• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.539-543
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• 2011

LNG cargo containment system (CCS) has the primary function of ensuring adequate thermal insulation with keeping natural gas below its boiling point. From the viewpoint of structural design, this LNG CCS can be treated as a laminated composite structure showing complex structural responses under the sloshing load which can be defined as a violent behavior of the liquid contents in cargo tanks due to external forced motions. As LNG CCS type, Mark III containment system from TGZ is considered in this paper and then its structural strength assessment is performed based on a simple higher-order shear deformation theory and maximum stress, maximum strain, Tsai-Wu failure criteria developed for laminated composite plates. The assessment is performed to the initial failure of the Mark III CS plate by investigating failure locations and loads.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1284-1285
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• 2006

We reported a P/M soft magnetic material with core loss value of $W_{10/1k}=68W/kg$, which is lower than that of 0.35mm-thick laminated material, by using high purity gas-atomized iron powder. Lack of mechanical strength and high cost of powder production are significant issues for industrial use. In order to achieve both low core loss and high strength by using inexpencive powder, the improvement of powder shape and surface morphology and binder strength was conducted. As the result, the material based on water-atomized powder with 80 MPa of TRS and 108 W/kg of core loss (W10/1k) was achieved.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.90-91
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• 2015

Heat insulator materials can be classified inorganic and organic. The organic material is due to toxic gas emission, when a fire occurs. And it has lower water resistance. The inorganic material is heavy and worse thermal performance than organic materials. In this study, cullet and fly ash were used as basic materials in order to secure a recycling technology of by-products which was mostly discarded and reclimed, and measure of physical properties of light-weight ceramic insulator.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.176-180
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• 2003

To obtain superconducting state, a reliable cryocooler system is required. Structural and thermal design have been performed to design cryocooler system operated with reverse Brayton cycle using gas neon as refrigerant. This cryocooler system consists of compressor recuperator, coldbox, control valves and has 1 ㎾ cooling capacity. Heat loss calculation was conducted for the given cryocooler system by considering the conduction and radiation through the multi-layer insulation (MLI) and high vacuum. The results can be summarized as; conduction heat loss is 7 W in valves and access port and radiation heat loss is 18 W through the surface of cryocooler. The full design specifications were discussed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.81-85
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• 2004

This paper describes the testing facility to demonstrate the performance of the distribution class circuit breakers and switchgears and the testing methods. The field-test evaluation system consists of two parts. One is the distribution system for simulation of the condition on interruption mode of switches which are installed in the system and tested by the AFG(Artificial Fault Generator) and the thunderbolt generator just like in the real field. The other is a laboratory for confirmation or the important characteristics regarding to the insulation, gas, environment durability of equipment. For the fatal failure mode, a FMEA(Failure Modes and Effects Analysis) technique which is a kind of a structural analysis to consider a counter-plan was emploved.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.1-12
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• 2012

In order to reduce energy consumption and greenhouse gas emission in building domain, thermal insulation of building is being enhanced. In a well insulated and tightened environment, internal heat gain caused by solar radiation, luminaires, electronic appliances and metabolism can be more important to thermal condition of building. This paper presents mathematical/physical models of quasi-adiabtic room and lighting fixtures using heat balance equation and thermal-electric analogy to quantify and modelize the heat gain due to luminaires. Experimental results are used to identify thermal parameters of theoretical models. And simulation results of models using Matlab/Simulink are conducted to verify the models and to investigate the thermal effect of lighting fixtures into quasi-adiabatic room.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2220-2222
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• 2005

Epoxy Insualtion spacers for supporting the conductors and partitioning the sections in $SF_6$ Gas insulated Switchgear(GIS), require higher electrical, Thermal and mechanical reliability with other principal components in GIS to be operated without any failure in use. In this paper, we describe the results of the performance evaluation of electrical and mechanical properties for extra high-voltage GIS according to KEPCO spec. and the requirements of the insulators for GIS specified by IEC 62271-203(2004).

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.392-395
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• 2003

The study of electric field analyses has been conducted on two kinds of bushings for 17.5kV $SF_6$ gas insulated recloser. In this paper, two model bushings and input conditions for the analyses are described in detail. The results of the electric field analyses are presented and compared with to find out the better design in two bushings. Finally some suggestions are given for improving the insulation characteristics of the bushings.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1812-1814
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• 2003

$SF_6$ 가스로 절연된 GIS(Gas Insulation Switchgears)는 매우 신뢰성이 높은 것으로 평가되어왔다. 그러나 GIS 내부에서 발생하는 결함에 대하여 완전하게 배제시키지 못하고 있으며, 이러한 부분방전 활동에 의한 대부분의 결함들이 GIS의 사고를 이끈다고 알려져 있다[1]. 따라서, GIS 내부에서 발생하는 부분방전 현상의 위치와 측정은 1940년대 초반부터 관심을 가져왔으며, 현재에는 부분방전 형태의 패턴이 사용된 부분방전 검출회로 및 신호의 전파와는 무관하다는 것을 알아낸 시점에 이르렀다. 이에 따라, 본 논문에서는 $SF_6$ 가스가 봉입된 GIS 내부에서 발생하는 부분방전 형태의 패턴인식을 위한 방법으로 NN(Neural Network)의 알고리즘 중 BP(Back-Propagation) 알고리즘을 이용하였다.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.198-199
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• 2007

The Cable Transit has an adaptable center hole for accommodating a cable to be passed through the wall(bulkhead/deck). The Cable Transits Sealing System must have important character which seal and protect against fire, smoke, gas, water, etc and consist of natal frame, sealing system and the cable, insulation. In this paper, introduced our cable transit organic expansion sealing material system, fire-resistance test and test result, etc. We carry to fire-resistance test in according to FTP Code Part 3(IMO Res. A. 754(18)) for A-60 class cable transit and the test result for our cable transit sealing system was satisfied.