• Solar Energy
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• v.18 no.1
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• pp.57-67
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• 1998

A study on a buoyancy effect by the temperature difference between a inner room air and a inflowing cool air and also by Inlet velocity can contribute greatly to enhance performance of air conditioning system, so the study on the distribution characteristics of inflowed cool air is important to analyze the cool air storage in a room. For this study, in the real-sized model room, the temperature differences between inflowing cool air and inner room air are 10, 20, $30^{\circ}C$, and the inlet velocities of inflowing cool air are 1, 2, 3m/s respectively as dynamic parameters. Also, a anemos and a vane type diffuser are used as inlet geometric conditions. Following conclusions have been obtained through this study. 1) In case of the anemos type diffuser, it is found that a dimensionless temperature profile is low and the distribution of the inflowed cool air is uniform. and also, all diffuusers have a low temperature of the inner room as increasing the inlet velocity. 2) A mixing takes place rapidly in case of the anemos type diffuser when the temperature difference is low ${\Delta}T=10^{\circ}C$ and the inletvelocity is high V=3m/s. and the mixing degree is higher with the anemos type diffuser than the vane.

• Land and Housing Review
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• v.5 no.4
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• pp.291-296
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• 2014

The apartment buildings were hard to emission of water vapor by reduced infiltration. The purpose of this study was to investigate the generation of indoor temperature and humidity in the recent construction of small size apartment buildings. The temperature and humidity were measured in 3 apartments in Seongnam and Daejeon city. During the winter indoor temperature and relative humidity were measured ranged from 20 to $24^{\circ}C$ and 40 to 60%. Generated humidity caused by various characteristics of the residents, rather than external influences. Compare daytime (6:00 to 22:00) and nighttime (22:00 to 6:00), the temperature is low and absolute humidity is high at nighttime. Condensation is likely to occur at nighttime. Using the cumulative relative frequency and absolute humidity, small apartments design criteria (temperature, relative humidity) can be set.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.389-392
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• 2018

In this paper, we try to make a pleasant environment by adjusting the fan moving by temperature and humidity in hot and humid room. To do this, we propose a fuzzy-based fan control using room temperature and humidity, collect environment data such as indoor temperature and humidity using Arduino, transmit it to Bluetooth communication, and adjust the operation time of fan according to fuzzy logic. To do this, connect a temperature and humidity sensor to the Arduino hardware, write the source code using the Arduino program on your computer, and code it in Arduino. Then, the environmental data obtained after collecting environmental data such as humidity from Arduino is transferred to the Arduino Control Module through Bluetooth communication. We use the fuzzy logic to control the time of fan operation according to environmental data such as temperature and humidity. At the end of this process, the fan will operate according to temperature and humidity to create a pleasant environment. Through this study, Arduino was simpler and easier to use than I thought, and I think it's easy to use and can be used in real life by using Arduino hardware, data acquisition, fuzzy logic, and control.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.19-24
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• 2000

밀폐된 실내에서 화재현상을 예측하기 위한 해석 방법은 Zone 모델과 Field 모델로 대별된다. Zone 모델은 상부층과 하부층의 온도, 시간에 따른 연기층의 높이 등을 실험값을 대입한 간단한 대수식으로 계산하여, 계산이 간편한 장점이 있으나 각 위치에 대한 온도와 유속을 구할 수 없다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.88-89
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• 2001

꿀벌의 실내월동에 이용되는 월동용 저온양봉사의 내부환경에 영향을 주는 요소에는 외기온, 저장봉군수, 환기량 등이 있다. 이러한 환경요인을 고려하여 설계 제작된 국내 월동용 저온양봉사의 성능 및 저장봉군수와 양봉사 내부온도의 관계를 분석하고자 경상북도의 7개 지역에 설치된 월동용 저온양봉사(내부크기 폭4.5m×길이3m×높이3m)에 대하여 2000. 11. 25부터 2001, 2. 15까지 실내월동 실험을 수행하였다. 실험대상 지역은 포항, 문경, 상주, 칠곡, 성주, 영양, 안동이며, 지역별 저장봉군수는 각각 14, 74, 85, 110, 163, 170, 260군이다(Table 1). 꿀벌의 월동기간 중 안동과 성주지역을 제외한 5개 지역의 실내 월동성적은 폐사율이 10％미만으로 대체적으로 우수한 것으로 조사되었으나, 월동기간중 지역별 외기온을 분석한 결과, 평균외기온 및 최저외기온이 가장 낮은 지역은 안동이었으며, 그 값이 각각 -3.1℃와 -9.4℃일 때 양봉사 내부의 평균온도와 최저온도는 5.2℃와 3.8℃로 나타났다. 반면에 평균외기온 및 최저외기온이 가장 높은 지역은 포항이었으며 그 값이 각각 1.3℃와 -4.1℃일 때 양봉사 내부의 평균온도와 최저온도는 각각 3.1℃와 1.2℃로 나타나 저온양봉사 내부의 온도환경 조절성능이 모두 우수한 것으로 판단되었다(Table 1). 또한 월동기간중 주.야간으로 양봉사 내.외부의 온도변화를 분석한 결과, 저장봉군수의 증가에 따라 주야간 모두 양봉사 내.외부 온도편차가 증가하는 경향을 나타내었으며 양봉사 내부의 주.야간 평균온도는 모두 꿀벌의 월동에 적정한 범위인 2℃-9℃를 유지하는 것으로 분석되었다(Table 2). 그리고, 월동기간중 외기온이 가장 낮은 시기(1월 13-19일)의 평균 외기온이 -8℃--9℃로 유사한 문경, 상주, 영양, 안동지역의 월동용 저온양봉사의 평균 내부온도는 각각 -2.0℃, -1.0℃, 0.2℃, 4.2℃로 나타나 저장봉군수가 증가함에 따라 월동용 저온양봉사의 내부온도가 증가하여 꿀벌의 월동에 적합한 온도범위를 유지함을 알 수 있었다. 실험기간동안 대부분의 저온양봉사 내부온도는 꿀벌이 월동하기에 적정한 온도범위(2℃-9℃)로 유지하였다(Fig. 1).

