• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.355-359
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• 2005

Fractional precipitation is a simple, efficient method for pre-purifying paclitaxel from plant cell cultures. The storage temperature of factional precipitation was optimized in terms of the yield and purity of paclitaxel with a fixed methanol concentration in water (61.5%, v/v), paclitaxel content in the crude extract (0.5%, w/v), and storage time (3 days). The greatest yield $({\sim}84%)$ was obtained with storage at a constant temperature $(0^{\circ}C)$ for 3 days. Conversely, the highest purity $({\sim}79%)$ was obtained with stepwise reduction in temperature over 3 days. For a constant storage temperature, the maximum purity $({\sim}67%)$ was obtained at $0^{\circ}C$. There was little difference in the yield of paclitaxel between -20 and $12^{\circ}C$. This pre-purification process serves to minimize solvent usage, and the size and complexity of the high-performance liquid chromatography (HPLC) operation required for paclitaxel purification.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.2
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• pp.177-186
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• 2017

This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.73-86
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• 1999

The ion-exchange method for the purification of primary coolant has been used broadly in PWR(pressurized water reactor)-type nuclear power plants due to its high decontamination efficiency, simple system, and easy operation. However, its non-selective removal of metal and non-radionuclides shortens its life, resulting in the generation of a large amount of waste ion-exchange resin. In this study, the feasibility of electrodeionization (EDI) was investigated for the purification of primary cooling water using synthetic solutions under various experimental conditions as an alternative method for the ion exchange. The results shows that as the feed flow-rate increased, the removal efficiency increased and the power consumption decreased. The removal rate was observed as a 1000 decontamination factor(DF) at a nearly constant level. For the synthetic solution of 3 ppm TDS (Total Dissolved Solid), the power consumption was 40.3 mWh/L at 2.0 L/min of feed flow rate. The higher removal rate of metal species and lower power consumption were obtained with greater resin volume per diluting compartment. However, the flow rate of the EDI process decreased with the elapsed time because of the hydrodynamic resistivity of resin itself and resin fouling by suspended solids. Thus, the ion-exchange resin was replaced by an ion-conducting spacer in order to overcome the drawback. The system equipped with the ion-conducting spacer resolved the problem of the decreasing flow rate but showed a lower efficiency in terms of the power consumption, the removal rate of metal species and current efficiency. In the repeated batch operation, it was found that the removal efficiency of metal species was stably maintained at DF 1000.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.4
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• pp.369-376
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• 2015

Chemicals are injected in order to remove a variety of organic substances contained in the water purification plant influent. It can be determined with measuring sedimentation turbidity 4~7 hours later, whether the chemical dosage rate is proper or not, which make the real-time feedback control impossible. In addition, manual operation in accordance with the Jar-Test carried out in the laboratory and the operator's experience may cause the experimental and human error by the changes of organic characteristics and water quality. Especially at night ad weekend, the rate have been determined only by the operator judgment owing to environment engineer's absence. Therefore, the decision of optimal chemical dosage rate using proposed intelligent control algorithm is expected to result in real-time injection and cost reduction.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.347-355
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• 2006

Anyang Stream including its main branch is the biggest branch stream of Han River in Korea. The geological and geomorphological characteristics were investigated to the affected area of Anyang Stream, in which rainfall characteristic was analyzed. The water quality surveyed that the analysis of water pollution used to biotic index and biological water pollution. The rainfall pattern in this area was like to that of typical Korea, but the rate of trigger and runoff during summer season(June~August) is more higher than mean of Korea. Before 2003, a dried stream is severe status, which was due to abundant runoff, but this status are improved. After 1997, water quality of stream is recovering status such as water pollution of stream steeply decreased. Especially after 2003, this trend is more quickly improved. Although, owing to the increasing of a T-N and SS at upstream wastewater were due to bad collection of industrial factories, livestock's and mans living, the water quality worsted at upstream. Water quality in total section of main stream was severely contaminated that water-quality limit is 5 with polysaprobic by water self-purification. That of main branch was 1~3limits with ${\alpha}$- and ${\beta}$-mesosaprobic in Anyang city area, But water quality in all area about another branch of Anyang stream except Anyang city area was almost under of 3 grades. Though trying of Anyang city for recover movement(completion of 2nd Sewage Treatment Plant and Water supply pipe system) on Anyang stream, water pollution states of upper branch in Anyang stream was not better than its of 2002 because it may be difference of control area on other cities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.138-141
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• 2015

K-water operates many Water Treatment Plants(WTP) to supply clean water to people. There are automation process control equipments collecting data at each step in WTP. The data collected is big enough to 370,000Tag/min from the K-water Water Treatment Plants. In the past, this big data was not important, we focused on the operating water purification process using the data. Currently, we increased the importance of attention to take advantage of Big Data. The research about the accident reduction and efficiency improvement in WTP are ongoing by data collection and analysis. In this paper, we analyzed the flow rate, power and pressure obtained in the accident case in WTP. We researched the methods for accident prediction and reduction.

