• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.84-85
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• 2021

The fire that broke out in a residential and commercial complex in Ulsan in October 2020 was large, but no deaths occurred. For this reason, there was a difference from the previous cases, so it was analyzed through field survey. The fire was expanded to the entire building by aluminum composite panels constructed by external heat method and SMC panels in evacuation safety zones, and fire was expanded to nearby mart due to wind on the day of the fire, and there were many evacuation spaces such as 15th, 28th, and rooftop heliports.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.3-8
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• 2008

Effect of external heating rate on the conversion efficiency for the steam reforming of methanol is investigated numerically considering both heat and mass transfer of the species in a packed bed microreactor. In a results from the numerical simulation, the conversion efficiency of methanol has been obtained for the external heating rate. The axial variation of mole fraction of methanol has been additionally presented for several cases of external heating rates. The results show that for the constant inlet temperature condition the conversion efficiency of methanol increases with external heating rate over the range of operating conditions.

• 한국화재소방학회논문지
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• 제27권6호
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• pp.15-20
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• 2013

반발 입자 군집 최적화 알고리즘을 이용하여 시편 표면에서의 대류열전달 계수, 방사율 및 화염에 의한 열유속을 예측하였다. 콘 칼로리미터를 이용하여 여러 열유속 조건 하에서의 방무목 시편의 표면 온도와 질량감소율 및 발화시간을 측정하였다. 본 연구에서 최적화된 대류열전달계수, 방사율 및 화염에 의한 열유속을 이용하여 계산된 표면온도는 실험결과와 각 열유속에 대하여 평균오차가 2% 내로 잘 일치하였다. 본 연구에서 제시한 방법을 이용하여 실험적 방법으로 직접 측정하기 매우 어려운 화염이 발생하는 표면에서 열전달과 관련된 여러 물리량을 구할 수 있다.

• Journal of the Korean Wood Science and Technology
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• 제30권3호
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• pp.18-25
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• 2002

Research to discuss the fire performance of materials requires tools for measuring their burning characteristics and validated fire growth models to predict fire behavior of the materials under specific tire scenarios using the measured properties as input for the models. In this study, burning characteristics such as time to ignition, weight loss rate, flame spread, heat release rate, total heat evolved, and effective heat of combustion for four types of wood-based materials were evaluated using the cone calorimeter and inclined panel tests. Time to ignition was affected by not only surface condition and specific gravity of the tested materials but also the type and magnitude of heat source. Results of weight loss rate, measured by inclined panel tests, indicated that heat transfer from the contacted flame used as the heat source into the inner part of the specimen was inversely proportional to specific gravity of material. Flame spread was closely related with ignition time at the near part of burning zone. Under constant and severe external heat flux, there was little difference in weight loss rate and total heat evolved between four types of wood-based panels. More applied heat flux caused by longer ignition time induced a higher first peak value of heat release rate. Burning characteristics data measured in this study can be used effectively as input for fire growth models to predict the fire behavior of materials under specific fire scenarios.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.49-55
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• 2004

This paper addresses a numerical simulation of the flow and heat transfer in a simplified model of helically coiled tube steam generator using a general purpose computational fluid dynamic analysis computer code. The steam generator model is comprised of a cylindrical shell and helically coiled tubes. A cold feed water entered the tubes is heated up, evaporates. and finally become a superheated steam with a large amount of heat transferred continuously from the hot compressed water at higher pressure flowing counter-currently through the shell side. For the calculation of tube side two-phase flow field formed by boiling, inhomogeneous two-fluid model is used. Both the internal and external turbulent flows are simulated using the standard k-e model. The conjugate heat transfer analysis method is employed to calculate the conduction in the tube wall with finite thickness and the convections in the internal and external fluids simultaneously so as to match the fluid-wall-fluid interface conditions properly. The numerical calculations are peformed for helically coiled tubes of steam generator at an integral type pressurized water reactor under normal operation. The effects of tube-side inlet flow velocity are discussed in details. The results of present numerical simulation are considered to be physically plausible based on the data and knowledge from previous experimental and numerical studies where available.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.308-311
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• 2008

As a severe accident mitigation strategy in a nuclear power plant, ERVC(External Reactor Vessel Cooling) has been proposed. Under ERVC conditions, where a molten corium is relocated in a reactor vessel lower head, a natural circulation two-phase flow is driven in the annular gap between the reactor vessel wall and its insulation. This flow should be sufficient to remove the decay heat of the molten corium and maintain the integrity of the reactor vessel. Preliminary experimental study was performed to estimate the natural circulation two-phase flow. The experimental facility which is one dimensional, the half height, and the 1/238 channel area of APR1400, was prepared and the experiments were carried out to estimate the natural circulation two-phase flow with varying the parameters of the coolant inlet area, the heat rate, and the coolant inlet subcooling. In results, the periodic circulation flow was observed and the characteristics were varied from the experimental parameters. The frequency of the natural circulation flow rate increased as the wall heat flux increased.

