• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.204-208
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• 2000

Little information is available for the temporal variation in air temperature profile within rice canopies under development, while much works have been done for a fully developed canopy. Fine wire thermocouples of 0.003 mm diameter (chromel-constantan) were installed at 10 vertical heights by a 10 cm step in a paddy rice field to monitor the air temperatures over and within the developing rice canopy from one month after transplanting (June 29) to just before heading (August 24). According to a preliminary analysis of the data, we found neither the daytime temperature maximum nor the night time minimum at the active radiation surface (the canopy height with maximum leafages) during this period, which is a typical profile of a fully developed canopy. Air temperature within the canopy never exceeded that above the canopy at 1.5 m height during the daytime. Temporal march of the within-canopy profile seemed to be controlled mainly by the ambient temperature above the canopy and the water temperature beneath the canopy, and to some extent by the solar altitude, resulting in alternating isothermal and inversion structures.

• Current Research on Agriculture and Life Sciences
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• v.2
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• pp.91-97
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• 1984

This study was performed to suggest the basic information for the development of covering method for increasing the effect of heat conservation in the unheated vinyl houses. Double and single covered vinyl houses were constructed and the inside temperature variation of the double covered vinyl house was compared to the single covered vinyl house. The results obtained for the vinyl houses were summarized as follows ; 1. With the outside temperature of $-1.0^{\circ}C{\sim}7.5^{\circ}C$ and the solar radiation of maximum $1.02MJ/m^2$, the double covered vinyl house was shown $1.2^{\circ}C$ higher than the single covered vinyl house in the daily mean of inside temperature. 2. The inside temperature of the double covered vinyl house was $2.3^{\circ}C$ higher in the daytime and $1.2^{\circ}C$ higher in the nighttime than that of the single covered vinyl house. 3. The inside temperature of the vinyl house were expressed by the formular (1)-(6) with the outside temperature and by the formular (7)-(10) with the solar radiation. 4. In the effect of heat conservation based on the outside temperature, the double covered vinyl house was 1.2 times in the daytime and 1.76 times in the nighttime in comparison with the single covered vinyl house.

• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.244-254
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• 2018

Ulaanbaatar, the capital of Mongolia, is subject to high levels of atmospheric pollution during winter, which severely threatens the health of the population. By analyzing surface meteorological data, ground-based LIDAR data, and radiosonde data collected from 2008 to 2016, we studied seasonal variations in particulate matter (PM) concentration, visibility, relative humidity, temperature inversion layer thickness, and temperature inversion intensity. PM concentrations started to exceed the 24-h average standard ($50{\mu}g/m^3$) in mid-October and peaked from December to January. Visibility showed a significant negative correlation with PM concentration. Relative humidity was within the range of 60-80% when there were high PM concentrations. Both temperature inversion layer thickness and intensity reached maxima in January and showed similar seasonal variations with respect to PM concentration. The monthly average temperature inversion intensity showed a strong positive correlation with the monthly average $PM_{2.5}$ concentration. Furthermore, the temperature inversion layer thickness exceeded 500 m in midwinter and overlaid the weak mixed layer during daytime. Radiative cooling enhanced by the basin-like terrain led to a stable urban atmosphere, which strengthened particulate air pollution.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.269-277
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• 2009

Ventilation equipment performs a central role to maintain comfort subway environment. So ventilation equipment of Busan subway line No.1 is required to improve thermal environment. In this study, conditions of thermal environment are presented to improve ventilation equipment at existing subway station platforms by measuring thermal environment of platforms operated ventilation equipment at 14 stations of Busan subway line No.1. AWS of data in comparison with the neighbouring platforms and thermal environment analysis. Thermal environment status of subway platform analysis results are as follows. 1)Daytime platform temperature was higher than outdoor temperature, but night time platform temperature was lower than outdoor temperature. 2)Train wind had effect on improving thermal comfort in platform. 3)When outdoor temperature is below $24^{\circ}C$, inlet air is able to lower than platform temperature. 4)Considering existing ventilation system, night purge systems is useful to improving platform thermal environment.

