• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.247-256
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• 2003

FEM analyses which are based on modified Cam-clay theory have been generally used in such cases as analyses of stability and displacement fur embankment construction on soft clays. However, the Modified Cam Clay Model can generate some problems in anisotropic stress conditions of field because the critical state theory has been developed through many laboratory tests in isotropic conditions. Thus, the applicability on the prediction of undrained shear strength and pore water pressure which was based on the critical state theory was evaluated by triaxial tests and numerical analyses in isotropic and anisotropic conditions. Used samples often come out in domestic area, together with general low plastic clays which are showing dilatant behavior in shearing process. They were evaluated by laboratory tests and FEM based on MCCM. From the results of test and numerical analysis, the predictions of undrained strength in low plastic clays well coincided with each other in both isotropic and anisotropic conditions. However, the generation of porewater pressure was often overestimated during undrained shearing in anisotropic conditions. The results can generate the errors in the prediction of stress path of field sites during loading such as construction of embankment on soft clays because the field is subjected to anisotropic conditions during loading.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.210-215
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• 2014

Pseudomonas nitroreducens TX1 was isolated from a rice field drainage in Taiwan. The bacterium is of special interest because of its capability to use a group of nonionic surfactants such as alkylphenol polyethoxylates even at high concentrations as a sole carbon source. In this study, a small cryptic circular plasmid, pTX1, was characterized from P. nitroreducens TX1. It is 2,286 bp in length with a GC content of 63.3% and harbors three open reading frames, $Rep_{pTX1}$ and functionally unidentified ORF1 and ORF2. The predicted $rep_{pTX1}$ gene product is homologous to Rep proteins of plasmids belonging to the pC194/pUB110 family, which is predominantly found in Gram-positive bacteria and is known to replicate by the rolling-circle mechanism. The copy number of pTX1 was estimated to be about 150 in each cell. Based on the genetic fingerprints and comparison with other plasmids, it is concluded that pTX1 replicates by a rolling circle mechanism which is rarely found for Pseudomonas plasmids.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.366-373
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• 2017

Urinalysis is considered to be easier and simpler than other tests. It has been known to cause no burden to patients, while offering important information on diagnosing, treating, and determining the prognoses of kidney and urinary tract diseases. Urinary sediments are usually performed by microscopic examination of centrifuged urine by technologist. The guidelines proposed by the Korean Association of External Quality Assessment Service are actually different from those actually practiced by medical institutions and taught to biomedical students in textbooks. Therefore, we verified whether different sediment preparation methods lead different test results. Specimens that tested positive from the occult blood and leukocyte esterase in the urine dipstick test were randomly selected for a microscopic examination. The differences in the urine sediment preparation affected the sediment concentrations, which influenced the cell grade and cell number per HPF. The first factor in determining the sediment concentration is the centrifugal force. Many medical institutions use 1,500 rpm as the centrifugal speed without considering the radius of the centrifuge; such a value may not be accurate for 400 G. Consequently, there were differences in urine concentrations, which influenced the results. The second factor is the amount of sediment in urine. Different amounts of the remaining supernatant led to different sediment concentration factors, again, causing different results. Furthermore, not only by using a pipette to obtain an accurate amount as stipulated, but also by roughly obtaining a drop, the microscopic examination using such a volume of sediment examined affected the results. Therefore, this study highlights the importance of standardization of urine sediment preparation procedures to promote consistency and accuracy across institutions.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1711-1715
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• 2007

