• 한국농공학회논문집
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• 제52권3호
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• pp.81-88
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• 2010

The purpose of this study is to analyze the spatial characteristics of Namgang-Dam watershed for a Total Maximum Daily Loads (TMDL). Three TMDL target sites, Gyeonghogang1, 2, Namgang-Dam2, are located within Namgang-Dam watershed. Under the current criterion for TMDLs, 3-year arithmetic mean BOD concentration of the target sites should not exceed the target concentration for 2 consecutive years. Two and three times of violation were observed for Gyenghogang2 and Namgang-Dam2 sites while no violation was found for Gyeonghogang1 site. However, no violation was found since 1999 for all three sites. Correlation between each 12 stations within the watershed were analyzed and cluster analysis was conducted to figure out the spatial characteristics of the watershed. Correlation coefficient between Gyonghogang1 and 2 was high (0.758) while the coefficients between lake station (Namgang-Dam2) and stream stations (Gyonghogang1 and 2) were very low. Dendrogram indicated that all of three Namgang-Dam stations were very close and Gyenghogang1, 2 stations were also close.

• 생약학회지
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• 제46권4호
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• pp.352-364
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• 2015

The aim of this study was to quantitatively analyze for quality assessment of eighteen marker compounds, including homogentisic acid, 3,4-dihydroxybenzaldehyde, spinosin, liquiritin, hesperidin, ginsenoside Rg1, liquiritigenin, ginsenoside Rb1, glycyrrhizin, 6-gingerol, atractylenolide III, honokiol, costunolide, dehydrocostuslactone, atractylenolide II, nootkatone, magnolol, and atractylenolide I, in Hyangsayukgunja-tang using an ultra-performance liquid chromatography-electrospray ionization-mass spectrometer. The column for separation of eighteen marker components were used a UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}$) and kept at $45^{\circ}C$ by gradient elution with 0.1% (v/v) formic acid in water and acetonitrile as mobile phase. The flow rate and injection volume were 0.3 mL/min and $2.0{\mu}l$, respectively. The correlation coefficient of all marker compounds was ${\geq}0.9914$, which means good linearity, within the test ranges. The limits of detection and quantification values of the all analytes were in the ranges 0.04-1.11 and 0.13-3.33 ng/mL, respectively. As a result, five compounds, homogentisic acid, 3,4-dihydroxybenzaldehyde, spinosin, liquiritigenin, and atractylenolide I, in this sample were not detected and the amounts of the 13 compounds except for the 5 compounds were $8.10-6736.37{\mu}g/g$ in Hyangsayukgunja-tang extract.

• 생태와환경
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• 제43권1호
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• pp.24-34
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• 2010

This study was carried out to analyze some influences on ecological health conditions, threaten by various stressors such as physical, chemical and biological parameters. We collected samples in 2008 from three zones of upstream, midstream and downstream, Gap Stream. We applied multi-metric fish assessment index (MFAI), based on biotic integrity model to the three zones along with habitat evaluations based on Qualitative Habitat Evaluation Index (QHEI). We also examined fish fauna and compositions, and analyzed relations with MFAI values, QHEI values, and various guild types. Chemical parameters such as oragnic matter (BOD, COD), nutrients (TP, $NH_3$-N), coli-form number (as MPN), and suspended solids (SS) were analyzed to identify the relationship among multiple stressor effects. Using the sentinel species of Zacco platypus, the population structures and condition factors were analyzed along with DNA damages related with genotoxicant effects by comet assay. This study using all these parameters showed that stream condition was degraded along the longitudinal gradient from upstream to downstream, and the downstream, especially, was impacted by nutrient enrichment and toxicant exposure from the point source, wastewater treatment plant. Overall results indicated that our approaches applying various parameters may be used as a cause-effect technique in the stream health assessments and also used as a pre-warning tool for diagnosis of ecological degradation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 폐기물 매립지의 공학적 특성과 개량기술
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• pp.33-66
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• 1992

Recently, waste landfills built on seashores have been increased because of the easy availability of broad area near the urban communities. To evaluate the performance of the marine clay landfill liner numerical contaminant transport analyses are performed by selecting the typical section of a waste landfill built on seashores and using hydraulic conductivity data obtained from the site. Also, the laboratory electrical resistivity test and the in-situ corrosion test are performed in order to analyze the influence of the soil and leachates composing the landfills on the construct ion materials. From the results of contaminant transport analyses, it is shown that the leachates can be migrated faster through narrow pervious channels than the wide homogeneous pervious tedium and the importance of good quality barriers to prevent the contaminant migration is recognized. In the laboratory electrical resistivity test all the earth materials except the cover soils saturated with distilled water have small resistivities, which shows a high potential of corrosivity of soils composing landfills. However, the degree of corrosion of specimens buried in the landfills was not so severe except the zinc and carbon steel specimens. This apparently conflict results present the necessity of the investigation of other major factors and the long term in-situ corrosion test.

