• Journal of the Korean Home Economics Association
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• v.38 no.11
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• pp.1-12
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• 2000

The purposes of the study were to investigate the effects of the debt burden which was measured objectively, the types of debts and socio-economic characteristics on the subjective debt burden of households. The questionaires for 457 households who hold some debts were analyzed using t-test, ANOVA and Duncan’s multiple range teat. The major finding are summarized as follows: (1) the objective debt burdens which were measured by three variables, that is monthly debt repayment, the ratio of debt repayment to household income and total debt amount, affected the subjective debt burden. The households in which the monthly debt repayment was over 200 thousand won, the debt repayment was over 20% of the household income and the total debt amount was over 15 minion won felt higher debt burden. (2) the types of debts, which were classified into four groups such as debts from financial institutes, debts from private sources, credit card debts and debt from retailers, influenced differently the subjective debt burden. Holding debts from financial institutes and debts from private sources increased the subjective debt burden whereas holding credit card debts and debt from retailers did not. (3) the level of subjective debt burden were different according to household income, change in income due to IMF crisis, financial assets, home ownership, residence, householder’s age, job and educational levee. Based on the results, criterion for household’s debt management were suggested.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.453-462
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• 2014

The levee and bridge pier in estuary of the Hangang River are exposed in a dangerous condition due to bank erosion and local scouring occurred since the summer season in 2011. At first, it is presumed that the high sandbar formed in river channel of the study area was an important element in the occurrence of bank erosion and local scouring. It can be presumed that the record-breaking depth of freezing due to cold wave for the long term during the winter season between 2010 and 2011 as well as the heavy intensive rainfall of 2011 had a decisive effect on the first damage of A section. The second damage of B section mainly occurred around the bridge pier constructed on the high water channel before it was washed away during the winter season between 2011 and 2012. It is considered that the second damage was caused by ice formation and ice floes.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.220-220
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• 2021

2020년 장마는 6월 중순부터 8월 중순까지 전국적으로 평균 687 mm의 강수가 내려, 1973년 이후 역대 2위 강수량을 기록하였으며, 연이은 태풍으로 큰 인명 및 재산 피해가 발생하였다. 특히, 섬진강 및 한탄천 등에서 계획홍수위를 초과하는 홍수로 인해 상당수의 제방이 월류로 인해 붕괴된 것으로 나타났다. 따라서, 향후 기후변화에 따른 연평균 강수량이 증가할 것으로 전망되는 가운데 집중호우로 인한 제방 붕괴 피해를 최소화하기 위한 고도화된 기술 개발을 통한 선제적 재발 방지대책이 필요한 시점이다. 한국건설기술연구원은 바이오폴리머라는 새로운 친환경 신소재를 이용하여 제방의 안정성 평가 기술 개발 연구를 수행하고 있다. 이에 안동하천연구센터에서는 실규모에 준하는 제방모형(높이 3 m, 사면경사 1:2, 길이 10 m 이상)을 제작하고, 제방 표면에 바이오폴리머 신소재를 처리하여 전방 월류 흐름 유도에 따른 실규모 제방붕괴실험을 수행하였다. 또한, 신소재 보강 및 무보강 조건에 따른 영상분석 기반 붕괴지연효과를 정량적으로 분석하여 신소재의 성능을 평가하였다. 하지만, 기존에 수행된 실험은 댐 붕괴 흐름과 같이 홍수파가 발생하여 제내지로 퍼져 나가는 형태로 진행되어, 보강공법의 검증에 있어 실제 하천에서 발생하는 횡월류 흐름을 재현하지 못한다는 한계를 가지고 있다. 본 연구에서는 횡월류 흐름(0.6 m³/s 이상)을 발생시켜 수리실험에 따른 축척효과(scale effect)를 최소화하고, 현장에 대한 충분한 자연성을 재현하는 것을 목표로 하여 실험을 수행하였다. 실험 조건은 1) 신소재가 처리된 식생 제방, 2) 신소재가 처리되지 않은 식생 제방으로 각각의 조건에 따른 횡월류 흐름 및 제방 붕괴를 유도하여 영상분석 기법(이미지 픽셀분석 및 3D 포인트 클라우드 모델링)을 통한 침식 저항에 관한 분석결과를 제시하였다.

• Journal of Korea Water Resources Association
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• v.44 no.2
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• pp.145-156
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• 2011

Two dimensional numerical model of high-order accuracy is developed to analyze complex flow including transition flow, discontinuous flow, and wave propagation to dry bed emerging at natural river flow. The bed slope term of two dimensional shallow water equation consisting of integral conservation law is treated efficiently by applying quasi-steady wave propagation scheme. In order to apply Finite Volume Method using Fractional Step Method, MUSCL scheme is applied based on HLL Riemann solver, which is second-order accurate in time and space. The TVD method is applied to prevent numerical oscillations in the second-order accurate scheme. The developed model is verified by comparing observed data of two dimenstional levee breach experiment and dam breach experiment containing structure at lower section of channel. Also effect of the source term is verified by applying to dam breach experiment considering the adverse slope channel.

