• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.53-58
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• 2002

To better understand the reservoir host range and distribution of hantaviruses in small mammal populations in Korea, a serological survey was conducted on 1,375 wild rodents and 62 insectivores captured in seven provinces during the six-year period, 1995 to 2000. As determined by the indirect immunofluorescent antibody (IFA) test, 90 ($13.1\%$) of 685 Apodemus agrarius, 47 ($13.6\%$) of 345 Apodemus peninsulae, and 4 ($6.5\%$) of 62 Crocidura laciura were seropositive against the Hantaan virus, while 38 ($13.5\%$) of 282 Eothenomys regulus were seropositive against the Puumala virus. Serological evidence for hantavirus infection was not found in 50 Microtus fortis, six Micromys minutus, six Mus musculus, and one Cricetulus triton. Our serological data indicate that hemorrhagic fever with renal syndrome (HFRS)-related hantaviruses are widely distributed in indigenous rodents in Korea. Particularly noteworthy was the high seropositivity rates among Apodemus peninsulae and Eothenomys regulus captured in certain mountainous regions, suggesting that HFRS may be under-reported among nearby residents or among individuals who might visit such areas for recreational or occupational purposes.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1694-1697
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• 2008

하절기의 태풍 및 장마시 유입되는 탁수는 수자원의 효율적 관리를 저해하는 요소로서, 현재 일부댐에 이러한 탁수의 장기화를 방지하고 탁수로 인한 하류부의 영향기간을 줄이기 위하여 선택취수시설이 설치되어 운영중에 있으며, 많은 댐을 대상으로 탁수발생 현상에 대하여 모델링 기법을 이용한 탁수거동 분석이 수행되고 있다. 본 연구에서는 태화강수계의 대곡천에 위치한 대곡댐 및 사연댐에 대하여 강우시 호내에 유입된 탁수의 거동을 분석하기 위하여 CE-QUAL-W2 모형을 구축하였다. 유입 탁도자료는 2007년 하절기 강우시 실측된 결과를 이용하였으며, 탁수가 유입된 이후 일별로 호내에서 측정된 수심별수온 및 탁도자료를 이용하여 모델을 보정하였다. 유입 이전의 조사시 표층 및 심층의 수온차이가 $1^{\circ}C$ 미만으로서 수온성층이 형성되지 않은 것으로 나타났으며 고탁수 유입시 탁수층이 중층 이하에서 바닥층까지로 유입되는 것으로 나타났으며, 보정결과 침강보다 자연적인 소멸 등의 침강 외적인 요인으로 인하여 탁도가 저감되는 것으로 분석되었으며 이에 대한 추가적인 검토가 필요한 것으로 판단되었다. 댐축에의 탁수층 도달시간을 검토한 결과 대곡댐은 18시간 이내, 사연댐은 30시간 이내에 댐축에 도달하는 것으로 예측되었다. 댐별 저수용량이 각각 9월 14일 기준으로 $10.3\;Mm^3$ 및 $17.2\;Mm^3$으로서 60% 가까운 차이를 보이나, 9월 18일 기준으로 $18.2\;Mm^3$, $24.2\;Mm^3$로 나타나 각각 $7.9\;Mm^3$, $7.0\;Mm^3$의 저수용량증가를 나타내었다. 실제로 유입된 양의 차이는 크지 않은 반면에 초기 체적의 차이가 크게 나타남($10.3\;Mm^3$, $17.2\;Mm^3$의 약 60% 차이)으로써 이러한 탁수층이 댐축에 도달하는 시간의 차이가 발생한 것으로 판단된다.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.75-85
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• 2006

In recent geotechnical engineering, geothermal approach has been on the horizon to deal with geoenvironmental issues, freezing and thawing problems, and seepage phenomenon in dams and embankments. In this study, geothermal characteristic through inner body of dams and its influence on the seepage flow were experimented by lab test and field instrumentation. Also, one of up-to-date temperature monitoring technique, called as multi-channel thermal line sensing, was evaluated its availability. As a result of lab test, it is found that the seepage flow has influence on the geothermal characteristic and a potential of finding phreatic line and seepage fluctuation could be possible by continuous temperature monitoring using thermal line sensing skills. These kine of geothermal information could be available to the modelling of water geo-structure interaction. Out of short-term field tests, clear water table and temperature distribution of a dam were easily found through temperature monitoring in holes located near a reservoir and holes within a depth of constant temperature layer. However, it is also found that the geothermal flow and finding seepage line could not be easily understandable through multi-channel temperature monitoring because of the existence of constant temperature field, thermal conductivity of soils and rocks, and unsaturated characteristics of geo-material. In this case, long-term geothermal monitoring is recommended to find sudden fluctuation of seepage line and amount of leakage.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.73-78
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• 2006

