• 설비공학논문집
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• 제26권11호
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• pp.512-521
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• 2014

Recently, multiple glazing units, frames, complex fenestration systems, and windows with shading devices have been developed to save cooling energy in buildings. However, very little work has been conducted on developing a direct experimental test method of the solar heat gain coefficient(SHGC) for new fenestration techniques. This study aims to develop and evaluate a test apparatus to measure the SHGC, according to the KS L 9107 test method. The performance of the solar simulator was class A, B, and A, for spectral match, non-uniformity, and instability irradiance, respectively. The differences between the measured and calculated SHGC values were found to range between 0.001 and 0.011, and for all test specimens they agreed within 4%. These results establish the validity of the test apparatus. This system is thus expected to be useful in assessing the energy performance for various types of fenestration.

• 대한기계학회논문집
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• 제11권2호
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• pp.234-242
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• 1987

본 논문에서는 변분법으로 유도한 최적조건을 수치계산에 적용키 위해 영역적 응법이 사용되었으며 불규칙한 형상의 방지에는 격자 적응법이 제시되었다. 설계 문 제로는 '국부 응력치의 일정 한도내에서 구조물 무게의 최소화' 또는 대등한 문제로 '제한된 구조물의 무게한도내에서 최대 국부응력치의 최소화'를 다루었다.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.437-441
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• 2022

In this study, we developed a neutron time-of-flight (nTOF) measurement system for a 1.7-MV tandem proton accelerator with a target covered with 300-nm-thick lithium (Li) layer. With implementation of beam chopping module after its ion source, the accelerator is configured to operate in pulsed-beam mode with a pulse width <50 ns at 20-kHz repetition rate. This enables the gamma flash-type nTOF measurement system to identify the neutron generated with 3-MeV proton beam energy. The nTOF system consists of a 30" cylindrical NaI(Tl) and four stilbene scintillation detectors. The NaI(Tl) scintillator is placed 50 cm from the Li target to measure the time of beam irradiation on the target, and the stilbene detectors are placed 2 and 2.4 m away to measure nTOF at each location. The nTOF system successfully measured the generated neutron energy at irradiated proton energies of 2.6 and 3.0 MeV with an average energy resolution of 15%.

• 비파괴검사학회지
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• 제34권4호
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• pp.290-298
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• 2014

초음파 두께 측정 방법은 초음파가 표면에서 되돌아오는 시간을 측정하여 두께를 측정하는 비파괴검사 방법이다. 이때 초음파 진행 시간은 펄스의 최대값을 이용하여 측정하기 때문에, 물체의 두께가 얇을 경우 펄스 신호가 서로 중첩이 되어 기존의 초음파 방법으로 측정하기 어렵다는 단점이 있다. 이러한 단점을 보완하기 위해 본 논문에서는 파워켑스트럼과 최소분산켑스트럼을 사용하여 두께를 측정하는 방법을 제안하고자 한다. 켑스트럼 신호 처리는 초음파 신호를 임펄스 트레인과 전달함수(초음파 펄스 신호)로 분리하기 때문에 표면에서 돌아오는 초음파 신호의 시간을 임펄스 트레인의 주기로 정확하게 측정할 수 있다. 제안된 방법을 검증하기 위하여 다양한 두께를 가진 철, 아크릴 시편에 대해 실험을 수행하였다. 두께가 얇은 시편에 대해서는 펄스가 중첩이 되기 때문에 기존방법으로 측정이 어려움을 알 수 있었다. 하지만 제안된 방법인 켑스트럼 초음파 신호 처리를 적용한 결과 임펄스 신호로 분리하기 때문에 두께를 정확히 측정함을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.272-272
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• 2012

Additional neutral particle analyzer has been installed to investigate the variation of fast ion tails with regard to the line of sight during 2012 KSTAR campaign. The system has the same photo-diode particle detector as previous system [1]. Both newly installed system and previous system modifield for 2012 campaign have two channels. One has a particle stopper transparent to hard X-ray, the other has no one. It will be used to separate the hard X-ray component from total hard X-ray and fast neutral counts. It is expected to measure fast ion tails more clearly through this extended system. A detailed system and calibration result will be presented in the conference.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.225-227
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• 2004