• 대한지리학회지
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• 제52권1호
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• pp.15-24
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• 2017

유역에서의 수질관리를 수행함에 있어 비점오염원의 관리는 매우 중요하면서 복잡한 경우가 많다. 비점오염원의 관리에서 가장 우선시 되는 것은 토사 유출량의 관리이다. 이는 주로 농경지에서 유출되는 토사와 그에 흡착된 인(phosphorous)을 관리하는 것이다. 이 연구에서는 전라남도 화순군에 위치하고 주암호의 상류에 해당되는 외남천 유역의 유출량과 토사 유출량을 공간분포형 모델을 이용해 모의하였다. 또한 필터스트립의 저감 효과를 분석하기 위해 GIS(Geographic Information System) 데이터를 이용하여 필터스트립을 모의하고 공간분포형 모델의 특성을 이용하여 토사 유출량이 심각한 지역의 공간분포를 파악하고 필터스트립의 저감 효과를 시각적으로 나타내었다. 토사 유출량이 가장 심한 소유역에 필터스트립을 설치한 결과 유출수와 토사 유출량이 각각 17.2%와 46.4%가 감소되는 것으로 예측되었다.

• Asian Journal of Innovation and Policy
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• 제10권1호
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• pp.39-67
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• 2021

This study investigated the policy instruments pertinent to the establishment of a regional innovation system in the Mekong Delta that facilitates the development of a countermeasure towards various issues of industrial and technological nature. First, we conducted the research with regard to the status and environment of the region. Second, a field visiting survey was implemented to analyze the results of international efforts and regional capacity to solve the problems attendant upon introducing technologies related to the Fourth Industrial Revolution. Third, we derived the key policy issues and challenges from the results of the field visiting survey and experts' conference with a deep focus on technological transfer and international cooperation to enhance the capability in the science and technology field. Fourth, we conducted the opinion survey of the experts from Korea and Vietnam to converge local opinions from both countries and analyzed the results. The range of research subjects is responding to climate change, managing water resources, coordinating energy and industrial structure, making a resilient Mekong regional ecosystem, smartification of local cities, and improving the life quality of citizens, and so on. The results of this study are expected to be the beginning of fundamental research in the mid to long-term view of the Mekong Delta region innovation system of Korea and Vietnam and to evaluate the master plan.

• 대한원격탐사학회지
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• 제38권6_1호
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• pp.1285-1300
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• 2022

탁도는 부유물질에 의한 빛의 산란 또는 흡수로 인한 수체의 흐림을 나타내는 수치로 수질 관리 분야에서 중요 지표로 활용되고 있다. 탁도는 소규모의 하천에서 변동성이 심할 수 있으며, 이는 국가하천의 수질에 직접적으로 영향을 준다. 따라서 고해상도의 탁도 공간정보 산출은 매우 중요하다. 이 연구에서는 Korea Multi-Purpose Satellite-3 및 -3A (KOMPSAT-3/3A) 영상으로부터 한강 수계 하천의 고해상도 탁도 매핑을 위한 eXtreme Gradient Boosting (XGBoost) 알고리즘 기반의 탁도 산출 모델을 개발하였다. 이를 위해 총 24장의 KOMPSAT-3/3A 영상과 150장의 Landsat-8 영상으로부터 계산된 대기 상단(Top Of Atmosphere, TOA) 반사율을 활용하였으며, Landsat-8 TOA 반사율은 KOMPSAT-3/3A의 관측 파장 대역에 적합하도록 교차검보정을 수행하였다. 국가수질자동관측망에서 측정된 탁도를 탁도 산출 모델의 참조자료로 사용하였고, 입력 변수로는 탁도가 실측된 위치에서의 TOA 분광반사율과 탁도 분석에 널리 이용되어 온 분광지수인 정규식생지수, 정규수분지수, 정규탁도지수, 그리고 Moderate Resolution Imaging Spectroradiometer (MODIS)의 대기 산출물(에어로졸 광학 두께, 수증기량, 오존)을 사용하였다. 또한 고탁도와 저탁도에 대한 KOMPSAT-3/3A TOA 분광반사율을 분석하여 탁도를 설명할 수 있는 새로운 정규탁도지수(new normalized difference turbidity index, nNDTI)를 제안하였고, 이를 탁도 산출 모델에 입력 변수로 추가하였다. XGBoost 기반 탁도 산출 모델은 현장관측 탁도와 비교하여 2.70 NTU의 평균 제곱근 오차(root mean square error, RMSE) 및 14.70%의 정규화된 RMSE(normalized RMSE)를 가지는 탁도를 예측하여 우수한 성능을 보였으며, 이 연구에서 새롭게 제안한 nNDTI가 탁도 산출에 있어 가장 중요한 변수로 사용되었다. 개발된 탁도 산출 모델을 KOMPSAT-3/3A 영상에 적용하여 하천 탁도를 고해상도로 매핑하였으며, 탁도의 시공간적 변동에 대한 분석이 가능하였다. 이 연구를 통하여 고해상도의 정확한 탁도 공간정보 산출에 KOMPSAT-3/3A 영상이 매우 유용함을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1159-1164
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• 2010