• Nutritional Sciences
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• v.6 no.2
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• pp.85-93
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• 2003

The purpose of this study was to investigate the effects of a butanol fraction of fraction of Alisma canaliculatum All. Braun et Bouche (Ac), and of selenium (Se), on plasma gllucose and lipid levee in streptozotocin (STD-induced diabetic rats. Male Sprague-Dawley rats, fed the AIN-93 recommended diet, were divided into five groups: a non-diabetic control group (no STZ treatment), and four 572-induced diabetic groups which consisted of a diabetic-control group, an Ac-treated group, an Ac-Se treated group, and a Se-treated group. Diabetes was induced in the rats by an injection of STZ into the tail vein at a dose of 45 mg/kg body weight. The butanol (BuOH) fraction of Ac was orally administered at a rate of 400 mg/kg body weight for 21 days to both the Ac and Ac-Se groups. The supplementation of selenium in the Se and Ac-Se groups was achieved by adding (freshly, every day) 2 mg of Se as Na$_2$SeO$_3$ per kg of feed. The rats'body weights and hematocrit (Hct) levels were measured, along with plasma levels of glucose, insulin, cholesterol, HDL-cholesterol, triglyceride (TG), and free fatty acids (FFA). Aminotransferase activities were also analyzed. The non-diabetic rats gained weight, while the diabetic rats lost weight - except in the Ac-Se group, which maintained their initial weight. The blood glucose levels of the Ac group and the Se group were significantly lower than for the diabetic-control group. The plasma triglyceride levels were lowered when both Ac and Se were administered to diabetic rats. The concentrations of plasma FFA in the Ac-Se group were significantly lower compared with the diabetic-control group. Plasma cholesterol levels and alanine aminotransferase activity in the Ac, Ac-Se, and Se groups were significantly lower when compared with the diabetic-control group. Aspartate aminotransferase activity was significantly lower in the Se group compared to the other diabetic groups. These data show that treatment with a butanol fraction of Ac in combination with Se has no synergistic effect. Plasma glucose levels tended to be low when Se was administered to diabetic rats. Supplementation of Se in diabetic rats did not elicit a significant increase in plasma insulin levels or result in hypolipemic effects.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.743-746
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• 2008

Recently, due to the effect of global warming and extreme rainfall, the magnitude of flood disaster and the frequency of flood is rapidly increasing. In order to mitigate the damage of human and property from this kind of meteorological phenomenon and manage water resources scientifically, effective operation of dam and reservoir is very important. In case of Andong dam which was not performed a flood control function needs to develop new types of dam safety management measure because of recent extraordinary flood by typhoons. In case of Andong dam and Imha dam, I am using HEC-5 model in order to apply reservoir simulation. In this case, complex conditions among 100-year floods , 200-year floods and PMF was used. Also, I modified the maximum outflow 3,800m3/s into 3,490m3/s and applied this modified discharge in order to secure freeboard in the downstream. In an analysis that I applied modified outflow by 100-year floods and 200-year floods to, the result showed that river didn't overflow in Andong area but some other places have relatively low freeboard. In the cases that I modified maximum outflow, results showed that freeboard of levee is larger than existed simulation. In the simulation that I applied 200-year floods and PMF to and under a condition connected with PMF, results showed overflowing the levees. Because of the difference between the frequency of dam outflow and the design flood in river, it is required to improve the existed flood plan in the downstream of Andong dam. As a result of this study, the optimal operation of reservoir systems can be proposed to mitigate the flood damage in the downstream of Andong dam and also can be used to establish the flood plans.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.54-54
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• 2020

