• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.3
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• pp.74-82
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• 2003

Under the assumption that the temperature of one location is closely related to land use characteristics around that location, this study is carried out to assess the impact of urban land use patterns on air temperature. In order to investigate the relationship, GIS techniques and statistical analyses are utilized, after spatially connecting urban land use data in Seoul Metropolitan Area with atmospheric data observed at Automatic Weather Stations (AWS). The research method is as follows: (1) To find out important land use factors on temperature, simple linear regressions for a specific time period (pilot study) are conducted with urban land use characteristics, (2) To make a final model, multiple regressions are carried out with those factors and, (3) To verify that the final model could be appled to explain temperature variations beyond the period, the model is extensively used for 5 different time periods: 1999 as a whole; summer in 1999; 1998 as a whole; summer in 1998; August in 1998. The results of simple linear regression models in the pilot study show that transportation facilities and open space area are very influential on urban air temperature variations, which explain 66 and 61 percent of the variations, respectively. However, the other land use variables (residential, commercial, and mixed land use) are found to have weak or insignificant relationship to the air temperatures. Multiple linear regression with the two important variables in the pilot study is estimated, which shows that the model explains 75 percent of the variability in air temperatures with correct signs of regression coefficients. Thus, it is empirically shown that an increase in open space and a decrease in transportation facilities area can leads to the decrease in air temperature. After the final model is extensively applied to the 5 different time periods, the estimated models explain 68 ∼ 75 percent of the variations in the temperatures is significant regression coefficients for all explanatory variables. This result provides a possibility that one air temperature model for a specific time period could be a good model for other time periods near to the period. The important implications of this result to lessen high air temperature we: (1) to expand and to conserve open space and (2) to control transportation-related factors such as transportation facilities area, road pavement and traffic congestion.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.4
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• pp.131-136
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• 2016

Horizontal geothermal heat exchanger is affected by various factors such as pipe length, soil temperature, and outdoor environment. Simulation program is convenient for responding to various factors. The objective of this study was to determine the feasibility of using EnergyPlus to predict exit air temperature through horizontal geothermal heat exchanger in domestic. The correlation coefficient between EnergyPlus results and experimental results was 0.825. The correlation coefficient between EnergyPlus results and mathematical results was 0.722, indicating "The two values can based on Lousi on values can be Our results indicate that it is possible to use EnergyPlus to predict exit air temperature through horizontal geothermal heat exchanger.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.173-177
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• 2005

The purpose of this study is to analyze the principal causes of increases in air temperature on platforms of railway station. We analyzed the distribution of air temperature on Shinkansen platforms at Station 'A' using Computational Fluid Dynamics (CFD). We focused on the factors that influence the temperature dynamics associated with heat generated by trains and station buildings and their effect on the ambient temperature on platforms. In the case of heat generated by trains, air temperature on Shinkansen platforms increased by 4 to 7 degrees compared to when trains generated no heat. When a 50-m high station building was located on the windward side of the platforms, air temperature on Platform X was 2 degrees higher than when the station buildings were absent. Air? temperature on platforms VII to IX increased progressively, and the maximum air temperature on platform VIII was 3 K higher than if station buildings were absent.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.9
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• pp.810-816
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• 2000

Thermal comfort plays an important role in modern office buildings. Four major factors affecting thermal comfort are air temperature, velocity, humidity and radiation temperature. Distribution of these thermal factors in indoor space depends largely on the air flow which is related to the method of supplying and extracting air. In this study, an experimental analysis on indoor thermal comfort is conducted to study the difference between a ceiling supply cooling system and a floor supply one. The two cooling systems are applied to an office space during summer season and the distributions of temperature, velocity, radiation temperature and PMV are measured. Results show that the floor supply cooling system is superior in terms of thermal comfort and energy saving. Studies need to be done, however, to reduce the vertical temperature difference of a floor supply air conditioning system.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.21-25
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• 2009

This study is about heat island as one of the urban climate variation factors in urbanized modern society, which compared and observed the thermal characteristics both the downtown location and the outskirt site in summer. The diurnal air temperature range at each point is $12.6^{\circ}C$ in the downtown location and $14.3^{\circ}C$ in the outskirt site, so, it was found that the diurnal air temperature range in the outskirt site was $1.7^{\circ}C$ higher than in the downtown location. There was 20 minutes difference to reach the highest temperature between globe temperature and air temperature in the downtown location, however, the time spent to reach the highest temperature between globe temperature and air temperature in the outskirt site was the same. When we compared the globe temperature between the downtown location and outskirt site, we found that the temperature in the outskirt site was lower than in the downtown location after sunset due to the sudden temperature drops, although the exposed time to insolation in the outskirt site is longer. The average of globe temperature difference on the sample days was $1.1^{\circ}C$, the average of surface temperature difference on the sample days was $1.0^{\circ}C$, and the average of air temperature difference on the sample days was $2.0^{\circ}C$ Thus, it was found that the average of air temperature difference was higher than the average of globe temperature and the average of surface temperature. The result of this study is that the urban environment factors have more effect on the air temperature difference than globe temperature and surface temperature.