하천에서는 나라마다 하천마다 구간마다 독특한 하도특성을 지니고 있다. 우리나라는 전 국토의 70 %가 산지로 이루어져 있으며, 이로 인하여 특이한 하도형태의 모습을 보이는 구간이 산재하고 있다. 그 대표적인 모습이 충적하도와 침식하도가 연속해 발생하는 과정에서 나타나는 것이 하천 협착부 구간이다. 이러한 하천협착부 주변지역은 전형적인 수해상습 구간이 되는 경우가 많다. 이러한 상황임에도 불구하고 현재까지 우리 나라에서는 이러한 협착부 구간에서 하도특성을 반영한 연구 및 설계 사례가 전무한 실정이다. 따라서, 본 연구에서는 낙동강 선산지역의 하천 협착부에서의 하도 수리학적 의미와 하도형태에 대하여 조사하고 분석하였다. 연구 결과, 모래하천인 조사구간의 저수로 하상에서 아주 미세한 유사분급 현상은 확인할 수 있었지만, 명쾌한 자연 영력에 의한 유사분급 현상이라 판단하기에는 어려운 부분이 있었다. 이는 완만한 하상경사, 균일성에 가까운 하상재료의 공급에 기인한다고 추정할 수 있었다. 그러나 이와 같은 자연적인 현상보다는 골재채취 등의 원인에 따른 유사분급이 확연하다고 추정되었다. 그리고 협착부의 배수구역에서 과거 활발했던 이동상 단단면 하도형태가 유심부의 이동과 더불어 최근 급격하게 복단면화가 진행되고 있음을 확인하였다. 이와 더불어 저수로의 하폭이 크게 줄어드는 현상을 확인할 수 있었다. 이와 같은 현상은 궁극적으로 이상홍수 발생시의 복단면 가중 또는 홍수단면적 축소, 저수로에서의 호안 또는 제방 아래부분의 국소세굴이 야기될 수 있음을 시사한다.원주교각에 대한 국부세굴 특성을 검토하였다. 또한 원주형의 교각에서는 단일원주보다는 원주군으로 설치되는 경우가 대부분이며 이때 교각의 직경(D)에 대한 교각 사이 간격$(L_d)$의 비$(L_d/D)$에 따른 전면교각에서의 수류변화의 영향이 후면교각에 작용하여 상호 복합적인 흐름 및 세굴특성을 나타내므로 이와 같은 복렬형 원주군의 세굴특성을 파상형 원주교각에 적용하여 국부세굴의 크기 변화를 해석하였다. 따라서, 교각주위에서의 수류특성 및 세굴의 변동은 원주군 및 교각파상의 크기와 간격 등과 같은 구조물의 배열조건과 Froude 수, 수심 등의 수리학적 조건에 따라 달라지므로 이의 조건을 체계적으로 변화시켜 가면서 교각주위에서의 국부세굴 및 세굴 감소특성을 검토하였다. 실험결과 오목 및 볼록 파상형 원주 주위에서의 세굴크기는 원형원주와 비교하여 전체적으로 감소하는 것으로 확인되었으며 특히 오목형 $B/\acute{h}=3$에서는 세굴경감효과가 탁월하여 70%이상 감소하는 것으로 확인되었으나 볼록형 $B/\acute{h}=5$에서는 세굴촉진특성이 나타나고 있는 것으로 나타났다. 따라서, 파상형 원주에서는 하강류나 와류를 파상형의 내부로 유도하여 세굴의 크기를 조절할 수 있는 최적의 파상이 존재하고 있는 것으로 예측되었다.원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.았다. 또한 저자들의 임상병리학적 연구결과가 다른 문헌에서 보고된 소아 신증후군의 연구결과와 큰 차이

• Journal of the Korean GEO-environmental Society
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• v.16 no.5
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• pp.55-66
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• 2015

Big tidal differences, which range from 3.0 m to 8.0 m, exist with regional locations at south and west shores of Korea. Under this ocean circumstance, since a large scour may occur due to multi-directional tidal current and transverse stress of the wind, the scour surrounding the wind turbine structure can make instability of the system due to unexpected system vibration. The hydraulic resistance capacity of soils consolidated under different pressures are evaluated by Erosion Function Apparatus (EFA) under unidirectional and bi-directional flows in this study. It was found that the flow direction change affects significantly on the sour rate and critical shear stress, regardless of soil types while the consolidation pressure affects mainly cohesive soil. Among geotechnical parameters, the undrained shear strength can be well-correlated with the hydraulic resistance capacity, regardless soil type while the shear wave velocity shows the proportional relationships with the hydraulic resistance capacities of fine grained soil and coarse grained soil, respectively.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.299-308
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• 2013

