• Journal of Korea Water Resources Association
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• v.30 no.2
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• pp.177-191
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• 1997

The influences of the space allocation of design rainfall and partition of the subbasin on the characteristics of urban storm runoff was investigated for the 6 drainage basins by applying SWMM model. It show the deviation of -54.68∼18.77% in the peak discharge when we applied the composed JUFF quantiles to the two zones which are divided by upper and lower region of the basin. Then it is compared with the value for the case of using uniform rainfall distribution all over the drainage. Therefore, it would be helpful to decrease the flood risk when we adopt the space distribution of the design rainfall. The effects of the partitioning the drainage on the computing result shows various responses because of the surface characteristics of the each basin such as slope, imperviousness ratio, buy we can get closer result to the measured value as we make the subbasin detailed. If we use the concept of the skewness and area ratio when we determine the width of subbasin, we can improve the computed result even with fewer number of subbasins. We expect reasonable results which close into the measured results in the range of relative error, 25%, when we divide the basin into more than 3 subbasins and the total urban drainage area is less than 10$\textrm{km}^2$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.138-150
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• 2003

In the mid-west coast of Korea where Mankyung and Dongjin rivers discharge fresh water, Saemangeum tidal dyke of 33 km long is under construction to reclaim the very shallow estuary region of 41,000ha. Main source of freshwater in this coastal area is Keum River locating closely north of the dyke. At present, the dyke connected with Gogunsan-Gundo separates this area into three regions; northwestern, southwestern and eastern (Saemangeum) region of the dyke, and the water in Saemangeum region is exchanged through one gap in the northern dyke and two gaps in the southern dyke. We have observed distributions and structures of temperature and salinity to examine the summer circulation related with low-salinity water in this coastal area in 1998 and 1999. In the surface layer off the northern dyke a tongue-like distribution of low-salinity extends 60 km long from Keum River estuary mouth to the northwest, forming plume front bounded by offshore water. In the inner region of Saemangeum dykes salinity distributions show that two river waters are merged together and the low salinity water is deflected toward northern gap of the dyke. In the surface layer off the southern dyke we observed small tongue-like distribution of another low-salinity water extending to the north from Gomso Bay. Based on the analysis of distributions of low-salinity water and frontal structures, we can suggest an anticlockwise circulation of coastal water around the dyke, composed by the estuarine water outgoing from the inner region of the dyke through the northern dyke's gap and the inflow through two gaps of southern dyke from offshore. After completing the dyke construction, this coastal circulation around the dyke will be, however, changed because fresh water discharge of Mankyung and Dongjin rivers will be routed artificially and directly into the area offshore of the southern dyke.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.136-137
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• 2003

동중국해로부터 동해(일본해)에 분포역을 가지는 대마난류계 꽁치자원은 해황에 따라 체장계급군이 추월 회류를 하는 모델이 개발되었다(Gong et al., 1983, 1985). 한편, 이 꽁치어군의 분포 밀도 및 어획량은 동해의 동측(일본측)보다 서측(한반도측)에서 높은 이유를 생산성, 해양구조 및 군집효과에 관련된다고 암시하였으나(공 과 이, 2001), 이 자원의 구조에 미치는 해황의 영향은 확실하게 설명되지 않았다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.211-212
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• 2000

유공충은 껍질(test)을 가지는 원생동물로 기수역(brackish) 내지는 해양에 널게 분포하고 있다. 대부분 석회질 혹은 사질(arenaceous)의 껍질로 구성되어 있으며, 해양퇴적물의 중요한 생물원 요소가 되고 있다(Matoba, 1975). 유공충은 서식환경에 따라 종조성을 달리하거나 종내변이(variety 혹은 ecophenotype)를 보이며 환경의 변화에 민감하게 반응한다. 본 연구에서는 한반도 동남부 연안해역의 내 대륙붕 니질대(nearshore mud belt) 및 영일만에 분포하는 저서성유공충의 분포특성을 파악하고 저질환경인자에 대한 반응 종을 탐색함으로써 연안환경에 서식하는 유공충의 환경지시자를 밝히고자 한다. (중략)

