• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.34-36
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• 2004

Cable 접속장치인 정격 25.8kV 600/1200A Plug-in socket의 절연설계, 전계분포해석 및 열계해석을 위하여 전자계 및 열해석 프로그램인 Flux2D를 이용하여 simulation하였다. Plug-in접속장치의 shield형상을 변화하면서 각종 금구류 및 접속장치의 절연물의 연면전계강도를 계산하여 기준전계와 비교 검토하여 전계해석 하였다. 해석결과 shield 의 위치와 형상의 변화에 따라 socket내부의 전계강도를 완화시키는 중요한 역할을 하고 있음을 보여주고 있다. 열해석은 도체저항의 Joule 열원으로 입력하였으며, 정상상태에서의 은도 분포는 설계에 영향을 주지 않는 것으로 분석되었다.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.61-62
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• 2017

The motor used as a drive in machine tools is the largest part of energy consumption. Therefore, it is essential to optimize the energy consumption of the motor to improve the energy efficiency of machine tools. In this paper, the energy consumption model of motor drives is derived from the operating conditions of machine tools. The validity of the derived model is verified through the experiments.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.4
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• pp.265-270
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• 1993

Trace amount of heavy metals in rain waters were determined after preconcentration by coprecipitaion technique. Indium was selected as a coprecipitating reagent and concentrated heavy metals were analyzed by a conventional AA spectrometer. Two areas, Cheng-Won and Tae-Ahn, were selected and comparison. The concentrations of Pb and Cd in Cheong-Won (raural) area were 14.3 .pm. 8.0 ppb and 2.77 .pm. 5.37 ppb, respectively. These values are higher than those of Tae-Ahn, which indicates that even a rural area is polluted by a nearly industrial area (Cheong-Ju). The isotope ratios of lead in rainwaters were very similar to theos of aerosol particles.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.1
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• pp.29-33
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• 2014

Recently, Difficult-to-cut materials are used in many manufacturing industry. But the difficult-to-cut materials are difficult-to-cutting process. So difficult to cut material cutting process was used after heat treatment through preheating for easy cutting process. In this study, Inconel 625 was preheating using laser heat source in computer simulation. Laser heat source temperature applied $1290^{\circ}C$ that suitable preheating temperature for Inconel 625. And temperature effects such as temperature distribution for moving heat source studied apply to similar actual process condition. Simulation results for heat treatment effects through temperature distribution verified.

• Journal of Power System Engineering
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• v.16 no.2
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• pp.36-42
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• 2012

본 논문은 고파워 전자소자로부터 에너지를 수확하는 열전생성기의 성능에 pellet의 기학학적 구조가 미치는 영향들을 보고한다. 열경계저항을 포함하는 열전모델을 적용하여, 다양한 경계조건들과 열원의 열율들에 대해 pellet의 높이, pellet의 단면적, thermocouple의 수를 최적화 하고, 이처럼 최적화된 pellet의 기하학적 구조를 갖는 열전생성기의 성능과 일반적인 pellet으로 구성된 열전생성기의 전력생성성능과 효율이 예측되고 비교되어진다. 예측된 결과는 최적화된 pellet으로 구성된 열전생성기가 일반적인 pellet으로 구성된 열전생성기보다 2-10배까지 생성효율이 우수함을 보여준다. 최적화된 pellet으로 구성된 열전생성기와 일반적인 pellet으로 구성된 열전생성기의 열적성능도 예측되고 비교된다.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.136-141
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• 2013

This study introduces and analyzes the energy for heating and cooling system in region with volcano-stratigraphic. The thermodynamic properties of air through the air blower installed at the entrance of borehole are measured. It estimates the availability of underground air for heating and cooling system through experimental data and theoretical analysis. Based on our conclusion from these calculations we predict possibility of over 40kW steady and stable energy source from underground. Therefore this underground air can be utilized in region with volcano-stratigraphic.

• Korean Journal of Biological Psychiatry
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• v.15 no.3
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• pp.219-223
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• 2008

Refeeding syndrome is a life-threatening but treatable condition occurring in any patients with starvation. Electrolyte imbalance, especially hypophosphatemia and fluid shift result in metabolic changes in various systems. The authors reported a case of refeeding syndrome associated with prolonged starvation due to delusion and hallucination in a 38-year-old schizophrenia patient. Hypophosphatemia, hypokalemia, edema and elevation of liver enzyme was occurred despite careful treatment. The symptoms were improved after consistent electrolyte supplement. Close observation and repetitive monitoring are important to prevent refeeding syndrome.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.142-144
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• 2003

The suspension insulators are subjected to harsh environment in service for a long time. Long term reliability of the insulators is required for both mechanical and electrical performances. We studied HRB characteristics to find out a deformation of suspension porcelain with alumina contents. These experimental results show that HRB intensity was affected severely by alumina contents, and the propagation properties was affected mainly by a distribution and shape of micro pores on porcelain samples.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.498_499
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• 2009

마이크로그리드는 소형 분산 에너지원(Micro-Source or Distributed Energy Resources: DER)으로 이루어진 분산전원항의 총칭으로, 다수의 수용가들을 위하여 수요지에서 전력을 생산 및 공급 하는 기술로 기본적으로 여러 수용가의 부하 및 분산발전기들이 하나의 덩어리(Cluster)를 형성하게 되는 새로운 개념의 배전망이다. 마이크로그리드를 간단하게 정의하면 "분산형 전원과 부하를 갖는 소규모 전력계통에서 복수의 전원 및 열원이 IT 관련 기술을 사용하여 일괄제어 및 관리되어 기존 전력계통으로부터 독립되어 운전할 수 있는 온사이트형 전력 공급 시스템"이라 할 수 있다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2237_2238
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• 2009

This paper describes the design process of three-phase squirrel cage induction moter. stator and rotor were modelled with the result obtained from loading distribution on the provided specification. For proving validity of the result obtained from loading distribution, through Maxwell simulator the first test target values, output and efficency, synchronous speed and etc, were compared with the design result.