• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.591-607
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• 2013

The objectives of the study were to evaluate the aquatic environment of an urban stream using various ecological parameters of biological biomarkers, physical habitat quality and chemical water quality and to develop a "Multimetric Eco-Model" ($M_m$-E Model) for the ecosystem evaluations. For the applications of the $M_m$-E model, three zones including the control zone ($C_Z$) of headwaters, transition zone ($T_Z$) of mid-stream and the impacted zone ($I_Z$) of downstream were designated and analyzed the seasonal variations of the model values. The biomarkers of DNA, based on the comet assay approach of single-cell gel electrophoresis (SCGE), were analyzed using the blood samples of Zacco platypus as a target species, and the parameters were used tail moment, tail DNA(%) and tail length (${\mu}m$) in the bioassay. The damages of DNA were evident in the impacted zone, but not in the control zone. The condition factor ($C_F$) as key indicators of the population evaluation indicator was analyzed along with the weight-length relation and individual abnormality. The four metrics of Qualitative Habitat Evaluation Index (QHEI) were added for the evaluations of physical habitat. In addition, the parameters of chemical water quality were used as eutrophic indicators of nitrogen (N) and phosphorus (P), chemical oxygen demand (COD) and conductivity. Overall, our results suggested that attributes of biomarkers and bioindicators in the impacted zone ($I_Z$) had sensitive response largely to the chemical stress (eutrophic indicators) and also partially to physical habitat quality, compared to the those in the control zone.

• KCID journal
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• v.1 no.2
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• pp.22-28
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• 1994

The calculation method for the Drought index based on the principal hydrological factors, such as precipitation, reservoir storage and river discharge, can estimate the duration and intensity of drought. It is not easy to establish an universal criteria o

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.244-248
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• 2013

We studied the development of schizandrin as a marker compound in Jangsu Omija. Schizandrin was validated for its LOD (limit of detection), LOQ (limit of quantitation), precision, accuracy, and recovery by HPLC relative to Omija powder. It showed a high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9990. The LOD and LOQ were 0.2 ${\mu}g/mL$ and 0.5 ${\mu}g/mL$, respectively. The intra- and inter-day precision of schizandrin calibration standards was 0.06~0.66% and 0.13~1.19%, respectively, and the intra- and inter-day accuracy of schizandrin was 98.35~103.30% and 98.35~103.00%, respectively. Overall, schizandrin was validated through our analytical methods as a marker compound in Jangsu Omija.

• Tunnel and Underground Space
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• v.10 no.1
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• pp.33-44
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• 2000

In order to investigate the effect of progressive collapse of underground circular opening on surface subsidence, laboratory model tests were performed. The modelling materials were sand which has been used as KS standard. Six test models which had respectively different depths of openings were produced. Surface subsidence and horizontal displacements were measured according to progressive collapse of underground opening. Some subsidence prediction method such as NCB method, profile function method and influence function method were considered to predict the subsidence of sand models. The profile function method approximated by Gaussian error function was finally suggested as the most appropriate to sand models.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.236-239
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• 2006

사전 예방적 국토환경정책을 수립하기 위해서는 국토환경관리를 위한 구체적인 수단과 도구로서의 기본 틀이 필요하다. 다매체적이며 동태적인 환경정보의 특성을 반영한 법제적 항목 56개, 환경생태적 항목 11개를 사용하여 최소지표법에 의한 평가를 실시하였다. 평가 결과 환경적 가치가 높은 1등급 지역이 우리나라 전체 면적의 45.74%, 2등급 23.74%, 3등급 17.47%, 4등급 6.05%, 5등급 6.68%로 도출되었다. 평가 결과의 적정성을 검토하기 위하여 행정자치부의 지목통계 자료와 비교한 결과 보전지역과 개발지역의 비율이 적절하게 평가된 것으로 나타났다.

• Water for future
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• v.24 no.1
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• pp.109-117
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• 1991

The governing equation of flow in porous media is developed on the bases of the continuity equation of fluid for transient flow through a saturated-unsaturated zone, and substitution of Darcy's law. The numerical solutions are obtained by finite element method based on the Galerkin principles weighted residuals. The analysis are carried out by using the unsteady storm data observed and rainfall intensities which are obtained by using the rainfall excess model in considering of the initial losses. The functional relationships between the hydraulic conductivity, capillary pressure head and volumetric water content are applied to the flow of water through unsaturated soil varied with changes of water content.