We investigated the effect of mulberry leaf extract (MLE) on blood biochemical parameters of white rats induced TCDD toxicity. Data were analyzed by One-way ANOVA and Post-Hoc Test. The numbers of leukocyte and platelet decreased by TCDD were increased dramatically after treated MLE (p<0.01). The concentration of calcium and magnesium decreased by TT were increased by MLE and shown a statistical significance (p<0.01) but the concentration of phosphorus increased by TT was decreased by MLE. In the test of parameters related to renal function, only the concentration of uric acid in the MLE group was decreased than it in TT group and shown a statistical significance (p<0.01). Also the concentration of blood glucose and the activity of amylase and lipase increased by TT were decreased after treated MLE and shown a statistical significance (p<0.01), and MLE had an control effect for elevating blood glucose. In the test of parameters related to liver function, the acticity of AST, ALT and ALP increased by TT was decreased after treated MLE and shown a statistical significance (p<0.01), and MLE had an improving effect for liver function. In the case of total cholesterol (T,cho), triglyceride( TG), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) related to lipid metabolism, the amount of T,cho, TG, LDL-C increased by TT were decreased after treated MLE and shown a statistical significance (p<0.01), and MLE had an ability of anti-hyperlipidemia. From these results, we concluded that MLE could mollified TCDD toxicity in white rats exposed to TCDD.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.6
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• pp.589-601
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• 2008

The variation of groundwater level near the Shingok weir has been analyzed. To consider the soil inhomogeneity, coefficient of effective permeability was computed to be 0.313 m/day in the horizontal direction, and 0.0423 m/day in vertical direction. Anisotropic ratio is 7.19. The river water level drawdown (caused by the removing of the weir) causes the groundwater level drawdown, and 3 months are required for the new steady condition. and groundwater flows from Han river toward Gulpo stream before the removing of the weir, but when the weir removed, the flow direction changes. The groundwater level falls maximum 30 cm in the areas under the influence of Han river, but, in the areas near Kulpo stream, groundwater level falls about 10 cm. The amount of groundwater use in the study area was investigated to be $52m^3/day$ and in this condition, groundwater level falls maximum 1m (before or after the removing of Shingok weir). therefore, the variation of groundwater level caused by the removing of Shingok weir is less than that caused by the usual use of groundwater.

• Economic and Environmental Geology
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• v.49 no.3
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• pp.167-179
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• 2016

Water quality of Oseepchun, Dogye area, was investigated quantitatively for its origin and hydrogeochemistry in relation to the influence of groundwater. Groundwater appears to be the principal source of Oseepchun from the water-quality monitoring data including redox potentials, composition of dissolved ions and their correlations, hydrogen and oxygen stable isotopic ratios, and the distribution and occurrence of contaminants. Water-quality type of the surface water was grouped by the water-rock interactions as $Ca-HCO_3$ type originated from carbonated bed-rocks in the Joseon Supergroup, (Ca, Mg)-$SO_4$ type related with dissolution of surfide minerals in coal beds of Pyeongan Supergroup, and (Ca, Mg)-($HCO_3$, $SO_4$) type of the mixed one. Locally water pollution occurs by high $SO_4$ from mine drainage and $NO_3$ from waste-treatment facility. Intensive precipitation in summer has no effect on the water type of Oseepchun, but increases the inflow of nitrate and chloride originated from land surface. Results of this study direct that groundwater-surface water interaction is intimate, and thus surface-water resource management should begin with groundwater characterization.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.73-88
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• 2007

