E급 스위칭 Mode DC-DC Converter에 관한 연구

남승식,김동희,노채균 嶺南大學校 工業技術硏究所 1992 연구보고 Vol.20 No.1

This paper proposes a DC-DC Converter of high frequency inverter control type of E class switching mode to reduce switching loss by constructing a resonance type DC-DC Converter. The steady state characteristics of the proposed circuit is analyzed by mormalized parameters. In addition, the characteristics of proposed DC-DC converter of E class switching mode is evaluated by describing the characteristics frequency, load, switching voltage and current. Based on the characteristic values, a method of circuit design is proposed. A constant output is controlled by PWM and PFM-TRC method using power MOSFET. By means of experiment, the proposed theory is proved and the results show that it can be used for practical purposes.

수출용 축양품종 가지의 염절임 공정의 최적화

남학식,김남우,황성희,윤광섭,신승렬 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2003 한국식품저장유통학회지 Vol.10 No.3

가지의 수출 경쟁력 향상을 위한 한 방안으로 수출용 가지품종인 축양품종을 염가공품으로 개발하기 위하여 염절임공정을 최적화하였다. 염절임 시간, 절임온도, 염농도를 독립변수로 하고 절임 후 수분함량, 염도, 표면과 내부의 색도 등을 종속변수로 하여, 중심합성계획법으로 실험을 설계하여 최적조건을 얻고자 하였다. 수립된 이차회귀모형으로 예측식을 수립할 수 있었으며 특히 수분함량이나 염도, 표면과 내부의 L과 b 값에 대하여 높은 적합도를 보여 최적조건을 수립하기 위한 제한 변수로 선정하였다. 염농도를 중심점(30%)에서 고정시켜서 얻은 절임시간과 온도는 각각 5.5~6.5일과 13-17℃였으며, 이때의 종속변수의 제한 요건으로는 수분함량 84%이하, 염도 14%이하 표면 L값 10-20, b값 0이하, 내부 L 값은 70-75, b 값이 16-18이었다. This study was conducted to the optimize salting process of eggplant for development new product and enhancement quality for export. Three variables by five level central composite design and response surface methodology were used to determine optimum conditions for salting time, temperature and salt concentration. Optimization of the process was conducted using the combination of the moisture content, salinity and color of surface and inside of salted eggplant. The regression polynomial model was suitable (P>0.05) by Lack-of-Fit analysis with highly significant. To optimize the process, based on surface response and contour plots, the individual contour plots of the response variables were superimposed. The optimum conditions for this process were 6 days and 15℃ at 30% concentration under the optimum of restricted variables as moisture content was below 84%, salinity was below 14%, L and b value of surface were 10 to 20 and below 0, L value and b value of inside were 70 to 75 and 16 to 18.

수강 등록 데이터의 빈출 패턴을 이용한 학업 진척도 및 상태 분석을 위한 시퀀스 데이터 마이닝

정효남·전성희·황준 서울여자대학교 컴퓨터과학연구소 2014 정보기술논문지 Vol.12 No.-

ZVS를 이용한 풀 브릿지 단일 전력단 고주파 공진 AC-DC 컨버터의 특성해석

남승식,황계호,오경섭,원재선,조규판,김동희 嶺南大學校 工業技術硏究所 2003 工業技術硏究所論文集 Vol.31 No.2

This paper proposes a single-stage high frequency resonant AC-DC converter using zero voltage switching with high input power factor. The proposed high frequency resonant converter ingegrates a half bridge boost rectifier as power factor corrector(PFC) and half resonant converter into a single stage. The input stage of the half bridge boost converter is working in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. Therefore, high power factor is achieved naturally. The results of simulation using the Pspice have demonstrated the feasibility of the proposed AC-DC converter. The proposed converter will be able to be practically used as power supply.

歷史環境法制의 내용과 문제점

남궁승태,박정희 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

분당지구의 담수어류 분포

권희석,이승휘,권순욱,주원남,박은호 漢陽大學校 環境科學硏究所 1991 環境科學論文集 Vol.12 No.-

신도시 계획에 따른 환경파괴 및 변화가 예상되는 분당지구의 어족자원을 보호하기 위하여 신도시 건설이전의 어류분포상을 조사하였다. 분당지구에는 잉어과 8종, 기름종개과 4종, 메기과, 뱀장어과, 송사리과, 드렁허리과, 극락어과, 구굴무치과 및 둑중개과 각 1 종을 포함하여 9 개과 19종이 분포하고 있었다. 최근 환경오염으로 감소추세에 있는 송사리, 드렁허리 및 버들 붕어가 이 지역에 존재한다는 것은 주목할 만한 것으로 특히 늪말지역의 늪지대는 신도시 건설 후에도 현재의 환경을 보존하여 이 지역 초, 중, 고등학교의 어류생태학 교육장으로 활용함이 좋을 것이다. 따라서 이 지역의 각별한 보호와 분별있는 개발이 요망된다. The freshwater fish fauna of Bundang Region, Kyungki-do, Korea, where dramatic environmental changes will be expected due to new city project, was censused to establish base line data for natural conservation program. Nineteen species belonging to 9 families were collected in this region. They were mainly cyprinids and cobitids. The Oryzias latipes, Monopterus albus, and Macropodus chinensis which are rare fish in recent years were found in this region. A swamp region called Neupmal is of particular interest in ichthyology excursion site for primary, middle and high school boy. Therefore, careful organization of new city plan and preservation of ichthyological fauna are strongly recommended.

