• Solar Energy
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• v.6 no.2
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• pp.22-32
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• 1986

This study was carried out to analyze solar radiation in plastic greenhouse which is covered with polyethylene or polyvinyl chrolide film. A computer model for solar radiation analysis in the plastic greenhouse was developed and solar gain factors for E-W and N-S oriented plastic greenhouse in the greenhouse farming area during winter were investigated. Solar gain factors for E-W plastic greenhouse were 60 to 75 percent which were 10 to 15 percent higher than those for N-S plastic greenhouse from November to January. However, the values were apparently decreased in February and reversed in March, showing 3 to 5 percent higher in E-W plastic greenhouse. About 67 to 72 percent of the total solar radiation was attributed to the south-directed wall and roof for the E-W plastic greenhouse and about 30 percent through walls and 60 percent through roofs for the N-S plastic greenhouse.

• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.129-139
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• 2008

This paper proposes a Ubiquitous Greenhouse Management System (UGMS) based on USN(Ubiquitous Sensor Network) which can be real-time monitoring and controlling of greenhouse's facilities by collecting environment and soil information with environment and soil sensors, and CCTV camera. The existing systems were controlled simply by temperature. Also, it was possible to monitor only at control room in a greenhouse. For solving problems of the exiting system, our system can remotely monitor and control greenhouse by considering environment information. The detail components are as follows. The system includes the sensor manager and the CCTV manager to gather and manage greenhouse information with soil and the environment sensors, and camera. Also the system has the greenhouse database storing greenhouse information and the greenhouse server transmitting greenhouse information to the GUI and controlling greenhouse. Finally, the GUI showing greenhouse condition to users exists in our system. To verify the executability of the UGMS, after developing the greenhouse model, we confirmed that our system could monitor and control the greenhouse condition at remote GUI by applying the UGMS's components to the model.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.393-402
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• 2021

As greenhouse gas emissions from maritime transport are increasing, the International Maritime Organization is continuously working to strengthen emission regulations. Liquefied natural gas (LNG) fuel is less advantageous as a point of CO₂ reduction due to the methane leakage that occurs during the bunkering and operation of marine engines. In this study, greenhouse gas emissions from an LNG-fueled ship were analyzed from the perspective of the life cycle. The amount ofmethane emission during the bunkering and operation procedures with various boil-off gas (BOG) treatment methods and gas engine specifications was analyzed by dynamic simulation. The results were also compared with those of other liquid fuel engines. As a result, small LNG-fueled ships without a BOG treatment facility emitted 32% more greenhouse gas than ships utilizing marine gas oil or heavy fuel oil. To achieve a greenhouse gas reduction via a BOG treatment method, a gas combustion unit or re-liquefaction system must be mounted, which results in a greenhouse gas reduction effect of about 25% and 30%. As a result of comparing the amount of greenhouse gas generated according to the BOG treatment method used with each tank size from the perspective of the operating cycle with the amounts from using existing marine fuels, the BOG treatment method showed superior effects of greenhouse gas reduction.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.399-406
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• 2018

The purpose of this study is to propose a methodology for estimating greenhouse gas emission reduction through HFCs used in the foam industry. This study investigated characteristics of HFCs and greenhouse gas emissions from production processes in the foam industry, which uses HFCs as a blowing agent. Also, we investigated fluorinated gas removal technology to determine a proper technology for the foam industry. And we confirmed the criteria and characteristics of External Project for methodology development. According to criteria of External Project and foam industrial process emission, a methodology for calculating the amount of greenhouse gas emission reduction in foam industry was developed. Lastly, we analyzed the amount of greenhouse gas emission reduction and KOC (Korea Of Offset) in the foam industry based on the domestic government's plan to reduce HCFCs and imported amount of HFCs used as a blowing agent. The results of this study demonstrate that linking greenhouse gas reduction in the foam industry and the domestic greenhouse gas reduction system can contribute to achieve the domestic greenhouse gas reduction goal.

• Journal of Biosystems Engineering
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• v.12 no.2
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• pp.16-27
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• 1987

Greenhouse farming was introduced to the Korean farmers in the middle of 1950's and its area has been increased annually. The plastic greenhouse, which is covered with polyethylene or polyvinyl chloride film, has been rapidly spread in greenhouse farming since 1970. The greenhouse farming greatly contributed to the increase of farm household income and the improvement of crop productivity per unit area. Since the greenhouse farming is generally practiced during winter, from November to March, the thermal environment in the plastic greenhouse should be controlled in order to maintain favorable condition for plant growing. Main factors that influence the thermal environment in the plastic greenhouse are solar radiation, convective and radiative heat transfer among the thermal component of the greenhouse, and the use of heat source. The objective of this study was to develop a simulation model for thermal environment of the plastic greenhouse in order to determine the characteristics of heat flow and effects of various ambient environmental conditions upon thermal environments within the plastic greenhouse. The results obtained are summarized as follows: 1. Simulation model for thermal environment of the plastic greenhouse was developed, resulting in a good agreement between the experimental and predicted data. 2. Solar radiation being absorbed in the plant and soil during the daytime was 75 percent of the total solar radiation and the remainder was absorbed in the plastic cover. 3. About 83 percent of the total heat loss was due to convective and radiative heat transfer through the plastic cover. Air ventilation heat loss was 5 to 6 percent of total heat loss during the daytime and 16 to 17 percent during the night. 4. The effectiveness of thermal curtain for the plastic greenhouse at night was significantly increased by the increase of the inside air temperature of the greenhouse due to the supplementary heat. 5. When the temperature difference between the inside and outside of the greenhouse was small, the variation of ambient wind velocity did not greatly affect on the inside air temperature. 6. The more solar radiation in the plastic greenhouse was, the higher the inside air temperature. Because of low heat storage capacity of the plant and soil inside the greenhouse and a relatively high convective heat loss through the plastic cover, the increase of solar radiation during the daytime could not reduce the supplymentary heat requirement for the greenhouse during the night.

