• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.937-942
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• 1993

Enzyme electrodes for amperometric measurement of ammonia was prepared by immobilization of L-glutamate dehydrogenase on an Immobilon-AV Affinity membrane and attachment to a glassy carbon electrode. Reduced nicotinamide adenine dinucleotide (NADH) was used as the electroactive species. The electrochemical oxidation of NADH was monitored at ＋1.0 volt vs. Ag/AgCl. Response was linear from $4.0\;{\times}\;10^{-5}\;to\;4.0\;{\times}\;10^{-4}$ M. The detection limit was 2.0 ${\times}\;10^{-6}$ M. Response time, the optimum pH and life time of enzyme immobilized membrane were 2 min, pH 7.3∼7.6 (Dulbecco's buffer solution) and about 25 days respectively. When the enzyme electrode was applied to the $NH_4^+$ determination with amperometric method, other physiological materials had no interference.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.325-331
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• 2009

We studied square-wave stripping voltammetry (SWV) to analyze quantitatively rutin contained in transparent skin-lotion using graphite electrode. The optimum analytical conditions for quantitative analysis of rutin were determined and the linear range was obtained of $1\;{\sim}\;8\;{\mu}g/mL$. The relative standard deviation of fifteen times repetition measurement for $0.1\;{\mu}g/mL$ of rutin was 0.080 and the detection limit was $0.01\;{\mu}g/mL$, respectively. We considered that this study could be used for quantitative analysis of active components contained in cosmetics.

• Journal of Information Technology and Architecture
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• v.9 no.2
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• pp.167-176
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• 2012

In Korean military measuring systems interoperability is based on LISI (Level of Information System Interoperability) model at the requirement generation and acquisition process. However, LISI model cannot be used for interoperability measurement of system of systems (SoS) because LISI model is focused on interoperability measurement of a given system or system pair. Also, LISI model cannot provide quantitative information for interoperability decision because of qualitative rather than quantitative approach. This paper proposes a quantitative interoperability measurement methodology of SoS. At the proposed methodology, mission threads and supporting systems are identified using architecture approach, and Interoperability of SoS is measured with systems multiplicity and resemblance coefficient. Finally, a case study is presented to show the usefulness of the methodology.

• Analytical Science and Technology
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• v.15 no.5
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• pp.410-416
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• 2002

In this study, a new quantitative analytical method has been developed for the rapid determination of vancomycin in human plasma and urine using liquid chromatography/tandem mass spectrometry (LC - MS/MS). Chromatography was carried out on a $C_{18}$ XTerra MS column ($2.1{\times}30mm$) with a particle size of $3.5{\mu}m$. The mobile phase was 0.25% formic acid in 10% acetonitrile and the flow rate was $250{\mu}L/min$. Vancomycin and caffeine (internal standard) were detected by MS/MS using multiple reaction monitoring (MRM). Vancomycin gives a predominant doubly protonated precursor molecule ($[M+2H]^{2+}$) at m/z 725.0 and a corresponding product ion of m/z 100.0. Detection of vancomycin was good, accurate and precise, with a limit of detection of 1 nM in plasma. The calibration curves for vancomycin in human plasma was linear in a concentration range of $0.01{\mu}M$ - $100{\mu}M$ for plasma. This method has been successfully applied to determine the concentration of vancomycin in human plasma and urine from pharmacokinetic study and relative studies.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.279-282
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• 2017

Chloride is known as the most important anion in salt-affected soils. We observed the degree of EC change upon AgCl precipitation was quantitatively related with the chloride concentration. Method validation and intercomparison with ion chromatography revealed the proposed method can provide rapid and moderately precise chloride concentrations in salt-affected soils.

• Journal of the Korean Chemical Society
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• v.45 no.3
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• pp.223-229
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• 2001

A method for the determination of glucose in human whole blood by chemiluminescence method using a stopped flow injection system has been studied. The method is based on the differences in the chemiluminescence intensities of luminol due to the different amounts of hydrogen peroxide produced from the glucose oxidase catalyzed reaction. The enzyme reactor was prepared by immobilization of glucose oxidase on aminopropyl glass beads and the chemiluminescence from a flow cell was measured by means of an optical fiber bundle. In order to obtain the optimum experimental conditions, effects of pH for the chemiluminogenic solution and enzyme reactor, flow rate and temperature on the chemiluminescence intensity were investigated. The calibration curve obtained under optimum experimental conditions was linear over the range from $1.0{\times}10^{-1}$ mM to 7.0 mM and the detection limit was $6.0{\times}10^{-2}$ mM. The proposed method was applied to the determination of glucose in whole human blood sample and the results were compared with those obtained by an official method. The present method was also evaluated by the results of recovery experiments.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.556-562
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• 2000

The determination of chlorite ion by flow injection analysis(FIA) with iodometric UV detection were investigated. Under rather acidic condition, chlorite ion react with iodide ion to form iodine and itself is reduced to chloride ion. The chlorite ion was determined indirectly by measuring absorbance of yellow colored iodine at 370 nm. The lengths of the mixing coil and the reaction coil, the pH of the acid stream, the concentration of the iodide ion, the injection loop volume, temperature, and flowrate were optimized as parameters for selectively determining a sort of inorganic disinfection by-product, chlorite ion by using FIA-UV detection setup. Masking agents for removing oxidants or interferences from the prepared water were tested. Independent calibration curve presented linear range of 0.002-0.2 mg/L for chlorite ion with a correlation coefficient of 0.999 or better. The limit of detection(LOD) was 0.18 ${\mu}g/L$ for chlorite ion.

• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.105-114
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• 2015

In the case of rapidly developed urban and industrial complex, the most area becomes impervious, which causes the increasing runoff and high probability of flooding. SWMM model has been widely used to calculate stormwater runoff in urban areas, however, the model is limited to interpreting the actual natural phenomenon. It has the uncertainty in the model structure, so it is difficult to calculate the accurate runoff from the urban basin. In this study, the model parameters were investigated and uncertainty was quantified using Uncertainty Quantification Index (UQI). As a result, pipe roughness coefficient has the largest total uncertainty and largest effect on the total runoff. Therefore, when the stormwater pipe network is designed, pipe roughness coefficient has to be calibrated accurately. The quantified uncertainty should be considered in the runoff calculation. It is recommended to understand the characteristics of each parameter for the prevention and mitigation of urban flood.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.455-455
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• 2011

개발로 인한 환경변화는 관련 분석모형을 통해 직접적으로 예측하기 하는 것이 가장 바람직하지만 데이터 취득의 어려움, 분석 방법론의 부재 등의 이유로 정량적 평가가 어려운 현실이다. 그렇기 때문에 수자원사업을 계획시 대부분 환경적인 영향을 매우 정성적인 형태로 평가하거나 수질과 같은 대표적인 항목에 대해서만 예측하는 수준이다. 기존의 연구 또한, 유역 또는 행정구역의 현재의 현 상황을 평가하기 위한 것이 주이며, 수자원사업과 관련성이 적은 항목도 일부 포함되어 있기 때문에 수자원사업의 특수성을 반영하기에 한계가 있다. 현 상황의 이러한 문제점을 인식하여 본 연구는 오늘날 대표적 의사결정 기법이라 할 수 있는 계층화분석과정(AHP)과 다속성효용이론(MAUT)을 활용하여 향후 수자원사업과 관련된 다기준의 사결정 과정에서의 환경성 평가방안을 제시하였다. 환경성 평가기준은 수질, 경관, 생태계 이렇게 세 가지 항목으로 구성하였고, 각 평가기준에 대한 수준을 직접적으로 대변 가능한 정량화 방안을 제시하였다. 그리고 앞서 정량화된 값을 표준화하기 위하여 MAUT 기법으로부터 평가기준별 효용함수를 도출하였다. 한편, 사업을 시행함에 따라 예상되는 환경성변화는 사업전 환경성과 사업 후 환경성을 비교하도록 하였고, 이때 해당사업의 특수성을 반영하고자 별도의 설문과정을 통해 평가기준별 가중치를 결정하였다. 본 연구는 환경성 검토시 생태학적, 물리적 분석에 기반을 둔 정량적 예측의 어려움을 보완하기 위해 정성적 예측을 추가적으로 제시하였고, 사업의 특수성과 평가항목이 갖는 일반성을 명확히 구분하여 의사결정 과정에서 주관적인 요소를 최소화하였다. 또한, 평가항목별 사업전후의 환경성을 비교, 검토함으로써 실제 사업추진 과정에서 개발로 인한 부정적 영향의 사전예방에 도움을 줄 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.106-106
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• 2016

매립공사시 매립토의 유실로 인한 공사기간의 지연, 공사비 증액 등이 발생할 수 있다. 이에 대한 정량적인 예측은 매우 중요하나, 그에 대한 연구는 상대적으로 미비하다. 본 연구에서는 매립토의 유실은 유입된 유사와 호안 표면의 유사가 흐름에 의해 공사구간을 빠져나간 양이라 정하였다. 매립공사에서 유실량의 산정은 매립물량 산정과 직결되며 이는 경제성 부분에서 매우 중요하다. 그러나 국내에서는 경험에 의존한 유실율을 기준으로 매립물량을 결정하고 있는 실정이고, 현장계측으로도 유실량을 정량적으로 판단하기 쉽지않다. 따라서 본 연구에서는 호안 주변의 흐름 특성을 고려한 매립토의 유실량을 정량적으로 평가하기 위한 방안으로 실험적 연구를 수행하였다. 수리실험은 길이 13.0 m, 폭 5.0 m의 직사각형 단면의 광폭 수로에서 수행하였으며 일정한 양의 유사를 유입하기 위해 자체 제작한 유사공급장치를 사용하였다. 매립토의 특성을 고려하기 위하여 일반모래($d_{50}=0.621mm$, SG=2.72)와 안트라사이트($d_{50}=1.547mm$, SG=1.61) 두 가지 유사를 사용하였고, 매립토 유실요인 중 흐름특성에 의해 외부로 유실되는 양을 보다 명확히 규명하기 위해 유사를 유입하기 전과 후의 양을 각각 직접 채취하는 원시적인 방법과 3D 스캔을 통한 방법을 이용하여 평가한 유실율과 비교 검토해 보았다. 두 가지 방법에 대한 상대오차는 최대 3.12%로 나타났다. 흐름조건에 따른 매립토의 유실율은 살펴보면 두 가지 유사 모두 한계유속(Vc)을 넘어서는 순간, 급격히 유실율이 증가하였고, 일반모래는 약 10 % 안트라사이트는 약 30%로 각각 나타났다. 향후 매립토의 특성인자의 영향을 명확하게 구분하기 위해 다양한 매립토를 활용하여 보다 많은 조건하에서 실험을 수행한다면 매립토의 유실량 산정의 정확성을 높일 수 있을 것이라 기대된다.