• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.537-542
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• 2009

For a period of over 6 years, more than 160,000 milk samples were collected and analyzed to determine the influence of different seasonal temperatures and geographic regional location on milk composition in South Korea. Fat, protein, lactose, non fat milk solids (NFMS) and total solids (TS) contents were significantly higher among dairy cows milked in winter season than other seasons (p<0.05). In contrast, freezing point (FP), milk urea nitrogen (MUN) and somatic cell count (SCC) were significantly higher in summer season than other seasons (p<0.05). The average SCC in the autumn season was $358{\times}10^3$/ml, which was lower than any other seasons (p<0.05). These results may be due to the changes in temperature during different seasons. Meanwhile, milk produced by dairy cows in central region had higher fat, protein, lactose, NFMS, TS and MUN and had lower SCC compared to other regions (p<0.05). Fat, TS, FP, MUN and citric acid in northeast region were lower than other regions (p<0.05). The SCC was significantly higher in southeast region than those of other regions (p<0.05). As a result, it might be possible that the differences in feeding management in each different region may affect the milk composition. In conclusion, present results indicated that milk composition is clearly influenced by both season and regional location. Therefore, based on these results, development of different feeding systems, according to season and region is needed to produce high quality and satiable milk production.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.155-158
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• 2001

The cultivation area of white spined cucumbers for export has continuously increased up to 121 ha in 2000. Since white spined cucumbers set fruits on lateral shoots, fruit yield is dependent upon the development of lateral shoots. Unfortunately, the major cultivation period is during winter season, October to February, when temperature and light are limited for the development lateral shoots. This experiment was conducted to investigate the effect of soil heating on the development of lateral shoots in white spined cucumbers. Number of lateral shoots were 13.7 and 11.7 in the soil heated treatment and in the control, respectively. Number of marketable fruits per plant was 45 in the soil heated treatment as compared to 38 in the control. Fruit yield was 81 ton per ha, an 18% increase, in the soil heated treatment. Soil heating not only increased number of long lateral shoots but also decreased curved fruits.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.1
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• pp.45-51
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• 2005

Total phosphorus(TP) removal was examined in a surface-flow wetland constructed in April 2003 during its initial operating stage from June to November 2003. Its dimensions were 87mL by 14mW. It was a part of a four-wetland-cell treatment system constructed near the Kohung Estuarine Lake located in the southern part of Korea. Effluent from a night soil treatment plant was discharged into the wetland and purified effluent from the wetland was discharged into Sinyang Stream flowing into the Lake. Cattails(Typha angustifolia ) from natural wetlands were cut at about 40 cm height and transplanted into the wetland. An average of 25.0$m^3$/day of effluent flowed from the plant into the wetland. Water depth was maintained about 0.2m and hydraulic detention time was about 5.2 days. Average heights of the cattail stems in June and October 2003 were 47.2 and 164.6cm, respectively. The average number of stems was 10.2 stems/$m^2$ in June 2003 and 18.8 stems/$m^2$ in October 2003. Average temperature of influent and effluent ranged 23.4 and $24.2^{\circ}C$, respectively. The average TP concentrations of influent and effluent were about 1.31, 0.50mg/L, respectively. TP loading rate of influent into the wetland averaged 26.81mg/$m^2$, day and average TP loading rate of effluent was 10.04mg/$m^2$, day. Monthly average TP removal by the wetland during the warm growing season of cattails(June to September) ranged 16.28~19.57mg/$m^2$, day and during the cold senescent period (October to November) ranged 12.62~13.90mg/$m^2$, day. TP removal in the wetland continued during the cold winter months and was primarily done by sedimentation and precipitation of phosphorus rather than phosphorus absorption by cattails and microorganisms.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.9
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• pp.590-598
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• 2008

In this study, performance of R170/R290 mixtures is measured on a heat pump bench tester in an attempt to substitute R22. The bench tester is equipped with a commercial hermetic rotary compressor providing a nominal capacity of 3.5kW. All tests are conducted under the summer cooling and winter heating conditions of $7/45^{\circ}C$ and $-7/41^{\circ}C$ in the evaporator and condenser respectively. During the tests, the composition of R170 is varied from 0 to 10% with an interval of 2%. Test results show that the coefficient of performance (COP) and capacity of R290 are up to 15.4% higher and 7.5% lower than those of R22 for both conditions respectively. For R170/R290 mixture, the COP decreases and the capacity increases with an increase in the amount of R170. The mixture of 4%R170/96%R290 shows the similar capacity and COP as those of R22. For the mixture, the compressor discharge temperature is $16{\sim}30^{\circ}C$ lower than that of R22. There is no problem with mineral oil since the mixture is mainly composed of hydrocarbons. The amount of charge is reduced up to 58% as compared to R22. Overall, R170/R290 mixture is a good long term 'drop-in' candidate to replace R22 in residential air-conditioners and heat pumps.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.3
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• pp.149-157
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• 2018