• Journal of Environmental Science International
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• v.17 no.10
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• pp.1129-1137
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• 2008

We investigated the ecological characteristics of reed populations growing in Korea and tried to select reed populations showing better growth patterns in waste landfill leachate. To examine the growth characteristics, 14 reed populations from various habitats were collected. Four reed populations were from inland reclaimed habitats, 4 reed populations from brackish or salt marsh habitats, and 6 reed populations from fresh water habitats. Total plant biomass after the treatment with landfill leachate showed that Daebudo and Nanjido reed populations had the higher biomass with 3755 g DW/pot and 3305 g DW/pot, respectively. Reed populations being sampled from the higher salinity and landfill habitats had relatively higher total biomass than that of other reed populations. Especially reed populations from landfill habitats showed higher biomass. Reed populations from Songjiho and Daebudo, which were believed to have tolerance to salt stress, also showed good growth patterns. Population from the fresh water habitats exhibited relatively lower tolerance to leachate treatment compared to others. From the results, we could conclude that reed populations from Nanjido and Daebudo with higher biomass and better salt tolerance were able to good candidates for purification of waste landfill leachate.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.240-247
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• 2014

This study was conducted as a restoration research in a mountain stream of hydrologic cycle system, which is a type of microsites purposely changing vegetation. The status of vegetation in the three experimental sites, water purification site, small dammed pole site, and aquatic plant restoration site, and one control site within the area of the mountain forest stream were investigated in three different periods, namely before sites restoration, year of sites restoration, and year after sites restoration. After one year of restoration, number of vegetation was increased in the small dammed pool and control site respectively. Vegetation coverage ratio of Zizania latifolia was increased at the water purification area. The effects of habitats restoration appeared to be good a year after the restoration of the experimental sites, in terms of families and species composition of the introduced vegetation, and stream flow. Therefore, the results of the study strongly suggest that fairly effective ways to restore and reproduce degrading mountain hydroecological habitats are by way of forming pool sites and small dams in intermittent mountain streams and re-vegetating with selected plants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.380-384
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• 2007

The COD removal capacity of aquatic plants, when foamed glasses were not used, showed 56% for Pistia straiotes, 48% for Phragmites japonica and 41% for Oenanthe javanica, but no significant COD removal was observed for Lythrum anceps. When the foamed glasses were used as support materials, the COD removal efficiency increased for all aquatic plants used in this study showing 69% fur Pistia straiotes, 68% for Pharagmites japonica 62% for Oenanthe javanica, respectively. The T-N removal efficiency of aquatic plants when foamed glasses were used as support materials showed 91% for Lythrum anceps and 93% for Phragmites japonica. Similar removal efficiency was observed as 94% for all aquatic plants planted as a group used in this study. The T-P removal efficiency of aquatic plants when foamed glasses were not used showed 35% for Lythrum anceps, 8% for Phragmites japonica, however, that, when foamed glasses were used, ranged 78% for Lythrum anceps, 43% for Phragmites japonica, showing that the foamed glasses increase the T-P removal efficiency of aquatic plants used in this study.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.171-171
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• 2011

상수도의 합리적인 운용과 관리를 위해서는 급수량 예측이 매우 중요하다. 기존 급수량 예측은 신경망과 칼만 필터법을 사용한 연구들이 대부분이었다. 이러한 연구결과들은 높은 상관결과를 갖고 있지만 이는 자기상관계수에 대한 높은 의존도에 따른 결과로 볼 수 있다. 즉, 예측의 결과가 전날 수요량을 거의 그대로 따라오는 경향을 띄어, 급수량 예측 그래프가 기존 그래프를 오른쪽으로 이동시킨 것과 같이 나타난다. 본 연구에서는 이러한 문제점들을 해결하기 위해서 물수요량을 예측하는데 있어서 효과적인 예측인자를 도출하는 것이 우선되어야 할 것으로 판단되었다. 이에, 물수요량 특성을 효과적으로 나타내어 줄 수 있는 예측인자로서 강수량, 최저온도, 최고온도, 평균온도 등을 1차적으로 선정하였다. 이들 예측인자들과 서울시 물수요량과의 상관성을 평가하여 최적의 예측인자 Set과 지체시간 등을 산정하였다. 이렇게 선정된 예측인자와 Bayesian 통계기법 기반의 회귀분석 모형을 구축하여 물수요량을 예측하였다. 본 연구에서 적용하고자 하는 계층적 Bayesian 모형은 유사한 특성을 가지는 자료계열들 사이에서 서로 보완이 될 수 있는 정보들을 추출함으로써 모형이 갖는 불확실성을 상당히 줄일 수 있는 방법이다. 이러한 모형적 특징은 생산량 예측에 대한 불확실성 저감 측면에서 장점이 있을 것으로 판단된다. 본 연구에서는 광암, 암사, 구의, 뚝도, 영등포, 강북 정수장을 대상으로 모형의 적합성을 평가하였다. 이러한 연구결과는 향후 정수장 운영계획 및 동일한 시스템을 갖는 상수도 급수량 예측 시 유용하게 사용할 수 있을 것이다.