• Atmosphere
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• v.30 no.3
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• pp.221-236
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• 2020

The Gangneung region has the complicated geographical characteristics being adjacent to East Sea and Taeback mountains, and thus sea breeze could play an important role in local weather in various aspects. This study aims to understand overall characteristics of sea breeze largely based on long-term (2009~2018) ground-based observation data. We also propose a selection criteria of sea breeze occurrence day; 1) daily precipitation is less than 10 mm, 2) surface wind direction is 0~110° (northerly to easterly) for more than 3 hours during the daytime, 3) wind direction is 110~360° for more than 3 hours during the nighttime, and 4) land and sea temperature difference is positive during the daytime, 5) sea and land sea-level pressure difference is more than 0.5 hPa. As a result, a total of 595 days was selected for the past 10 years. The occurrence of sea breeze is the highest in late Spring to early Summer (May to June). The passage time of sea breeze at the inland station (1.6 km farther inland) is one hour later than the coastal station. On the typical sea breeze event of April 12, 2019, the passage speed and duration of sea breeze was 15 km hr^-1 and about 9 hours, respectively, with its depth of about 500 m and its head swelling. The current results emphasize the critical role of sea breeze in forecasting surface temperature and wind, and contribute to relieve heat wave especially in summer in the Yeongdong region.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.919-928
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• 2006

The present study applied an atmospheric flow field model in Gwangyang-Bay which can predict local sea/land breezes formed in a complex terrain lot the development of a model that can predict short term concentration of air pollution. Estimated values from the conduct of the atmospheric flow field were used to evaluate and compare with observation data of the meteorological stations in Yeosu and the Yeosu airport, and the effect of micrometeorology of surround region by the coastal area reclamation was predicted by using the estimated values, Simulation results, a nighttime is appeared plainly land breezes of the Gwangyang-bay direction according to a mountain wind that formed in the Mt. of Baekwooun, Mt. of Youngchui. Land winds is formed clockwise circulation in the north, clockwise reverse direction in the south with Gangyang-bay as the center. Compared with model and observation value, Temperature is tend to appeared some highly simulation value in the night, observation value in the daytime in two sites all, but it is veil accorded generally, the pattern of one period can know very the similarity. And also, wind speed and wind direction is some appeared the error of observation value and calculation results in crossing time of the land wind and sea land, it can see that reproducibility is generally good, is very appeared the change land wind in the nighttime, the change of sea wind in the daytime. And also, according to change of the utilization coefficient of soil before and after development with Gwangyang-Bay area as the center. Temperature after development was high $0.55\sim0.67^{\circ}C$ in the 14 hoots, also was tend to appear lowly $0.10\sim0.22^{\circ}C$ in the 02 hours, the change of u, v component is comparatively tend to reduced sea wind and land wind, it is affected ascending air current and frictional power of the earth surface according to inequality heating of the generation of earth surface.

• Journal of the Korean Solar Energy Society
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• v.35 no.1
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• pp.9-19
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• 2015

Pyranometer have many uncertainty factors (sensitivity function, thermal offset, other spectral effect, geometric, environment, and equipment etc.) than pyrheliometer. The solution for most of the uncertainty factors have been researched, but the problem for thermal offset is being continued research so far. Under the clear sky, due to the thermal offset of pyranometer, the diffuse and global radiation have been negative value for the nighttime and lower value for the daytime, respectively. In order to understand the uncertainty of the thermal offset effect, solar radiation are observed and analyzed using Ji and Tsay method and data from modified pyranometer. As a result of performing temperature correction using the modified pyranometer, the slope (dome factor; k) and intercept ($r_0$) from a linear regression method are 0.064 and $3.457g{\cdot}m^{-2}{\cdot}k^{-1}$, respectively. And the solar radiation is decreased significantly due to the effect of thermal offset during nighttime. The solar radiation from modified pyranometer increased approximately 8% higher than its observed by general pyranometer during daytime. By the way, these results did not generalize because its result is for only single case in clear sky. Accordingly, it is to required for accurate results obtained by the various cases (clear, cloudy and rainy) with longterm observations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.161-171
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• 1970

