• 생명과학회지
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• 제11권3호
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• pp.230-234
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• 2001

The cyclodextrin glucanotransferase(CGTase) gene of Bacillus macerans was expressed in Saccharomyces cerevisiae and the recombinant CGTase was partially purified from the yeast culture supernatant. The optimal pH and temperature of the CGTase were found to be 6.0 and 5$0^{\circ}C$, respectively. The pH and temperature stabilities of the recombinant enzyme were significantly enhanced and the half life at 55$^{\circ}C$ was about 60 hr. When the recombinant CGTase was reacted with 5% soluble starch, the conversion yield of total cyclodextrin (CD) from starch was estimated to be 41% at 48 hr, whereas the wild type enzyme showed the yield of 12%. This improvement of conversion yield and thermal stability of CGTase may be useful for the development of low-cost CD production process.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권4호
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• pp.177-183
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• 2002

A pulsed tracer gas technique is applied to measure the distributions of local mean age and local mean residual-life-time of air in a half-scale experimental chamber, The airflow patterns in the chamber are visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is at either bottom-left (Case 1), bottom-right (Case 2), or top-left (Case 3) location. Results show that the distributions of local mean age and local mean residual-life-time are different from each other, but both of them are closely related to the airflow pattern in the space. Included are discussions on explaining the variations of overall room ventilation effectiveness depending upon airflow rates for three different supply-exhaust configurations.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.279-280
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• 2007

Airway wall thickness is an important bio-marker for evaluation of pulmonary diseases such as stenosis, bronchiectasis. Nevertheless, an image-based analysis of the airway tree can provide precise and valuable airway size information, quantitative measurement of airway wall thickness in CT images involves various sources of error and uncertainty. So we have developed an accurate airway wall measurement technique for small airways with three-dimensional (3-D) approach. To illustrate performance of these techniques, we used airway phantom that consisted of 4 acryl tubes with various inner and outer diameters. Results show that evaluation of interpolation and deconvolution methods of airways in 3-D CT images, and significant improvement over the full-width-half-maximum method for measurement of not only location of the luminal and outer edge of the airway wall but airway wall thickness.

• 전기전자학회논문지
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• 제23권4호
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• pp.1218-1223
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• 2019

HVDC 시스템에서 풀-브리지 서브 모듈 구조는 하프브리지 서브 모듈에 비해 부품 수가 증가하지만 100 % 여유율 확보가 가능하여 고장률을 크게 줄일 수 있다. 그러나 풀-브리지 서브 모듈은 여유율 보장과 암(arm) 단락 방지를 위한 데드 타임(dead-time)을 확보하기 위해 복잡한 제어 알고리즘이 필요하다. 이 문제를 해결하기 위해 풀-브리지 서브 모듈과 동일한 부품 수와 100 % 여유율을 갖는 병렬 하프브리지 구성의 고장률을 분석한다. 기존의 부품 고장 분석에 고장나무분석 방법을 적용하여 서브 모듈의 동작 위험을 반영함으로써 서브 모듈의 수명주기를 보다 정확하게 예측할 수 있다. 병렬 하프브리지 서브모듈의 타당성 검증을 위해 FTA 기반 분석 방법과 기존의 PCA 기반 방법으로 분석된 고장률을 비교한다.

• 가정과삶의질연구
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• 제30권3호
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• pp.179-192
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• 2012

