• Fire Science and Engineering
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• v.26 no.2
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• pp.40-52
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• 2012

This paper presents the uncertainty analysis results of fire modeling input parameters for motor control center in switchgear room of nuclear power plants. FDS (Fire Dynamics simulator) 5.5 was used to simulate the fire scenario and Latin Hyper Cube Monte Carlo simulations were employed to generate random samples for FDS input parameters. The uncertainty analysis results of input parameters are compared with those of the model uncertainty analysis and sensitivity analysis approaches of NUREG-1934. The study results show that the input parameter uncertainty analysis approach may lead to more conservative results than the uncertainty analysis and sensitivity analysis methods of NUREG-1934.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.239-242
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• 2011

NFPA-805 불확실도 분석 요건에 따른 경수형 원전 스위치기어실 모터제어반의 화재시나리오에 대한 입력변수 불확실도 평가를 수행하였고 이를 통해 화재모델링의 불확실도 평가방안을 제시하였다. 화재모델링은 FDS5를, 불확실도분석은 MOSAIQUE를 사용하였고 Wilks 방법에 근거하여 93회의 latin hypercupe 샘플링을 수행하였다. 스위치기어실 케이블의 최소 평균손상시간은 212초로 예측되어 화재발생시 스위치기어실의 화재진압은 약 4분 이내에 이루어져야 하는 것으로 확인되었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.420-424
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• 2008

The new MOV(motor-operated valve) diagnostic system MOVIDS(MOV intelligent diagnostic system) was developed. Its remote diagnostic methods with high accuracy have improved the applicability. This enables the diagnostic tests and the evaluations of many MOVs not only at the valves but also in remote places like MCCs(motor control centers). The remote diagnostic ability of the new system reduces the cost and the man power for diagnosing MOVs and eliminates the danger of the toxic or radioactive environments to which workers might be exposed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.317-319
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• 2015

기존 육지초인용으로 사용되는 전구식 회전형 대형등명기는 고압방전등을 사용하고 있어 고장발생 빈도가 높고 긴급수리에 장시간이 소요되어 기능 유지가 어려우며, 제품 가격이 높아 신규 설치 및 등명기 교체 시 비용 부담이 가중되는 문제점이 대두되고 있다. 따라서 기존 광원(메탈할라이드 램프 또는 텅스텐할로겐 램프)의 문제점을 개선하고, IALA에서 권고하는 규격을 만족하는 효율성과 안정성을 확보한 LED 대형등명기 개발이 국 내외에서 활발하게 수행되고 있다. 이러한 LED 대형등명기는 LED 모듈을 안정적으로 구동하는 LED 드라이버와 정확한 등질구현을 위한 모터제어회로가 필요하다. 또한 LED 모듈 및 LED 드라이버 고장 시 예비장치로 절환이 가능한 회로설계 및 교체유지관리가 용이한 제어반 기구개발 및 특성연구가 필요하다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2186-2187
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• 2011

승강장 스크린도어(PSD: Platform Screen Door)는 철도, 경전철 및 지하철 승강장 내 추락, 전동차 사이의 끼임 등의 안전사고 방지 및 승강장의 공기오염 개선, 장애인, 노약자 등의 탑승편의에 관한 문제, 승강장내의 쾌적한 환경문제 제공 등을 위해 전동차 승강장의 선단에 고정 및 가동 도어를 설치하여 승강장과 선로를 차단함으로써 이용 고객의 안전사고를 예방하는 설비를 말한다. 국내 업체들은 기술 투자를 통해 종합 제어반 및 각종 조작반, RF장치 등 상당 부분 국산화를 이루었지만, 짧은 기간 동안 승강장 스크린 도어를 설치하면서 승강장 스크린 도어 시스템의 핵심이라 할 수 있는 승강장 스크린 도어용 제어장치(DCU: Door Control Unit)의 완전한 국산화는 이루지 못한 채 외국 제품을 도입하여 설치하고 있거나 DC 모터를 적용한 제어장치를 개발하여 설치하고 있는 실정이었다. 본 연구에서는 BLDC 모터를 적용한 제어장치를 국산화하여 시제품을 제작하였고 월미도의 은하레일에 제어기를 설치하여 성능을 검증하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1249-1255
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• 2010

An ultra high- pressure system generally consists of a hydraulic power unit, an oil supply unit, an electrical power supply device, and an electrical control device. The hydraulic power unit supplies the hydraulic power to the intensifier to create generate ultra high pressure. The intensifier amplifies increases the pressure using the oil supplied from by the hydraulic power unit. The electrical supply devices and control devices maintain are provided for the electric motors, valves, and sensors. In this study, instead of a flow-control device, a pressure-control type device was mounted on a manifold block in the hydraulic power unit instead of the flow-control type. A servo valve was fitted in the intensifier, and the performance characteristics of the intensifier varied according to the variations of in the pressure cycle and with the temperature of the operating oil in the hydraulic power unit.

