• 폴리머
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• 제28권5호
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• pp.412-425
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• 2004

팽창 흑연을 포함한 NBR/GTR 발포체를 제조하고, 이들의 난연특성 및 발포특성에 팽창 흑연이 미치는 영향을 조사하였다. 고무재료로 NBR만을 사용한 경우 팽창 흑연 30 phr, 폐타이어 고무분말 (GTR)을 포함한 경우 팽창 흑연 10 phr 범위 내에서, 발포특성에 있어서는 팽창 흑연을 사용하지 않은 경우와 유사한 셀 구조 및 첨가제 분산을 가짐을 알 수 있었다. 한계 산소 지수 (LOI) 분석 결과 팽창 흑연의 함량이 증가함에 따라 LOI가 증가함을, 콘칼로리미터 분석 결과 LOI분석 결과와 유사한 경향성을, 즉 LOI가 증가함에 따라 열방출속도 (HRR), 총열방출량 (THR) 등이 감소함을 알 수 있었다. 또한 상기한 조성 내에서 우수한 난연특성을 즉, 낮은 열방출속도, 총열방출량, 유효연소열 (EHC) 등을 가짐을 알 수 있었다. 연기밀도에 있어 콘칼로리미터 분석에서의 A-COY와 유사한 경향성을, TGA 분석에 있어 LOI 및 콘칼로리미터 분석결과와 대체적으로 유사함을 알 수 있었다.

• 한국인터넷방송통신학회논문지
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• 제19권1호
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• pp.9-14
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• 2019

소형 밀리미터파 추적 레이다는 저속으로 기동 중인 큰 RCS를 갖는 바다위의 함정 표적에 대하여 TWS(Track While Scan) 방식을 통하여 실시간으로 표적을 탐색, 탐지 하여 추적하는 펄스 방식의 레이더이다. 본 논문에서는 저속으로 기동을 하지만 채프, 디코이 등 다양한 기만체를 운영하는 함정 표적에 대하여 LPRF와 DBS, 및 HRR 신호처리 기법을 통하여 표적 정보를 획득하고 추적하기 위하여 고속의 CPU가 탑재된 보드 개발과 표적정보를 실시간 처리하기 위하여 FPGA(Field Programmable Gate Array)를 활용하여 실시간 FFT 연산이 가능한 DFT(Discrete Fourier Transform) 모듈 설계를 포함한 신호처리기 구조를 설계하고 성능시험을 통해 구현한 신호처리기를 검증하였다.

• 한국융합학회논문지
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• 제10권5호
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• pp.79-84
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• 2019

20대 무용전공자들을 대상으로 트레드밀 보행운동이 유산소 운동능력에 미치는 영향을 알아보고자 하였다. 20대 한국무용 전공자 10명과 일반 여대생 10명을 대상으로 트레드밀 보행운동을 실시하였다. 측정은 실험 전과 후에 심박수 회복율, 최대산소섭취량, 최대환기량, 젖산 회복율을 측정하였다. 이렇게 얻어진 자료는 SPSS win 16.0을 이용하여 분석하였다. 실험 후 유산소 운동능력의 변화를 비교해 보면 대조군보다 실험군에서 심박수 회복율과 젖산 회복율에서 유의한 증진의 효과가 나타났으며, 최대환기량과 최대산소섭취량에서는 유의하게 증가하지 않았다. 실험전후 집단 간 검증에는 심박수 회복율에서 유의한 수준으로 높게 나타났다. 한국무용 전공자의 트레드밀 훈련을 통해 유산소성 운동능력을 증진시켜 기초체력의 향상에 도움이 줄 수 있으며 과학적인 운동처방의 근거가 되는 기초자료를 제시하는데 많은 도움이 될 것으로 사료된다.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4195-4208
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• 2022

In this study, operator habitability was numerically evaluated in the event of a fire at the main control bench board (MCB) in a reference main control room (MCR). It was investigated if evacuation variables including hot gas layer temperature (HGLT), heat flux (HF), and optical density (OD) at 1.8 m from the MCR floor exceed the reference evacuation criteria provided in NUREG/CR-6850. For a fire model validation, the simulation results of the reference MCR were compared with existing experimental results on the same reference MCR. In the simulation, various input parameters were applied to the MCB panel fire scenario: MCR height, peak heat release rate (HRR) of a panel, number of panels where fire propagation occurs, fire propagation time, door open/close conditions, and mechanical ventilation operation. A specialized-average HRR (SAHRR) concept was newly devised to comprehensively investigate how the various input parameters affect the operator's habitability. Peak values of the evacuation variables normalized by evacuation criteria of NUREG/CR-6850 were well-correlated as the power function of the SAHRR for the various input parameters. In addition, the evacuation time map was newly utilized to investigate how the evacuation time for different SAHRR was affected by changing the various input parameters. In the previous studies, it was found that the OD is the most dominant variable to determine the MCR evacuation time. In this study, however, the evacuation time map showed that the HF is the most dominant factor at the condition of without-mechanical ventilation for the MCR with a partially-open false ceiling, but the OD is the most dominant factor for all the other conditions. Therefore, the method using the SAHRR and the evacuation time map was very useful to effectively and comprehensively evaluate the operator habitability for the various input parameters in the event of MCB fires for the reference MCR.