The purpose of this study is to investigate the variable factors influencing children's interpersonal relationship skills and analyze the effects of marital perspective-taking ability, managing responses of young children and emotional intelligence on the interpersonal relationship skills of children. The study subjects were young children aged from four to seven attending private kindergartens or public day care centers in Seoul or Kyeongki-do and their mothers. The results are as follows : 1) First, marital perspective-taking abilities were indicated higher on boys than girls, children in a full-day program than those in a half-day program, university graduates or higher degree holders than collage graduates, single-income families than double-income families. In case of managing responses of young children, boys showed high avoidance of offensive disposition and girls showed high emotions dissipation. Also, young children in a full-day program showed non-responses on managing responses but high responses on emotions dissipation, and children of mothers with bachelor's degree or higher education showed support and children from double-income family showed no responses in high. Moreover, emotional intelligence of young children in a full-day program was higher than that of children in a half-day program, interpersonal relationship skills were showed higher on girls than boys, half-day children than full-day ones, children from single-income family than those from double-income family. 2) Meaningful relationships were indicated between these variables; managing responses of young children, emotional intelligence and interpersonal relationship skills by partly showing correlations. 3) Children in a half-day program with low in emotions dissipation, non-responses, offensive dispositional managing responses but high on Avoid, emotional intelligence showed high interpersonal relationship skills.

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.14-20
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• 2001

On the bending process, metal-strap plays an important role in dispersing the stress generated in wood. Therefore, the metal-strap has more influence on the property of bentwood materials. The effect of the metal-strap thickness for bentwood was examined. The effect of metal-strap on the bending properties of Korean red pine(Pinus densiflora Sieb. et Zucc.)was investigated in this research. The metal-strap thickness is divided into 4 kinds such as 1.0, 0.8, 0.6, 0.4 mm. The specimens were selected by grain such as annual ring angles, flat grain and half-edge grain specimens. As a result of this study, the bending ability of 1.0, 0.8 mm, thickness of half-edge grain specimens was better than flat grain specimens but the result of 0.6, 0.4 mm were reversed. The bending ability of half-edge grain was better than flat grain and the grade was higher. When the processed specimens were dried, the radius of curvature(ROC) was decreased became drying-stress was not perfectly dispersed. An optimum drying-condition would deminish this phenomenon.

• 대한의용생체공학회:의공학회지
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• 제29권6호
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• pp.484-492
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• 2008

Sit to stand(STS) movement is one of the most common activity in daily life. In addition, Korean traditionally stand up from various sitting heights in one's daily life compared to other foreigners. As Korea enter rapidly to the aging society, needs of the elderly's independent life are increasing. Therefore the importance of research about the analysis of elderly's activity in daily life is rapidly increasing. In this study, we analyzed joint movements and changes of muscle length during STS(sit-to-stand) at various sitting heights(table seat, bath seat, bottom) in the Korean elderly's daily life by using the motion analysis and musculoskeletal modeling. Ten Korean elderly and young were participated in this experiment. Three heights of sitting posture which could represent typical sitting in Korean daily life were chosen as table seat(42cm), bath seat(21cm) and bottom(0cm). As the results, the elderly showed both smaller knee/hip flexion and larger trunk flexion relatively in comparison to the young during table seat STS. The elderly also showed larger dorsiflexion and smaller ROM of knee, hip, trunk compared to the young during bath seat STS. Additionally, the elderly showed larger plantarflexion, hip flexion, smaller knee flexion and trunk flexion during the first half of bottom STS and larger knee flexion, hip flexion and trunk flexion during the second half of bottom STS. In addition, we could know contraction and relaxation characters of major muscles in lower limb during various STS through the analysis of changes in muscle length by musculoskeltal modeling.

• 한국환경농학회지
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• 제34권4호
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• pp.328-335
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• 2015

본 연구는 생산단계 방울토마토 중 fluopicolide 및 metrafenone의 경시적 잔류변화를 조사하여 반감기를 산출함으로서 생산단계 잔류허용기준을 설정하고자 수행하였다. Fluopicolide 및 metrafenone 농약을 안전사용기준에 준하여 각각 포장 1, 포장 2 지역으로 나누어 기준량 처리하였으며, 약제처리 2시간 후를 0일차로하여 0, 1, 2, 3, 5, 7, 10일차에 시료를 채취하여 분석하였다. 두 약제 모두 LC-MS/MS를 이용하여 분석하였으며, MLOQ(Method Limit of quantitation)는 0.005 mg/kg이었다. 분석결과, fluopicolide 회수율은 92.7∼94.8%이었고, metrafenone의 회수율은 82.6 ∼88.0%이었으며, 두 약제 모두 표준편차는 10% 미만이었다. 방울토마토 중 각각의 농약에 대한 반감기는 fluopicolide의 경우 15.0일(포장 1)과 12.8일(포장 2)로 나타났으며, metrafenone의 경우 18.9일(포장 1), 21.5일(포장 2)로 나타났다. fluopicolide 및 metrafenone에 대하여 방울토마토 수확 10일 전 잔류량이 각각 0.27 mg/kg, 2.29 mg/kg이하로 나타난다면 수확 시 잔류량은 MRL 수준 이하일 것으로 판단된다.

