• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.1948-1950
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• 1997

In this paper, we compose of the single current source inverter for utility interactive photovoltaic system. According to insert parallel resonant circuit, the do reactor decreases the distortion of dc current and output current. Therefore, we decrease the do reactance and control modulation factor to operation at the maximum power point around of solar cell.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.473-475
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• 1996

In this paper, bilateral variable-ratio dc chopper system for electric vehicle is proposed. We present the method which is able to simplify the main synthetic chopper circuit by selecting among the forward powering, forward regenerative braking, backward powering, and backward regenerative braking only by control signal. By conducting the experiment with separately excited dc motor, it is confirmed that two quadrant chopper can drive four quadrant operation.

• 경영과정보연구
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• 제9권
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• pp.41-63
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• 2002

Recently junior colleges in Korea have been working to meet changes in industrial and educational surroundings by establishing new departments, integrating and abolishing existing ones, or adjusting departmental quotas. These endeavors need to be based on analysis of industrial policies, both national and international, and of the industrial trend of the region in which the particular college is located. They also need to take into consideration change in educational policies and the direction of the college's specialization. This study aims to provide some foundation materials for these endeavors. As a result, it has considered changes in industrial and educational surroundings and analyzed the whole spectrum of departments existing at Korean junior colleges, with a focus on business-related ones. To summarize, each college offers departments, having taken into consideration its regional, industrial, and educational environments. The result of this study may be utilized by colleges when they establish new departments, integrate and abolish existing ones, and adjust departmental quotas.

• 한국응용과학기술학회지
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• 제3권2호
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• pp.17-22
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• 1986

Compositional and quantitative changes of 4-desmethylsterols in soybean (Glycine max. cv. Gangrim) seed and pod at six stages of development from flowering were investigated. The content of 4-desmethyl-, 4-monomethyl- and 4,4-dimethylsterols in developing soybean seed and pod was found to vary between 0.16-0.35, 0.04-0.12 and 0.04-0.06%, respectively. The predominating 4-desmethylsterols were sitosterol, campesterol and stigmasterol. The proportion of sitosterol in seed decreased to 57.0% with maturation, while in pod increased up to 88.7%. ${\triangle}^{7,22,25}$ Stigmastatrienol estimated 7.5% was detected in the fully mature seed.

• 한국환경보건학회지
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• 제4권1호
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• pp.37-40
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• 1977

녹용이 동물체에 미치는 영향을 조사하기 위한 일환으로 녹용 침출액을 집토끼에 주사한 후 여기에서 여섯개의 조직(골격근, 간, 신장, 부신, 비장, 심장근)을 선택 적출하여 disc-gel electrophoresis로 수용성 단백 분획상을 비교 하여 보았다. 대조군과 5일간 주사한 군에서 간, 신장, 부신, 비장에서는 서로 동일한 영동분획상이 나타났으나 골격근과 심장근에서는 대조군보다 실험군(5일간과 15일간 녹용침출액을 주사한 군)의 영동대에서 하나의 영동대가 더 나타났다. 한편 15일간 주사한 실험군과 5일간 주사한 실험군 사이에서는 단백분 획상의 차이점이 없음을 알았다. 이와 같은 변화는 녹용의 어떤 특수성분이 주로 근육형 조직에서만 백질을 합성하는 기작에 영향을 끼친 것이 아닌가 사려된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.438-440
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• 1994

The output power of photovoltaic(PV) system is variation due to the change in the insolation, temperature and etc. This problem can be overcome if the system is connected to storage batteries and the power system. According to, this paper propose photovoltaic Voltage Source Inverter, which would be connected utility interactive system. It has been experimentally verified that maximum power can be obtained by varing modulation index(MI).

• 한국안광학회지
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• 제1권1호
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• pp.103-108
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• 1996

본 실험에서는 매질의 굴절률을 측정하는 간단한 방법을 소개하고 주위에서 쉽게 구할 수 있는 매질을 사용하여 몇 가지 물질의 굴절률을 측정하여 실제 값과 비교해 보았다. 실험결과 증류수, 알콜, 아크릴의 굴절률은 각각 $1.32{\pm}0.006$, $0.36{\pm}0.01$, $0.48{\pm}0.005$의 값을 얻을 수 있었다. 이 실험값들은 실제값과 일치하는 결과이다.

• 한국안광학회지
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• 제1권1호
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• pp.41-51
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• 1996

안경은 벗으면 일종의 광학기구이나, 착용하면 안광학계와 합성광학계를 이루어 시력을 교정한다. 이때 시력교정용 안경테는 렌즈와 눈으로 조합된 광학계의 기능을 조정하는 보조적 역할을 하여 시기능교정에 영향을 미친다. 안경테를 잘못 선택할 경우, 시기능교정에 제약을 받게되며 더 나아가서는 새로운 굴절이상이나 안위이상을 일으켜 안정피로는 물론 시력저하를 초래할 가능성도 있다. 그래서, 전문지식을 갖춘 안경사가 안경테를 선택하고 조정해야만되는 당위성을 본고를 통해 고찰한다.

• 대한방사선기술학회지:방사선기술과학
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• 제15권1호
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• pp.107-113
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• 1992

Inverter type X-ray apparatus has been introduced and used several hospitals. Principle of inverter type X-ray generators are such as to convert the frequency of commercial power supply to high frequency and to control the high voltages for X-ray tube. Inverter generators are now on the way for futher development to elliminate single phase generators and three phase generators. We compared inverter type X-ray apparatus with conventional single phase 2 peak and three phase 12 peak, apparatus in the following aspects X-ray out put to tube voltage, linearity of X-ray out put to mA, HVL according to mA contrast to kV.

• 대한방사선기술학회지:방사선기술과학
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• 제2권1호
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• pp.37-43
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• 1979

High kilovoltage technique as compared with low kilovoltage in taking chest radiogram has much advantages. Authors performed an experiment by using acryl phantom to make the technical chart at 120KV and obtained the results as follows; 1. Increase and decrease of tube voltage in thickness change was 3.2KV per cm at variable technic chart. 2. At fixed kilovoltage technic chart, increase and decrease was $0.12{\sim}0.2$ mAs per cm in chest thickness. 3. Increase and decrease of distance was 1.3inches per cm in thicknese change