• Journal of the Korean earth science society
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• v.23 no.6
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• pp.455-460
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• 2002

The purpose of this study is to analyze the sixth curriculum textbooks of high school science courses in relation to the greenhouse effect concept and find the incorrect descriptions of that concept and then suggest some improved schemes. Some incorrect descriptions, pictures and tables on the greenhouse effect concept were found in texts. They might contribute to forming and/or reinforcing misconceptions about that concept: the important greenhouse gases, the changes caused by the greenhouse effect, global warming, energy sources, greenhouse experiments and physical processes. Therefore some improved schemes were suggested

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.308-314
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• 2000

Objects of this study were to find the cooling effect of solar-heated greenhouse with rock bed storage in summer season and to suggest operation method of cooling energy saving in summer cropping greenhouse. Experiments were performed to analyze inside environment variation of solar-heated greenhouse. When we took account of different shading and ground conditions of greenhouse, we could conclude that inside average daytime temperature of the solar-heated greenhouse was 2.0∼2.4$^{\circ}C$ lower than the general greenhouse in summer season.

• Elastomers and Composites
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• v.55 no.2
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• pp.114-119
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• 2020

The effect of a greenhouse-covering material on its indoor environment and on the characteristics of cherry tomatoes grown in it was investigated. The conventional polyethylene (PE) film on the greenhouse roof was replaced by a polycarbonate (PC) sheet, while maintaining the main structural frame intact. Color changes and the formation of water droplets on the PC surface were avoided by applying coextrusion and coating layers. When compared to the PE greenhouse, the PC greenhouse enabled increased light transmittance and thus a higher indoor temperature during both summer and winter. The thermal insulating property of the PC sheet effectively reduced the heating loss by approximately 55% during winter. The cherry tomatoes grown in the PC greenhouse exhibited superior fruit characteristics in terms of size, weight, and sugar content. The total amount of cherry tomatoes produced per unit area (1,000 ㎡) in the PC greenhouse was found to be greater by approximately 19% compared to that in the PE greenhouse.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.225-231
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• 2001

This study was conducted to examine effect of different environment conditions in glass, PC, PET and PE greenhouses controlled by different environment control systems on the growth of green pepper. Light transmittance of 64.7% in the glass greenhouse was the highest among different green-houses. Air temperature was the highest in the glass greenhouse when ventilators were closed, and was the highest in the PE greenhouse when ventilators were open. Air relative humidity was the highest in the PE greenhouse during 24 hours. The amount of solar energy accumulated in soil was the greatest in the glass greenhouse and this energy released during the night escaped through covering materials. Latent heat and solar energy affected air temperature increased in greenhouses. The air temperature of glass greenhouse was 27.5$^{\circ}C$ at 11 O clock, which was the highest air temperature among the all greenhouse types. Clear differences were observed in leaf area and plant height at 30 days after transplanting. Days to first flowering was the shortest in the glass greenhouse with 72.7 days. Flower shedding was the greatest in the PE greenhouse with 12.6%. Days to fruit harvesting was the shortest in the glass greenhouse with 14.3 days. Fruit quality, such as fruit length, fruit diameter, fruit flesh thickness, and vitamin C content, was the best in the glass greenhouse. Percent marketable fruits was the highest with 95.3% when the pepper was grown hydroponically in the glass greenhouse.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1136-1145
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• 1996

This study was to develop the most effective cooling system which is needed to cool greenhouse during summer night to get early blooming of strawberries. Various cooling systems were designed and constructed to utilize the cool air and water from tan abandoned coal mine. Cooling systems built for this study were an evaporative cooling system with pad, cooling system using a small or large radiator , and duct cooling system using cool are drawn from coal mine. These systems were individual tested to investigate their effects on cooling greenhouse during summer night. Also, a combined cooling system was tested with operating an evaporative cooling system, small radiator, and duct cooling system simultaneously. The results in this study showed that individual cooling systems such as evaporative cooling system, small radiator, and cooling duct had about the same effect on cooling greenhouse. The combined system had little better cooling effect than that of individual cooling syst m except the large radiator . The most effective system for cooling of greenhouse was obtained with using a large a large radiator as the heat exchanger. With operating a large radiator, temperature inside the greenhouse was dropped to about 15-16$^{\circ}C$ while outside temperature was 23-24$^{\circ}C$ during summer night.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.262-268
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• 1998