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.4
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• pp.91-98
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• 2017

Electrical impedance tomography is a nondestructive imaging technique to reconstruct unknown conductivity distribution based on applied current data and measured voltage data through an array of electrodes attached on the periphery of a domain. In this paper, an inverse method based on truncated singular value decomposition is proposed to solve the inverse problem with the generalized Tikhonov regularization and to reconstruct the conductivity distribution. In order to reduce the inverse computational time, truncated singular value decomposition is applied to the inverse term after the generalized regularization matrix is taken out from the inverse matrix term. Numerical experiments and phantom experiments have been performed to verify the performance of the proposed method.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.373-378
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• 2008

기존에는 잠재위험도와 해당지역 하나의 강우관측소에서의 기왕최대강우량을 이용하여 계획빈도를 결정하였다. 그러나 기왕최대강우량은 이미 발생한 최대강우량이기 때문에 안전치를 고려해 산정한 계획빈도를 따라가지 못하였고, 잠재위험도에 따른 계획빈도의 범위가 매우 작은 문제점이 있었다. 따라서 본 연구에서는 문산천 유역의 기왕최대강우량과 잠재위험도를 이용하여 계획빈도를 산정하는데 필요한 가중치를 결정하였다. 본 연구에서는 수도권지역 6개의 기상청 강우관측소 강우량 자료를 사용하여 크리깅기법으로 공간분포를 시키고자 하였다. 또한, 기왕최대강우량으로 계획빈도를 연결시키는데 있어서 발생하는 문제점을 해결하기 위하여 계획빈도의 가중치를 산정하고자 하였다. 문산천 유역에 잠재위험도 산정에 따라 계획빈도를 결정한 결과, 크리깅기법으로 문산천 유역에 기왕최대강우량에 해당하는 계획빈도는 160년 정도이며, 회귀식으로 각 소유역별로 계획빈도를 산정한 결과 약 110년에서 120년까지 분포하였다. 이렇게 산정된 계획빈도를 공시지가와 홍수량으로 가중치를 구하여 소유역별로 분포시킨 계획빈도 값은 대략 100년에서 200년으로 산정되었다. 잠재위험도와 피해액 산정기법을 이용하여 문산천에 최적 홍수방어대안을 선정하고자 하였다. 최적 대안을 선정하기 위한 방법론을 제시하고 이에 따라 잠재위험도를 산정하고 유역 분담량을 결정하여 적합한 구조적 홍수방어시설물을 Decision Tree라는 의사결정을 통하여 계획하고 조합하여 3개의 적정 홍수방어대안을 선정하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.170-170
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• 2021

본 연구에서는 토지이용변화 예측 모형으로 산출된 토지이용도를 사용하여 용담댐 소유역의 지표유출량을 비교 및 분석하였다. 토지이용예측모형은 DynaCLUE 모형을 사용하였으며, 토지이용 면적 시나리오는 2000년, 2007년 및 2013년 실제 중분류 토지이용도를 기반으로 회귀식을 산정하였다. 모의된 토지이용도는 실제 토지이용도와 공간적인 분포 및 면적 비교를 통해 변환 탄성계수와 변환 행렬을 수정하여 검·보정하였다. DynaCLUE 모형으로 모의된 토지이용도는 공간적인 분포에서 초지가 실제 토지이용도와 차이가 발생하였으나, 각 토지이용별 면적을 비교한 경우 모의 토지이용도와 실제 토지이용도가 매우 유사하게 나타났다. CLUE 모형으로 모의된 토지이용도에서 발생하는 공간적인 불확실성은 복잡한 용담댐 소유역의 토지이용을 반영할 Driving factor가 부족하여 발생하는 것으로 판단된다. 산출된 모의 토지이용도를 SWAT 모형의 입력 자료로 사용하여 2013년 용담댐의 소유역 지표유출량을 모의하였다. SWAT으로 산정된 유출량의 보정은 SWAT-CUP의 SUFI-2 알고리즘을 이용했으며, 보정된 모의 지표유출량과 실제 유량 측정값을 비교한 결과 유의미한 비교 결과가 나타났다. 향후 토지이용예측모형을 이용하여 토지이용 변화를 수문 분석에 반영하는 추가 연구가 필요할 것으로 판단된다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.339-341
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• 2003