• 설비공학논문집
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• 제17권8호
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• pp.729-735
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• 2005

In this study, external condensation heat transfer coefficients (HTCs) were measured on a horizontal smooth tube at the saturated vapor temperature of $30^{\circ}C,\;39{\circ}C,\;and\;50^{\circ}C$ for R22, R410A, R407C, and R134a with the wall subcooling of $3\~8^{\circ}C$. The HTCs of all refrigerants are the highest at $30^{\circ}C,\;39{\circ}C,\;and\;50^{\circ}C$ in order. This trend is due to its excellent thermodynamic properties of the liquid phase. The measured data of HTCs were compared with the calculated ones by Nusselt's equation for a smooth tube. Measured HTCs of R22, R134a, R410A are $4.2\~7.5\%$ higher than prediction respectively while those of R407C are $15.6\~28.9\%$ lower than the prediction.

• 혜화의학회지
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• 제13권2호
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• pp.303-315
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• 2004

1. The acupuncture & moxibustion of hysterorrhea is focussed on bloody uterine discharge, leukorrhea and we must carefully diagnose the etiology & the machanism of disease. 2. The causes of hysterorrhea are dampness, impairment of seven emotion, irregular food intake, excessive intercourse and they are impotantly related to liver, spleen, kidney, the ren channel the chong channel 3. Using external medical treatment for Leucorrhea is washing and fumigation on vagina, to wash vagina, to insert vagina, cleansing theraphy and use with Suppository such as YONGYEOMGO(龍鹽膏), KAMISASANGJASAN(加味蛇床子散), SASANGSACHUNGSEJE(蛇床子洗劑). 4. The efficacy of medicines to use external medical treatment is as follow to helpcirculation of blood, to warm spleen and stomach, to warm blood, to warm uterus and remove cold, to remove heat and dry moisture, to down heat-product, to contract bloodvessel, to counteract poison and destory virus, to make enerey and blood.. 5. The diagnosis is grossly divided into the flowing downward of damp-heat, the weaknessof the qi of the spleen, dificiency of yuan of the kidney and according to the each diagnosis we should select adquate points representing the treatment of cooling(zhongji, yinlingquan, xingjian, etc), desiccation, heiping qi(qihai, zusanli, sanyinjiao, etc), tonificating yang (guanyuan, mingmen, shinshu, etc). 6. The moxibustion is the warming the lower jiao and eliminating the cold, the points are the mingmen point, the zhongji point, the guanyuan point, etc 7. Besides the acupuncture & moxibustion of hysterorrhea, we can make use of acusetor, ear acupuncture, endermosis, dong shi shen fa.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.527-530
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• 2010

전투기에 장착되는 정보수집용 포드의 냉각 장치인 ACM에 대한 성능 시험평가를 수행하였다. 시험평가 대상인 ACM은 역 브레이튼 공기 사이클로 작동되는 터보기기로서, 항공기의 비행속도에 의한 램 공기를 에너지원으로 사용하여 추가적인 에너지의 공급 없이 냉각 기체를 발생시킨다. 또한 습기에 민감한 전자장비의 냉각에 이용하기 위하여 열교환기를 함께 구성하였다. 성능시험을 통하여 개발 대상 ACM 및 열교환기는 요구 성능을 만족함을 확인하였다.

• 대한기계학회논문집B
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• 제33권8호
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• pp.596-603
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• 2009

The performance of proton exchange membrane fuel cell (PEMFC) is seriously changed by the humidification condition which is intrinsic characteristics of the PEMFC. Typically, the humidification of fuel cell is carried out with internal or external humidifier. A membrane humidifier is applied to the external humidification of residential power generation fuel cell due to its convenience and high performance. In this study, a simple static model is constructed to understand the physical phenomena of the membrane humidifier in terms of geometric parameters and operating parameters. The model utilizes the concept of shell and tube heat exchanger but the model is also able to estimate the mass transport through the membrane. Model is constructed with FORTRAN under Matlab/$Simulink^{(R)}$ $\Box$environment to keep consistency with other components model which we already developed. Results shows that the humidity of wet gas and membrane thickness are critical parameters to improve the performance of the humidifier.