• Solar Energy
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• v.19 no.4
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• pp.55-62
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• 1999

This study was performed to find out the influence of experimental factors on dehumidification performance and furthermore to suggest an optimal combination of factors of a total heat exchanger in a solar air conditioning system. The experimental apparatus was set up in a climate-controlled chamber where the temperature and humidity was maintained constant. In order to find out the contribution ratio of factors on dehumidification performance, the table of orthogonal arrays $L_8(2^7)$ was used. According to the results, the most influential factor on dehumidification performance was the concentration of LiCl(Lithium Chloride) solution. The next influential factors were the temperature of LiCl solution and the air flow rate. The packed layer height, packed material, and flow rate of LiCl solution had no influence on the dehumidification performance under these experimental conditions. Through the three level experiments of $L_{27}(3^{13})$, it was found that the optimal combination was $A_2B_0G_2$(concentration of solution 30 wt%, temperature of solution $15^{\circ}C$, air flow rate $253m^3/h$).

• Food Science and Preservation
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• v.9 no.2
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• pp.137-143
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• 2002

Temperature and humidity are the most important factors and should be effectively controlled for the cold storage of graius. Fuzzy logic can be easily implemented to the MIMO(Multi-Input Multi-Output) control systems. For the cold storage in grain bin, fuzzy logic was applied to an air conditioning system. The capacities of the grain bin and the air conditioner are 80 tons and 30㎾, respectively. Also, the target values of temperature and relative humidity in outlet duct of the air conditioner were 8$\^{C}$ and 75%, respectively. In order to control temperature and relative humidity of air, a damper in inlet duct was manipulated for temperature control and a heater was used for humidity control. Temperature deviation and change of temperature deviation were used as input parameters for the fuzzy system. Humidity was only considered as a load. The experimental results showed that the controlled temperature of exhausted air was maintained at 8$\pm$2$\^{C}$. Relative humidity of the air was also controlled at the target relative humidity of 50∼80%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.4
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• pp.325-336
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• 2000

During the last decade, an increasing interest in Underfloor Air-Conditioning(UFAC) systems has emerged. The purpose of this paper is to evaluate comprehensively the indoor environmental performance of office buildings with UFAC system in order to develope the design prototype of this system. In this paper, 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.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.3
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• pp.177-190
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• 1998

The concentrations of air pollutants In large cities such as Pusan area have been increased every year due to the increasing of fuels consumption at factories and by vehicles as well as the gravitation of the population. In addition to the pollution sources, time and spatial variation of air pollutants concentration and meteorological factors have a great influence on the air pollution problem. Especially , its concentration is governed by wind direction, wind speed, precipitation, solar radiation, temperature, humidity and cloud amounts, etc. In this study, we have analyzed various data of meteorological factors using typical patterns of the air pressure to investigate how the concentration of air pollutants is varied with meteorological condition. Using the relationship between meteorological factors (air temperature, relative humidity, wind speed and solar radiation) and the concentration of air pollutants (SO2, O3) , experimental prediction formulas for their concentration were obtained. Therefore, these prediction formulas at each meteorological factor in a pressure pattern may be roughly used to predict the air pollutants concentration and contributed to estimate the variation of its value according to the weather condition in Pusan city.

• Atmosphere
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• v.34 no.3
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• pp.273-281
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• 2024

Analyzing the information about climate change on Korean Peninsula is essential for the national defense. In this study, we used HadGEM3-RA model output (a member of CORDEX-EA) and analyzed the 3 operational weather factors (VMC, runway temperature, WBGT), which affect the aircraft field. The number of future limited days was quantitatively calculated based on the model outputs applying SSP1-2.6 and SSP5-8.5 and the operational limits of the previous three factors, and the spatial distribution, time series, and correlation of each result were analyzed. In conclusion, it was analyzed that the number of limited days by VMC would decrease, resulting from the rise in temperature and the drop in relative humidity. This means the operational environment in VMC will improve. On the other hand, the number of limited days by the runway temperature and WBGT would increase, resulting from the rise in temperature. This means the operational environment in runway temperature and WBGT will worsen.