• Fire Science and Engineering
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• v.32 no.1
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• pp.57-65
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• 2018

In this study, a post-fire safe shutdown analysis (PFSSA) including multiple spurious operation (MSO) treatments for cables was conducted with an imaginary nuclear power plant for training using a deterministic fire analysis code. The imaginary nuclear power plant for the training consisted of a reactor containment building and an auxiliary building, including a total of 22 fire areas. The equipment including valves, pumps, emergency diesel generators, switch gears, motor control centers, and logic controllers were located in each fire area of the imaginary plant. It was assumed that each equipment is connected with two cables and that each cable passes through the fire areas along the cable trays. A database containing the information on the equipment and cables for the imaginary plant was constructed for the fire area analysis. The fire area analysis was performed for several assumed MSO scenarios, equipment logics, and cable logics. A mitigation measure using a three hour rated wrap was applied to the failed cables and cable trays after the fire area analysis.

• Fire Science and Engineering
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• v.26 no.1
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• pp.61-67
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• 2012

In the three-phase power system using the three-phase motor, when any one-phase is open-phase, the unbalanced current flows and the single-phase power supplied by power supply produces overcurrent to motor coil. As a result, the enormous damage and electrical fire can be given to the power system. Recently, the thermal over-current relay (THR) or electronic motor protection relay (EMPR) is mostly used as the open-phase detection device of the three-phase motor. When the over-current or overheat of electric line is generated, it detects and operates circuit breaker, but there is the defect that the sensing speed is slow, the operation can be sometimes failed, and the precision is decreased. In order to improve these problems, this paper is proposed a new control circuit topology for openphase protection using semiconductor devices. Therefore, the proposed open-phase protection device (OPPD) enhances the sensing speed and precision, and has the advantage of simple fitting in the three-phase motor control panel in the field, as it manufactures into small size and light weight. As a result, the proposed OPPD protects the three-phase motor, minimizes the electrical fire from openphase, and contributes for the stable driving of the power system. The performance and confidence of the proposed OPPD is confirmed by a great variety of the experiments of operation characteristic.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.293-302
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• 2014

This study was carried out to develop rain shelter which can make an appropriate size and environment for Chinese cabbage rainproof cultivation. Fifty three farms with chinese cabbage rainproof cultivation system have been investigated to set up width and height of rain shelter. Mostly the width of 6m was desired for rain shelter and the height of 1.6m for their eaves, so these values were chosen as the dimensions for rain shelter. After an analysis of their structural safety and installation costs by the specifications of the rafter pipe, Ø$25.4{\times}1.5t$ and 90cm have been set as the size of rafter that such size costs the least. This size is stable with $27m{\cdot}s^{-1}$ of wind velocity and 17cm of snow depth. Therefore it is difficult to apply this dimension to area with higher climate load. In order to sort out such problem, the rain shelter has been designed to avoid damage on frame by opening plastic film to the ridge. Once greenhouse band is loosen by turning the manual switch at the both sides of rain shelter and open button of controller is pushed then switch motor rises up along the guide pipe and plastic film is opened to the ridge. Chinese cabbage can be damaged by insects if rain shelter is opened completely as revealed a field. To prevent this, farmers can install an insect-proof net. Further, the greenhouse can be damaged by typhoon while growing Chinese cabbage therefore the effect of an insect-proof net on structural safety has been analyzed. And then structural safety has been analyzed through using flow-structure interaction method at the wind condition of $40m{\cdot}s^{-1}$. And it assumed that wind applied perpendicular to side of the rain shelter which was covered by insect-proof net. The results indicated that plastic film was directly affected by wind therefore high pressure occurred on the surface. But wind load on insect-proof net was smaller than on plastic film and pressure distribution was also uniform. The results of structural analysis by applying pressure data extracted from flow analysis indicated that the maximum stress occurred at the end of pipe which is the ground part and the value has been 54.6MPa. The allowable stress of pipe in the standard of structural safety must be 215 MPa or more therefore structural safety of this rain shelter is satisfied.