Several triterpenoid saponins from root of Pulsatilla koreana Nakai (Ranunculaceae) were studied and their biological activities were reported. It is difficult to analyze triterpenoid saponins using HPLC-UV due to the lack of chromophores. So, evaporative light scattering detection (ELSD) is used as a valuable alternative to UV detection. More recently, a charged aerosol detection (CAD) has been developed to improve the sensitivity and reproducibility of ELSD. In this study, we developed and validated a novel method of high performance liquid chromatography coupled with a charged aerosol detector for the simultaneous determination of four triterpenoid saponins: pulsatilloside E, pulsatilla saponin H, anemoside B4 and cussosaponin C. Analytes were separated by the Supelco Ascentis$^{(R)}$ Express C18 column (4.6 mm ${\times}$ 150 mm, 2.7 ${\mu}m$) with gradient elution of methanol and water at a flow rate of 0.8 mL/min at $30^{\circ}C$. We examined various factors that could affect the sensitivity of the detectors, including various concentrations of additives, the pH of the mobile phase, and the CAD range. Linear calibration curves were obtained within the concentration ranges of 2 - 200 ${\mu}g$/mL for pulsatilloside E, anemoside $B_4$ and cussosaponin C, and 5 - 500 ${\mu}g$/mL for pulsatilla saponin H with correlation coefficient ($R^2$) greater than 0.995. The limit of detection (LOD) and quantification (LOQ) were 0.04 - 0.2 and 2 - 5 ${\mu}g$/mL, respectively. The validity of the developed HPLC-CAD method was confirmed by satisfactory values of linearity, intra- and inter-day accuracy and precision. This method could be successfully applied to quality evaluation, quality control and monitoring of Pulsatilla koreana.

• 대한토목학회논문집
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• 제32권4D호
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• pp.367-376
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• 2012

도로면 크랙실링 공법은 도로면에 발생된 크랙을 초기에 효과적으로 보수함으로써 후속 크랙 방지 및 동결피해 방지를 통해 도로의 평균상태지수를 높일 수 있는 예방적 차원의 유지보수 공법이다. 그러나 재래식 크랙실링 공법은 도로상에서 작업이 수행되므로 매우 위험하고, 노동 집약적이며, 노무자의 숙련도에 의해 작업 품질 및 생산성에 큰 영향을 받는 문제점이 있는 것으로 분석되었다. 따라서 국내외에서는 재래식 크랙실링 공법을 자동화하기 위해 다양한 형태의 자동화 장비를 개발해 오고 있으나 실용화 실적은 매우 제한적인 것으로 조사되었다. 크랙실링 자동화 장비의 실용화를 위해서는 말단장치의 성능(생산성, 품질 향상 측면)이 매우 중요한 요인이나 기존에 개발된 일부 크랙실링 자동화 장비의 말단장치는 크랙실링의 품질 제고를 위한 필수 작업 기능을 갖추고 있지 못하고 말단장치 내에서 실런트가 응고되는 등 문제점을 지니고 있는 것으로 분석되었다. 따라서 본 연구에서는 기존에 연구 개발된 크랙실링 자동화 장비 말단장치의 비교 분석을 통해 현장 적용성이 높고 품질 제고가 가능한 크랙실링 자동화 장비 말단장치의 설계안 및 실물(full-scale)제작을 통한 기술적 타당성을 제시하고자 한다.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3275-3279
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• 2014

A mass balance method for purity assessment of thermolabile organic reference materials was established by combining several techniques, including liquid chromatography with UV/VIS detector (LC-UV), Karl-Fischer (K-F) Coulometry, and thermal gravimetric analysis (TGA). This method was applied to three fluoroquinolones like enrofloxacin, norfloxacin and ciprofloxacin. LC-UV was used to analyze structurally related organic impurities based on UV/VIS absorbance spectra obtained in combination with LC separation. For all three organic reference materials, the UV/VIS spectra of the separated impurities were similar to that of the major component of the corresponding materials. This indicates that the impurities are structurally related to the respective reference material sharing common chromophores. Impurities could be quantified by comparing their absorbances at the wavelength of maximum absorbance (${\lambda}_{max}$). The water contents of the reference materials were measured by K-F Coulometry by an oven-drying method. The total inorganic impurities contents were assayed from ash residues in TGA analysis with using air as a reagent gas. The final purities estimated from results of those analytical techniques were assigned as ($99.91{\pm}0.06$), ($97.09{\pm}0.17$) and ($91.85{\pm}0.17$)% (kg/kg) for enrofloxacin, norfloxacin and ciprofloxacin, respectively. The assigned final purities would be applied to the reference materials which will be used as calibrators for the certification of those compounds in matrix CRMs as starting points for the traceability of their certified values to SI units.