본 연구에서는 제방의 세굴이나 붕괴를 방지하기 위해 바이오폴리머(Biopolymer) 기반 신소재를 활용한 흙 제방의 보강공법을 제시하였다. 바이오폴리머 기반 제방의 보강공법은 흙과 바이오폴리머를 소량만 섞어도 흙의 강도 증진시킴과 동시에 빗물에 대한 내침식성과 식생의 생장을 촉진하는 생태성도 뛰어나기 때문에 제방 사면을 보호할 수 있는 친환경적이고 효율적인 공법이다. 이에 안동하천연구센터는 실증실험을 통한 신소재 제방 보강공법의 안정성 검증을 목표로 2 건의 월류붕괴 실험을 수행하였다. 첫 번째는 흙 제방 조건(Case 1)이며, 두 번째는 바이오폴리머 혼합 토양을 사면에 도포한 후 식생이 활착된 조건(Case 2)이다. 제방 붕괴에 따른 수로 내 수위변화를 측정하기 위해 압력식 수위계를 설치하였으며, 영상분석을 위한 다수의 카메라 및 드론을 활용하여 실험의 전 과정을 실시간 촬영하였다. 또한, 제내지 측 사면을 대상으로 월류에 따른 붕괴 지연효과를 정량적으로 제시하기 위해 이미지 픽셀 변화 측정 기법을 통한 시간에 따른 표면 손실률을 산정하였다. 흙 제방과 신소재 처리 제방의 시간에 따른 표면손실률을 비교한 결과, Case 2의 사면손실률이 Case 1에 비해 약 1.5~2.3 배 지연되는 것을 확인하였다. 하지만 단일 조건만으로 실험군과 비교군의 붕괴지연 결과가 제방 성능을 평가함에 있어서 일반화될 수 없으므로 이러한 정량적 평가는 다소 한계가 있다. 향후 이러한 부족한 부분을 해결하기 위한 노력과 다양한 조건의 추가실험을 통한 계측 데이터 및 붕괴지연시간의 평균값을 도출하여 신소재 제방의 안정성을 평가하기 위한 타당한 결과를 도출할 예정이다.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.304-313
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• 2019

Biopolymer based on microbial β-glucan and xanthan gum is effective for vegetation and has a function of enhancing soil strength, which can be used as soil reinforcement and stabilization materials in river embankment. The purpose of this study is to verify the vegetation effect of the surface of levee by biopolymer with seed spraying method. Mixed soils with biopolymer were used to cover the surface of embankments. The strength is higher in biopolymer-treated soil and xanthan gum based biopolymer has advantage for quality control in field scale. In addition, the vegetation of F. arundinacea and L. perenne showed various reactions with types of biopolymers. Biopolymer has a positive effect on the vegetation of them. In contrast, root growth tended to decrease in biopolymer-treated soils. The results indicate that root growth is slow down due to increasing ability to retain water in biopolymer-treated soil. In order to apply biopolymer to river embankment, it is necessary to examine the effects of biopolymers on a wide range of plant species in river embankment.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.78-83
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• 2013

BACKGROUND: This study was performed to investigate the change of deltamethrin residue after spraying for control of hygienic insects in bush of levee at Bansuk-dong stream (A) and Juk-dong ditch (B) in Yuseong, Daejeon. The drop concentrations and disappearance of deltamethrin residue in stream water were determined to evaluate the toxic effects of stream ecosystem. METHODS AND RESULTS: Water samples were collected at 7 points including 0, 5, 10, 20, 40, 70 and 100 m downstream from the deltamethrin spraying point. Water sample was partitioned into dichloromethane, and was determined with GC/${\mu}$-ECD. Limit of Quantitation of deltamethrin was 0.04 ${\mu}g/L$. Recoveries of deltamethrin at two fortification levels of 0.4 and 2.0 ${\mu}g/L$ were $91.57{\pm}3.13%$(n=3) and $94.40{\pm}4.59%$(n=3) in A stream, and $88.24{\pm}3.33%$(n=3) and $85.20{\pm}3.73%$(n=3) in B stream, respectively. Residue of A stream were from <0.04 ${\mu}g/L$ to 0.48 ${\mu}g/L$ and B stream were from 0.08 ${\mu}g/L$ to 14.95 ${\mu}g/L$ under practice application condition. And residues were from <0.04 ${\mu}g/L$ to 0.2 ${\mu}g/L$ in A stream treated deltamethrin with 1.0 mg level at the upper region. CONCLUSION(S): Practice application of deltamethrin for the pest control of waterside was not much shown toxic effect to ecosystem of stream.

• Journal of Korea Water Resources Association
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• v.47 no.6
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• pp.561-572
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• 2014

The backwater effect at a tributary junction increases the risk of flood damage such as inundation and levee overflow. In particular, the rapid increase in water level may cause injury to persons. The purpose of this research is the development of the real-time flood forecasting technique as a part of the non-structural flood damage reduction measures. To this end, the factors causing a water level rising at a junction were examined, and the empirical formula for predicting flood level at a junction was developed using the calculated discharge and water level data from the well-constructed hydraulic model. The water level predictions show that average absolute error is about 0.2~0.3m with the maximum error of 1.0m and peak time can be captured prior to 0~5 hr. From the results of this study, the real-time flood forecasting system of a tributary junction can be easily constructed, and this system is expected to be utilized for reduction of flood inundation damage.