• 한국자동차공학회논문집
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• 제18권5호
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• pp.115-123
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• 2010

Cool-down performance after soaking is important because it affects passenger's thermal comfort. The cooling capacity of HVAC system determines initial cool down performance in most cases, the performance is also affected by location, and shape of panel vent, indoor seat arrangement. Therefore, optimal indoor designs are required in developing a new car. In this paper, initial cool down performance is predicted by CFD(computational fluid dynamics) analysis. Experimental time-averaging temperature data are used as inlet boundary condition. For more reliable analysis, real vehicle model and human FE model are used in grid generation procedure. Thermal and aerodynamic characteristics on re-circulation cool vent mode are investigated using CFX 12.0. Thermal comfort represented by PMV(predicted mean vote) is evaluated using acquired numerical data. Temperature and velocity fields show that flow in passenger's compartment after soaking is considerably unstable at the view point of thermodynamics. Volume-averaged temperature is decreased exponentially during overall cool down process. However, temperature monitored at different 16 spots in CFX-Solver shows local variation in head, chest, knee, foot. The cooling speed at the head and chest nearby panel vent are relatively faster than at the knee and foot. Horizontal temperature contour shows asymmetric distribution because of the location of exhaust vent. By evaluating the passenger's thermal comfort, slowest cooling region is found at the driver's seat.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권1호
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• pp.7-12
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• 2013

$SnO_2$ (tin oxide) 박막은 물리적, 전기적 성질이 우수하여 첨단산업의 다양한 분야에서 널리 응용/개발되고 있다. 이의 응용대상은 다양한 센서, 윈드쉴드(windshield) 윈도우의 히팅 요소, 태양전지, flat panel diplay에서의 투명전극을 들 수 있다. 본 연구에서는 대면적 기판에 대한 APCVD 공정개발을 위하여 실험용 2세대 크기의 유리기판에 $SnO_2$ 박막증착 실험을 수행하였다. 증착 온도가 증가함에 따라 증착 두께가 두꺼워지고 이에 따라 면저항은 감소, 투과도는 감소, 연무도 (haze)는 증가함을 확인하였다. 증착을 위한 전구체인 $SnCl_4$의 유량이 증가함에 따라 증착 두께 역시 증가하고 이에 따라 면저항은 감소한다. 그러나 투과도와 연무도는 $SnCl_4$ 유량의 영향을 거의 받지 않는다는 것을 확인하였다.

• 한국농공학회논문집
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• 제47권3호
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• pp.29-37
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• 2005

This study was carried out to file up structural design data for optimizing Pleurotus eryngii growing houses. Design data are including current farm status of Pleurotus eryngii growing houses in the aspect of structural configuration as well as environmental conditions to be controlled and maintained inside. A structural analysis was performed for the on-farm structures as well as some structures modified and suggested through field survey and analysis. The results are summarized as follows. According to the results of status analysis, Pleurotus eryngii growing houses were categorized as arch-roofed simple type and sandwich panel type. Though the size of Pleurotus eryngii cultivation facilities were considerably diverse, the basic dimensions of Pleurotus eryngii cultivation facilities showed relatively similar pattern: more or less of 20m of length, $6.6\~7.0m$ of width, $4.6\~5.0m$ of peak height, $1.2\~1.6m$ of bed width, and 4 layers of bed. In the aspect of spatial use of cultivation facilities, suggested models were shown to be mostly reasonable in the aspect of heating and cooling, micro-meteorological stability, land use efficiency per unit floor area, etc.. Especially, the standard models suggested so far were thought to be not efficient in its surface area and spatial volume per unit floor area as well as its uneffective structural design in the area around ceiling. In the results of structural analysis for the models suggested through this study by using those section frames to be found on farms, the panel type structures of both single span and double span were estimated to be over designed, whereas arch-roofed pipe houses were mostly found to be under-designed.