• 한국환경농학회지
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• 제22권3호
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• pp.220-226
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• 2003

복숭아의 생산단계에서 잔류허용 기준과 최종 소비단계에서의 잔류양상 평가자료로 활용하기 위하여 복숭아에서의 procymidone, chlorfyrifos 및 ccypermethrin의 포장상태에서와 실온($20^{\circ}C$) 및 저온($4^{\circ}C$) 저장시 잔류양상을 알아보았다. Procymidone의 포장상태에서의 반감기는 표준량 3.1, 배량 3.4일로 나타났고, chlorpyrifos는 포장상태에서 표준량 7.2, 배량 5.8일로 나타났으며, cypermethrin은 표준 10.1, 배량 14.4일로 나타났다. 약제 살포 후 초기 부착량이 MRL 이하로 내려갈 때까지의 시간을 계산해 본 결과 배량으로 살포 할 경우 procymidone과 chlorpyrifos는 안전사용기준 보다 시간이 오래 걸렸지만, 표준량으로 사용할 경우 별다른 문제가 없는 것으로 나타났다. 저장기간 중의 procymidone, chlorpyrifos, cypermethrin의 반감일수는 $20^{\circ}C$에서 4.6, 10.2, 12.9일 이며, $4^{\circ}C$에서는 16.1, 14.3, 13.1일로 저온에서의 반감기가 실온에서보다 더 긴 것을 알 수 있었다. 한편 세척방법에 의한 잔류농약의 제거율은 수돗물에서는 최고 procymidone 82.9%, chlorpyrifos 27.0%, cypermethrin 24.0%로 나타났고, 세제를 사용 할 경우 procymidone 88.8%, chlorpyrifos 59.0%, cypermethrin 59.4%의 제거율을 보였다.

• 콘크리트학회논문집
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• 제25권6호
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• pp.621-630
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• 2013

철근부식을 현장에서 평가하기 위해 다양한 부식측정방법이 있으나, 반전위(HCP: half cell potential)방법이 많이 사용되고 있다. 균열이 발생한 RC 구조물은 균열폭으로 유입되는 염화물, 이산화탄소 등에 의해 부식이 가속화 된다. 이 연구는 염해에 노출된 균열을 가진 RC 보의 HCP을 측정하여 부식정도를 평가하는데 목적이 있다. 이를 위해 세가지 물-시멘트비(w/c 0.35, 0.55, 0.70)와 다양한 피복두께(10~60 mm)를 가진 RC 보를 제조하였으며 하중을 가하여 균열폭을 0.0~1.5 mm로 유도하였다. 35일간 촉진염해분무시험을 통하여 부식을 촉진하였으며 이후 HCP과 부식길이를 평가하였다. 균열이 클수록, w/c가 높을수록, 피복두께가 작을수록 HCP은 증가하였으며, 각각의 영향인자를 정량화하여 균열을 가진 RC 보의 HCP 평가식을 도출하였다. 또한 Life365 프로그램을 이용하여 부식방지 피복두께를 도출하고 HCP평가식을 통한 부식방지 피복두께와 비교하였다. 균열부 콘크리트에서는 차이가 발생하였으나, w/c 0.6이하의 건전부 콘크리트에서는 두가지 방법에서 모두 근접한 부식저항 조건을 도출하였다.