• 제목/요약/키워드: fence

검색결과 434건 처리시간 0.025초

AC PDP의 새로운 전극구조에 따른 전기.광학적 특성연구 (The study on the electrical and optical characteristics of the new electrode structure for AC PDP)

  • 허민녕;김군호;김동현;김규섭;이호준;박정후
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1579-1581
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    • 2001
  • Nowadays, the most serious problems in AC PDP are high cost and a complex manufacturing process. To solve these problems, Fence electrode structure are newly suggested. In this paper, we investigated the the electrical and optical characteristics as the structure of Fence electrode was changed, and suggested the optimum width and arrangement of electrode.

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블레이드 앞전 3차원 형상 변형에 의한 터빈 캐스케이드 내의 이차유동 제어 (Secondary flow Control in the Turbine Cascade with the Three-Dimensional Modification of Blade Leading Edge)

  • 김정래;문영준;정진택
    • 대한기계학회논문집B
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    • 제26권11호
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    • pp.1552-1558
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    • 2002
  • The blade leading edge is modified to control the secondary flow generated in the turbine cascade with fence by intensifying the suction side branch of the horseshoe vortex. The incompressible Navier-Stokes equations are numerically solved with a high Reynolds number k-$\varepsilon$ turbulence closure model for investigating the vortical flows in the turbine cascade. The computational results of total pressure loss coefficients in the wake region are first compared with experiments for validation. The structure and strength of the passage vortex near the suction surface are examined by testing various geometrical parameters of the turbine blade leading edge.

고무하우징을 갖는 장력센서의 변형거동 해석 (Stress Analysis of a Tension Sensor with a Rubber Housing for a Fence Intrusion Detection System)

  • 이형욱;장광걸;허훈;강대임
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집A
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    • pp.698-703
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    • 2001
  • This paper is concerned with the nonlinear hyperelastic problem fur the incompressible characteristics of the rubber. Tension sensor is a strain gage type load cell element for a fence intrusion detection system and consists of the sensing part and the rubber housing. The analysis includes an elastic analysis and a hyperelastic analysis of a tension sensor for the deformed shape and variation of the maximum strain on the sensing part with respect to the vertical load. Numerical results show that the hyperelastic model is stiffer and less deformed than the elastic model. Comparing with the experimental test data, we know the hyperelastic model is the better approximation than the elastic model.

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154kV 변전소의 전자계와 유도전압계산 (The calculatation of induced voltages and electromagnetic fields in 154kV sub)

  • 최창혁;한풍
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 E
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    • pp.1659-1662
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    • 1998
  • This paper is to analyze electromagnetic fields on a 154kV substation system and induced voltages on the substation fence when the network is operating in a normal condition or a fault condition in which one phase is shorted with the overhead ground wire. Also, changing the scalar potential and electromagnetic fields that are changed in accordance with changing resistivity and permeability of ground are studied. A finding of the study is that the scalar potential and electromagnetic fields are raised near the tower: The values of electric field on the corner of fence and at the edge of the ground grid are higher than other locations.

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저가형 GPS 기반 가상펜스 시스템 경계영역설정 알고리즘 (Border Algorithm for Virtual Fence Based on Low Cost GSP)

  • 나대영;전흥석;이철원
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2017년도 제56차 하계학술대회논문집 25권2호
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    • pp.368-371
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    • 2017
  • 본 논문에서는 GPS기반 가상펜스 시스템과 가상펜스 알고리즘에 대해서 이야기하고, GPS기반 가상펜스 시스템에서 가축의 이탈을 방지하기 위해 설정하는 영역인 경계영역을 설정하기 위한 알고리즘을 제안한다. 그리고 경계영역을 설정하기 위해 필요한 파라미터를 정의하는 실험을 진행하였으며, 속력이 빨라지면 정확도가 증가하는 GPS의 특성에 의해서 가상펜스 시스템에서 가상펜스 디바이스의 안전지역 이탈시 자극이 발생하는 시간이 빨라짐을 확인할 수 있었다.