A sensor networkis composed of a large number of sensor nodes, which are densely deployed either inside the phenomenon or very close to it. One of the most important constraints on sensor nodes is the low power consumption requirement. Sensor nodes carry limited, generally irreplaceable, power sources. Therefore, while traditional networks aim to achieve high quality of service (QoS) provisions, sensor network protocols must focus primarily on power conservation. This paper presents the characteristics of energy consuming, average delay in 802.11 MAC, S-MAC that is specifically designed for wireless sensor networks. We analyze the energy consuming state in the 802.11 MAC in the simulation topology nodes, and measure average delay in 802.11 and S-MAC. Energy efficiency is the primary goal in this protocol design. 802.11 MAC is more efficient than S-MAC in the average delay, throughput. However S-MAC is an energy efficient protocol, a tradeoff between energy efficiency and delay.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.157_158
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• 2009

Recently, the growth of electric railway technology steadily keep up in the korea, and occupancy rate of electric railway system increased as a transportation method so energy consumption of railway system is increasing. According to this reason, the many studys of energy consumption in the railway system are in progress. In this context, the TTX(Tilting Train eXpress) needs to measure and analyze energy consumption and regenerative energy. In this paper, because of driving of TTX in the Ho-Nam railroad and Jung-Ang railroad, consumpted and regenerated energy are measured. This measured data is classified and analyzed as driving mode.

• 전기학회논문지
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• 제56권12호
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• pp.2122-2126
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• 2007

A special PM-Tube(Photo Multiplier Tube) that is using the photoelectric effect has been designed and manufactured to measure the radiation energy of arc in a gas circuit breaker(GCB). The PM-Tube, LLG(liquid light guides), ND(neutral density) filter, and a model gas circuit breaker have been combined for the reception and the transmission of the light and a simplified synthetic test facility with the arc energy measuring system has been established. In the case of $SF_6$ gas pressure $5kg.f/cm^2$ and arc length 20mm, the radiation energy increases with the arc current but it tend to be saturated in the above 20kA. Under the arc current 20kA, the total radiation energy has the biggest value around 8kA and was not exceeded 40% of the total arc energy.

• Journal of Magnetics
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• 제18권3호
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• pp.250-254
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• 2013

In this research, the linear electrical generator in wave energy farm utilizing resonance power buoy system is studied. The mechanical resonance characteristics of the buoy and the wave are analyzed to maximize the kinetic energy in a relatively small wave energy area where WRPS is operated. In this research, we chose an analog model of the linear electrical generator of which size is one-hundredth of an actual size of it in WPRS (Wave energy farm utilizing Resonance Power buoy System) prior to verifying the characteristics of actual model of linear electrical generator in WRPS. In addition, the finite element analysis is conducted using commercial electromagnetic analysis software named MAXWELL to examine the electric characteristic of linear generator. Finally, for the verification of dynamic and electric characteristics of linear generator, the prototype was manufactured and the experiments to measure the displacement and the output electric power were performed.

• 환경정책연구
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• 제11권1호
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• pp.75-97
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• 2012

본 논문의 목적은 OECD국가를 중심으로 온실가스 감축에 대비하여 에너지 원단위(原單位) 측정의 다른 방법으로서 에너지효율함수와 원단위의 효율함수의 추정을 통하여 에너지효율을 측정하는 것이다. 실증결과는 기존의 전통적 에너지원단위와 확률변경함수에 의한 에너지 효율이 크게 연관되어 있지 않았음을 보여준다. 에너지효율 함수와 원단위 효율함수의 효율도 다소 상이하였다. 에너지 투입효율함수에 의한 에너지효율은 GDP, 자본스톡, 노동, 에너지투입량의 순서로 민감하게 반응하는 것으로 보인다. 향후 투입요소 간 최적 결합을 통한 에너지 절감이 필요하고 에너지 소비가 작은 제품의 생산을 통한 저탄소 경제성장의 추구가 요구된다