To verify reinforcing effect of grouting materials on the water leakage region in dike, we performed various hydraulic test and we also applied electric resistivity survey including electrical resistivity tomography(ERT) to see resistivity variation before and after grouting. As the results of dipole-dipole array survey along dike, resistivity distribution after grouting was without noticeable spatial variation. Long term resistivity monitoring results at dike with Schlumberger array electric resistivity survey showed that the decreasing region of apparent resistivity and one dimensional inversion results were the occupied region by grout after grouting. From the ERT using check holes to inspect the effect of grouting, we could find that the ERT is quite effective to evaluate spatially grout region in dike.

• Journal of the korean society of oceanography
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• v.37 no.1
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• pp.35-44
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• 2002

To assess the relative contribution of bacterial and phytoplankton biomasses to particulate organic matter (POM) in the water column, microbial abundance and biomass were from two transects in the western channel of the Korea Strait in 1996. Bacterial abundance had a mean value of $5.9{\times}10^5$ cells/ml and chlorophyll-a averaged 0.14 ${\mu}g/l$. Bacterial abundance in the Korea Strait showed a positive relationship with chlorophyll-a concentration, while the distribution of POM did not covary with chlorophyll-a. Particulate organic carbon (POC) and nitrogen (PON) concentrations were greater in August than in October. Bacterial carbon (POC) and nitrogen (PON) concentrations were greater in August than in October. Bacterial carbon and nitrogen biomasses were 7.29 ${\mu}gC/l$ and 1.24 ${\mu}gN/l$, respectively, during the study periods. Bacterial biomass was larger in October than in August due to the autumn phytoplankton bloom. Phytoplankton biomass based on chlorophyll-a was 7.67 ${\mu}gC/l$ for carbon and 1.10${\mu}gN/l$l for nitrogen. The ratio of bacterial carbon (BC) to phytoplankton carbon (Cp) averaged 0.95 in the Korea Strait in 1996. Bacteria may play a more significant role in the dynamics of POM than phytoplankton do in August, with BC/Cp ratio of 1.26. The ratio of BC to Cp increased with a decrease in chlorophyll-a concentration. Averaged over all the samples in both cruises, the contribution of microbial biomass to POC and PON was about 43% and 51%, respectively. Bacterial assemblage constituted a significant fraction of POC (21%) and PON (27%). Phytoplankton accounted for 22% of POC and 24% of PON. Microbial biomass played a more important role in the dynamics of POC and PON in October than in August due to a significant increase in microbial biomass in the southern transect (transect-B) in October by the autumn phytoplankton bloom. This study showed that marine microbes may constitute a significant part in the reservoir of POM in the Korea Strait.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.303-306
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• 2016

Floating PV system is installed on the water such as artificial lake, reservoir, river for the purposes of zero energy town and/or large scale of PV station. There are electrical gains from cooling effect by water and reflection of water surface. Particularly, floating PV power station with high efficiency solar cell modules receives a lot of attention recently. Floating PV system is installed on the water, which means grounding method to the frame of solar cell and electrical box such as connector band and distribution panelboard should be applied in different way from grounding method of PV system on land. The grounding resistance should be 10[${\Omega}$] in case the voltage is over 400[V] in accordance with Korean Standard. The applicable parameters are the resistivity of water in various circumstances, depth of water, and length of electrode in order to meet 10[${\Omega}$] of grounding resistance. We calculated appropriate length of the electrode on the basis of theoretical equation of grounding resistance and analyzed the relation between each parameters through MATLAB simulation. This paper explains grounding system of floating PV power station and presents considerations on grounding design according to the resistivity of water.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.23-33
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• 1996

