• 한국농공학회논문집
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• 제46권6호
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• pp.3-10
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• 2004

The fundamental study of hydrologic redesign of Donghwa area located in a sccond tributary of Seomjin river was performed. The amounts of hydrologic design were estimated using the available cumulated hydrology data provided by Korea Agricultural and Rural Infrastructure Corporation (KARICO). The management status of The water resources in Donghwa area was also widely surveyed. The probability rainfalls, probable maximum precipitation (PMP) and probability floods were estimated and subsequently their changes analyzed. The amount of 200 year frequency rainfall with l day duration was 351.1 mm, 2.5 % increased from the original design value, and The PMP was 780.2 mm. The concentration time was reestimated as 2.5 hours from existing 2.4 hours. Soil Conservation Service(SCS) method was used to estimate effective rainfall- The runoff curve number was changed from 90 to 78, therefore the maximum potential retention was 71.6 mm, 154 % increased from the original value. The Hood estimates using SCS unit hydrograph showed 8 % increase from original value 623 $m^3$/s to 674 $m^3$/s and The probable maximum Hood was 1,637 $m^3$/s. Although the Row rate at the dam site was increased, the Hood risk at the downstream river was decreased by the Hood control of the Donghwa dam.

• 설비공학논문집
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• 제17권4호
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• pp.333-340
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• 2005

Horizontal air-jet effect has been utilized in some air conditioning systems in order to control the contaminated air indoor. In the present study, the flow and heat transfer of the contaminated air from a range hood system has been investigated with or without horizontal air-jet effect when the hood fan is on or off. For the present numerical experiment, PAT Flow code has been used. From the present numerical simulations, it has been shown that the air jet of a range hood generates coanda effect confining the contaminated air in a certain region. Furthermore, the qualitative relation between the flow rate of the capture air jet and the distribution pattern of the contamination has been discussed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.604-611
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• 1998

High-speed railway trains entering and leaving tunnels generate finite amplitude pressure wave which propagate back and forth along the tunnels, reflecting at the open ends of the tunnels and at other discontinuities such as ventilation shafts and the train themselves. In present day railways, the magnitudes of the pressure waves are much too small to cause structual damage, but they are a serious potential source of aural discomport for passengers on unsealed trains. Almost always do the pressure waves propagating along the tunnels lead to a hazardous impulse noise near the exit portal of the tunnel. In order to alleviate such undesirable phenomena, some control strategies have been applied to the compression wave propagating inside the tunnel. The objective of the current work is to investigate the effect of tunnel entrance hoods on the entry compression wave at the vicinity of the tunnel entrance. Three types of entrance hoods were tested by the numerical method using the characteristics of method for a wide range of train speeds. The results show that the maximum pressure gradient of compression wave can be considerably reduced by the tunnel entrance hood. Desirable hood shape for reduction of the pressure transients and impulse noise was found to be of abrupt type hood with its cross-sectional area 2.5times the tunnel area.

• 설비공학논문집
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• 제27권9호
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• pp.468-474
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• 2015

When oil is used for cooking in detached or apartment houses, large amounts of oil-mist, smoke, and particulate substances are generated and dispersed into the indoor-air environment. These pollutants diffuse into the surroundings and spread their odor while rising fast at a high temperature due to the heat energy from the gas range. Although the exhaust gas is discharged from the exhaust hood, which is installed on the top of a gas range to remove the diffuse pollutants, the exhaust conditions can vary greatly because they depend on the shape of the exhaust hood and the discharge rate. In this paper, the air that is required for the gas-exhaustion process is supplied by an air curtain that surrounds the kitchen hood, and the pollutant-capturing efficiency varies depending on the angle of the discharge grills; the pollutant-capturing efficiency was studied using a numerical-analysis method. The results indicate that the pollutant-capturing efficiency is not significantly changed by a change of the discharge-grill angle at a low air-discharge rate; however, at a high air-discharge rate, the efficiency value increases with an increase of the discharge-grill angle, whereby the best value occurs at 30 degrees and the efficiency decreases above this angle. Below 30 degrees, the effect of the discharge rate on the capturing efficiency is more than that of the discharge-grill angle.

• 방사성폐기물학회지
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• 제9권3호
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• pp.161-167
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• 2011

사용후핵연료 운반용기 표면온도가 $85^{\circ}C$를 초과할 경우, 대인용 보호막(Personnel Barrier) 또는 운반용 덮개(Transport Hood)를 설치하여 운반 중 운반용기 표면에 사람이 직접 접근할 수 없도록 하여야 한다. 운반용 덮개가 설치된 경우, 열적 안전성 평가의 한 가지 경우인 정상조건 열해석 시, 외부환경 경계조건(환경온도 및 외부복사온도)으로 적용하기 위해서 운반용 덮개 내부 열 환경 조건(내부 공기온도 및 운반용 덮개 표면온도)을 계산해야 한다. 따라서 본 연구에서는 운반용 덮개 내부 공기온도 및 표면온도를 계산하기 위한 해석적 방법 및 열전달 특성에 대한 분석을 수행하였고 CFD 해석 결과와 비교를 통해 타당성을 검증하였다.

