• 제목/요약/키워드: Hong Chan-yoo

검색결과 184건 처리시간 0.032초

AC PDP 구동회로의 에너지 회생에 관한 연구 (A Study on the Energy Recovery of AC PDP Driving Circuits)

  • 정우창;강경우;유종걸;홍순찬
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 추계학술대회 논문집
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    • pp.267-270
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    • 2003
  • In this paper, a new energy recovery circuit for AC PDP(Plasma Display Panel) is proposed to decrease a sustain voltage and voltage stress on switching elements. In the proposed circuit, two auxiliary capacitors are connected directly to the power source through switching elements and inductors when ground potential is supplied to the panel. Therefore, the voltage across auxiliary capacitors can be increased by turns over the half of the source voltage. Because the intrinsic capacitance of PDP is charged sufficiently from the auxiliary capacitors, the level of sustain voltage and the voltage stress on the switching devices are decreased. To verify the validity of the proposed energy recovery circuit, computer simulations using PSpice program are carried out.

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스마트 러닝 환경에서 학습자 평가 관리를 위한 웹 및 앱 개발 (Web and App Development for Students' Assessment Management in Smart Learning Environment)

  • 문지은;김병준;박윤하;임혜린;홍유진;반창준;박찬정
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2014년도 추계 종합학술대회 논문집
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    • pp.87-88
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    • 2014
  • 최근 스마트 러닝이 학교현장에서 자리매김하고 스마트 기기도 활용이 됨으로써, 과거에는 수행할 수 없었던 평가방식과 학습활동의 관리가 가능해졌다. 하지만, 아직도 학교현장을 위한 앱이나 웹 프로그램의 개발은 활성화되고 있지 않다. 본 연구에서는 학생들이 수업시간에 직접 스마트기기를 활용하여 학생들의 학습활동을 평가하고 이를 데이터화함으로써 향후 학생들 스스로의 자기관리나 교사들의 학습자 지도에 도움이 될 수 있는 웹응용과 앱을 개발함을 목적으로 한다.

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아파트 내부공간에 대한 거주자 의식 및 평가 (Resident's consiousness and evaluation toward apartment interior space)

  • 지순;이연숙;유성희;오찬옥;최병숙;홍선경
    • 대한가정학회지
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    • 제24권1호
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    • pp.75-93
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    • 1986
  • This research is to understand the residents' responses and evaluation about their apartment interior environment and thereby to be used as the basix data for designing residential space environment of new apartment complex in Sanggae area. The specific obectives of research were 1) to examine the residents' vale and life style concerning several specific rooms, 2) to find out residents' evaluation on physical characteristics, and 3) to understand residents' preference and demand for characteristics of interior space. Research method used was personal interview using a structured questionnaire. Residents living in 13, 15, 18, 22, 25 pyung in three selected large apartment complex areas provided dada : 777 questionnalires were used for analysis. Data were analyzed using the SPSS computer package. The statistics used were frequency, percentage, mean, F-test, χ\sup 2\-test, Duncan's multiple range test, Pearson's correlation coefficient.

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댐, 제방 배수기능 개선을 위한 일방향 배수필터 (One-way Drainage Filter for Drain ability Improvement of Dam and Embankment)

  • 김홍택;유찬호;김현태
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.814-819
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    • 2008
  • 본 연구에서는 기존의 배수필터를 개선함으로써 댐, 제방의 외부 유입 침투수를 차단할 수 있는 일방향 배수필터의 가능성을 확인하였다. 일방향 배수필터는 댐, 제방 내부의 침투수는 외부로 배출시키면서 외부의 유입 침투수는 차단하도록 여러 겹의 시트를 겹치도록 고안한 것으로, 본 연구에서는 일방향 배수필터의 가능성을 확인하고자 실내모형실험을 수행하였다. 실내모형실험을 진행하는 동안 계측되는 간극수압계를 이용하여 모형 댐, 제방의 거동을 확인하여 일방향 배수필터의 적용 가능여부를 확인하였다.

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케이블을 이용한 사면안정 공법 적용성 평가 (An Estimation on Application of Slope Stabilization Method Using PC Strand Cable)

  • 김홍택;백승철;유찬호;장충길;민경남
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.984-991
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    • 2008
  • In this study, to evaluate the slope and tunnel stabilization method using pc cable with bulbed. To estimate the application of tunnel support using field tests and numerical analysis results. The reinforcement effects of slope stabilization method reinforced by PC cables were estimated compared with conventional soil nail system that reinforce the slope using rebar.

