• 드라이브 ㆍ 컨트롤
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• 제2권3호
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• pp.6-13
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• 2005

• 드라이브 ㆍ 컨트롤
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• 제3권2호
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• pp.14-19
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• 2006

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기설비전문위원
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• pp.131-135
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• 2005

Stabilization of electric power is the most important thing is such place as computing center having business critical equipment. However, ability to cope with electrical quality shift and power failure is very weak from UPS output side to load in those electricity system, though UPS is generally used for power stabilization. this problem can be solved by duplication of power source using newly configured UPS and small sized transfer switch even in case of UPS failure.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.683-689
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• 2018

To evaluate equipment survivability of the polymer Viton, used in sealing materials, the effects of its thermal degradation were investigated in severe accident (SA) environment in a nuclear power plant. Viton specimens were prepared and thermally degraded at different SA temperature profiles. Changes in mechanical properties at different temperature profiles in different SA states were investigated. The thermal lag analysis was performed at calculated convective heat transfer conditions to predict the exposure temperature of the polymer inside the safety-related equipment. The polymer that was thermally degraded at postaccident states exhibited the highest change in its mechanical properties, such as tensile strength and elongation.

• 한국콘텐츠학회논문지
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• 제13권3호
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• pp.307-317
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• 2013

본 연구는 연구장비 구축관계에 기반한 사회네트워크 분석을 적용하여 연구기관 네트워크의 구조적인 특성과 지위적인 특성을 분석함으로써 연구장비 정보의 전달과 관련된 연구기관의 역할을 살펴보고 구축된 연구장비의 활용 가능성을 높일 수 있는 정책방안을 모색하고자 수행되었다. 국가 R&D사업을 통해 연구장비가 구축된 연구기관들의 네트워크에서는 구조적 특성으로 낮은 밀도를 보였고 네트워크 내에서 연구장비 정보의 전달이 어려운 형태로 나타났다. 지위적인 특성의 비교를 통해 네트워크 내에서 연구장비의 정보를 보다 효과적으로 전달할 수 있는 기관들은 정부출연연구기관에서 한국전자통신연구원, 한국생산기술연구원, 한국화학연구원 등, 대학에서 성균관대학교, 경북대학교 등으로 분석되었다. 연구장비가 단독으로 구축된 고립 연구기관을 연계하는 가상화 노드는 네트워크를 활성화시킬 뿐만 아니라 효과적으로 연구장비의 정보를 전달할 수 있는 매개자 역할을 하는 것으로 나타났다. 연구결과로 연구장비의 활용 가능성을 높이는 방안으로는 연구기관들 간의 폭넓은 관계형성을 지원하는 장비구축 과제정책이 필요하며, 연구장비 정보전달에 보다 적합한 기관들을 활용하는 지원정책, 그리고 고립된 연구장비 보유기관의 장비정보를 매개하는 가상화 기관의 설립정책이 필요하다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.35-36
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• 2005

An ejector driven by a liquid is a fluid transfer equipment to be used under a poor suction condition, which means that there exists a possibility to occur a cavitation. It is a highly reliable device because it has no movable part in it, that is only a passive equipment. The ejector is an inevitably necessary one to overcome a poor pumping condition and to mix uniformly two fluids, however it has a low efficiency since it requires a pump for its operation. This study is for the development of a new-type liquid ejector with the application of a nozzle shape alteration, which maximize the suction performance of it. which provides the increased competition with the domestic industries. Also, the increased performance opens a new manufacturing method to use a commercial pipes for the production of an ejector, which is based on a trivial loss of a performance. However, this minor loss can be sufficiently compensated by the increased performance of a new-type ejector. Therefore, the developed ejector by this study can considerably reduce the manufacturing time and cost while its performance is largely increased.

• 한국광학회지
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• 제18권1호
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• pp.31-36
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• 2007

직경과 초점거리가 수 mm인 카메라폰 렌즈의 성능을 평가하는 변조전달함수(Modulation Transfer Function: MTF) 측정장치를 개발 하였다. 전체 측정장치는 물체부, 상분석부, 렌즈 마운터로 구성되며, 물체부는 비축상 측정을 위하여 회전한다. 렌즈의 정밀한 정렬을 위하여 정밀한 수평형 거치대를 제작하였으며 광축 조정과 렌즈의 기울어짐 등의 문제를 매우 효과적으로 개선하였다. 시험렌즈의 초기정렬이 끝나면 자동으로 MTF를 측정하며 측정시간은 10초 이내이다.

• International Journal of Air-Conditioning and Refrigeration
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• 제16권2호
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• pp.64-69
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• 2008

Electronic and telecommunication industries are constantly striving towards miniaturization of electronic devices. Miniaturization of chips creates extra space on PCBs that can be populated with additional components, which decreases the heat transfer surface area and generates very high heat flux. Even though an air-cooling technology for telecommunication equipment has been developed in accordance with rapid growth in electrical industry, it is confronted with the limitation of cooling capacity due to the rapid increase of heat density. In this study, liquid-cooling heat exchangers were designed and tested by varying geometry and operating conditions. In addition, air-cooling heat exchangers were tested to provide performance data for the comparison with the liquid-cooling heat exchangers. The liquid-cooling heat exchangers had twelve rectangular channels with different flow paths of 1, 2, and 12. Silicon rubber heaters were used to control the heat load to the heat exchangers. Heat input ranged from 293 to 800W, and inlet temperatures of working fluid varied from 15 to $27^{\circ}C$. The heat transfer coefficients were strongly affected by flow conditions. All liquid-cooling heat exchangers showed higher cooling performance than the air-cooling heat exchanger. The heat exchanger with 2-paths could provide more controllability on the maximum temperature than the others.

• 터널과지하공간
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• 제29권3호
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• pp.135-147
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• 2019

본 논문은 기계시스템의 하중추정 기법 및 적용사례 소개가 목적이다. 이를 위해 진동기반 하중추정 기법의 이론적 배경 및 하중정량화 절차를 구체적으로 설명하였다. 또한 충격하중 및 진동이 발생하는 천공장비에 적용하여 진동기반 하중추정 기법의 적용성과 한계점을 분석하고 이에 대한 대응책에 대해 논의하였다. 마지막으로, 하중추정 기술의 추가 연구의 필요성을 토의하고, 새로운 충격하중 측정기술 개발을 위한 방법론을 제안하였다.

• International journal of advanced smart convergence
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• 제6권2호
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• pp.16-23
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• 2017

In contemporary modern society, people are constantly exposed to many kinds of noise, such as that from machinery, aircraft, construction sites, or road traffic. Noise is considered one of the most indispensable and influential parts of human life. This study investigates the acoustic characteristics of noise transfer from external sources to the human ear. For this study, we measured and analyzed various types of noise environments, installed monitoring speakers in a semi-anechoic room, and conducted intentional noise-filled experiments. In this environment, the size of the sounds generated by use of a portable device was also measured and the SNR (signal to noise ratio) calculated to study the influence of the noise. As sound is transmitted to the ear and the human body, it affects not only auditory damage but also other parts of the body. In this paper, we propose a proper SNR for noise emitted by portable IT equipment to prevent hearing loss when IT equipment is used.