• Proceedings of the KSME Conference
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• 2000.04b
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• pp.296-303
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• 2000

Study on natural convection in a rectangular enclosure with a heating point has been studied by numerical and experimental methods. The governing equations were solved by a finite volume method, and for pressure term was used a SIMPLE algorithm. The parameters considered for numerical study are positions and surface temperature of a heating point i.e. Y/H = 0.25. 0.5. 0.75 and $11^{\circ}C{\leq}{\Delta}T{\leq}59^{\circ}C$. The results of isotherms and velocity vectors have been represented for various parameters. Based on the numerical data. the mean Nusselt number in the space can be expressed as a function of Grashof number

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.120.1-120.1
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• 2014

고온 plasma는 전자, 이온, 중성입자로 구성된 이온화된 기체로 국소열평형 상태의 구성입자가 수천도에서 수만도에 이르는 큰열용량을 갖는 불꽃형태를 이루고있다. 따라서 고온 plasma는 고온, 고열로 대상물질을 용융 또는 기화시켜 물질의 물리적상태를 변화시키는 열원역활을 하거나, 높은반응성을 갖는 입자들에 의한 화학반응을 촉진하는 반응촉매로 작용하여 고기능성 부품소재, 에너지 환경, 원자력, 항공우주,유가금속 재활용등의 분야에서 핵심적인 역활을 하고 있슴니다. 본 발표에서는 연구소에서 지금까지 국책과제로 수행되었던 고온 plasma을 유해폐기물(병원, 유독 액상폐기물, 군화공폐기물, 중금속 함유 폐기물, 폐 plastic 가스화 등)처리에 관한 전반적인기술을 소개하고져함.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.178-180
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• 2006

광은 식물의 광합성 작용뿐만 아니라 조직이나 기관의 분화, 종자의 발달 등 식물의 형태형성에도 관여하는 중요한 요인 중 하나이다. 불량한 광환경조건 하에서는 작물의 생육부진 뿐만 아니라 다양한 생리장해 및 병발생 등을 유발하기 때문에 경제적으로 광효율을 증가시키기 위하여 적절한 시설구조를 채택해야 한다. 또한 작물의 생육과 품질을 향상시키기 위하여 보광 및 차광 등 광환경 관리기술 개발이 요구된다. 본 연구에서 도입한 적외선램프는 새로운 인공광원으로서 태양광과 80% 정도 유사하고 용도에 따라 근적외선, 중적외선 및 원적외선이 방사되도록 할 수 있으며, 적은 전력소모량과 발생되는 열원은 겨울철 온풍난방기를 보조하거나 대체할 수 있어 에너지 절감효과를 동시에 기대할 수 있다. 따라서 본 연구는 인공광원에 대한 기초연구로서 인공광원의 종류별 분광특성을 비교 분석하고, 일몰 후 적외선램프의 조사 시간이 배추와 상추 유묘의 생장에 미치는 영향을 구명하고자 실시하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.350-355
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• 2004

This paper deals with the design of a heat dissipation system, which consists of a heat source of power semiconductor devices, a heat sink ;md a fan for the forced air cooling. It suggests the method of appropriately dividing the whole heat transfer system into analytical subsystems and also presents the correspondent analytic or experimental design equations for the subsystems. The experimental results on the designed heat dissipation system for the 400kW IGBT inverter show less than 10［%］ error with respect to the design temperature and therefore verify the validity of the proposed analytical design method in the steady state.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.514-517
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• 2003

Polymeric suspended insulators for subway and electrical track line had been designed and manufactured. The main elements to design polymeric insulators were the insulation ability and the optimal structure. To get the insulation ability, electrical and mechanical tests according to standards had done on housing rubbers and FRP cores and selected the sample with best properties as a insulator. The insulator shape and fitting parts with minimum electrical stress was simulated by FEM electrical field analysis program. The manufactured insulator set had been tested and estimated the electrical and mechanical according to ES and KS, and showed good characteristics in these tests.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.206-209
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• 1994

This paper has been researched bondability of electronic devices, such as lead frame and thick film of Ag/Pd on an alumina substrate by different heat sources. To obtain the bonds with high quality, it is very important to control both the thermal distribution of the bonds and it stability, because electronics components is consist of different materials. Therefore, this paper clarifies not only heat mechanism of micro parallel gap resistance bonding method and pulse heat tip bonding method but also investigates selection of heat sources with micro-electronic materials for bonding. Finally, it is realzed fluxless bonding process with filler metal such as plating layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.43-45
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• 1988

Four W/Cu system(60wt%W-40wt%Cu, -0.lwt%Ni, -0.5wt%Ni, -0.lwt%C) and four WC/Cu system(60wt%WC-40wt%Cu, -0.lwt%Ni, -0.5wt%Ni, 0.lwt%C) electrical contacts were prepared by a press-sinter-infiltration process to compare with their properties. Hardness and electrical conductivity are proportional to the refractory metal(W or WC) properties and showed the effect of additives. Arc erosion trend of switch test is changed by current level. High currant test at 1kA showed a different crack formation pattern and erosion mode between W/Cu system and WC/Cu system contacts.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1467-1469
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• 2002

This paper aims to investigate the characteristics of braided thermoplastic and thermosetting composite and pressure relief for polymer arrester. In general, braided composite has potential for improved impact and delamination resistance. Manufacturing processes of the braided composite could also be automated and could potentially lead to lower costs. Therefore, in consideration of characteristics of pressure relief for polymer arrester, the fabric pattern of braided composite was studied. And polymer arrester module was manufactured with braid.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.317-318
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• 2005

This paper presents the analysis on the properties of porcelain insulators with the manufactured year. The domestic porcelain insulators manufactured in 1995, 1997, and 2002 and the imported one are prepared. The content of alumina was increased with the manufactured year, and the hardness of ceramic parts showed the same trend. Moreover, the distribution and the size of pore were more decreased and reduced on the junction parts between the glaze and the ceramic. Therefore, we concluded that the domestic porcelain insulators have been improved with the lapse of time.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.129-132
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• 2002

대체 에너지(태양광, 풍력등)의 전력저장 시스템으로 널리 사용되는 겔형(Gel Type) 밀폐형 연(鉛)축전지의 노화 특성 평가 및 충전회로에 관하여 연구하였다. 납 합금을 이용한 기판 주조 기술과 전해액(Gel) 배합기술이 축전기 성능과 수명을 좌우하며 또한 배터리 충전 시스템에 따른 온도 상승이 치명적인 영향을 미치게 된다. 따라서 본 연구에서는 적외선 열화상 장치를 이용한 내부 열원 추적에 의해 노화정도를 측정하며 축전지 수명시험을 통해 입수한 데이터와 비교 평가하고자 한다. 현재 실험실 충방전 수명시험을 마치고 (주)코윈텍이 부안 해창 공원에 설치한 30kW급 풍력발전 시스템에 적용하여 Field Test를 시험중이다.