• KSBB Journal
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• v.15 no.5
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• pp.489-496
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• 2000

Several culture systems including batch, two-stage CSTR, semi-fed batch, and two-stage cyclic fed-batch were investigated for the efficient production of the Fab fraction of PDC-E2 specific human monoclonal antibody using high cell density recombinant E. coli. A two-phase batch system and a two-stage continuous system were examined to overcome plasmid instability problems, by separating the growth and the production stages. The cell density and productivity of the two-stage continuous culture was better than that of the two-phase batch fermentation. In the two-stage continuous culture system with DO-stat, the cell growth and the productivity were superior to those of the system without the DO control. Also, almost total plasmid stability was maintained in the two-stage continuous culture system. Modified M9 medium was selected as an optimum feeding medium for the fed-batch process, and the optimum C/N ratio determined to be 2:3. The optimum feeding rate was $0.6g/\ell/hr$ for a constant feeding strategy in semi-fed batch system. When the feeding medium was fed by pulsing, it was observed that more frequent pulsing resulted in improved cell growth. The linear feeding method was the most efficient of the various feeding methods tested. Finally, high cell density culture using a two-stage cyclic fed batch system with pH-stat was tried because the linear feeding method showed limitations in terms of obtaining high cell densities, and a cell density of $54 g/\ell$ was achieved. It was concluded that the two-stage cyclic fed batch system was the most efficient system for high cell density culture of the systems tested. However, productivity improvements were lower than expected due to the extremely high accumulations of acetate, although the low levels of residual glucose were maintained.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.229-240
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• 2003

An in vitro test and a broiler feeding trial were conducted to test the effect of hydrothermal treatment of wheat bran on phytate-P degradation and it’s feeding effect on performance of broilers. Hydrothermal treatment of wheat bran was carried out at 55$^{\circ}C$ with pH 5.5 buffer solution. Phytate-P content of wheat bran decreased quadrically as the wheat bran: buffer solution ratio increased from 1:0.5 to 1:5. Phytate-P degradation was not significantly affected by incubation times above 10 min., drying temperature (55$^{\circ}C$, 65$^{\circ}C$ and 75$^{\circ}C$) or pH of the buffer solution (5.5 and 7.0). A feeding trial was conducted with 240 sex separated d-old broiler chickens (Ross$^{\circledR}$). Broilers were randomly housed to 24 cages of 10 birds each. Six cages (3 of each sex) were assigned to 4 treatments: Control-normal level of non-phytate-P (NPP); LP-low NPP treatment which had 0.1% lower NPP than Control; LPWB-LP with wheat bran which provided 475 IU of plant phytase per kg diet; LPHWB-LP with hydrothermally treated wheat bran. Results of the feeding trial showed that broilers in the LP treatment gained significantly less than other treatments in starter period (1-21d) but only male broilers for growing LP gained significantly less than Control in the grower (22-35d) and overall period. There were no significant differences in weight gain among the birds of LPWB, LPHWB and Control. Feed intake during the overall period was not significantly different between LPWB and Control but that of LP was lower than LPHWB and that of LPHWB was lower than Control. Feed/gain ratio was significantly lower in LPHWB and LP than in Control and LPWP. Mortality was highest in LPHWB. Availability of crude fat, crude ash and Ca was significantly lower in LP than other treatments. Availability of P and Zn was higher in LPWB and LPHWB than in Control and LP. Availability of P, Mg and Zn was highest in LPHWP treatment. Excretion of P was significantly lower in low NPP treatments than in Control. Serum Ca level was highest whereas serum P level was lowest in LP. Tibial crude ash content was higher in wheat bran treatments, but lower in LP than Control. However, tibial Ca content was higher in Control and LP than wheat bran treatments. Tibial P content of LP and LPWB was lower than Control. However, tibial content of Fe was highest in LP. It was concluded that wheat bran, a source of plant phytase, could be used in low NPP broiler diets to prevent the depression of performance. Reduction of P excretion can be achieved concomitantly. Hydrothermal treatment of wheat bran was effective in improving utilizability of some minerals but was not effective in improving performance of broilers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.659-666
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• 2005