• Journal of the Korean Data and Information Science Society
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• v.23 no.3
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• pp.457-465
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• 2012

The purpose of this study is to analyze the association between indicators and to find statistical models based on important indicators at 'College Notifier' in Korea Council for University Education. First, Pearson correlation coefficients are used to find statistically significant correlations. By variable selection method, the important indicators are selected and their coefficients are estimated. As variable selection method, backward and stepwise methods are employed.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.1-8
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• 2011

In this study, a wind hazard map over Korea peninsula based on geographical information is developed, which consists of the surface roughness model, the topographical effect model and the homogeneous wind model. The surface roughness model is assessed to evaluate the effect of the surface roughness on the wind field near ground. The topographical effect model is assessed to quantify the effect of the speed-up caused by topology, which is calculated by adopting the topographical effect factor in Korea building code (2005). The homogeneous wind map is created either by a frequency analysis method for meteorological data or a typhoon simulation. The results show that the wind hazard map can be applied to the determination of insurance premium as well as the assessment of loss and damage.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.796-800
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• 2009

토목구조물 및 사면의 붕괴는 집중호우가 내리는 경우 많이 발생하고 있으며, 특히 사면에서는 붕괴까지의 변형이 급속히 진행되어 이를 사전에 예방하기는 매우 어려운 현실이다. 침투 및 배수과정에서의 사면 붕괴는 강우침투로 인한 지반의 물리적 특성변화가 직접적으로 사면의 안전계수 변화에 영향을 주는 것으로 판단되며, 이때 발생하는 물리적 특성변화로는 침투시 사면 내 지반의 단위 중량은 증가하여 전단응력의 증가 및 전단강도 감소현상이 발생하며, 이와 반대로 사면 내 배수로 인하여 전단응력의 감소 및 전단강도의 증가현상이 발생한다. 따라서 본 연구에서는 강우침투로 발생하는 지반의 포화도 변화를 지반 내 투수계수의 함수로 설명하여 강우로 인한 지반의 침투 및 배수과정을 규명하고자 한다. 일반적으로 지반 내 지하수의 침투과정은 라플라스 공식을 적용한다. 그러나 라플라스 공식은 정상 상태(Steady State)일 경우에만 사용할 수 있고, 강우 등으로 인한 지하수의 수두 변화가 발생한 비정상 상태(Unsteady State)의 경우에는 부적합하므로 사면과 옹벽 등의 토질구조물에서는 안전성 변화를 계산할 수 없다. 이를 위해 사면 내 지반의 침투 및 배수과정을 투수계수의 함수로 나타내어, 강우의 침투과정을 Fourier Series, 변수분리법 및 섭동함수를 사용하여 식으로 유도함으로서 강우에 의한 지반의 침투 및 배수과정에 따른 사면 내 지하수의 분포를 예측한다. 침투과정 해석을 위하여 지표에서 포화대까지의 깊이 10m의 모델사면 및 지표부터 포화대까지의 포화도는 직선으로 비례한다는 가정을 적용한다. 먼저 푸리에 급수를 이용, 시간에 따른 온도를 열전달에 관하여 편미분하여 발생하는 열확산계수를 투수계수로 변환함에 따라 지하수의 시간과 수직방향거리에 대한 지반의 포화도를 산정한다. 변수분리법은 산정된 포화도에 지반의 초기조건과 경계조건를 고려하기 위해 적용하며, 변수분리법에 의해 산정된 지하수 분포를 섭동함수법으로 과도 및 정상상태로 분류한다. 본 연구의 수행으로 인해 얻어진 결과를 요약하면 다음과 같다. 첫째, Fourier Series와 변수분리법, 섭동함수를 이용하여 강우에 의한 지반의 포화도 변화를 수식적으로 나타낼 수 있으며 둘째, 지반에서의 강우침투과정을 식으로 표현함으로서, 깊이별 시간에 따른 포화도의 영역이 상부로부터 하부로 전이되는 과정을 알 수 있다. 셋째, 푸리에 급수를 이용한 지반의 침투계산으로 강우로 인한 지반의 포화영역 및 불포화영역을 명확히 구분할 수 있으며, 각 깊이별 포화도를 계산하여 각 구간에서 불포화구간의 전단강도에 대한 보다 정확한 계산이 가능하리라 판단된다.

• Journal of Korean Society of Transportation
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• v.35 no.5
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• pp.375-384
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• 2017

The aim of this study is to develop evaluation indicators for parking environment in residential areas. Recently, lots of local governments in korea are implementing projects for parking environment improvement. However, there are no indicators for parking environment evaluation except for the rate of parking supply by registered cars. So, it is really difficult to prioritize projects and monitor the result of projects. Therefore, this study presents six indicators for parking environment evaluation and its weights using AHP through the survey. The result of this study proposed the assessment model for parking environment based on indicators and it was found that actual data in Incheon can be simulated in reality. And this result also is expected to help monitoring and selecting projects.