방위산업에 있어서 향후 국과연의 역할에 기대를 건다

안태영,An, Tae-Yeong 한국방위산업진흥회 1992 國防과 技術 Vol.- No.163

GaN을 적용한 브릿지리스 PFC에서 스위칭 주파수에 따른 효율특성에 관한 연구

안태영 청주대학교 2018 産業科學硏究 Vol.36 No.1

In this paper, a GaN switch is applied to a 2kW class large capacity bridgeless power factor correction (PFC) circuit to report the comparative test results according to switching frequency variation from 50kHz to 100kHz. Especially the efficiency was 98.36% at a switching frequency of 60kHz and 98.2% at 100kHz while the efficiency was reduced to 98.29% at 50kHz. This was estimated because the core loss of the inductor and the switching loss of the GaN were proportional to the switching frequency. When the frequency was below a certain value, a decrease in efficiency was observed due to an increase in current ripple and power loss by the insufficient inductance in the test circuit. Therefore, in the bridgeless PFC with GaN FET, once the switching frequency and the optimum inductance value were determined, the power conversion efficiency was not improved even when the switching frequency was increased.

천호지 저질토에서 분리한 철환원세균의 특성

안태영,박재홍,이일규,전은형 한국미생물학회 2002 미생물학회지 Vol.38 No.2

금속 이온 환훤 세균에 의한 철(III)환원은 생물지구화학적 물질순환(biogeochemical cycle)에 무척 중요하다. 이는 크롬(Ⅵ)이나 우라늄(Ⅵ)과 같은 독성 중금속 물질의 환원과 유기물질의 산화에 모텔이 되기 때문이다. 총 37균주의 Fe (III)환원 세균을 소양호와 천호지의 저질토에서 각각 분리하였다. 두 정점 중 초기 Fe (II)의 함유량이 가장 높았던 것은 소양호의 저질토였으나 Fe (III)환훤능은 반대로 가장 낮은 Fe (II)함유량을 보여 주었던 천호지가 높게 나타났다. 또한 분리한 균주 중 천호지에서 분리한 균주 C2와 C3가 가장 높은 Fe (III) 환훤능을 보여 주었으며 이 균주를 이용하여 다양한 전자 공여체의 이용 여부를 실험하였다. Glucose, yeast extract, acetate, ethanol, toluene등을 이용하여 실험한 결과 두 균주 모두 glucose와 yeast extract만을 전자 공여체로 이용하였다. 또한 전자 수용체로 토양에 광범위하게 존재하는 humid acid와 nitrate를 이용하였으며 수율이 높은 nitrate reduction에 의해 환원되었던 humic acid가 다시 재 산화되는 것을 관촬할수 있었다. 활성능이 우수한 균주 C2와C3의 165S rRNA유전자 분석 결과에 의하면 Aeromonas hydrophila와 95%의 유사성을 보여주었다. Microbial Fe (III) reduction is important for the biogeochemical cycle in the sediment of freshwater system. Also, the Fe (III) reducing mechanism make a model of oxidizing organic compounds and reducing toxic heavy metals, such as chrome or uranium. Thirty-seven strains which have Fe (III) reducing activity were isolated from sediments in lake Soyang and Chunho reservoir. The initial concentration of Fe (II) was the highest in sediments of lake Soyang. However, the highest Fe (III) reducing activity was shown in Chunho reservoir. All isolates were tested for Fe (III) reducing activity. Strains C2 and C3, which were isolated from sediments of Chunho reservoir, showed the highest activity. These strains were tested to see if they utilize various electron donors such as glucose, yeast extract, acetate, ethanol and toluene. Significantly, glucose and yeast extract were used as electron donors. Also these strains were conformed to use humid acid and nitrate as electron accepters. The 16S rRNA sequences of strains C2 and C3 were closely related to Aeromonas hydrophila with 95% similarity.

