• Journal of the Korean earth science society
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• v.33 no.3
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• pp.219-232
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• 2012

The intensive observation (ProbeX-2010) was performed to investigate an urban effect on summer rainfall over the Seoul metropolitan area from 13 August to 3 September 2010. Two kinds of urban effect were detected. First, weak rainfall (${\leq}1\;mm\;hr^{-1}$) was observed more frequently in the downwind area of Seoul than any other area of the country. The high frequency of weak rainfall in the downwind area was also confirmed from the recent five years of observational data (2006-2010). Because the high frequency was more apparent in mountainous regions during nighttime, the weak rainfall seems to be caused by a combined effect of urbanization and topography. Second, sporadically, a convective system was developed rapidly in the downwind area of Seoul, causing heavy rainfall (${\geq}10\;mm\;hr^{-1}$). It can be most clearly seen in series of radar images around 1300-1500 KST 27 August 2010. We investigated in detail the synoptic and local weather and upper air conditions. As a result, not only urban-induced high sensible heat but also conditionally unstable atmosphere (especially unstable in low level) and low level moisture were pointed out as important factors that contributed to urban-induced heavy rainfall.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.163-164
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• 2010

In this paper, the plan to invigorate regional marine tourism is discussed. The southwest area of Jeonnam province is famous for its beautiful islands and seashore line which has richness and variety of marine life. A solution of tourists increment by leisure sports utilizing islands and coastline will be proposed MTB tournament held at islands that has historic backgrounds and scenic beauty and its effect on influx of tourist were tracked first. Next application of mud flats boot around seaside and connection with experience program of seaside village were also examined. These activities will contribute to development of marine tourism and increase of income for regional people.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.320-320
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• 2023

강우 데이터는 수문기상, 환경, 농업, 자연재해, 그리고 수자원 시스템 분야에서 가장 필수적인 기본 요소 중 하나이다. 또한 강우 데이터는 수문학적 분석에서 활용되는 필수 입력 자료 중 하나로 관측 데이터의 품질에 따라 수문 모형을 이용한 모의 결과물의 정확도가 결정된다고 할 수 있다. 따라서, 강우 관측소별로 강우 데이터의 품질을 어떻게 관리하느냐에 따라 수문 모형의 활용 범위 및 수자원 관리의 효율성이 결정될 수 있다. 강우의 시공간적 변동성은 수 많은 인자들과 직간접적으로 연계되어 있기 때문에 미계측 강우 자료에 대해 직접 관측이 아닌 수치 모형을 이용하여 강우의 발생과 강우량을 산정하는 것은 매우 복잡한 과제 중 하나이다. 현재 국내에서 운용되고 있는 강우 관측소의 경우에도 미계측 된 강우 데이터가 존재함으로써 강우 데이터의 활용에 제한이 생기는 경우가 있다. 따라서, 이러한 미계측 데이터의 추정 및 보완은 보다 효과적인 수재해 방지, 수자원 관리를 위한 필수 과제 중 하나이다. 일반적으로, 미계측 강우를 산정하기 위해서 Kriging, Thiessen, 등우선법, 그리고 역거리 관측법 등 다양한 수문학적 방법들이 적용되고 있다. 이러한 방법들은 산악효과나 강우 관측소의 분포 상태 등을 고려하지 못하기 때문에 측정하는 지역에 따라 강우 추정 오차가 커질 수 있다는 한계가 있다. 최근에는 데이터 관측 시스템과 빅데이터 기술의 발전과 활용 가능한 데이터의 양이 증가함에 따라 머신러닝을 활용한 사례가 증가하고 있다. 머신러닝은 데이터 사이의 관계를 기반으로 분류, 회귀, 그리고 예측 문제에 주로 사용되는 기법 중 하나이다. 따라서, 본 연구에서는 광주광역시 지역에 위치한 주요 강우 관측 지점들을 대상으로 미계측 된 시강우 데이터를 추정 및 복원하고자 한다. 여기서 데이터 추정 기술이란 미계측 강우의 발생 유무 및 강우량을 추정할 수 있는 기술을 의미한다. 이를 위해 대표적인 머신러닝 알고리즘인 인공신경망(Artificial Neural Network) 및 랜덤포레스트(Random Forest)를 적용하였다.

• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.21-34
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• 2013

Permanent Scatterer InSAR (PSInSAR) technique extracts permanent scatterers exhibiting high phase stability over the entire observation period and calculates precise time-series deformation at Permanent Scatterer (PS) points by using single master interferograms. This technique is not a good method to apply on nature environment such as forest area where permanent scatterers cannot be identified. Another muti-temporal Interferometric Synthetic Aperture Radar (InSAR), Small BAseline Subset (SBAS) technique using multi master interferograms with short baselines, can be effective to detect deformation in forest area. However, because of the error induced from phase unwrapping, the technique sometimes fails to estimate correct deformation from a stack of interferograms. To overcome those problems, we introduced new multi-temporal InSAR technique, called Temporarily Coherence Point InSAR (TCPInSAR), in this paper. This technique utilizes multi master interferograms with short baseline and without phase unwrapping. To compare with traditional multi-temporal InSAR techniques, we retrieved spatially changing deformation because PSs have been found enough in forest area with TCPInSAR technique and time-series deformation without phase unwrapping error. For this study, we acquired ERS-1 and ERS-2 SAR dataset on Augustine volcano, Alaska and detected deformation in study area for the period 1992-2005 with SBAS and TCPInSAR techniques.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.748-754
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• 2010

The contents of soil organic matter (SOM) and $Al_o+1/2Fe_o$ in soils are important criteria for the classification of new Andisols in Soil Taxonomy system. There are many soil types in Jeju Island with various soil forming environments. This paper was conducted to estimate the contents of soil organic matter and the content of ammonium oxalate extracted Al and Fe ($Al_o+1/2Fe_o$) using various environmental variables and to make soil property maps using a statistical analyses. The soil samples were collected from 321 locations and analyzed to measure the contents of SOM and $Al_o+1/2Fe_o$. It was analyzed the relationships among them and various environmental variables such as temperature, precipitation, net primary product, radiation, evapotranspiration, altitude, soil forming energy, topographic wetness index, elevation, difference surrounded area, and distances from the shore and the peak. We can exclude multi-collinearity among environmental variables with principal component analysis and reduce all the variables to 3 principal components. The contents of SOM and $Al_o+1/2Fe_o$ were estimated by multiple regression models and maps of them were made using the models.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.529-533
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• 1995

안장은 인체하중이 집중되고, 자전거의 충격과 진동이 직접 전달되는 부위로서 주행 안락도를 높이고 buttock의 discomfort를 감소시킬 수 있도록 설계되어야 한다. 본 연구의 목적은 인체곡면을 본뜬 안장형상 설계를 통하여 buttock의 국부적 discomfort를 감소시키고자 하는 것이다. 인간의 앉은자세에 대한 해부학적 고찰을 통해 좌골결절(Ischial Tuberosity)과 치골결합면(Symphyseal Surface)이 안장과 직접 맞닿는 면으로 파악되었으며, 이들 부위에 대한 집중적 개선이 이루어져야 할 것으로 제안되었다. 문헌조사를 통해 의자설계시 고려해야 할 인체치수 및 지침을 파악하였으며, 안장과 의자의 기능비교를 통해 이를 선별적으로 적용하였다. 인체곡면 측정을 위해 Rod Matrix(3cm 간격, 13*20)방법을 이용하여 10명의 buttock contour를 측정하였으며, 측정된 자료를 분석하여 안장의 곡면형상을 결정하였다. General Comfort Rating, Body Part Discomfort 등의 주관적 안락도 평가방법을 통하여 기존 자전거 안장과 본 연구를 통해 개발된 안장을 비교 평가한 결과, 전반적인 안락도의 향상과 좌골결절 및 치골 결합부의 discomfort 감소효과를 가져온 것으로 파악되었다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.141-144
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• 2007

