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연료전지 발전시스템 구현을 위한 전력변환장치 하드웨어 세부설계 (Detailed Design of Power Conversion Device Hardware for Realization of Fuel Cell Power Generation System)

  • 윤용호
    • 한국인터넷방송통신학회논문지
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    • 제22권1호
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    • pp.135-140
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    • 2022
  • 연료전지 발전시스템은 수소와 산소의 반응 작용에 의해 직접 전기를 발생하는 스택(Stack) 이외에 메탄올, 천연가스 등 각종 연료로부터 수소를 만들어 내는 개질기와 스택에서 발전된 직류전압을 안정된 교류전압으로 변환시켜주는 전력변환기 등으로 구성되어진다. 이러한 시스템의 연료전지 출력은 직류로 가정에서 사용하기 위해서는 전력변환장치를 통하여 교류로 변환시키는 인버터 장치가 필요하다. 또한 연료전지 전압이 30-70V 정도로 이를 인버터 동작 전압인 380V 정도로 승압하기 위하여 DC-DC 승압형 컨버터를 사용한다. DC-DC 승압형 컨버터는 연료전지 출력과 인버터 사이에 존재하는 직류전압 가변장치로 연료전지 출력전압의 변동에 반응하여 컨버터의 일정 출력전압을 만들어 내므로 인버터는 연료전지의 전압 변동에 무관하게 일정한 전원을 공급 받을 수 있다. 따라서 본 논문에서는 연료전지발전 시스템의 구성 원 중 연료전지 출력전압(30-70V)을 입력으로 받아 계통연계에 적용되는 인버터의 주요 전원인 풀 브리지(Full-Bridge) 컨버터의 하드웨어 세부설계에 대하여 논하고자 한다.

의류제조업체의 패션 정보활동에 관한 연구 (A Study on the Fashion Information Activities of Clothing Manufactures)

  • 송미령
    • 복식
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    • 제22권
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    • pp.135-158
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    • 1994
  • The fashion industry of today is closely re-lated with the information activity. This study investigates now they take advantage of the fashion information by analysing some related fields including fashion design. Furthormore this study identify the factor which makes the design activity distinctive and predict and fu-ture trend in design. The purposes of this study through analysis are : to help find the way to facilitate the fashion industry and to develop the fashion merchandising in order to activate the re-cession of manufacturers and to improve competitiveness in the world market and to contribute to the academic achievement in the study of fashion merchandising. In the experimental approach the tasks of research are as follows: Research 1: The application of fashion infor-mation is discussed in terms of process and level. Research 2: The differences of the fashion design activities are captured on the basis of the characteristics of manufactures and fashion specialists and fashion information ac-tivities. The factors are identified which pre-dict and discriminate the results of fashion de-sign activities. The questionaire and interview were conduc-ted among women's clothing manufactures in Seoul and their fashion specialists in charge of merchandise development. The methods of survey were designed on the basis of theories developed so far and on he advice from the social scientists and fashion specialists. the methods were corrected and complemented through the 1st and 2nd preliminary investigations before their application For data analysis cronbach's a coefficient fre-quency percentage average standard devi-ation pearson's correlation coefficient were calculated and t-test F-test(ANOVA) Duncan's multiple range test regression and Discriminant analysis were conducted. The results of analysis throughout the experimen-tal studies were as follows: 1. The analysis of fashion in formation (1) the present application of information a. The source of information : Both the foreign and the domestic information came mostly from fashion journals magazines newspapers and other periodicals, the main source of market information was collected from the survey of popular items in recent years the data about the life-style of customers and their tastes for wearing were widely used as the information about consumers. b. The applicaton of information : The most widely used information was about fabrics. The foreign information was prefered on the whole. The domestic problems pointed out in this investgation were that the domestic journals showed the lack of specialty and the special organizations for fashion informatino were in urgent need. (2) The research of fashion information a. The various processes and levels of in-formation activities: Among the process of collection analysis and distribution the collec-tion process showed a good acheivement whereas the distribution whereas the distribution didn't. In levels of the systematic activities the acceptance of support and the utility of supported instruments the first indicated a high degree whereas the second showed lowest. b. The correlationship among subvariables : There was a significant correlation between the collection and the analysis process. The systematic activities revealed close relation-ship with the analysis process and the accept-ance of support with the distribution process. The close correlation was found between the utility of supported instruments and the analy-sis process. 2. The analysis of the fashion design activities (1) No significant differences were found in the design activities when the characteristics of companies were compared only. (2) According to the characteristics of fashion specialists the one with age experi-ence and high income showed rather good achievement but no significant differences were captured among sex department in charge title academic background education in abroad and field experience (3) The fashion information activities were strongly correlated with the design achieve-ment : The analysis process and the system-atic activity level had a great influence on the design activities. (4) In order to examine which cha-racteristics in (1-3) made it possible to pre-dct and discriminate the achievement in de-sign activities the Discriminant analysis was carried out. The results were as follows: the fashion information activities showed the highest discriminant rate. Next came the in-come level experience and age in that order Those four variables discrimated 37 from 50 who showed great achievement in design area (74%) and 51 from 83 in low achievement group (81%) Thus the total discriminant rate was 77.5%.

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채소류 모잘록병균에 길항하는 Bacillus ehimensis YJ-37의 대량배양 최적조건 (Optimization of Large Scale Culture Conditions of Bacillus ehimensis YJ-37 Antagonistic to Vegetables Damping-off Fungi)

  • 주길재;김진호
    • 생명과학회지
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    • 제12권3호
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    • pp.242-249
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    • 2002
  • 본 연구는 채소류 모잘록병균인 R. solani AG4에 길항하는 미생물 B. ehimensis YJ-37의 500$m\ell$ 플라스크 배양, 5 $\ell$ jar fermentor 배양, 2,000 $\ell$ 대형탱크의 배양 조건 및 길항물질 생성능을 조사하였다. 500$m\ell$ 플라스크 배양에서의 길항물질 최적생산조건은 1.5% starch, 0.6% peptone, 0.3% $Na_2$HP $O_4$, 0.15% MgC1$_2$, pH 8.0, 배양온도 32$^{\circ}C$, 배양시간 54시간으로 나타났고, 이때 미생물의 수는 1.42$\times$$10^{ 8}$ cfu/$m\ell$21g-DCW/$\ell$), 항진균 활성은 13.9mm로 나타났다. 5$\ell$ jar fermenter 배양에서의 길항물질 최적생산조건은 플라스크배양에서의 최적 생산조건에서 공기주입량과 교반속도를 변화시켜 조사한 결과, 공기주입량 2 vvm, 교반속도 200 rpm, 배양시간 48시간 이후 미생물의 수와 균체의 량은 2.06 $\times$ $10^{8}$ cfu/$m\ell$ 및 30g-DCW/$\ell$, 항진균 활성은 13.4 mm로 나타났다. 2,000 $\ell$ 대형탱크 배양에서는 교반속도 200 rpm, 산소주입량 30 vvm으로 고정하고 10일간 배양하여 미생물의 생육 및 길항물질 생성능을 조사한 결과는 미생물의 수와 균체의 량은 0.81 $\times$ $10^{8}$ cfu/$m\ell$와 12g-DCW/$\ell$, 항진균 활성은 8.6mm로 나타나 5$\ell$ jar fermenter 배양에 배해 균의 수는 1/10로 줄었으며 항진균 활성도 64%로 낮게 나타났다.다.