Two transistor 포워드 DC-DC 컨버터의 효율 특성에 관한 연구

안태영,이광택 전력전자학회 2007 전력전자학회 논문지 Vol.12 No.1

In this paper, we present an analytical method that provides fast and efficient evaluation of the conversion efficiency for Two transistor forward (TTF) DC-DC converter. In the proposed method, the conduction losses are evaluated by calculating the effective values of the ideal current waveform first and incorporating them into an exact equivalent circuit model of the TTF converter that includes all the parasitic resistances of the circuit components. While the conduction losses are accurately accounted for the diode rectification, the core losses are assumed to be negligible in order to simplify the analysis. The validity and accuracy of the proposed method are verified with experiments on a prototype TTF converter. An excellent correlation between the experiments and theories are obtained for the input voltages of 390V, output voltage 12V and maximum power 480W. 본 논문에서는 Two transistor forward(TTF) DC-DC 컨버터의 회로방식에 대한 전력변환 효율특성을 빠르고 효과적인 분석 방법에 대해 보고한 것이다. TTF 컨버터의 회로 구성 소자 중에서 내부 기생저항만을 고려한 등가회로를 유도하고 이상적인 동작 파형을 이용하여 전류의 실효값과 전도손실을 유도하였다. 해석을 간단하게 하기위해서 정상상태 결과로부터 코어 손실은 무시하였으며, 다이오드의 손실과 전도손실 만을 고려하였다. 해석결과의 타당성을 검토하기 위해서 시험용 TTF 컨버터를 구성하여 검증하였다. 입력전압 390V, 출력전압 12V, 최대전력 480W의 조건에서 실험결과와 해석결과와 비교적 잘 일치한다는 것을 본 논문에서 확인 하였다.

전해커패시터 노화에 따른 스위칭 전원장치의 사용기한 추정에 관한 연구

안태영 청주대학교 2012 産業科學硏究 Vol.29 No.2

The degradation of electrolytic capacitor is determined by using a relation that the worse electrolytic capacitors have larger their internal impedances. The LC tuning circuit detects a spectrum of an arbitrary frequency in the ripple voltage of a switching power supply output (the samp1ing frequency is usually the switching frequency of the power supply). A detected dc signal (relating to degradation) is compared with the reference voltage. One of the LC tuning circuit method for the measurement of electrolytic capacitor has been developed.

피부미용사 커뮤니케이션 유형이 커뮤니케이션 만족과 직무성에 미치는 영향

안태영 한국뷰티경영학회 2017 한국뷰티경영학회지 Vol.5 No.2

한강 수계의 미생물의 분포와 활성도

安泰永,郭魯泰 단국대학교 1995 論文集 Vol.29 No.-

From November 1989 to August 1990, distributions of heterotrophic bacteria and coliform bacteria were investigated 8 times at 8 stations in Han River and 4 times at 10 stations in the tributary streams. In order to measure the heterotrophic activity, glucose uptake rate was also analysed. The distribution of heterotrophic bacteria ranged from 1.9 x 10 exp(3) to 7.1 x 10 exp(6) CFU/ml (mean value; 6.5 x 10 exp(5) CFU/ml) in main stream of Han river. Total coliform bacteria and fecal coliform bacteria ranged from 10 to 2.5 x 10 exp(5) CFU/ml and from 5 to 1.1 x 10 exp(3) CFU/ml respectively. The glucose uptake rates ranged from 0.3%/h to 51.5%/h with 4.1%/h of average uptake rate. At the downstream stations along the river, the number and activity of bacteria were high. The seasonal variation of bacterial number and activity was found to be lower than stational one. The activity of microorganisms was showed the highest value in spring and the distribution of heterotrophic bacteria was the highest in summer.

영전압 스위칭 풀브릿지 컨버터의 손실 분석에 관한 연구

안태영 청주대학교 2010 産業科學硏究 Vol.27 No.2

In this paper, we present an analytical method that provides fast and efficient evaluation of the power losses and the conversion efficiency for phase-shift controlled full-bridge converter. In the proposed method, the magnetic core losses are evaluated by the curve fitting methode of the core loss graph first and incorporating them into an exact sub circuit model of the phase-shift controlled full-bridge converter that includes all the core losses of the circuit components. The validity and accuracy of the proposed method are verified with experiments on a prototype converter. An excellent correlation between the experiments and modelling are obtained

평균 전류 제어용 UC3854의 PSpice 모델링에 관한 연구

안태영,주정규 청주대학교 산업과학연구소 2002 産業科學硏究 Vol.20 No.1

This paper describes operation through simulation after modeling UC3854, an exclusive IC using the average current mode of current mode controls. Also, we applied the modeled IC to Boost Converter and then observed operation characteristic in the circuit as variable factor of Boost converter was applied in the circuit, and also forecast result of conditions that can happen in a real experiment.

배전류형 동기정류기의 효율 개선에 관한 연구

안태영,이봉준 청주대학교 산업과학연구소 2002 産業科學硏究 Vol.20 No.1

In this paper, we report the experimental results of the Forward-flyback DC-DC converter with current doubler and synchronous rectifier. The experimental converter, that has a output voltage 1.8V, output current 25A, maximum power of 45W, switching frequency of 300kHz and input voltage range of 36-75V, has been successfully implemented. As a result, in the entire voltage range the measured full load efficiency was above 86%.