2000년 9월에서 2003년 1월까지 부산 지하철역을 대상으로 CO, NO, $NO_2$ 그리고 $O_3$등 오염물질 4가지를 측정하고 그 결과를 계절별로 분석하여 요약하면, 봄에는 실내인 승강장에서 연산동역과 남포동역의 NO, $NO_2$ 농도가 높았다. 여름과 가을에는 연산동역의 승강장 $O_3$ 농도가 다른 역에 비해서 높은 것으로 나타났다. 겨울에는 다른 계절에 비해서 NO, $NO_2$는 대부분 역에서 입구가 높게 나타났고, $O_3$농도가 모든 역에서 아주 낮은 농도분포를 보였다.

• Journal of the Korean Geographical Society
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• v.38 no.5
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• pp.659-666
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• 2003

This study is a comparative analysis on the variabilities of spring precipitation and atmospheric circulations of 500hPa surfaces between dry years and wet years over the Korean Peninsula. The distribution of variabilities of precipitation in spring are different from month to month. In March, the pattern is west-high and east-low, in April, north-high and south-low, in May, east-high and west-low respectively. In the distribution of 500hPa geopotential height anomaly, dry years of March show west-high and east-low pattern in that negative anomaly zones are formed around the Korean Peninsula and western coast of the northern Pacific Ocean, and positive anomaly zones are formed in the inland of East Asia centered on Siberia. Consequently, the Korean Peninsula and neighboring regions experience dry season when the zonal flows are strong with the positive anomaly zones of zonal components. On the contrary in the wet years the westerlies are weak since the pattern is east-high and west-low in which the positive anomaly zones are formed over the Korean Peninsula centered on the Aleutian Islands and western coast of the northern Pacific Ocean and the negative anomaly zones are formed in the inland of East Asia centered on Tibet Plateau and Siberia. The dry years of April and May show north-high and south-low patterns in that negative anomaly zones are found from the center of the northern Pacific Ocean to the eastern coast of East Asia, and the positive anomaly zones are found in the center of East Asia extending from Aleutian Islands to Tibet Plateau. On the contrary, in the wet years the patterns show south-high and north-low. This study identified not only that there are contrary atmospheric circulation patterms between dry years and wet years over Korean Peninsua in spring, but also there are different atmosphric circulation patterns between early and late spring.

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.255-269
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• 2017

Five year term monitoring investigating variation of allochthonous originated gravels are has been conducted in the beach gravel deposit of the Island Dokdo natural reserve which takes purity and uniqueness with enormous attention though a number of areas. The beach gravel deposits near the dock of the Dongdo and near the accommodation facility of the Seodo comprise various types of gravels including basalt, trachyte, and tuff from the Dokdo itself, and granite, rhyolite, gneiss, quartzite, marble, and concrete from elsewhere. The types of the allochthonous gravels on the basis of the study in 2011 and in 2016 shows no difference, so is the ranking of abundance of the allochthonous gravels; granite-concrete-gneiss in turn on the Dongdo, concrete-gneiss-granite in turn on the Seodo. Nevertheless, the relative ratio of the allochthonous gravel area against the total area is decreased. While it is suspected that the disintegrated facility and the influx of material for construction are the main 2 reasons for the contamination by allochthonous gravel, diminished total contamination ratio indicate that supervising allochthonous material has been improved; at least not worse during the 5 years. On the other hand, it is inferred that gradual influence of rockfall also has been made the gravel beach changed. Therefore, consistent rockfall investigation must be inquired.