This study were performed to find the cooling effect and to provide design data during summer season. for the Pad ＆ Fan system of Venlo type greenhouse. The temperature and humidity variation along the greenhouse width and wind velocity in the greenhouse were surveyed. Also, the influence of shading on the cooling effect were analyzed. While Pad ＆ Fan system were operated, the temperature, humidity and wind velocity in greenhouse were different by the distance from the Pad and the height from the ground. The temperature difference between Pad and Fan was about 8.1$^{\circ}C$~10.4$^{\circ}C$ without shading and about 4.4$^{\circ}C$~5.5$^{\circ}C$ with shading.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.407-421
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• 2018

In this paper, I analyze the GHG (greenhouse gas) emission factor of the domestic railway transportation sector using the LMDI (Log Mean Divisia Index) methodology. These GHG factors are the emission factor effect, energy intensity effect, transportation intensity effect, and economic activity effect. The analysis period was from 2011 to 2016, and the analysis objects were an intercity railway, wide area railway, and urban railway. The results show that the GHG emission of railway transportation sector decreased during these 6 years. The factors decreasing the GHG emission are the emission factor effect, energy intensity effect, and transportation intensity effect, while the factor increasing the GHG emission is the economic activity effect.

• Journal of Bio-Environment Control
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• v.1 no.1
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• pp.14-20
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• 1992

For the high quality and low cost agricultural crops in greenhouse cultivation, it is necessary to use natural energy as much as possible. In order to reduce the fossil fuel consumption and maximize the solar energy utilization in greenhouse heating, a latent heat storage material was developed as a relatively highly concentrative solar energy storage medium. And a solar energy-latent heat storage system was designed and constructed. The experimental research on greenhouse heating effect of the system was performed.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.321-326
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• 2000

This study was performed to analyze the variation of inside temperature of greenhouse according to shading methods. We used two shading method of external and internal method. The shading effect of external screen was superior to internal screen. Soil temperature of greenhouse without screen was higher than outside soil temperature, but the value of greenhouse with internal and external screen was lower than outside.

• Journal of Biosystems Engineering
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• v.19 no.3
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• pp.211-221
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• 1994

In this study, to maximize the solar energy utilization for greenhouse heating during the winter season, solar energy-underground latent heat storage system was constructed, and the thermal performance of the system has been analyzed to obtain the basic data for realization of greenhouse solar heating system. The results are summarized as follows. 1. $Na_2SO_4{\cdot}10H_20$ was selected as a latent heat storage material, its physical properties were stabilized and the phase change temperature was controlled at $13{\sim}15^{\circ}C$. 2. Solar radiation of winter season was the lowest value in December, and Jinju area was the highest and the lowest value was shown in Jeju area. 3. The minimum inner air temperature of greenhouse with latent heat storage system(LHSS) was $7.0{\sim}7.5^{\circ}C$ higher than that of greenhouse without LHSS and was $7.0{\sim}11.2^{\circ}C$ higher than the minimum ambient air temperature. 4. Greenhouse heating effect of latent heat storage system was getting higher according to the increase of solar radiation and was not concerned with the variation of minimum ambient air temperature. 5. The relative humidity of greenhouse with latent heat storage system was varied from 50 to 85%, but that of greenhouse without LHSS was varied from 30 to 93%. 6. The heating cost of greenhouse with solar energy-latent heat storage system was about 24% of that with the kerosene heating system.