1. The higher the temperature of the sea water, and the smaller the size of the oriental brown shrimp, the higher the feeding rate of the shrimp will be as long as the temperature ranges from $19^{\circ}\;to\;30^{\circ}C$, and each shrimp weighs from 1.6 to 14.9 grams. The average daily feeding rate is between 18 to 44 percent. 2. The nighttime feeding rate is always higher than the daytime feeding rate. However, the daytime feeding rate can be raised to from 22 to 37 percent of the daily feeding rate iii the non-sediment, dark or direct-sunshine-shielded conditions. Growth can thus be accelerated to that extent under such conditions. 3. When anchovy and short-necked clam meats were simultaneously used as food, a greater quantity of anchovy meat was consumed than short-necked clam meat both during the daytime and nighttime. When anchovy and short-necked clam meats were simultaneously given, the averaged daily feeding rates of anchovy and short-necked clam meats were 12.9 percent and 10.3 percent, respectively. 4. The following equation applies to the relationship between the freight of the oriental brown shrimp (W in grams) and their daily growth rate (DGR in percent): log DGR=0.7035-0.7864 log W. The daily growth rate is in inverse proportion to the size of the shrimp. 5. The efficiency of food conversion of the oriental brown shrimp fluctuates between 2.8 and 7.8 percent without extensive difference depending on the size of the shrimp. This was very small as compared with the corresponding figures so far known for fish and cuttlefish.

• Journal of the Korean Geophysical Society
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• v.8 no.3
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• pp.159-167
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• 2005

Turbulent fluxes of sensible heat and latent heat were analyzed at King Sejong station in the austral summer of 2002 (December) and 2003 (January and February). Monthly mean air temperatures of January and February (2.2oC) were similar to those averaged over 1988 to 2001. Precipitation was less in January and greater in February than those averaged over last 14 years. In December of 2002 and January, there was precipitation primarily when easterly wind blew usually. The frequency of snowfall was equal to or larger than that of rainfall. In the mean while, precipitation primarily in forms of rainfall occurred with westerly wind in February. In addition, while for easterly wind, temperature and humidity was low, temperature and humidity were high in case of westerly wind. Based on flux footprint, measured flux mainly came from within 300 m with maximum of 40 m upwind, indicating the insignificant role of the sea around the study site. Half-hourly downward short wave radiation amounted up to ∼ 1000 Wm-2 and net radiation ranged from -50 to 600 Wm-2. Half-hourly sensible heat flux was positive at daytime with maximum of ∼ 400 Wm-2, except the 27th and 28th in February of 2003 when it was negative all day despite of positive net radiation at short daytime. Latent heat flux was positive with maximum of ∼ 130 Wm-2. Depending on wind direction, the partitioning of net radiation into the sum of sensible heat flux and latent heat flux was larger than 0.8, indicating the strong source of the land surface for the atmospheric heating. The daytime averaged Bowen ratio (=sensible heat flux /latent heat flux) was significantly greater than 1, indicating that sensible heat flux was the main source to heat the atmosphere over the site.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.160-165
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• 2005

Since the growth and quality of oak mushrooms are sensitively affected by environmental conditions, an adequate environmental control is very essential to improve the yield and quality under protected cultivation. In this study, the diameter, thickness, length and hardness of cap and stipe, the dry weight, fresh weight and moisture content of the mushrooms were analyzed under the environmental conditions such as night air temperatures (control, $5{\~}11^{\circ}C$ and $12{\~}18^{\circ}C$), relative humidities in the daytime (control, humidifying for 6 h and 12 h), and wind velocities (control, fan-operation for 6 h and 12 h). At a lower night temperature, the quality of the mushrooms was improved, and considered to be optimum at $3{\~}8^{\circ}C$ in terms of fresh weight and quality. At $70{\~}80{\%}$ of relative humidity in the daytime, the fresh weight was increased, but the quality decreased. Considering the quality, the relative humidity in the daytime is adequate at around $50{\%}$. At 6 h of maintaining the wind velocity at $1{\~}2\;my{\cdot}s^{-1}$, the growth and quality were better, but the lightness became higher at 12 h although the fresh weight was reduced by evaporation. It is concluded that even though both of the yield and quality are not easily improved at a same time, optimum approaches should be required by using the relationship among environmental factors and the growth and quality.