The purpose of this study was to compare the intake status of calcium, phosphorus, iron, and zinc of Korean adults residing in different regions. Subjects were recruited and divided into three groups according to the districts where they lived, which included rural (n=137), coastal (n=100), and urban district (n=117). Subjects were interviewed using a general questionnaire and 24-hour recall method for dietary intake. The average age of the subjects were 58.1 years for rural district, 57.7 years for coastal district, and 48.6 years for urban district. There was no significance in total food intake by regions. The food intakes from cereals, mushrooms, vegetables of rural district, that from fishes of coastal district, and those from sugars, milks, oils of urban area were the highest among three districts. The calcium, phosphorus, iron, and zinc intakes were $60.1\%,\;123.9\%,\;95.2\%,\;and\;73.1\%$ of RDAs, respectively. The calcium intakes as percentage of RDA in rural and coastal district were significantly (p<0.01) lower than that in urban district. A larger number of subjects from coastal or urban district ate under $75\%$ of zinc RDA compared to those from rural village. Major sources of dietary calcium in total subjects were anchovy, kimchi, milk, soybean curd, rice, ice cream, sea mustard, yogurt, loach, and welsh onion. Rice supplied $15.5\%$ for phosphorus, $22.1\%$ for iron, and $35.9\%$ for zinc of total intake. Except for rice, major sources of dietary zinc were pork, beef, small red bean, dog meat, chicken, jacopever, soybean curd, glutinous millet, and kimchi. In conclusion, the food and mineral intakes of adults differed according to the regions in which they resided. The food and nutrient intakes of coastal district were not satisfactory, and calcium and zinc intakes of three regions did not meet RDAs. Therefore, it is required unique and discriminatory nutritional education with each region for increasing intakes of calcium and zinc.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.105-119
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• 2023

Water supply is decreasing due to climate change, and coastal and island regions are highly dependent on groundwater, reducing the amount of available water. For sustainable water supply in coastal and island regions, it is necessary to accurately diagnose the current condition and efficiently distribute and manage water. For a precise analysis of the groundwater flow in the coastal island region, submarine fresh groundwater discharge was calculated for the Seongsan basin in the eastern part of Jeju Island. Two methods were used to estimate the thickness of the fresh groundwater. One method employed vertical interpolation of measured electrical conductivity in a multi depth monitoring well; the other used theoretical Ghyben-Herzberg ratio. The value using the Ghyben-Herzberg ratio makes it impossible to accurately estimate the changing salt-saltwater interface, and the value analyzed by electrical conductivity can represent the current state of the freshwater-saltwater interface. Observed parameter was distributed on a virtual grid. The average of submarine fresh groundwater discharge fluxes for the virtual grid was determined as the watershed's representative flux. The submarine fresh groundwater discharge and flux distribution by year were also calculated at the basin scale. The method using electrical conductivity estimated the submarine fresh groundwater discharge from 2018 to 2020 to be 6.27 × 10⁶ m³/year; the method using the Ghyben-Herzberg ratio estimated a discharge of 10.87 × 10⁶ m³/year. The results presented in this study can be used as basis data for policies that determine sustainable water supply by using precise water budget analysis in coastal and island areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2107-2111
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• 2009

인근의 저수지의 높이를 높여 도심구간의 하천 유량이 얼마나 증가되는지 확인하기 위해 지천 상류에 위치한 유역면적 65.8 $km^2$인 청양의 도심하천 위치에서 1966년부터 2007년까지 유량을 모의하고, 목표유량을 0.31 $m^3/s$로 설정하여 상류에 위치한 유역면적 17.5 $km^2$, 저수량 512만 $m^3$인 칠갑지의 숭상으로 방류량 증가에 따른 하천유량의 증가효과를 분석한 결과는 다음과 같다. 첫째, 칠갑지 없는 경우 청양 도심하천 유황은 연평균하여 풍수량 1.49 $m^3/s$, 평수량 0.44 $m^3/s$, 저수량 0.20 $m^3/s$, 갈수량 0.16 $m^3/s$로 분석되었으며, 목표유량 0.31 $m^3/s$보다 0.15 $m^3/s$ 적게 나타났다. 둘째, 칠갑지로부터 682 ha의 논에 관개용수를 공급하는 경우 용수공급량/유역면적은 453.9 mm, 단위유역 용수공급량/강우량 비율은 39.1 %, 용수공급량/유입량 비율은 96.5 %, 용수공급량/저수량 비율은 163.7 %, 유입량/저수량 비율은 226.5 %였으며, 이수안전도는 일단위 52.4 %, 일단위 96.9 %였다. 셋째, 현재 규모의 칠갑지 운영을 고려한 청양 도심하천의 유황은 연평균하여 풍수량 1.40 $m^3/s$, 평수량 0.42 $m^3/s$, 저수량 0.19 $m^3/s$, 갈수량 0.16 $m^3/s$로 분석되어 갈수량은 칠갑지가 없는 경우와 같게 나타났다. 넷째, 칠갑지 규모를 5 m 더 높인 경우 청양 도심하천의 유황은 풍수량 1.40 $m^3/s$, 평수량 0.43 $m^3/s$, 저수량 0.24 $m^3/s$, 갈수량 0.20 $m^3/s$로 분석되어, 목표유량 0.31 $m^3/s$보다 0.11 $m^3/s$ 적게 나타났다. 다섯째, 칠갑지 규모를 10 m 더 높인 경우 청양 도심하천의 유황은 풍수량 1.42 $m^3/s$, 평수량 0.47 $m^3/s$, 저수량 0.27 $m^3/s$, 갈수량 0.23 $m^3/s$로 분석되어, 목표유량 0.31 $m^3/s$보다 0.08 $m^3/s$ 적게 나타났다. 여섯째, 칠갑지 규모를 15 m 더 높인 경우 청양 도심하천의 유황은 풍수량 1.43 $m^3/s$, 평수량 0.47 $m^3/s$, 저수량 0.27 $m^3/s$, 갈수량 0.23 $m^3/s$로 분석되어, 10 m 높인 경우와 같게 나타났다. 결과적으로 칠갑지 규모를 높여 하천유량의 증가효과는 한계가 있는 것으로 밝혀졌으며 최적규모 결정을 위해서는 추가 연구가 필요하며, 부족유량을 충족하기 위해서는 다른 방법이 추가로 필요한 것으로 나타났다.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.34-51
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• 2020

