• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.866-867
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• 2008

Among many tests to verify the characteristics of power system apparatus, the short circuit test is performed to verify the performance characteristics of the apparatus under the short-circuited power system. The verification of the short-circuit performance is inevitable for the reliability of power system and the safety of the operator around. The short circuit performance test requires the suitable power source and Korea Electrotechnology Research Institute has 4000 MVA, 500 MVA short circuit generators for the short circuit performance test. This paper will study on the parameters of short-circuit generator and the estimation of them.

• Journal of Advanced Marine Engineering and Technology
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• 제28권2호
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• pp.243-251
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• 2004

Absorption chiller/heater can utilize the unused energy of the daily life waste heat, the industry waste heat. the solar energy and the earth energy. These can contribute to energy savings. But the absorption chiller/heater has a demerit that the size of absorption chiller/heater is larger than that of the vapor compression type based on same capacity. In this study. the experimental apparatus of an absorber is manufactured as a plate. which is newly applied in an absorber. The experimental apparatus is composed of a plate type absorber. which can increase the heat exchange area per unit volume and thus facilitating to deeply investigate more detail features instead of that done by the existing type. i.e.. horizontal tube bundle type. The characteristics of heat transfer and refrigeration capacity are studied experimentally. The absorption enhancement by using surfactant is closely examined through the experiment and comparative figures are presented in quantitative and qualitative analysis.

• KSBB Journal
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• 제19권3호
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• pp.241-244
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• 2004

진탕플라스크 배양액의 균 증식도를 자동측정하기 위하여 자동화 FIA장치를 경제적으로 제작하였으며, 이를 이용하여 대장균을 Nutrient broth 배지에 접종하여 배양하면서 그 증식도를 자동측정하였다. 멸균 NB를 이송용액으로 하고 10분 간격으로 자동측정하였을 때 큰 오차 없이 증식양상을 세밀하게 측정할 수 있었다. 증류수를 이송용액으로 사용한 경우에는 NB를 이송용액으로 사용한 경우에 비하여 측정오차가 더 컸으며, 특히 배양후반부에서의 오차가 크게 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.175-176
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• 2012

In this study, coupler on the safety of meeting the requirements and construction and economy to satisfy the number of parts to minimize an LK-DK coupler has been developed, affordability existing reinforcing bar joint, welded joint, mechanical joints, compared with a favorable one to the understanding, and also facilitate the construction and logistics, etc. I've found that there is no additional pay because the amount of product performance through the tensile test after test, if commercialization is expected to be greater ramifications.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.114-120
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• 2014

In this paper, a method for multi-physics analysis of the temperature-dependent properties of an oil-immersed transformer is discussed. To couple thermal fields with electromagnetic and fluid fields, an algorithm employing a user defined function (UDF) is proposed. Using electromagnetic analysis, electric power loss dependent on temperature rise is calculated; these are used as input data for multi-physics analysis in order to predict the temperature rise. A heat transfer coefficient is applied only at the outermost boundary between transformer and the atmosphere in order to reduce the analysis region. To verify the validity of the proposed method, the predicted temperature rises in high-voltage (HV) and low-voltage (LV) windings and radiators were compared with the experimental values.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1704-1706
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• 2002

With increasement of use in electricity energy, quality of electric apparatus has been recognized as important factor in distribution and transmission line. Especially In laboratories, lightning and switching impulse performances of electric apparatus have been carrying out by impulse voltage generator (IVG), simulated into lightning and switching surge circuit. In this paper, we describe triggering system of impulse voltage generator(IVG) for extra high voltage, which has been newly designed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.260-262
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• 2002

The scope of applications industrial or household manufactures, is on the increase. In this study, it applies a principle of induction heating to food dryness for preservation of food. And it applies indirect heating process using overheating steam, which analyzes thermal characteristic of heating apparatus depending on its construction. It was verified that application of proposed process was appropriate by drying test of food.

• 유공압시스템학회논문집
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• 제5권1호
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• pp.1-5
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• 2008

Pneumatic driving systems have hard non-linear characteristic and large friction force compared with driving power. Hence, it cannot be robust against parameter uncertainties, modelling error, disturbance and noise. In this study, we apply a mixed $H_2/H_{\infty}$ control to the generalized plant for a pneumatic driving apparatus system including parameter uncertainty and disturbance. In order to design the $H_2/H_{\infty}$ controller, we use the LMI technique. To evaluate control performance and robust stability of the designed controller, we compare it with a conventional controller such as PVA(Position-Velocity-Acceleration state controller) using the simulation results. As a result, it can be known that designed controller shows better robust stability than the conventional controller.

• 대한토목학회논문집
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• 제31권3C호
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• pp.103-108
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• 2011

본 연구에서는 대변형율 시험을 위한 공진주/비틂전단 시험기의 한계점과 해결방안을 기술하였다. 대변형율 시험의 세가지 한계점은 첫째, 시험기의 제한된 회전거리이며 둘째, 시험기의 제한된 비틂력과 셋째, 변형측정 시스템의 한계 등이 있다. 대변형율 시험의 제한요소 중에서 시험기의 제한된 회전거리를 해결하기 위하여 시료 받침대를 개량하였으며 비틂력을 향상 시키기 위하여 가진기 팔의 개수를 증가시키고 가진기 코일의 연결방법을 변경하여 보다 강한 비틂력을 얻을 수 있었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1041-1044
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• 1996

The plastic-film-covered hill planter is a new-type seeding machine, including tow types which are mounted by 11kw and 40 kw tractors. It is made up of fertilizing , plastic-film covering perforating film and hole seeding, soil sealing apparatus, and can work at 5-7kw/h. The plastic-film covering and seeding of cotton, corn and soybean can all use this machine. The plastic-film-covered hill planter is mainly composed of plastic film covering unit, drum-type hill-drop unit and furrow coverer, some other types are also equipped with fertilizer drill unit. It can do combined work of covering plastic film , sowing , plastic film perforating , soil covering at one time, and it is suitable to the covering plastic film as well as planting of the grandulated crops, such as cotton , corn, soybean and so on.