• 한국화재소방학회논문지
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• 제27권4호
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• pp.41-46
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• 2013

본 연구는 가구류를 구성하는 주요 재료의 열적조건에 따른 반응특성과 화염전파해석에 필요한 열해리 물성을 제공하기 위해 열중량분석을 수행하였다. 실험대상 시편은 가구류에 널리 적용되는 MDF 판재와 코팅재, 합성피혁과 쿠션재 등이며 가열율 $10^{\circ}C/min$, 최대 온도 $600^{\circ}C$까지 실험을 수행하였다. 실험결과 MDF 소재의 경우 $324^{\circ}C$에서 피크 반응을 나타냈었으며 MDF 코팅재의 경우 초기 피크반응온도가 $270{\sim}280^{\circ}C$로 감소하였다. 합성피혁과 폼 소재의 경우 재료를 구성하는 폴리머의 종류에 따라 기준온도와 기준 반응율이 차이를 보였으나 기준온도는 $270^{\circ}C$와 $420^{\circ}C$ 정도로 비교적 유사한 경향을 나타냈다. Lyon 등이 제시한 방법에 의해 반응상수와 활성화 에너지를 산정하기 위해 시편의 기준 온도와 기준 반응율을 제시하였으며 이러한 기초 물성연구를 통해 화염전파특성을 이해함과 동시에 화재해석의 신뢰성을 향상시키는데 기여하고자 한다.

• 한국항공우주학회지
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• 제36권12호
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• pp.1216-1221
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• 2008

본 논문에서 고려된 저궤도 위성은 고정형 태양 전지판을 가지기 때문에 낮구간(daylight) 동안에 태양전지판이 태양지향(sun-pointing) 자세를 유지하고, 관측 임무 수행을 위해 태양 전지판 방향과 반대방향에 위치한 탑재체가 지구지향(nadir-pointing)이 되도록 자세를 변경한다. 이 때 낮기간의 대부분을 차지하는 태양지향 자세에서는 위성 패널(panel)로 입사하는 외부 열환경 요인이 지구 복사열과 알비도(Albedo)이기 때문에, 비교적 안정적인 열환경 조건을 가지고 있다. 이에 반하여, 관측 임무를 수행하는 궤도 10% 정도의 지구지향 자세에서는 위성의 열환경 조건에 가장 지배적인 영향을 주는 태양광이 위성 패널에 영향을 준다. 비록 위성이 비교적 짧은 시간 동안에 지구 지향의 자세를 유지하지만, 이러한 열한경 조건의 변화 때문에 위성의 열설계에서 지구지향의 임무 자세에 따른 열적 영향에 대한 검토가 필요하다. 본 연구에서는 열해석 모델에 관측 임무 구간 동안의 지구지향 자세를 반영한 열해석 결과를 통하여 그 영향을 알아보았다.

• 설비공학논문집
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• 제28권11호
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• pp.458-465
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• 2016

The purpose of this research is to improve the thermal effiency of solar collector and to quantitatively analyze its performance. Solar thermal systems have been limited to water heating systems mainly using low-temperature range. However, through diverse developments, the application has been extended to medium- and high-temperature fields such as solar heating, solar air conditioning, and solar thermal industrial process. Among the diverse research, this research is specially focusing on enhancement of the thermal performance by minimizing the heat loss coefficient of flat plate solar collectors. In order to do it, a front-side glazing material and a back-side insulation material with high insulated structure is proposed and based on computational analysis, the performance of energy collecting volume of the proposed solar collector is analyzed. The research shows that the proposed structure has the excellent performance at medium- and high-temperature range. therefore, it is expected that the proposed structure can easily replace existing technologies.

• 대한가정학회지
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• 제28권3호
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• pp.67-85
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• 1990

The purpose of this study was (1) to investigate changes in house and kitchen forms and behaviors in the kitchen area of Korean family houses from the Yi-dynasty to the present, and (2) to develop a housing conceptual framework on the basis of the ecosystem approach through analysis of changes in Korean family houses. The documentary research method wad used fro this study. The major findings were that the traditional Korean houses were composed of separate buildings and had various floor levels with the maru(a wooden floor) as the center of the open plan. The introduction of foreign style house forms from the era of enlightenment, in the year 1876 to the Korean war in 1950 changed traditional Korean houses into Korean-western style houses. More recent increased population and urbanization accelerated to change from the traditional Korean house form to an apartment style. At the present time, however, many kinds of house forms, from a highly modernized style with convenient facilities to a primitive style, which cannot even meet the basis needs of daily life, coexist together. The Kitchens in traditional Korean houses had no plumbing, drainage, or work centers. They had simple adobe furnaces which were used for cooking and for heating the ondol, a kind of panel heated floor by which the heat and smoke run under the floor to the chimney. This made the kitchen floor level lower than the floors of other spaces. The residents entered the kitchen through the madang(atrium). The influence of the western style kitchen, the development of technology, and improvements of nation-wide economic status have made today's kitchen space covenient and hygienic. The floor level of the kitchen was raised to the same level of other spaces. Formerly the major function of the kitchen was raised to the same level of other spaces. Formerly the major function of the kitchen space was cooking and heating floors. This had changed, and the kitchen is now, the place for family and social interaction. A housing conceptual framework was developed on the basis of these findings.

