• Journal of Biosystems Engineering
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• 제24권4호
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• pp.335-342
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• 1999

Air and flue gas temperature distributions in the space heater for greenhouse were measured to develop a thermal design technology for the space heater. Also, the characteristics of the fan supplying air to the space heater were investigated. The temperature of the flue gas inside the flue gas tube was linearly decreased as the lenght of than those of the flue gas with the oxygen concentration of 8.25% at the last exit of the second flue gas tube. Thus, the operating efficiency of the space heater could be increased with low air ratio decreased exhausting gas temperature and saved the energy consumption with decreased excess air flow. The temperature of the air supplied by fan was increased slowly around the first flue gas tube, meanwhile, increased sharply around the second flue gas tube due to large LMTD (Logarithmic Mean Temperature Difference) at the first flue gas tube than which of the second flue gas tube.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1313-1318
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• 2000

Crack behaviors at the downstream face of the concrete gravity dam were studied considering influence of the wintertime air temperature. It is assumed that inside area of 15m away from the dam surface in which temperature is presumed to be $15^{\circ}C$ is not affected from the annual air temperature variation. Water temperature at the upstream face and air temperature at the other faces were considered as outer boundary conditions to get temperature distribution inside of the dam using ADINA-T. These temperature distributions were transferred to FRANC2D to obtain equivalent stress intensity factors and crack propagation paths. Results obtained from changing initial crack locations and direction, air temperatures, and water levels were discussed. And crack behaviors at the upstream face were studied partly.

• 한국토양비료학회지
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• 제28권3호
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• pp.266-269
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• 1995

볏짚을 사용한 구(볏짚 5톤+NPK:110-70-80kg/ha)와 볏짚을 사용하지 아니한 구(NPK : 110-70-80kg/ha)에서 벼의 출수기에 2시간 간격으로 메탄 배출량을 24시간 측정하고 지온(地溫)과 기온(氣溫)의 변화(變化)에 따른 상관관계(相關關係)를 고찰하였다. 1. 볏짚을 사용하지 아니한 삼요소구(三要素區)에서는 메탄배출은 지온(地溫)의 변화와 상응하게 변화하나 기온 상승이 급격한 오전 11시부터 오후 5시까지는 메탄배출량이 기온상승에 부응하는 증가경향을 보이지 않았다. 2. 볏짚을 시용한 삼요소구(三要素區)에서는 메탄 배출의 일 변화 양상이 지온의 변화와는 상관이 적고 기온이 상승하는 오전 11시~오후 5시에 매탄배출량이 급격히 증가하여 기온의 변화와 상관이 깊어 보였다. 3. 메탄 배출에는 지온(地溫) 외에도 기온(氣溫)과 메탄생성의 기질(基質)이 되는 유기물(有機物)의 존재(存在)가 중요함이 인정되었다.

• Agricultural and Biosystems Engineering
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• 제3권2호
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• pp.65-72
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• 2002

Temperature is the most influential environment parameter which affects the quality change of agricultural products in cold storage. Therefore, it is essential to keep the uniform temperature distribution in the storage room. This study was performed to analyze the air movement and temperature distribution in the forced recirculating cold storage facility and to simulate optimum storage method of green groceries using 3-D CFD(three dimensional computational fluid dynamics) computer simulation which applied the standard $textsc{k}$-$\varepsilon$ turbulence model and FVM(finite volume method). The simulation was validated by the experimental results for onion storage and the simulation model was used to simulate the temperature and velocity distribution in the storage room with reference to the change of storage method such as location of storage, no stores, bulk storage, and pallet storage. In case of no stores, internal airflow was circulated without stagnation and consequently air movement and temperature distribution were uniform. In case of bulk storage, air movement was stagnated so much and temperature distribution of onion was not uniform. Furthermore, the inner temperature of onion roses more than the initial temperature of storage. In case of pallet storage, air movement and temperature distribution of onion were so uniform that the danger of quality change was decreased.