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터널 보강재로서의 케이블 볼트의 적용성 평가 (Application on Cable bolt as Tunnel Support System)

  • 김영호;유찬호;한범석;김승욱;김홍택
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.1530-1535
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    • 2009
  • The cable bolt is useful underground space support system such as mining in Europe. In spite of favorable strength characteristics, past record of the cable bolt is rarely in Korea. In this study, to evaluate the mechanically characteristics the cable bolt on tunnel support system. To conduct the laboratory strength test in order to enquire material properties as reinforcement material and numerical analysis was performed considering laboratory test results. To estimate the behavior characteristics on tunnel system in which supported by the cable bolt system and compared the behavior characteristics with the rebar rock bolt system result.

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Method to Enhance Color Gamut up to 89 % in Bottom Emission Active-Matrix Organic Light Emitting Device

  • Kim, Hwa-Kyung;Choi, Hong-Seok;Yoo, Dong-Hee;Kim, Woo-Chan;Yoon, Jong-Geun;Yang, Joong-Whan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.43-46
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    • 2007
  • Though bottom emission AM-OLED has advantages in respect of mass production, the bottom emission type is underrated due to its low aperture ratio and low color gamut, compared with top emission type. In this paper, we demonstrate that the color gamut up to 89 % can be simply achieved by depositing dielectric multilayers, whose thicknesses are determined using an optical simulation program, prior to formation of Si layer.

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고분자전해질형 연료전지의 성능해석 및 효율에 관한 연구 (TA Study on the Performance and the Efficiency in Polymer Electrolyte embrane Fuel Cell)

  • 김홍건;김유신;양성모;나석찬
    • 한국공작기계학회논문집
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    • 제14권4호
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    • pp.75-80
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    • 2005
  • An experimental study is carried out to investigate the performance and the efficiency humidifying Membrane Electrolyte Assembly and having the double-tied catalyst layers in a fuel cell system which is taken into account the physical and thermal concept. Subsequently, an electric output produced by PEMFC(Polymer Electrolyte Membrane Fuel Cell) is measured to assess the performance of a stack, and the efficiency is also evaluated according to the different situation in which unit cell is placed with and without the humidification of the MEA. It is found that the measured values of stack voltage and current are influenced by the stack temperature, humidification, and the double-tied catalyst layers which give more enhanced values to be applied to electric units.

섬유종류에 따른 섬유보강 모르타르의 파괴저감성능 평가 (Evaluation of fracture reduction performance of fiber reinforced mortar according to fiber type)

  • 노종찬;김규용;김홍섭;구경모;윤민호;유재철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2013년도 추계 학술논문 발표대회
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    • pp.38-39
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    • 2013
  • In this study, in regard to fiber reinforced mortar mixing steel fiber and 4types of organic fiber, impact test was carried out. Because to predict fracture reduction performance with flexural, tensile strength when types of fiber were different as impact reduction performance of concrete is closely related with toughness such as flexural strength, tensile strength and fracture energy etc. As a result, enhancement of toughness by fiber reinforcement controls the spall of rear. On the other hand in case of steel fiber relatively turned up high toughness in appropriate load compared with organic fiber but in same mixing rate, impact reduction performance by projectile showed low performance due to few number of an individual of mixing.

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경계전류모드를 사용한 Adapter용 브리지리스 정류회로의 성능 개선 (Performance Improvement of Bridgeless Rectifier Circuit for Adapter Using Boundary Current Mode)

  • 유호원;임승범;정연호;이준영;홍순찬
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2007년도 하계학술대회 논문집
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    • pp.172-174
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    • 2007
  • The AC-DC Adapter has been widely used in Mobile Phones, Note Book PC, LCD monitors, and portable electronic products. Recently, high-power-density Adapter was developed. This adapter increases power factor using a bridge diode rectifier and PFC, however, there are weak points that improving efficiency is limited. In the bridgeless rectifier circuit proposed in this paper, there is no PFC, however, the power factor and efficiency are improved by BCM and ZCS operations.

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