• Journal of Environmental Science International
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• v.30 no.11
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• pp.907-914
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• 2021

In this study, strawberry cultivation environment in a greenhouse located in Jeonju was monitored and internal environmental parameters were analyzed. Temperature, humidity, RAD, and PPF sensors were installed to monitor environmental conditions in the test greenhouse. Data were collected every 10 minutes during four winter months from sensors placed across the greenhouse to assess its permeability and environmental uniformity. Temperature and humidity inside the greenhouse were relatively uniform with negligible deviations among the center, south, and north; however, it was judged that further analysis of gradients of these parameters from the east to the west of the greenhouse would be needed. Both RAD (Total solar radiation) and PPF (Photosynthetic photon flux) had high values on the south and were low on the north and the reduction rate of these parameters was 54% and 61%, respectively, indicating that a significant amount of light could not be transmitted. This implied a significant decrease in the amount of light entering the greenhouse during winter. Therefore, it is concluded that environmental control devices and auxiliary lighting are needed to achieve uniform greenhouse environment for efficient strawberry cultivation.

• Journal of the Korean Solar Energy Society
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• v.21 no.3
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• pp.51-60
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• 2001

A greenhouse equipped with latent heat storage system was built to obtain various thermal properties, such as greenhouse air temperature, soil surface temperature, energy flow in latent heat storage, etc., which could be used in validation of greenhouse numerical model to be developed in this study. This numerical model expressed with Newton-Raphson method was programed by C-language and utilized to simulate greenhouse thermal behavior. Greenhouse air temperature and soil surface temperature predicted by the greenhouse model developed in this study were very close to the measured data obtained through almost 3 years of experiment. Therefore, it is concluded that the greenhouse model developed and verified by measured data could be utilized for simulating various thermal behaviors of greenhouses equipped with latent heat storage system to be used for energy saving purposes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.5
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• pp.435-441
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• 2020

Sentinel-2A satellite imagery provides VNIR (Visible Near InfraRed) and SWIR (ShortWave InfraRed) wavelength bands, and it is known to be effective for land cover classification, cloud detection, and environmental monitoring. Greenhouse is one of the middle classification classes for land cover map provided by the Ministry of Environment of the Republic of Korea. Since greenhouse is a class that has a lot of changes due to natural disasters such as storm and flood damage, there is a limit to updating the greenhouse at a rapid cycle in the land cover map. In the present study, we utilized Sentinel-2A satellite images that provide both VNIR and SWIR bands for the detection of greenhouse. To utilize Sentinel-2A satellite images for the detection of greenhouse, we produced high-resolution SWIR bands applying to the fusion technique performed in two stages and carried out the detection of greenhouse using SVM (Support Vector Machine) supervised classification technique. In order to analyze the applicability of SWIR bands to greenhouse detection, comparative evaluation was performed using the detection results applying only VNIR bands. As a results of quantitative and qualitative evaluation, the result of detection by additionally applying SWIR bands was found to be superior to the result of applying only VNIR bands.

• Journal of the Korean Solar Energy Society
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• v.27 no.3
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• pp.15-21
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• 2007

The purpose of this study is to provide the basic data for passive control and energy conservation strategies of multipurpose greenhouse. Passive design strategies which are appropriate to Jeju environmental circumstance were applied in the multipurpose greenhouse. The field measurement were conducted to examine relationship of micro climate and indoor thermal environment in the multipurpose greenhouse. The result of this study can be summarized as follow ; (1) The indoor temperature was ranged from 5 to $21^{\circ}C$ without a heating system, when the exterior temperature was -1 to $19^{\circ}C$. (2) The multi-purpose greenhouse requires almost no heating energy in winter, when it is used as a greenhouse, an exhibition hall or a cafeteria.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.286-291
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• 2011

Onsite usage of construction equipment accounts for a 6.8% of air pollution in Korea. The high concentration of carbon dioxide in such emissions impact not only climate change, but also people's health. However, greenhouse gas emissions from onsite equipment usage have not yet been fully investigated. This study presents a comparative analysis on how much greenhouse gas is generated by various equipment types used in different construction activities. Two ongoing cases which involve a typical road construction project in Korea were selected for the comparison purpose. Greenhouse gas emissions from each onsite equipment usage of the different activities were estimated on the ground of design documents. The estimates were compared and analyzed to derive the main sources of greenhouse gas emissions. The result showed that earthwork constituted the largest part-more than 90%-among work types. Dump truck, bulldozer, and loader were major sources for such emissions. The study results are expected to be used as a basis for reduction of greenhouse gas emission from onsite equipment usage.