• 한국환경과학회지
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• 제9권4호
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• pp.303-309
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• 2000

The relationship between air temperature and sea surface temperature and studied using the daily air temperature and sea surface temperature data for 25 years (1970~1994) at 9 coastal stations in Korea. Seasonal variations of air temperature have larger amplitudes than those of sea surface temperature. The seasonal variations of air temperature leads those of sea surface temperature by 2 to 3 weeks. The anomalies of sea surface temperature and air temperature with time scales more than 1 month are more ghighly correlated than those of short term, with time scales less than 1 month. Accumulated monthly anomalies of sea surface temperature and air temperature for 6 months shwoed higher correlation than the anomailes of each month. The magnitudes of sea surface temperature and air temperature anomalies are related with the duration of anomalies. Their magnitudes are large when the durations of anomalies are long.

• Smart Structures and Systems
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• 제19권2호
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• pp.137-149
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• 2017

Under the interference of the temperature effect, the alternation of cable force due to damages of a cable-stayed bridge could be difficult to distinguish. Considering the convenience and applicability in engineering practice, simple air or cable temperature measurements are adopted in the current study for the exclusion of temperature effect from the variation of cable force. Using the data collected from Ai-Lan Bridge located in central Taiwan, this work applies the ensemble empirical mode decomposition to process the time histories of cable force, air temperature, and cable temperature. It is evidently observed that the cable force and both types of temperature can all be categorized as the daily variation, long-term variation, and high-frequency noise in the order of decreasing weight. Moreover, the correlation analysis conducted for the decomposed variations of all these three quantities undoubtedly indicates that the daily and long-term variations with different time shifts have to be distinguished for accurately evaluating the temperature effect on the variation of cable force. Finally, consistent results in reducing the range of cable force variation after the elimination of temperature effect confirm the validity and stability of the developed method.

• 한국군사과학기술학회지
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• 제4권1호
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• pp.264-273
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• 2001

The conjugate heat transfer from a protruding module in a horizontal channel with a variation of air temperature is experimentally investigated. It is an aim of this study is to estimate temperature difference between a module and air. This study is performed with a variation of parameters that are air temperatures($T_i,=25^{\circ}C{\sim}55^{\circ}C),$ thermal resistance($R_c=158 K/W),$ air velocities ( 4V_i=0.1$ m/s~l.5 m/s ), and input power (Q=3 W, 7 W ). The results show that as the thermal resistance increases, the effect of air temperatures are decreased. And input power was most effective parameter on the temperature difference between a module and air.

• 설비공학논문집
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• 제30권2호
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• pp.83-91
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• 2018

A datacenter is a high energy consuming facility whose cooling energy consumption rate is 10~20 times larger than general office buildings. The higher the temperature of supply air from a CRAC (computer room air-conditioner) is supplied, the more energy efficient cooling is possible because of improving the COP of a chiller and advanced range of outdoor air temperature available for the economizer cycles. However, because the temperature of cold air flowing into server computers varies depending on air mixing configurations in a computer room, the proper supply air temperature must be considered based on the investigation of air mixing and heat dissipation. By these, this study aims to understand the effects of variation of the supply air temperature on the air flow distributions, temperature distributions and rack cooling efficiencies. Computational fluid dynamics (CFD) aided in conducting the investigation. As a result, the variation of the supply air temperature does not affect the air flow distributions. However, it mainly affects the temperature distribution. From the results of CFD simulations, Rack cooling indices (RCIHI and RCILO) were evaluated and showed the ideal state set at $19^{\circ}C$ of the supply air temperature.

• 한국환경복원기술학회지
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• 제12권1호
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• pp.44-51
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• 2009

In order to determine air temperature difference by canopy layer in the forest, air temperatures were observed at Seolleung Park, Gahngnam-ku, Seoul. from November 9, 2007 to November 8, 2008 by 10 minute interval. The data were analyzed in terms of diurnal variation based on annual and monthly temperature difference. Using calm, less cloudy and no rainy weather data, average air temperature difference between forest and grass was observed as $0.8^{\circ}C$. The maximum air temperature difference was observed at 22:10, 23:20, 23:30 and 23:40 by $2.13^{\circ}C$ and the minimum one observed at 13:00 by $-0.84^{\circ}C$ in diurnal variation. The maximum temperature difference occurred at 19 : 50 on September by $3.67^{\circ}C$, Overall the air temperature in the forest was higher than that of grass at night and lower in midday.