• 한국식품조리과학회지
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• 제11권1호
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• pp.44-50
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• 1995

건조표고버섯, 생표고버섯, 느타리버섯, 양송이버섯을 조리방법을 달리하여 조리한 후 기계적, 관능적 특성을 측정한 결과는 다음과 같다. 1. 느타리버섯 갓의 응집성과 탄성에 있어서는 조리방법간에 유의차가 없었으나 그외의 다른 버섯들의 경도, 응집성, 탄성, 점착성, 씹힘성은 조리방법별 시료간에 모두 유의한 차이를 보였다. 2. 생표고버섯은 Microwave 처리에 의해 모든 기계적 측정치가 낮아졌으나 그 외의 버섯들은 Microwave처리에 의해 전 기계적 특성들에 있어서 높은 측정치를 나타내었고 소금물로 데친 시료의 Texture 측정치는 가장 낮은 값을 나타내었다. 3. 가열조리의 관능검사에 있어서는 튀김과 볶음조리에 대한 기호가 가장 높았고 데침, 찜, Microwave처리군 중에서는 소금물로 데친 시료의 기호도가 가장 높았다. 4. 버섯요리의 관능검사결과 튀김요리를 제외한 회, 볶음, 전, 전골요리에 있어서 각 연령집단간에 유의한 차이가 있었다. 회, 볶음, 튀김, 전에서 성인집단이 가장 높은 기호를 보였고 튀김은 중학교 여학생이, 전골은 고등학생집단이 가장 선호하였다. 전체적으로 보았을때 전골, 회, 튀김, 볶음, 전의 순으로 버섯요리에 대한 선호도가 높았다.

• Journal of Nutrition and Health
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• 제49권3호
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• pp.201-212
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• 2016

Purpose: Needs for reevaluation of food code standards and regulations for cooked foods produced in restaurants and institutional foodservice to minimize risk factors leading to foodborne outbreaks are on the rise. The purpose of the study was to propose updated standards for cooked foods of restaurants by testing whether or not experts agree to include them as a standard. Methods: Qualitative and quantitative research methods were applied via a survey by email and workshop hold for experts panel discussions. Results: Seven newly proposed standards were selected as follows: (1) sanitizing vegetables and fruits with no heating process after washing, (2) rapid cooling of cooked foods after heating process, (3) monitoring cooking temperatures, (4) minimum 2 hours holding after cooking for temperature control of safety (TCS) foods without temperature control, (5) banning practices for workers such as bare hands handling of ready-to-eat foods, (6) maintaining cleanliness of food contact surfaces for disposable products, and (7) cold holding standards for sushi. Conclusion: The proposed proposal can be utilized as control measures for preventing foodborne illness in restaurants. However, a feasibility study should be conducted to test whether they are applicable to the field of restaurant operation.

• 한국화재소방학회논문지
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• 제23권3호
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• pp.110-120
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• 2009

터널의 경우 타구조물에 비해 화재빈도가 상대적으로 높지는 않으나, 밀폐된 공간이라는 특성상 5분 이내 $1000^{\circ}C$ 이상으로 급격한 온도상승이 발생할 수 있으므로, 화재발생시 대형 인명피해 및 화재 후 막대한 보수 보강비용이 파생된다. 이러한 터널화재로 인한 구조적 손상을 규명하기 위해, KS F 2257-1과 EFNARC 규정에 부합하고 터널 콘크리트 라이닝의 화재손상평가가 가능한 가열로를 개발하였다. 개발된 가열로를 실증실험에 사용하여 터널화재 시나리오(ISO, $1^{\circ}C$/SEC, MHC, RWS)에서의 콘크리트 PC패널라이닝의 폭렬특성과 화재손상범위를 ITA기준을 적용하여 평가하였다. 실증실험결과 ISO 화재조건에서는 30mm, $1^{\circ}C$/SEC에서는 20mm, MHC에서는 100mm, RWS에서는 50mm로 화재손상범위가 평가되었으며, 폭렬깊이는 RWS와 MHC 화재조건에서 30mm가 발생하는 것으로 나타났다.