가 진행 되고 있다. 특히 교량 구조물의 교각의 경우에는 상부구조의 고정하중 및 활하중을 지반에 전달하여 주는 역할을 하기 때문에, 역으로 지진이 발생하였을 경우 교각의 내진성능에 따라서 교량의 안전도에 많은 영향을 미칠 수 있다. 또한 산악지역이 국토의 70%이상을 차지하는 우리나라의 지형적인 특성상 고교각을 이용한 장대교량의 건설이 필요하며 도시지역의 교통량 증가로 인한 도시고속도로의 건설 등 고가교의 필요성이 점차 증가하고 있다. 그러나 CFT(Concrete Filled Tube)부재의 경우에는 콘크리트가 3축 구속 상태로 존재하지만 자중이 크며 내진 성능이 떨어지는 단점을 가지고 있다. 이러한 단점을 보완하기 위하여 CFT부재의 단면을 중공으로 만듦으로써 부재를 경량화하고 내부 튜브를 삽입하여 내부를 구속 시킨 내부 구속 중공 CFT 부재(Internally Confined Hollow CFT Member, ICH CFT)가 개발되었다. 이는 콘크리트가 내 외부 튜브에 의하여 구속되어 3축 구속 상태로 존재함으로써 콘크리트 중공부로의 취성파괴를 방지하여 연성도 및 강도를 향상시켜주며, 단면의 감소로 인해 재료비를 절감 할 뿐 아니라 자중 감소로 인해 내진 설계에도 유리하다. 현재 내부 구속 중공 CFT 부재에 대한 연구가 많이 진행되고 있지만, 튜브를 삽입함으로써 부재의 중공부로 발생하는 구속력의 특성을 해석적으로 정립한 연구는 미비한 실정이다. 본 연구에서는 압축을 받는 중공 CFT 부재에 내부 튜브를 삽입함으로써 발생하는 콘크리트의 구속력을 해석적 연구를 통하여 수행하였으며, 구속력을 파악하기 위한 평가 방법으로는 구속 콘크리트의 중공비와 직경, 외부튜브의 두께, 내부튜브의 두께 등으로 평가하였다. 해석적 연구 결과, 내부 튜브를 삽입함으로써 발생되는 외부 구속력은 이론적 수식에 의한 구속 응력값과 비슷한 값을 가지지만 내부로 발생하는 구속력은 이론적 수식에 의한 구속 응력값에 도달하지 못하는 것을 확인할 수 있었다.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.25-31
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• 2008

As we choose ground control points for aerial triangulation, we have a lot of problems in a mountain, a costal area, a desert, the foreshore etc because they don't have clear topography for control points and it spends a lot of cost and occurs problems of accuracy. In this study, we compare and analyze between ground control points from LiDAR intensity, digital map with ground control points from the field survey as doing AT each. As the result, the average error was ${\pm}1.02m$ from using LiDAR intensity, ${\pm}1.13m$ from using digital map. this result can present the control points from LiDAR intensity is 0.11m better than from digital map.

• Atmosphere
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• v.16 no.4
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• pp.359-370
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• 2006

Terrain height variance spectra for the Korean mountain region are calculated in order to determine an adequate grid size required to resolve terrain forcing on mesoscale model simulation. One-dimensional spectral analysis is applied to specifically the central-eastern part of the Korean mountain region, where topographical-scale forcing has an important effect on mesoscale atmospheric flow. It is found that the terrain height variance spectra in this mountain region has a wavelength dependence with the power law exponents of 1.5 at the wavelength near 30 km, but this dependence is steeply changed to 2.5 at the wavelength less than 30 km. For the adequate horizontal grid size selection on mesoscale simulation two-dimensional terrain height spectral analysis is also performed. There is no directionality within 50% of spectral energy region, so one-dimensional spectral analysis can be reasonably applied to the Korea Peninsula. According to the spectral analysis of terrain height variance, the finer grid size which is higher than 6 km is required to resolve a 90% of terrain variance in this region. Numerical simulation using WRF (Weather Research and Forecasting Model) was performed to evaluate the effect of different terrain resolution in accordance with the result of spectral analysis. The simulated results were quantitatively compared to observations and there was a significant improvement in the wind prediction across the mountain region as the grid space decreased from 18 km to 2 km. The results will provide useful guidance of grid size selection on mesoscale topographical simulation over the Korean mountain region.