In this research, the psychological and physiological reactions of the driver were measured during winter to evaluate thermal comfort. The experiment was conducted using 3 different cases which are hot air heating, warm-wire seat heating and hot air & warm-wire seat heater operating simultaneously. With regard to psychological reaction, the warm-wire heating mode was the most preferred. The reason is that it is dry in other cases. With regard to EEG response, thermal comfort increased by 37% in warm air mode heating. In addition, when the warm-wire heating mode and the hot air & warm-wire heating mode were simultaneously operated, the thermal comfort continuously increased by between 17% and 20% for 20 minutes after boarding. Under the change of the autonomic nervous system, the thermal stress level increased by 23% after 15 minutes on board in the hot air heating mode and decreased continuously by 13% during the warm-wire seat heating mode. We recommended the hot air heating mode is only used for a short time to raise the inside temperature during the early boarding period and that warm-wire seat heating mode be actively utilized.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1109-1116
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• 2009

To the development of construction techniques and construction of glass-walled structure is generalized. Existing wall to support the role of the vertical load was lose. Features and the beautiful side of the curtain wall job was to be highlighted. Carriage access to the interior of the windows will cause pain in the neck with a cold feeling. And in the windows, drafty windows, under floor heating occurs despite the condensation phenomenon occurs. droplets that occurs around the window (the cause of the mold) in summer and winter, the heat energy and move through the glass is warmer outside. Therefore, to reduce energy efficiency affects absolutely. When you apply heat to the carriage window, the surface of the glass system, the spread of the cold air does not occur. Therefore, energy savings cars and heating of the interior is cold.

• Fire Science and Engineering
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• v.24 no.4
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• pp.109-115
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• 2010

Maximum pressure difference in central core type 80th super_tall buildings was estimated as 75 Pa during no outside wind due to the winter stack effect. Maximum pressure difference of 225 Pa can be obtained depending on the location of air injection fan during the stairway pressurization at fire. Bottom_only air injection system provided the best results in the sense of required air flow rates and pressure distributions. Top_only air supply system was estimated as the worst for this country. It revealed that the decrease of the temperature in the stairway due to the cold outside air injection reduced the required flow rates of the fan and significantly changed the distribution of pressure differences.

• Atmosphere
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• v.16 no.2
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• pp.111-124
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• 2006

This study examines seasonal variability of the surface energy balance at the King Sejong Station, Antarctica, using measurements and estimates of the components related to the balance for the period of 1996 to 2004. Annual average of downward shortwave radiation at the surface is 81 $Wm^{-2}$ which is 37% of the extraterrestrial value, with the monthly maximum of 188 $Wm^{-2}$ in December and the minimum of 8 $Wm^{-2}$ in June. These values are relatively smaller than those at other stations in Antarctica, which can be attributed to higher cloudy weather conditions in Antarctic front zone. Surface albedo varies between ~0.3 in the austral summer season and ~0.6 in the winter season. As a result, the net shortwave radiation ranges from 117 $Wm^{-2}$ down to 3 $Wm^{-2}$ with annual averages of 43 $Wm^{-2}$. Annual average of the downward longwave radiation shows 278 $Wm^{-2}$, ranging from 263 $Wm^{-2}$ in August to 298 $Wm^{-2}$ in January. The downward longwave radiation is verified to be dependent strongly on the air temperature and specific humidity, accounting for 74% and 79% of the total variance in the longwave radiation, respectively. The net longwave radiation varies between 25 $Wm^{-2}$ and 40 $Wm^{-2}$ with the annual averages of 30 $Wm^{-2}$. Accordingly, the annual average energy balance is dominated by radiative warming of a positive net all-wave radiation from September to next March and radiative cooling of a negative net all-wave radiation from April to August. The net all-wave radiative energy gain and loss at the surface is mostly balanced by turbulent flux of sensible and latent heat. The soil heat flux is of negligible importance in the surface energy balance.

• Atmosphere
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• v.24 no.2
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• pp.151-158
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• 2014

This study investigated a method for the discrimination of precipitation type using thickness of geopotential height at 1000~850 hPa and improved Matsuo's scheme over South Korea using 7 upper-level observations data during winter time from 2003 to 2008. With this research, it was suggested that thickness between snow and rain should range from 1281 to 1297 gpm at 1000~850 hPa. This threshold was suitable for determining precipitation type such as snow, sleet and rain and it was verified by investigation at 7 upper-level observation and 10 surface observation data for 3 years (2009~2011). In addition, precipitation types were separated properly by Matsuo's scheme and its improved one, which is a fuction of surface air temperature and relative humidity, when they lie in mixed sectors. Precipitation types in the mixed sector were subdivided into 5 sectors (rain, rain and snow, snow and rain, snow, and snow cover). We also present the decision table for monitoring and predicting precipitation types using model output of Korea Local Analysis and Prediction System (KLAPS) and observation data.

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.291-302
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• 2008

Seasonal variation of species composition in the coastal waters off Wangdol-cho were investigated using the catches by gill net and trammel net from 2002 to 2004. A total of 58 species was collected and classified into 15 orders and 34 families. Of the 58 species identified, Scorpaeniformes and Perciformes accounted for 62.1% of the species. 35 species in 11 orders and 22 families were collected by gill net and 51 species in 15 orders and 30 families were collected by trammel net. The number of species was high in summer and autumn and lowest in winter. Catches were correlated with sea water temperature. The numbers of individuals and their biomass were 5,295 inds. and 1,890 kg, with the highest values achieved in summer and the lowest in spring. The most dominant species were Pleurogrammus azonus and Gadus macrocephalus. The seasonal species community showed a high similarity between summer and autumn.