• Title/Summary/Keyword: IkB

검색결과 841건 처리시간 0.028초

PCB 캐패시터를 이용한 플라이백 SMPS 출력 리플 저감 대책 (A utilization of PCB capacitor to reduce the output voltage ripple in Flyback SMPS)

  • 김태근;정교범;이완윤
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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    • pp.102-105
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    • 2003
  • The leakage inductance of the High frequency Transformer(HFT) in the flyback topology can be used an inductor of the Low Pass Filter(LPF) to reduce ripple and ripple noise in the output voltage. But, the values of leakage inductance and magnetizing inductance in the HFT are within $\pm20[{\%}]$). And the operating temperature of the HFT increased by the leakage inductance. Therefore, the leakage inductance of the HFT in the flyback topology has minimum and the LPF has non-polarity ceramic capacitor in the output stage. In this paper, the LPF in the flyback topoBogy takes PCB capacitor using double layer of PCB without non-polarity ceramic capacitor. Its experimental results show the reduced ripple noise and the reduced ripple in the output stage.

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Enhancement of the luminous efficiency of organic light-emitting diodes utilizing a wide-bandgap impurity doped emitting layer

  • Choo, D.C.;Bang, H.S.;Kwack, B.C.;Kim, T.W.;Seo, J.H.;Kim, Y.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1447-1450
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    • 2007
  • The electrical properties of organic lightemitting devices (OLEDs) with wide-bandgap impurity-doped emitting layers (EML) were investigated. While the luminous efficiency of OLEDs with a NPB or a DPVBi-doped $Alq_3$ EML did not vary significantly with the current density, that of the OLEDs with a BCP-doped $Alq_3$ EML changed dramatically.

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경쟁적 전력시장에서 혼잡을 고려한 송전설비계획 기준설정에 관한 연구 (A Study on a Criterion of Transmission Planning in a Competitive Electricity Market)

  • 김종만;한석만;김발호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.866-868
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    • 2005
  • In a competitive environment of electric power industry, developing the technological criterions and methodologies on transmission planning is becoming new challenge to transmission system planner. The use of a locational signal and the provision of a indicative plan to control the transmission investment reasonably is very important in the viewpoint of a regulator. The main target of this study is to develop a systematic criterion of transmission expansion planning. And system congestion cost is considered. The proposed methodology was demonstrated with several case studies.

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태양 중분산 분광 망원경 개발 (DEVELOPMEMT OF MID-RESOLUTION SOLAR SPECTROSCOPIC SYSTEM)

  • 조경석;조경석;문용재;장비호;김수진;김연한
    • 천문학논총
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    • 제18권1호
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    • pp.61-67
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    • 2003
  • In 2002, a new solar spectroscopic system with the Coelostat type has been installed at Korea Astronomical Observatory. It was designed to observe solar spectra in the range from 3000 to 8000${\AA}$ with the spectral resolution of 1${\AA}$/mm. The system is composed of a 40cm diameter Coelostat with 9m focal length, spectroscopic system with 600groove/mm grating, and a IK ${\times}$ IK CCD detector. By developing observational softwares for this system, we have successfully observed solar Ha spectra. In this paper, we development of telescope control and observational softwares.

ATSC 3.0 기반 모바일HD 물리계층 필드테스트 결과: 제주테크노파크 100W 실험국과 제주시내 이동측정을 위주로

  • 전성호;임보미;박성익;이재권;장진영;이권익
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2017년도 추계학술대회
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    • pp.28-31
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    • 2017
  • 지상파 방송 3사(KBS/MBC/SBS) 수도권 본방송 파라미터와 동일하게 설정한 제주테크노파크 100W 실험국에서 ATSC 3.0 신호를 발사한 뒤, 제주시내 일대를 이동하면서 양시청 여부는 물론 실측값을 수집하였다. 결론적으로, 현재 전송파라미터 구성으로 송수신 정합에 이상 없이, 기술적인 관점에서 수도권 모바일HD 본방송이 가능함을 검증하였고, 커버리지 산출에 필수적인 물리계층 성능 지표인 ESR5에 대한 기준값, 즉 변조오류율(MER) 기준으로 11.3dB, 수신 신호 세기(Level) 기준으로 -85.0dBm 정도임을 도출하였다.

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부하동특성 해석을 위한 유도전동기의 최적 축약법 (Optimal Aggregation of Induction Motors for Analysis of Load Dynamics)

  • 이종수;이봉용;정태호;이상중
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1990년도 하계학술대회 논문집
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    • pp.113-120
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    • 1990
  • This paper presents a new aggregation method of induction motors for the load flow and transient stability analysis. The proposed method aggregates a group of motors into a single motor considering the variations of the system voltage and frequency so that the aggregated model represents the dynamic characteristics of the system accurately. The performance of the Method is shown by numerical simulation and is compared with that of LOADSYN algorithm.