The conventional monitoring of water quality constrained by time and equipment produce neither complete nor synoptic geographic coverage of pollutant distribution, transport, and water quality. To circumvent these limitations in temporal and spatial measurements, the use of remote sensing is increasingly being involved in the lacustrine environmental research. Consequently, satellite remote sensing, with its synoptic coverage, is used to obtain the eutrophication-related water quality parameters in Daecheong reservoir in this study. The approach involved acquisition of water quality samples from boats of 15 sites on 20 June 1995 and 30 sites on 18 March 1996, simultaneous with Landsat-5 satellite overpass. Regression models have been developed between the water quality parameters and Landsat Thematic Mapper(TM) digital data. The best regression model was determined based on the correlation coefficient which was higher than 0.6. As a result, satellite remote sensing can provide meaningful information on water quality parameters. The regression models developed in this study show good relationship for transparency, turbidity, SS, and chlorophyll, but not for TN and TP because their spectral characteristics are not well defined.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.796-803
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• 2012

Potential feasibility of nutrients removal and biofuel production with microalgae was evaluated in batch culture. Distribution of microalgae in fresh water including reservoir and river was investigated to search for the species with high content of lipid that could converted into biofuel. Green algae, Chlorella and Scenedesmus sp., these are known as species containing high lipid content for biodiesel production, were observed in both summer and autumn season. However another highly lipid-containing species, botryococcus sp. was not observed in this study. In mixed culture of microalgae using synthesized wastewater medium, green algae were found to be dominant, comparing to other species of diatoms and blue-green algae. And microalgae were also capable of removing nitrogen and phosphorus in batch experiments. During the culture period of 14 days, removal efficiencies of nitrate and phosphorus were 30% and 82%, respectively. Furthermore, content of the intracellular lipid extracted from algae cell was as favorable as 12-30% in the mixed culture where Scenedesmus and Chlorella sp. were dominant. Therefore the mixed culture of microalgae could be applied to biofuel production and tertiary wastewater treatment, even though there are economic barriers to overcome.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.840-848
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• 2009

Spatial and temporal distributions of POC and DOC were surveyed in the North Han River system, Korea The proportion of algal cells was calculated in four reservoirs (Lakes Soyang, Paro, Chunchon, and Uiam). Monthly average DOC concentrations ranged from 1.5 to 2.3 mg C/L, and POC showed larger variation than DOC (range 0.3 to 1.9 mg C/L). The average proportion of POC in TOC was higher than those of typical natural lakes. Due to the influence of the Asian summer monsoon, the seasonal variation in POC concentration depended on heavy rain events occurring during the summer. POC concentrations increased during the summer monsoon season due to turbid storm runoff laden with debris, while DOC concentrations did not increase. The highest POC concentrations were observed in Lake Soyang in 2006 when a severe rain event occurred. In two deep stratified reservoirs (Lake Soyang and Paro) storm runoffs formed an intermediate turbidity layer with high POC and chlorophyll concentrations which is thought to originate from terrestrial debris and periphyton transported by inflowing streams. The proportion of algal cells in total POC was much lower than for most natural lakes, and it varied with season; low in the monsoon season and high in dry seasons with algal blooms. An analysis of POC concentration and chlorophyll a concentration showed that the ratio of POC/Chl.a varied from 24 to 80.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.4
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• pp.57-68
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• 2001

It is matter of common knowledge to give impetus to the water resources development to cope with increasing demand and supply for the water utilization project including agricultural living and industrial water owing to the economic and civilization development in recent years. Regional design rainfall is necessary or the design of the dam reservoir levee and drainage facilities for the development of various kinds of essential waters including agricultural water. For the estimation of the regional design rainfall classification of the climatologically an geographically homogeneous regions should be preceded preferentially This study was mainly conducted to derive the optimal regionalization of the precipitation data which can be classified by the climatologically and geographically homogeneous regions all over the regions except Cheju and Wulreung islands in Korea. A total of 65 rain gauges were used to regional analysis of precipitation. Annual maximum series for the consecutive durations of 1, 3, 6, 12, 24, 36, 48 and 72hr were used for various statistical analysis. Both K-means clustering and mean annual precipitation methods are used to identify homogeneous regions all over the regions. Nine and five homogeneous regions for the precipitation were classified by the K-means clustering and mean annual methods, respectively. Finally, Five homogeneous regions were established by the trial and error method with homogeneity test using statistics of $\chi$$^2$ distribution.