• Explosives and Blasting
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• v.27 no.1
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• pp.47-52
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• 2009

Blasting is necessary for excavation processes since more than 70% of korean land is consist of mountains. The vibration and noise accompanied by blasting processes usually bring about public complaints. Blasting patterns are chosen by economical efficiency, stability and construction conveniency. However, there are many alternatives without control to settle the popular complaint. To prevent those alternatives, standard blasting method for design and construction were suggested by MLTM (Ministry of Land, Transport and Maritime Affairs) in 2006. However, standard blasting pattern of MLTM was designed in a lump irrespective of types of rocks. Economical loss may occur by ignoring the characteristics of rocks for the applications to the rocks with low intensity, such as shale, or containing many joint. We deduced some economical progresses by performing test blasting with adjusted drilling spacing and length of burden considering the characteristics of local rock. This paper suggests the start of case studies for different applications. Economic improvement can be expected by applying those results deduced from case studies to design and construction.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.207-215
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• 2009

Generally, traffic accidents can be influenced by variables driving conditions including geometric, roadside design, and traffic conditions. Under the circumstance, homogeneous roadway segments were firstly identified using typical geometric variables obtained from field data collections in this study. These field data collections were conducted at highways located in several areas having various regional conditions for examples, outside metropolitan city; level and rolling rural areas. Due to many zero cells in crash database, a Zero Inflated Poisson model was used to develop crash prediction model to overestimated results in this study. It was found that EXPO, radius, grade, guardrail, mountainous terrain, crosswalk and bus-stop have statistically significant influence on vehicle to vehicle crashes at rural multi-lane roadway segments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.7
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• pp.51-58
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• 2005

In 1990, GPS which had been developed for the military purposes became available to the civilian community. Since then these satellite navigation systems have been used extensively in the industrial areas such as car navigation, airplanes, communications, science and surveying. If we are dependent on GPS, however, there are some foreseeable problems in the areas of national security and sovereignty. Current GPS satellite constellation provides limited performance for the country like Korea and Japan where mountain area and urban canyon do not allow the wide skyline. To solve these problems, many countries plan to make other alternative navigation systems.In this paper, RNSS(Regional Navigation Satellite System) is designed to provide communication service with high elevation angle. It is shown, that system does not only have good navigation performance, but also improve GPS performance in Korea and its neighboring areas.

• The Journal of Engineering Geology
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• v.5 no.2
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• pp.167-179
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• 1995

The only three elements such as RQD, N -value and Es were used as a quantitative standard for the design of supporr pattern determidetion on subway line 8th in Seoul. Because the support pattern that was obtained by these elements could not he determined on the basis of the quantitative of geology and the orientations and properties of discontinuity planes, there have been some problems in determining the economic support pattern and tunnel stability. Therefore, in an attempt to determine the stable and economic support pattern with more quantitative elements, more flerrible rock mass classification with geologic conditions was performed by using RMR at 1745 sections and Q-system at 374 sections within Seongnam block on subway line 8th. Then, rusults by these two methods were compared with standard support pattern of the subway line 8th. Moreover, relationships between geology, geologic structures and topography to rock mass grades were studied. According to the rusult of this study, it is judged that the standard support pattern designed with PD-4 or PS - 4 should have been subdivided into 4~6 support patterns. Some sections where geologic structures such as faults and joints are developed tend to have rock mass grades. And they also have low rock mass grades near valley. On thr other hand, they show intermediate grades at piedmont area and the greatest ones at high mountains.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.431-439
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• 2000

In this study, a GIS-application model to determine the optimal route of eco-friendly forest roads and to evaluate the environmental and engineering features of the route was developed. The model consists of five modules for managing spatial and attribute data, determining the optimal route for forest road projection, evaluating environmental and engineering efficiency of forest roads, analyzing characteristics of mountain terrains and report-writing. Using the pull-down menu system, these modules were integrated to be user-friendly for forest field practitioners. Visual Basic 6.0 and Avenue were used as the programming tool and the commercial GIS softwares, ArcView 3.1, Spatial Analyst and 3-D Analyst were used as the basic engine of the model for GIS analysis. In this paper, discussed are the principles for forest road projection and evaluation and structures and application features of the model.

• Journal of Korea Water Resources Association
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• v.36 no.4
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• pp.633-645
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• 2003

The techniques of GIS and remote sensing are being applied to hydrology, geomorphology and various field of studies are performed by many researcher, related those techniques. In this paper, curve number change detection is tested according to soil map and land cover in mountain area. Neural networks method is applied for land cover classification and GIS for curve number calculation. The first, sample area are selected and tested land cover classification, NN(84.1％) is superior to MLC(80.9％). So we selected NN with land cover classifier. The second, curve number from the land cover by neural network classifier(57) is compared with that(curve number) from the land cover by manual work(55). Two values are so similar. The third, curve number classified by NN in sample area was applied and tested to whole study area. As results of this study, it is shown that curve number is more exact and efficient by using NN and GIS technique than by (using) manual work.