제조합 대장균에서 과발현된 Citrobacter freundii KCTC2006 유래의 β-Tyrosinase를 이용한 3,4-Dihydroxyphenyl-L-alanine의 생산

이승구,노현수,홍승표,이규종,왕지원,태동년,엄기남,방상구,김영준,성문희 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.1

재조합 대장균에서 대량발현 시킨 Citrobacter freundii KCTC 2006 유래이 효소 β-tyrosinase를 이용하여 pyrocatechol, sodium pyruvate, ammonium acetate로부터 3,4-dihydroxy phenyl-L-alanine을 생산하기 위한 연구를 수행하였다. 이 효소반응에 적합한 온도 및 pH 조건은 각각 18℃와 8.5로 결정되었고, 반응액 중의 ammonium acetate와 sodium pyruvate의 농도는 각각 300 mM, 50 mM 이상으로 조절하는 것이 적합하였다. Pyrocatechol의 경우는 20 mM에서 가장 높은 반응성을 나타냈으나, 기질을 반복적으로 첨가하며 장시간 동안 효소반응을 수행하는 경우에는 pyrocatechol의 고갈을 피하기 위하여, 20 mM에서 50 mM 사이로 조절하였다. 한편, 반응액 중에 ethanol을 10% 첨가한 경우에는 반응속도가약 20% 증가하였다. 이상과 같은 효소반응특성에 기초하여 조제한 기질용액에 β-tyrosinase를 1 unit/㎖ 농도로 가하고, pyrocatechol과 pyruvate가 고갈되지 않도록 간헐적으로 첨가하면서 효소반응을 수행한 결과, 24시간 만에 85.2%의 수율로 31.6g/ℓ의 3,4-dihydroxyphenyl-L-alanine를 생산할 수 있었다. By using the β-tyrosinase of Citrobacter freundii KCTC2006, which was cloned and overexpressed in Escherichia coli, 3,4-dihydroxy phenyl-L-alanine (L-DOPA) was synthesized efficiently from pyrocatechol, sodium pyruvate, and ammonium acetate. Optimal temperature and pH for the reaction were determined to be about 18℃ and 8.5, respectively. The effects of substrate concentrations were also examined at different concentrations of ammonium acetate, sodium pyruvate, and pyrocatechol. Ammonium acetate and sodium pyruvate increased the reaction rate until the concentrations reached to 300 mM and 50 mM, respectively. Although pyrocatechol showed the optimal concentration at 20 mM, it was controlled between 20 mM and 50 mM to avoid the depletion of substrate during the enzymatic synthesis. Based on above results, a reaction medium for the production of L-DOPA was prepared and incubated with 1 unit/㎖ of β-tyrosinase. Pyrocatechol and sodium pyruvate was added to the reaction solution intermittently to avoid the substrate depletion during the enzymatic reaction. After 24 hour of reaction, 31.6 g/ℓ L-DOPA was accumulated in the reaction solution as soluble and precipitated ones and the conversion yield was about 85.2%.

랫드에서 신우황청심원의 급성 및 아급성독성시험

오승민,남혜윤,김준수,연제덕,신대희,이진영,박대규,조명행,정규혁 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1

The acute and subacute toxicity of New Woohwangchungsimwon(NWCH) which was used l-muscone as substitutive material of musk were investigated in S.D. rats. In intraperitoneal acute toxicity test, rats(Sprague-Dawley, SPF) were injected intraperitoneally with dosages of 0, 540, 750, 1,070, 1,500 and 3,000 ㎎/㎏. Body weights were significantly decreased at 540 ㎎/㎏ dose group in both sexes and abnormal autopsy findings were founded in both sexes at all treated groups. Intraperitoneal LD_50 of NWCH was 812.3 ㎎/㎏ in male and 872.3 ㎎/㎏ in female rats. In the subacute toxicity study, NWCH was administrated orally to both sexes of rats for 4 weeks as several doses(0, 320, 800 and 2,000 ㎎/㎏). There were neither dead animals nor significant changes of body weights during the experimental period. In addition, no differences were found between control and treated groups in clinical signs, urinalysis, hematology, serum biochemical analysis, and other findings. Above data strongly suggest that no observed adverse effect level of NWCH might be over 2,000 ㎎/㎏/day in this study.

패밀리 레스토랑 서비스 인카운터에 관한 연구

유정남,박정영,조남재,김승희 경기대학교 부설 소성종합관광연구소 2002 여가관광연구 Vol.6 No.-

의복유형과 헤어스타일이 남성의 인상형성에 미치는 영향

임남영,강승희 服飾文化學會 2003 服飾文化硏究 Vol.11 No.3

The purpose of this study was to examine the effect of clothing type and hair style on men's impression formation. The experimental design was 4×2×2×2 (clothing type×hair style×perceiver's age×perceiver's role)factorial design with between-subjects design. The stimuli of color photographs of male in his 20's model and semantic differential scale were used. The data were obtained from questionnaires completed by 881 men and women in the metropolitan area of Seoul. The SPSS package was used for data analysis which includes factor analysis, t-test, and Cronbach's a to measure the reliability. This study showed the following results. Four factors were derived to account for the dimensions of impression formation. These were dignity, activity, individual character, and social intercourse. Men evaluated individual character factor higher than women did. Dignity factor was evaluated higher by students, while social intercourse factor was evaluated higher by office workers. The clothing type of shirts/pants was evaluated to be more active and more sociable than of jacket/pants. Men wanted to exhibit natty image and women did elegant image through clothes.