이동 애드 혹 네트워크(MANET)는 지리적, 환경적인 요인으로 기존의 네트워크를 설치할 수 없는 산악과 같은 고립된 지역에 설치할 수 있는 이동 노드들로 구성된 네트워크이다. 또한 인포스테이션은 전송지연에 민감하지 않는 정보들을 적은 비용으로 효율적으로 전송할 수 있는 시스템이다. 본 논문에서는 등산객이 무선 이동 노드를 휴대함으로서 이동 애드 혹 네트워크를 구성하고, 또한 인포스테이션이 결합된 등산객 조난 구조 시스템을 제안한다. 등산객은 이동 중에 만나는 다른 등산객과 위치정보를 공유하고, 이를 인포스테이션에 전송함으로써 다른 노드들의 위치 추적을 가능하게 한다. 이 시스템은 노드들간의 연결이 지속적이지 않은, 노드의 이동성을 통한 간헐적인 네트워크를 구성하게 된다. 따라서 시스템 구축비용이 적게 들고, 또한 인포스테이션을 통해 노드에 저장되어 있는 위치정보를 전송함으로서 필요한 메모리 용량을 감소시키는 효과도 있다. 그러므로 제안된 시스템을 활용한다면, 조난된 등산객의 위치를 신속히 파악할 수 있어, 효율적인 구조 활동이 가능하게 할 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.61-70
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• 2010

In case of low benefit project with low traffic or high-priced project, existing analysis of cost and benefit tends to present a low feasibility. However, considering the improvement of environment, intensification of disaster prevention, public stability of countryside area and formation of good scenery, these projects can have a feasibility. This paper analyzes and summarizes the indirect benefit of some ripple effects, caused by road projects, and presents the methodology and process in order to change the indirect benefit into monetary value.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.374-388
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• 2016

In Jeju-Do, there is the 1100 Road, 516 Road, and Bijarimro, which are typical mountain sight-seeing roads in Jeju. These roads are local roads that have been the location for many traffic accidents. This study focused on these roads, categorized the type of traffic accident and analyzed the accident characteristics. The major accident factors were analyzed through trip AHP analysis, Comparative analysis of the velocity distribution and the factors affecting traffic accidents were analyzed. Tourists took many trips on these roads. The mixing rate of the rental cars was 36.70%~71.60% in 1100 road and Bijarimro. Currently, these local roads are regulated by a speed limit of 60km/h. However, it might be necessary to reduce the speed limit to 40km/h considering the geometric line form of the road and the climate in these areas. The speed limit of more than 40km/h is found 87.0% on 516 Roads, 88.57% on 1100 roads, and 93.1% on Bjarimro, In these roads, the speed ratio is higher as described above. Therefore, these roads have been found to have a higher risk of traffic accidents by overspeeding driving. The overspeed driving ratio of these roads was 87.0%~93.1%, The overspeed driving enforcement method at one spot has only the effect of reducing the speed at that enforcement place; the effect cannot be expected for the other places or sections. It is necessary to introduce a section overspeed driving enforcement system utilizing the average velocity in these areas to prevent traffic accidents.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.495-502
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• 2011

The plastic optical fiber has been previously known to have the limits in fabrication and care, due to its lack of flexibility and durability. Recently, an innovative technology of 'water-resistant & flexible optical fiber', in which the surface of etched POF(i.e., plastic optical fiber) is to be coated with a type of synthetic resin, has been developed. In this study, the post-treated POF-based flexible textiles were evaluated in terms of luminance, physical visibility and perceived visibility, according to the fabric lengths and colors of the light source. The POF-based flexible textile with 10cm fabric length and green light source appeared to show relatively higher illuminating effects. The maximum distance for perceived visibility of the POF-based flexible textiles was found to be 100m. Therefore, the results of this study are expected to be utilized as a fundamental for the further studies to develop the digital color clothing with application of POF-based flexible textile.