In order to clarify the lime-based building method used in the Joseon Dynasty, lime materials, production techniques, and mixing methods recorded in ancient literature were examined. In ancient Joseon Dynasty literature, the use of low grade limestone as a raw material was recorded, and the use of pozzolanic materials such as Hwangtoh, white clay, and roof tile powder as mixing aids to enhance the strength of lime was recorded. In addition, various lime hydration and mixing methods were recorded, and based on re-experiments carried out with regards to this, a physical property evaluation was deemed to be required in accordance with the various types of raw lime materials, lime hydration methods, and mixture ratios. In the early Joseon Dynasty, lime was used for various aspects, but frequent problems were experienced due to lack of supply and poor production techniques. In the late Joseon Dynasty, lime production techniques developed along with mass production. Based on analysis of the manufacturing techniques of Hoegwagmyo lime mortar in the 16^th and 18^th centuries during the Joseon Dynasty, it was found that mixing ratios and the methods described in the ancient literature had been applied. It was confirmed that the mixing ratio differed depending on mixing materials and lime quality. Since the mixing ratio of Hoegwagmyo lime mortar changed over time and it was produced strictly on the basis of a guidebook, it is believed that if continuous scientific analysis of the Hoegwagmyo lime mortar production method were carried out, this would be helpful for ascertaining the chronological methodology of Hoegwagmyo.

• Membrane Journal
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• v.30 no.3
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• pp.190-199
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• 2020

The utilization of multiple water sources becomes important due to the master plan for development of water supply released by Ministry of Environment, Korea in 2018. In this study, therefore, the analysis of comprehensive effect in blending applicable water sources in Daesan where 100,000 ㎥/d seawater desalination plant will be constructed for industrial use was performed. The increase in mixing ratio of other water sources with seawater reduced salinity up to 50%, but negatively impacted the turbid and organic matter. Lab-scale reverse osmosis performance test also found that membrane fouling was exacerbated in blended water condition. The simulation results of reverse osmosis indicated 39% energy saving on average is expected at the one-to-one blending ratio, however, long-term performance test at the pilot-scale plant is highly required to evaluate the inclusive impact of mixing seawater and other water sources.

• 한국공간정보시스템학회:학술대회논문집
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• 2003.11a
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• pp.78-83
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• 2003