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영구자석을 이용한 상전도 자기 부상 열차용 전자석 개발 연구 (Development of a hybrid-type magnet for MAGLEV vehicle using permanent magnet)

  • 이석원;신판석;정현갑;김봉섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 A
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    • pp.308-311
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    • 1998
  • Experiments and design efforts have been made to develope a hybrid-type magnet for magnetically levitated(MAGLEV) vehicle using NdFeB permanent magnet. The permanent magnet, which embedded in both poles of the magnet, has been designed, analyzed using FEM program. The model is manufactured and tested to verify its performance.

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Use-Case Approach 기반의 Test Case 추출을 위한 아두이노 펌웨어 설계 연구 (A Study on Arduino Firmware Design for Test Case Extraction based on Use-Case Approach)

  • 장우성;박병호;김영철;박용범
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2013년도 추계학술발표대회
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    • pp.1015-1018
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    • 2013
  • 최근 임베디드 펌웨어를 객체 지향 어플리케이션과 함께 개발하는 경우가 증가하고 있다. 하지만 기존의 펌웨어는 절차적 설계를 기반으로 하기 때문에 어플리케이션과 다른 설계 기법이 필요하여 개발 비용과 테스트 비용이 증가한다. 그렇지만 아두이노를 사용하면 펌웨어를 객체 지향 설계가 가능하다. 본 논문은 객체지향 적용 펌웨어를 설계에 초점을 두고, Gary E.Mogyorodi의 Test Case 생성 방법을 적용하여, 실제 펌웨어를 시험을 하고자 한다. 이 방법이 가능하면 일반적인 펌웨어와 어플리케이션을 같은 방법으로 설계 및 테스트가 가능하다. 적용사례로써, 한백전자 HBE-SmartCAR의 펌웨어를 아두이노 기반으로 설계 및 추출된 Test Case 실행을 통해, 설계와 구현이 동일함을 검증이 가능하다.

인삼열매추출물의 용매분획물이 LPS로 유도된 RAW264.7 세포에 대한 항염활성 (Anti-inflammatory Activity of Solvent Fractions from Ginseng Berry Extract in LPS-Induced RAW264.7 Cells)

  • 이가순;김관후;성봉재;김선익;한승호;이석수;양혜;유영춘
    • 한국약용작물학회지
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    • 제22권6호
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    • pp.449-456
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    • 2014
  • Anti-inflammatory activity of the extracts of ginseng berry (GBE) was investigated through the evaluation of its inhibitory effect on the production of inflammatory meditator, nitric oxide(NO), tumor necrocis factor-alpha (TNF-${\alpha}$), interleukin-6 (IL-6) in LPS-induced RAW264.7 macrophage cells. GBE was fractionated using n-hexane, chloroform, ethylacetate, buthanol and $H_2O$, sequentially. RAW264.7 cells were induced $100ng/m{\ell}$ of lipopolysaccharide (LPS) and treated with 0, 1.6, 8, 40 and $200{\mu}g/m{\ell}$ of GBE fractions. LPS-induced NO production on all of GBE fractions was inhibited with increasing added concentration of GBE fractions. Chloroform fraction of GBE was the most effective in inhibiting LPS-induced TNF-${\alpha}$ production. Hexane, chloroform and $H_2O$ fractions of GBE exhibit strong inhibition LPS-induced IL-6 production. Especially, $H_2O$ fractions of GBE was the most effective in inhibiting LPD-induced IL-6 production without significant cytotoxicity in RAW264.7 cells, and reduced the activation of mitogen-activated protein kinases (MAPK) and IkB phosphorylation. These results indicate that $H_2O$ fractions of GBE exhibits strong anti-inflammatory effects by inhibition of NF-kB by inhibition of p-38 on MAPK and IkB phosphorylation.

Interspecific Hybridization of the Bumblebees Bombus ignitus and B. terrestris

  • Yoon, Hyung-Joo;Kim, Seong-Yeol;Lee, Kyeong-Yong;Lee, Sang-Beom;Park, In-Gyun;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제18권1호
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    • pp.41-48
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    • 2009
  • The large bumblebee, Bombus terrestris, indigenous to Europe and used extensively for high-value crop pollination, has been artificially introduced in several parts of the world. Here we show the interspecific hybridization between bumblebee species, B. terrestris and B. ignitus, under laboratory conditions. The mating and oviposition percentages of the interspecific hybridization of a B. terrestris queen with a B. ignitus male were higher than those of the intraspecific mating of B. ignitus. Furthermore, the competitive copulation experiment indicated that the mating of B. ignitus males with B. terrestris queens was 1.8-fold more frequent than with B. ignitus queens. The interspecific hybridization of a B. ignitus queen with a B. terrestris male produced either B. ignitus workers or the B. ignitus male phenotype, and the hybridization of a B. terrestris queen with a B. ignitus male produced B. terrestris males. Genetic tests using a portion of the mitochondrial COI gene for the parent and hybrid phenotypes indicated that mitochondrial DNA in the interspecific hybridization was maternally inherited. Our results indicated that interspecific hybridization occurred between B. ignitus and B. terrestris, which suggests that the hybridization will have a negative impact of competition and genetic pollution of native bumblebees.