• Geophysics and Geophysical Exploration
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• v.19 no.3
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• pp.121-130
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• 2016

Several factors are discussed that should be considered in measuring thermal conductivity of rock cores with a PEDB (potable electronic divided bar) system, which is relatively accurate and easy to operate, and can measure the thermal conductivity of rock cores for various diameters. Then the system is applied to measure thermal conductivity of 70 rock cores from Ulleung Island. Air temperature affects most on the thermal conductivity measurements, so that it is very important to minimize the temperature change during the measurement. Other factors such as the temperature of heat source, averaging time window on the thermal conductivity measurements do not affect much compared to air temperature. Slightly higher thermal conductivity is measured when using the thermal contact paste between the sample and heat source or heat sink. Especially, rock cores with irregular surface showed bigger difference. Repeatability showed less than ${\pm}0.3%$ for standard samples and less than ${\pm}4%$ for rock samples, respectively, when the room temperature changes within $1^{\circ}C$ during the measurements. Thermal conductivity of the rock cores from Ulleung Island roughly increases as depth increases but does not show any dependency on the rock types.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.102-106
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• 1997

본 연구는 실내 온열환경에 대한 인간의 온냉감을 정밀하게 평가하기 위해 바닥난방이 실시되고 있는 겨울철 아파트의 거실에 대하여 공간내의 온도분포를 조사하는 동시에 신체부위별로 온냉감을 조사하였다. 실내의 온도분포 측정은 서울과 부산의 두 장소에서 실시하였으며, 온냉감에 대한 평가는 서울에서 남자 31명, 여자 71명, 부산에서 남자 11명, 여자 23명에 대하여 수행되었다. 결과는 중앙집중식 난방이 실시되고 있는 거실의 바닥으로부터 10cm높이와 170cm 높이에서의 온도차이는 서울의 아파트가 3.2 $^{\circ}C$, 부산의 아파트가 2.$0^{\circ}C$로 나타났다. 겨울철 실내의 온냉감 조사는 하루 3 회 실시되었으며, 신체의 3개부위에 대한 온냉감과 전체적인 온냉감이 7점 척도로 평가되었다. 결과는 발과 얼굴, 무릎과 얼굴, 발과 전신사이에 온냉감의 차이가 있는 것으로 나타났다. 발과 무릎 부위가 얼굴에 비하여 추운느낌을 강하게 가지며, 전체적인 온냉감은 얼굴부위에서의 평가와 유사한 수준을 나타냈다. 난방이 단순한 온도조절의 범위를 넘어 인체의 온열쾌적감을 만족시키기 위해서는 신체의 부위별로 느끼는 온냉감을 정밀하게 평가하여 난방의 방법을 조정하여야 하는데, 이 연구의 결과는 난방의 방법 결정에 기초자료로 활용될 수 있을 것이다.

• Fire Science and Engineering
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• v.19 no.4 s.60
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• pp.18-25
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• 2005

In this study, numerical analysis of two-dimensional unsteady natural convection of air in a square enclosure heated from below, was performed as a basic research of fire science. SIMPLE algorithm was used to the pressure term of momentum equations in the numerical analysis. The numerical analysis were studied for the two model cases and two heat conditions, respectively, which are different with insulation of enclosures and position of heat applied. Also, the ceiling temperatures of enclosure were measured to compare the accuracy of numerical analysis, and it is found that the temperature predicted by numerical analysis were agreed well with the measurements. Streamline and isotherm of the each model case were acquired for each time step.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.326-328
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• 2015

Function of the window of the building is an environment of the room through the entry of solar radiation. It is vulnerable to significant energy conservation off the thermal efficiency. Also this summer, cooling costs are weighted because of excessive solar radiation. In this paper, we develop a windows automatic control system to use the indoor environmental information, such as home temperature, humidity, light intensity, solar radiation. The system collects the indoor environment information using a variety of sensor, using the collected information, and controls the motor to the system to control the window.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.4
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• pp.213-220
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• 2016

The objective of this study is to investigate the cooling performance of an air-conditioning system for a special purpose vehicle under tropical and severe weather conditions. In order to evaluate and compare the cooling performances, the dual refrigeration cycle using R-134a was tested on a special purpose vehicle with various refrigerant charge amounts and indoor temperatures. The cycle was tested considering indoor cooling speed and compression ratio (discharge pressure), and was optimized at the refrigerant charge amount of 1.5 kg and outdoor temperature of $40.0^{\circ}C$. The time to reach indoor temperature of $15.0^{\circ}C$ increased by 86.5% and 38.1%, at the indoor temperatures from $25.0^{\circ}C$ to $32.5^{\circ}C$ and from $32.5^{\circ}C$ to $40.0^{\circ}C$, respectively. In addition, with the increase in indoor temperature from $25.0^{\circ}C$ to $40.0^{\circ}C$, the cooling capacity increased by 7.3%, from 19.1 kW to 20.5 kW, but decreased by 7.0% from 4.67 to 5.1.