• 한국군사과학기술학회지
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• 제5권2호
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• pp.195-206
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• 2002

The conjugate heat transfer from the simulated module in a horizontal channel with the variation of inlet air temperature is experimentally investigated. The aim of this study is to estimate temperature difference between a module and inlet air. This study is performed with the variation of parameters that are inlet air temperature(Ti=25~$55^{\circ}C), thermal resistance( $R_c$=0.05, 4.11, 158 K/W), inlet air velocity(Vi=0.1~1.5m/s), and input power(Q=3, 7 W). The results show that the effect of inlet air temperature is little, at the case of using conductive board. And input power was most effective parameter on the temperature difference between module and Inlet air.

• 설비공학논문집
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• 제26권12호
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• pp.553-558
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• 2014

Geothermal energy can be used with a geothermal heat pump or an earth-to-air heat exchange system (EAHES), which is referred to as a "cooling tube" in Korea. In this study, we suggest EAHES burial guidelines in terms of the parameters of buried pipe length and air velocity regarding the exit air temperature of EAHES. The exit air temperature for EAHES in three regions (Changwon, Busan and Seoul) was calculated with variation in buried pipe length and air velocity at ${\Phi}100mm$ and ${\Phi}200mm$. In conclusion, variation in the buried pipe length is more effective than that of air velocity to achieve the required exit air temperature.

• 한국환경복원기술학회지
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• 제13권1호
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• pp.32-39
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• 2010

The air temperature-reducing effects by irrigation reservoir in urban area was investigated at Ilwol Pond (IWP). Air temperature and humidity data were observed at 10minute interval from September 1th, 2008 to August 31th, 2009. Air temperature of IWP and Sumsung Apartment (SAT) were analyzed to examine air temperature-reducing effects by IWP in terms of diurnal and seasonal variation. As a result, the average air temperature difference between IWP and SAT was $0.6^{\circ}C$ and the nighttime shows more air temperature-reducing effects. The dominant air temperature-reducing effects by IWP occurred at fall night and summer daytime. However, the air temperature-reducing effects by IWP is lower to that by Arboretum (ARB).

• 생물환경조절학회지
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• 제19권3호
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• pp.165-170
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• 2010

본 연구는 감나무 생육 및 과실 특성의 연차 변이에 대한 주요 기온 요인을 알아보고자 수행하였다. 연차 변이는 3월과 4월의 평균기온, 적산일수 빛 적산온도에서 가장 컸다. 25개 기온 요인 중 제1주성분으로는 연 평균 기온 요인들 14개, 제2주성분으로는 4월 기온요인들 3개로 추출되었으며 그 누적 기여율은 52.2%이었다. 제1주성분에 양의 영향력을 크게 받은 연도는 1990년, 음의 영향력을 크게 받은 연도는 1980년과 1986년으로 나타났다. 감나무의 전엽일, 개화일 및 과실 성숙일의 연간 편차는 4.0~6.7일 범위였으며 변이계수는 개화일, 전엽일에서 개화일까지의 일수가 가장 켰다. 그리고 파실 특성 중 과중, 당도, 경도는 연차 변이가 적었으나, 종자수는 평균 4.0개, 연간 편차 1.3개, 변이계수가 32.8로 연차 변이가 가장 컸다. 감나무 생육 및 과실 특성과 기온 요인들 간 다중회귀분석 결과, 개화일에서 과실 성숙일까지의 일수는 10월의 평균기온 및 적산일수, 전엽일에서 개화일까지의 일수는 4월 평균기온, 과중은 3월 평균기온과 10월 평균기온의 영향을 가장 크게 받은 것으로 나타났다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.446-451
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• 2008

Air washer remove dust on the air and use for humidification. But the last should be applied to the semiconductor and FPD industry, air washer has focused on removing pollutants. In addition, air washer within the clean room remove the pollutants as well as use for humidification in Winter. However, there is no research in the country, and for research purposes, the evaluation was conducted by atomizing water temperature variation and L/G variation. Performance evaluation results are the same conditions as the entrance of air washers ($23^{\circ}C$, 45%RH). Cooling effect is enhanced when atomizing water temperature is lower. The larger the performance of humidification to L/G lower the temperature increases.