• Journal of Biosystems Engineering
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• 제24권1호
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• pp.31-40
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• 1999

The objective of this study were to develop a cooling simulation model for fixed-bed of rough rice and to analyze the factors affecting cooling time of rough rice. A computer simulation model based on equilibrium conditions between grain and air was developed to predict temperature and moisture content changes during cooling of rough rice. the result of t-test showed that there were no significant differences between predicted and measured temperature changes on significance model agreed well with measured values. This cooling simulation model was applied to analyze the effect of some factors, such as air flow rate, cooling air temperature and humidity, initial grain temperature and moisture content, and bed depth, on cooling time of rough rice. Cooling rate increased with increase of air flow rate and bed depth whereas it decreased with increase of cooling air temperature and humidity and initial grain temperature. Among these factors, the most important factor was air flow rate. Specific air flow rate of 0.35㎥/min㎥ was required for cooling rough rice in 24 hours.

• 한국환경과학회지
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• 제19권2호
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• pp.125-136
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• 2010

The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. A sensitivity analysis of indoor environment factors was carried out to grasp influences along with changes of atmospheric conditions. An integrated multizone model was used to predict these sensitivities. This model was applied to an apartment with six zones. Airflow rates are influenced very seriously by changes of wind direct or wind velocity, but are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air temperatures are influenced very directly by changes of outdoor air temperature, but are influenced very slightly by wind direction or wind velocity and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air humidities are influenced very directly by changes of outdoor air humidity, but are not influenced at all by changes of outdoor air contaminant concentration and have little or no influence by changes of wind direction, wind velocity, or outdoor air temperature. Indoor air contaminant concentrations are influenced very seriously by changes of wind direct or wind velocity, but are influenced somewhat by changes of outdoor air contaminant concentration and are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity.

• International Journal of Air-Conditioning and Refrigeration
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• 제9권3호
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• pp.36-45
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• 2001

During the last decade, an increasing interest in Underfloor Air-Conditioning (UFAC) systems has emerged. The purpose of this paper is to evaluate the indoor environmental performance of office buildings with UFAC system in order to develope the design prototype of this system. The physical measurements and the Interviewing survey of occupant's sensation responses to the environment were carried out. Measurements and survey were made of the thermal environmental factors such as air temperature, relative humidity, air velocity, globe temperature, and the other several environmental factors such as the sound level and the illuminance of working plane, etc. And, the air quality was evaluated by measuring the concentration of suspended particles, carbon monoxide, and carbon dioxide in the room. Furthermore, the paper appraises the various indoor environmental factors of the room by using post-occupancy evaluation (POE) method in office building with UFAC system, and thus, it suggests the basic data for assessing the indoor comfort based on field measurements and survey .

• 한국기후변화학회지
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• 제7권4호
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• pp.507-512
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• 2016

This study was conducted to classify agroclimatic zones in South Korea. To classify the agroclimatic zones, such climatic factors as amount of rainfall from April to May, amount of rainfall in October, monthly average air temperature in January, monthly average air temperature from April to May, monthly average air temperature from April to September, monthly average air temperature from December to March, monthly minimum air temperature in January, monthly minimum air temperature from April to May, Warmth Index were considered as major influencing factors on the crop growth. Climatic factors were computed from monthly air temperature and precipitation of climatological normal year (1981~2010) at 1 km grid cell estimated from a geospatial climate interpolation method. The agroclimatic zones using k-means cluster analysis method were classified into 6 zones.

• 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.

• 대한기계학회논문집B
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• 제30권12호
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• pp.1188-1195
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• 2006

This paper examines the critical air temperature at which frost formation does not occur on a cold plate in order to improve the efficiency of a heat pump. The critical air temperature on test points is obtained from numerical analysis and a correlation of the critical air temperature is derived as a function of frosting factors (air absolute humidity, air velocity, and cold plate temperature) by least square method. Experiments are carried out to verify the correlation proposed in this study, and the prediction obtained with the correlation agrees well with the experimental data. Based on the correlation, we propose the non-frosting regions according to frosting factors.

• 설비공학논문집
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• 제11권5호
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• pp.642-646
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• 1999

Factors governing the rate of heat exchange comprise the air temperature, the speed of air movement, relative humidity, and relation indoors. Recently, there are many researches on the transient analysis of indoor environmental factors such as the dry bulb temperature, relative humidity and air velocity in miniature models. The purpose of this study is to measure the environmental factors and to analyze and evaluate the characteristics of indoor environment with the different envelope structures using a granite dome model. According to the variation of humidity, the state of interior relative humidity for clay model has an equal tendency, although a little range of variation is shown in comparison to the cement model.

• 설비공학논문집
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• 제29권4호
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• pp.149-158
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• 2017

In general, the air-side j and f factors of evaporators or condensers are obtained through single-design tests performed under air-dry and wet-bulb temperatures. Considering that the indoor or outdoor air temperatures vary significantly during the operation of an air conditioner, it is necessary to confirm that the experimentally-obtained j and f factors are widely applicable under variable air conditions. In this study, a series of tests were conducted on a two-row slit-finned heat exchanger to confirm the applicability. The results showed that, for the dry-surface condition, the changes of the tube-side water temperature, water-flow rate, and air temperature had virtually no effect on the air-side j and f factors. For the wet condition, however, the f factor was significantly affected by these changes; contrarily, the j factor is relatively independent regarding this change. The formulation of the possible reasoning is in consideration of the condensation behavior underneath the tube. The wet-surface j and f factors are larger than those of the dry surface, with a larger amount for the f factor.

• International Journal of Air-Conditioning and Refrigeration
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• 제9권1호
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• pp.71-76
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• 2001

Factors governing the rate of heat exchange comprise temperature, air velocity, relative humidity, and relation indoors. Recently, there are many researches on the transient analysis of indoor environmental factors such as dry bulb temperature, relative humidity and air velocity in miniature models. The purpose of this study is to measure the environmental factors and to analyze and evaluate the characteristics of indoor environment in different envelop structures using granite dome models. The interior relative humidity is constant regardless of exterior humidity although a little range of variation is shown in comparison to the cement model.

• 한국조경학회지
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• 제28권2호
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• pp.39-48
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• 2000

The purpose of this study is to investigate the factors affecting temperature of urban parks to grasp the relationship between the land coverage in open space as well as the forest condition and decreasing city temperature by difference of purposed are. Futhermore, this research interpreted the relationship between wind direction, air temperature, the land coverage of the green space, the number of tree, green volume, height of tree and the mitigation of city temperature with the revolution analysis. The result of this study is that cool air in open space move leeward and decreasing city temperature is influenced by the difference of the land coverage in open space. Specifically, in order of the arbo $r_{-a}$rbor in the forest zone, the increase of the number of trees was related with temperature surrounding significantly. This study found that the use possibility of the green volume was recognized as the index of the green volume relative to air temperature surrounding. Green space of the city control area is more effective decreasing temperature than that of housing zone.