The goal of this research is to develop and apply the generalized regression neural networks model(GRNNM) embedding genetic algorithm(GA) for the estimation and calculation of the pan evaporation(PE), which is missed or ungaged and of the alfalfa reference evapotranspiration ($ET_r$), which is not measured in South Korea. Since the observed data of the alfalfa 37. using Iysimeter have not been measured for a long time in South Korea, the Penman-Monteith(PM) method is used to estimate the observed alfalfa $ET_r$. In this research, we develop the COMBINE-GRNNM-GA(Type-1) model for the calculation of the optimal PE and the alfalfa $ET_r$. The suggested COMBINE-GRNNM-GA(Type-1) model is evaluated through training, testing, and reproduction processes. The COMBINE-GRNNM-GA(Type-1) model can evaluate the suggested climatic variables and also construct the reliable data for the PE and the alfalfa $ET_r$. We think that the constructive data could be used as the reference data for irrigation and drainage networks system in South Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.467-467
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• 2016

암거는 일반적으로 용수나 배수용의 수로가 도로, 철도, 제방 등의 아래에 매설 된 수로를 지칭한다. 이러한 암거는 산업발전으로 사회기반시설의 신설 및 확충, 재정비 등으로 많이 활용되고 있다. 최근 들어 기후로 인한 재해가 급증하면서 이러한 시설물에 대한 안정성 및 관리에 대한 관심이 높아지고 있는 것이 현실이다. 특히 소하천은 집수면적 및 유로연장이 짧고 하상경사가 급하기 때문에 홍수에 취약하다. 즉, 빨라진 유속으로 인해 구조물 주변의 세굴에 의한 유실, 토사유출로 인한 하상퇴적, 부유물로 인한 차단으로 인해 통수에 지장을 받아 피해가 발생하게 된다. 이러한 암거시설물 피해는 2차 피해로 이어질 수 있으며 사회기반시설 파괴로 도시기능이 마비되고 인근 주변지역에 침수로 인한 재산 및 인명피해까지 발생시킬 수 있는 피해 잠재능력을 보유하고 있다. 그러나 피해에 대한 예방대책은 유지관리를 통해 지속적으로 관리하는 것이 대부분의 지침 등에 소개된 내용들이다. 본 연구에서는 암거를 대상으로 암거의 폐색으로 인해 암거주변에서 변화되는 흐름특성을 축소모형을 통해 검토하고자 하였다. 암거 축소모형실험은 1.5m 폭을 갖는 직선수로에서 수행하였으며, 암거모형은 도로암거표준도(2008)를 참조하여 $3m{\times}3m$ 수로암거를 대상으로 1/10 축소모형을 제작하였다. 암거유입부 퇴적으로 인한 암거의 차단률(차단면적/암거단면적)은 차단이 발생하지 않는 0% 조건에서부터 10%, 20%, 30%, 40%, 50% 조건에 대해 실험을 수행하였다. 실험결과 차단에 따른 암거 상류단의 수위는 차단이 없는 암거의 경우에 비해 차단율이 높아질수록 암거유입부 수위는 20.4% ~ 82.7% 상승하는 것으로 나타났다. 암거의 차단률이 40% 이상일 경우 높아진 수위로 인해 암거통로의 윗상면부까지 다다르고 있으며 50%일 경우 암거를 통과하는 흐름이 자유수면흐름이 아닌 오리피스 흐름이 발생하는 것으로 나타났다. 암거유입부 차단으로 인한 암거주변의 최대유속은 암거 직하류부에서 주로 발생하여 암거 유출부에서의 최대유속은 차단율이 증가할수록 선형적으로 증가하는 것으로 나타났으며 암거 유출부에서의 유속은 차단전의 조건(0%) 대비 4.2% ~ 35.5% 까지 상승하는 것으로 나타났다. 이와 같은 결과를 토대로 고려하였을 때 대부분 산지부에서 설치되는 암거의 경우 유속이 불가피하게 증가하게 됨으로 유속에 따른 유속조절방안(차단 및 우회시설) 및 세굴대책을 세워야 할 것으로 판단된다.