• 한국자동차공학회논문집
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• 제1권1호
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• pp.22-31
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• 1993

Spark-ignition engine knock is affected by engine operating conditions such as engine speed, spark timing and intake air temperature. In this study the effect of intake air temperature on knock characteristics was studied experimentally using a 4-cylinder carburetor spark-ignition engine. The cylinder pressure data at 2000rpm were taken for intake air temperature range of $30^{\circ}C$ to $80^{\circ}C$ with $10^{\circ}C$ interval. And 80 consecutive cycles were taken at each experimental condition. As the same spark timing, as the intake air temperature increased by $50^{\circ}C$, the mean knock intensity increased about 20kPa. This effect corresponds to that of spark timing advance of 3 crank angle degrees.

• 한국주거학회논문집
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• 제20권3호
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• pp.105-112
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• 2009

The purpose of this study is to investigate a top floor, indoor, thermal environment by comparison between the indoor air temperature and the rooftop surface temperature, and between the indoor air temperature and the outdoor air temperature using an experimental model. The model experiment was conducted with 4 cases,: no-rainfall, 1 em-height, 10 em-height and 20em-height of rainfall on the rooftop. According to the results of the height of stored rainfall, the average air temperature difference between the indoor and outdoor air with 1, 10 and 20 em-height of rainfall on the rooftop was $4.0^{\circ}C$, rooftop $1.2^{\circ}C$ and rooftop $1.0^{\circ}C$, respectively. The upper 10 em-height of rainfall on the rooftop acted to decrease the indoor air temperature on the top floor.

• 응용통계연구
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• 제5권1호
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• pp.59-80
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• 1992

본 논문의 목적은 서울지방 겨울기온의 예측을 위한 확률모델의 개발과 그 응용에 있다. 겨울기온의 회귀추세, 주기성 그리고 종속성들의 연중, 연간변동을 과거 30년(1959-1989) 일일자료를 기초로 하여 분석하였다. 기온예측을 위한 확률모델을 개발하고 그 응용을 위한 통계적 절차를 제안하였다. 겨울철기온의 특성인 이상기온의 출현과 삼한사온현상의 실체도 논하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.189-200
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• 1999

Combustion characteristics of a regenerative combustor for high temperature air combustion have experimentally studied. Temperature measurement on regenerative ceramic material and combustor has been carried out with changing equivalence ratio at constant turn-over period. Stable and unstable combustion region have been found and also detailed averaged temperature profile with respect to various air flow conditions have been obtained.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.648-653
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• 2001

This study represents the numerical analysis of natural convection of a microenvironments with a air permeability in the clothing air-layer. The clothing air layer of shoulder and arm was used for numerical analysis model. As a numerical analysis method, we adopted a finite volume method for two-dimensional laminar flow, and analyzed the flow and thermal characteristics of velocity, temperature and concentration in the air layer between body and clothing. As a temperature boundary conditions, we considered that a body skin has a high temperature with $34^{\circ}C$ the environmental temperatures are $5,\;15\;and\;25^{\circ}C$ for various permeability coefficients. The distributions of concentration, temperature and velocity were showed that two large cells were. formed at horizontal and vertical air layer, respectively. As the temperature difference between body skin and environment decrease, the heat transfer was decreased rapidly.

• 한국연소학회지
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• 제3권1호
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• pp.49-57
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• 1998

High temperature preheated and diluted air combustion has been developed as the technology to realize higher thermal efficiency. In this type of combustion, there are many interesting phenomena which cannot be observed in room temperature air combustion. The characteristics of the combustion, investigated using a 3500 kcal/h LPG fired test facility, are described. The flame is demonstrated to have a blue and green in color and has a large volume. As the preheated air temperature increased up to $1000\;^{\circ}C$, the NOx emission incrased exponentially over a few hundred ppm with 11% $O_2$ correction. But, it drastically reducedabout 20ppm when the air was diluted from 21% $O_2$ to 5% $O_2$.