• 한국터널지하공간학회 논문집
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• 제16권2호
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• pp.193-201
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• 2014

본 논문은 토압식 쉴드TBM(EPB shield TBM)의 후드부에 대한 시뮬레이션 시스템 개발에 대한 연구결과이다. 최근 토압식 쉴드TBM은 터널굴착에 많이 활용되고 있다. 토압식 쉴드TBM의 후드부 시스템은 터널굴착에서 매우 중요하기 때문에 후드부 시스템의 설계 및 operation parameter의 평가를 위하여서는 시공전에 사전 시뮬레이션이 요구된다. 본 연구를 위하여 모형 시뮬레이션 장비 시스템을 설계 개발하였다. 개발된 시스템의 검증을 위하여 모형실험을 실시하였으며, 개발된 시스템을 이용하여 얻은 결과는 현장에서 얻을 수 있는 토압식 쉴드TBM의 거동과 유사한 결과를 보여주었다. 이 결과로부터 토압식 쉴드TBM 굴진시 지반 loss는 후드부 챔버에 발생되는 토압의 변화에 많이 의존되는 것으로 나타났다. 따라서 본 연구에서 개발된 시뮬레이션 장비 시스템은 토압식 쉴드TBM공사 전 operation parameter를 평가하는데 매우 유용하게 활용될 수 있을 것으로 기대된다. 또한 다양한 지반조건에서의 TBM operation에 관한 정보를 제공할 것이다.

• 대한교통학회지
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• 제24권3호
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• pp.95-102
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• 2006

본 연구에서는 첨단안전차량기술 중 보행자 보호를 위한 차량기술의 적용에 따른 교통안전 측면의 효과를 계량화하는 방법론을 개발하였다. 보행자 보호를 위한 Active Hood Lift System (AHLS)의 도입으로 인해 감소하게 될 보행자 사망자수를 계량화하여 교통안전효과를 분석하였다. 이를 위해 실제 보행ft차량 충돌사고 자료와 시뮬레이션 자료를 이용하여 모형을 구축하고 모형의 결과를 통계적으로 분석하는 일련의 절차를 수행하였다 본 연구에서 개발한 방법론 및 연구 결과는 향후 다양한 첨단차량기술의 효과분석을 위한 참고자료로 유용하게 사용될 것으로 기대된다. 나아가, 본 연구의 결과물은 보행자 보호를 위한 교통안전정책 수립을 위한 의사결정을 지원하는 기초 자료로도 활용될 수 있어 그 의의가 크다.

• 에너지공학
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• 제27권4호
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• pp.92-97
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• 2018

본 연구는 자동차 엔진룸 내부에서 엔진과 연계된 부품의 냉각효과를 높이기 위해 후드 개발을 위한 수치해석을 다루고 있다. 급격한 온도편차에서 유발되는 엔진룸내 부품 온도를 저감시키면 부품에 대한 내구성 저하를 최소화 할 수 있다. 따라서, 본 연구에서는 차량 엔진룸 주요 부품 중에서도 온도제어가 비교적 용이한 발전기, 배터리, ECU 및 파워스틸 오일 등 4가지 부품을 목표로 엔진룸 냉각용 후드 개발을 위한 수치해석을 수행하였다. 그리고 수치해석을 검증하기 위하여 수치해석에서 가정하였던 동일한 조건으로 실험을 수행하여 비교하였다.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.162-170
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• 2005

Although the numbers of pedestrian fatalities and injuries are steadily declining worldwide, pedestrian protection is still an important issue. Extensive researches have been carried out in the field of pedestrian protection in order to establish pedestrian safety regulations. The automobile hoods and bumpers, which pedestrians frequently run into during accidents, should be safely designed for pedestrians. Two analysis methods are utilized to design safe structures of the hood and the bumper. They are real experiment and computer simulation. In this research, a method is developed to simultaneously utilize the results from the experiment and the simulation. For design, orthogonal arrays are employed to combine the two methods. Based on this method, a hood and a bumper are designed to protect pedestrians.

• 설비공학논문집
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• 제18권4호
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• pp.359-369
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• 2006

This study aims deriving analysis the flow characteristic of kitchen hood system with using 3-D numerical analysis method and improving the system to expel pollutes more efficiently. This system is applied with $k-{\varepsilon}$ turbulent model and using incompressibility viscosity flow range and boundary condition which are related to Bossinesq approximation following density variation in control volume. To understand the flow characteristics of four models, this study only focuses on velocity field, temperature field, and concentration field varying with followings whether separation plate is set or not and the shapes of separation plates. The quantity of air, speed of exhaust fan and temperature and concentration of heating source are concerned as constant values.