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An Experimental Study for Noise Reduction of the Cross-Flow Fan of the Room Air-Conditioners

  • Koo, Hyoung-Mo
    • International Journal of Air-Conditioning and Refrigeration
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    • 제8권2호
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    • pp.89-100
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    • 2000
  • Present study explains some experimental results on the aerodynamic noise of the cross-flow fan usually installed in the indoor unit of the room air-conditioners and provides a simple reduction method of radiating sound to decrease the total noise level. The spectra of the noise of the cross-flow fan were analyzed by the spectral decomposition method to characterize the generated sound. The unsteady fluctuating flow field was also measured using the I-type hot-wire probe. Comparing the spectral characteristics of the sound and the flow velocity, a useful noise reduction method was proposed, which bounds the region with a fence where the flow fluctuations were noticeably changed in the same fashion as the source spectral distribution functions vary. To validate the proposed method for reducing noise generated by the cross-flow fan, the sound pressure levels of the cross-flow fan system were compared with and without the bounding fence for various flow rates.

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다중 채널 동축 케이블의 초고주파 측정용 보드 설계 (A Design of Microwave Measurement Board for Multi-channel Coaxial Cable Assembly)

  • 문수덕;김진규;황희용
    • 산업기술연구
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    • 제27권A호
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    • pp.169-175
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    • 2007
  • In High-Speed DSP systems, crosstalk between transmission lines of multi-channel can degrade the performance of equipment operations. This paper presents a microwave board to measure multi-channel coaxial cable assembly. The designed board has good performances from DC to 3 GHz, which have improved characteristic impedance, reduced crosstalk by using via fence, and low transmission loss. Using the designed board, we can measure characteristics of DUT(Device Under Test) such as return loss, insertion loss, crosstalk phase delay, and characteristic impedance. The measured results are used to improve performances of a produced coaxial cable assembly.

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신개념 낙석방지울타리의 낙석 지지능력 평가 (Energy Absorbing Capacity for New Rockfall Protection Fence)

  • 문영종;정형조;박기준;이인원
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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    • pp.293-298
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    • 2003
  • The rockfall protection fences are installed to reduce rockfall damage in roads side slopes. The energy absorbing capacity of widely used rockfall protection fences is about 50kJ, But in many cases, rockfall protection fences are easily damaged even by a low level of rockfall energy. The objective of this paper is to verify the energy absorbing capacity of rockfall protection fences and investigate the behavior of them by rockfall. The LS-DYNA3D, a finite elements analysis program for dynamic movement of three dimensional objects, is used to perform the numerical simulations. In the result it is shown that rockfall protection fences absorb half of standard absorbing energy or less than it. It is inadquate for the rockfall protection fences to perform the principal function. To improve the performance of the fences, new rockfall proctection fence is proposed and numerical simulation is performed.

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에어컨용 직교류홴의 저소음화를 위한 실험적 연구 (An experimental study for noise reduction of the cross-flow fan of the room air-conditioners)

  • 구형모
    • 설비공학논문집
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    • 제11권6호
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    • pp.871-879
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    • 1999
  • Present study explains some experimental results on the aerodynamic noise of the cross-flow fan usually installed in the indoor unit of the room air-conditioners and provides a simple reduction method of radiating sound to decrease the total noise level. The spectrums of the noise of the cross-flow fan were analyzed by the spectral decomposition method to characterize the generated sound. The unsteady fluctuating flow field was also measured using the I-type hot-wire probe. Comparing the spectral characteristics of the sound and the flow velocity, a useful noise reduction method was proposed which bounds the region with a fence where the flow fluctuations were noticeably changed in the same fashion as the source spectral distribution functions vary. To validate the proposed method for reducing noise generated by the cross-flow fan, the sound pressure levels of the cross-flow fan system were compared of the experimental rig with and without the bounding fence for various flow rates.

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대기 경계층내에서 바람에 의해 발생되는 부유 물질 제어를 위한 Windbreaks의 풍동 시뮬레이션 (Wind-Tunnel Simulation of Windbreaks to Control Windblown Dusts in the Atmospheric Boundary layer)

  • 강건
    • 한국환경과학회지
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    • 제4권1호
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    • pp.29-40
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    • 1995
  • Transport rate of windblown dusts such as soil, sand, snow is proportionate to $U*_^3 and U_*$, friction velocity, approximately to flow velocity of ink Therefore, through measurement and the flow velocity of wind, it turned out that, considering different velocity distributions caused by downstream distance and porosity percent, windbreaks with appropriate porosity rate to the Protection area should be chosen for the optimal fence effect. In the economic respects better are fences with gap of 20%~30%. Among the windbreaks to have the optimal fence effect.

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