• 한국응용과학기술학회지
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• 제24권2호
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• pp.182-189
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• 2007

Used polyurethane was chemically degraded by treatments with flame retardants such as tris(3-chloropropyl) phosphate (TCPP), triethyl phosphate (TEP), and trimethyl phosphate (TMP). The structure of degraded products (DEP) was analyzed by FT-IR and P-NMR and it turned out to be phosphorus containing oligourethanes. Rigid polyurethane foam was produced by using the degraded products (DEP) as flame retardants. The flammability of recycled rigid polyurethane was investigated. The recycled polyurethane shows a reduced flammability over virgin polyurethane. In order to evaluate flame retardant properties of the recycled polyurethane foams with various amounts of DEP, the combustion parameters of the foam was measured by a cone calorimeter. Scanning electron micrograph of recycled PU shows the same uniform cell morphology as virgin PU.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.575-578
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• 2006

In designing smoke-control system of rescue station in train tunnel, a purpose is to prevent a disaster by proposing the jet fan operation together with smoke-control curtain in tunnel fire. This study has investigated the relationship of the Heat Release Rate(HRR) and a adequate ventilation velocity to control the fire propagation in tunnel fire, and has improved the effect of the smoke-control curtain on preventing the flow of pollutants. In this study, Computational Fluid Dynamics(CFD) simulations with ST AR-CD(ver 3.24) were carried out on predicting the fire spreading and the flow of pollutants, considering jet fan operations and effect of smoke-control curtain. Our simulation domain is the full scale model of the 'DAEGWALLYEONG' 1st tunnel. The results represent that ventilation operation can control the fire spreading and pollutants effectively to prevent a disaster.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.285-291
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• 2003

An experimental method to measure Q-parameter in-situ is described. The basic idea comes from the fact that the side necking near a crack tip indicates the loss of stress triaxiality, which can be scaled by Q. From the out-of-plane displacement and the in-plane strain near the surface of side necking, stress field averaged through the thickness is calculated and then Q is determined from the difference between the stress field and the HRR field corresponding to the identical J-integral. To prove the validity, three-dimensional finite element analysis has been performed for a CT configuration with side-groove. Q-value which was calculated directly from the near-tip stress field is compared with that determined by simulating the experimental procedure according to the proposed method, that is, the Q-value determined from the lateral displacement and the inplane strain. Also, the effect of location where the displacement and strain are measured is explored.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.15-18
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• 2008

A study on the fire and smoke behavior on experiments and analysis through STAR-CD in using about behavior analysis of the smoke. Kerosene of 3L in using on the experimental garden of 30cm in diameter same applies to heat release rate(HRR), buoyant force by Plume can be calculated at a rate of 1m/s. The result of experiment in average of velocity were 0.29m/s, and interpreted result were 0.28m/s. Besides, it is proved by interpreted that behavior of smoke movement can be not observed in the experiment. After smoke is Plume increased, ceiling-jet in formation being descend in smoke layer will be more thick smoke layer, and then vertical wall is collapsed in formation of wall-jet being descend. It is defined that smoke layer is more thick through descending course in wall-jet and ceiling-jet.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2011년도 추계학술논문발표회 논문집
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• pp.193-196
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• 2011

본 연구는 주거시설의 대표적인 가연물을 고정가연물과 적재가연물로 구분하여 가연물의 연소특성을 실험결과에 대한 연구이다. 고정가연물은 7종에 대하여 Cone Calorimeter로 적재가연물은 2종 Furniture Calorimeter로 실험을 실시하였다. 고정가연물의 경우 접착성분을 지니고 있는 시트지의 경우가 HRR등이 높게 측정되었으며, 적재가연물의 경우 섬유성분과 플라스틱으로 구성되어 있는 의자가 높게 측정되는 것을 알 수 있었다.

• Nuclear Engineering and Technology
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• 제34권6호
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• pp.610-618
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• 2002

A study of the conceptual data modeling to realize the decommissioning database on the HRR-1&2 was carried out. In this study, the current state of the abroad decommissioning database was investigated to make a reference of the database. A scope of the construction of decommissioning database has been set up based on user requirements. Then, a theory of the database construction was established and a scheme on the decommissioning information was classified . The facility information, work information, radioactive waste information, and radiological information dealing with the decommissioning database were extracted through interviews with an expert group and also decided upon the system configuration of the decommissioning database. A code which is composed of 17 bit was produced considering the construction, scheme and information. The results of the conceptual data modeling and the classification scheme will be used as basic data to create a prototype design of the decommissioning database.