OGC(Open GIS Consortium, Inc.)에서 2000년에 XML의 지리정보 처리를 위한 GML 1.0이 제안된 이후 최근 GML 3.0이 발표되기까지 국제적으로는 다양한 GIS 응용분야에서 GML을 현실 문제에 이용하고자 하는 시도가 이루어지고 있다. 현재 우리나라에서도 국가 GIS(NGIS)에서 GML을 도입하여 국내 표준안으로 추진하고자 다양한 기반연구가 진행되고 있다. 본 연구는 중요한 GIS 응용중의 하나인 지질자원 정보 분야에서 GML을 활용하기 위한 기반연구로서 우리나라의 표준 지질도(또는 수치지질정보)와 기타 지질자원 정보 인프라 구축에 적용될 수 있는 다양한 지구과학자료를 대상으로 하였다. 따라서 본 연구에서는 지질자원 분야에서의 GML 응용을 위한 기반 데이터 모델과 이를 처리하기 위한 아키텍처를 UML 기법으로 설명하고, 이를 바탕으로 시험 구현된 운용환경에서 실제 대상 지역을 선정하여, 연구지역에 대한 지질자원 정보의 GML 적용 사례를 제시하고자 한다. 이를 위한 연구 내용으로는 수치 지질도를 XML-GML의 기본 스키마구조에 따라 엔코딩한 뒤, 주제정보의 표현을 위한 XSLT, SVG 파일 변환 처리 등을 수행하였다. 결론적으로 본 연구는 지질자원 분야의 정보화 인프라 구축을 목적으로 하는 기초 시험연구로 수행되었는 바, 우리나라에서는 2001년 이후 GIS 수치 주제도로서 수치 지질도의 보급이 활성화되면서, 이 정보를 제작/공급하는 기관이나 업무에 사용하는 기관 등에서 GML 기반으로 데이터를 제작하거나 운용이 가능할 것으로 생각된다. 또한, 다른 분야에서 GIS 주제정보를 다루는 경우에도 GML을 주제정보와 연계하여 현실 문제에 적용이 가능한 창조 모델로 이용될 수 있을 것으로 생각된다.}94,\;29.4{\pm}30.3,\;45.1{\pm}44$로 Mel 10군과 Mel 30군이 유의적인 감소를 보였으나(p<0.05) 이들 두 군 간의 차이는 나타나지 않았다. 이상의 결과로, 랫트에서 복강수술 후 melatonin 10mg/kg투여가 복강 내 유착 방지에 효과적이라고 생각된다.-1}{\cdot}yr^{-1}$로서 두 생태계에 축적되었다.여한 3,5,7군에서 PUFA 함량이 증가한 반면, SFA 함량은 감소하여 P/S 비율, n-3P/n-6P 비율은 증가하는 경향이었으며 이는 간장의 인지질, 콜레스테롤 에스테르, 총 지질의 지방산조성에서도 같은 경향을 볼 수 있었다.X>$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 대부분을 차지하였다. 야생 돌복숭아 과육 중의 지방산 조성은 포화지방산이 16.74%, 단불포화지방산 17.51% 및 다불포화지방산이 65.73%의 함유 비율을 보였는데, 이 중 다불포화지방산인 n-6계 linoleic acid$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 지질 구성 총 지방산의 대부분을 차지하는 함유 비율을 나타내었다.했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실

• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.239-258
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• 2013

This study aims to examine that Jeollabuk-do 14 cities and counties's job creation policy would lead to a virtuous circle of the local economy through measuring the ratio of spatial mismatch. We suppose that the higher proportion of spatial mismatch in a city or county is, the lower multiplier effect contributes the local economy, especially in the income of residents and the influx of population. For the analysis, this study uses Korean Regional Employment Survey Micro-data and calculates the labor demand self-sufficiency(LDSS) rate of every local labor market for measuring the degree of spatial mismatch. Also we calculate the LDSS rate of employment status, industry, job classification and wage for testing the independency of local labor market. After analyzing, just Jeonju, Gunsan, Iksan, and Namwon could be regarded as independent local labor market where LDSS rates are above 75% in most criteria. But other local labor markets depend on outer labor supplies. For the development of regional economy, it is necessary to consider the creation of 'good jobs' that can induce the labor in parallel with the quantitative increase of employment.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.507-520
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• 2009

The purpose of this study is to analyze the changes in the housing instability of low-income households through their residential mobility. The concept of housing instability is measured by taking into consideration of housing types, number of moves, period of homelessness, and housing affordability index. The result of this study shows that housing instability of low-income households owned their homes is mainly caused from their old housing built in at least 1980, and that of tenant households is due to the heavy burden of rent-to-income ratio. By using multinominal logit model, the study finds that low-income tenant households are more likely to move upwards as they are man-headed, aged and relatively high-income if we categorize residential mobility into four types: upwards, equivalent, trade-off, and downwards migration. Considering that the share of homeowners moving downwards increases while the share of tenants moving upwards decreases as they reside increasingly nearby Seoul, the study finds that low-income households living in big cities are no better off to improve their residential instability for themselves than the low-incomes in local small and midium cities. Furthermore, both low-income owners and tenants are less likely to move downwards as the ratio of single-family housing in former residence increases. Such finding has a policy implication that government needs to maintain affordable single-family housing stock rather than supplying excessive unaffordable multi-family housing in order to enhance residential instability of low-incomes households.