• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.9-18
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• 1999

Natural ventilation in a four and one-half span, double polyethylene commercial greenhouse was investigated with actual data collected at Quailcrest Farm near Wooster, Ohio. Moreover, a computational fluid dynamics (CFD) numerical technique, FLUENT V4.3, was used to predict natural ventilation rates, thermal conditions, and airflow distributions in the greenhouse. The collected climate data showed that the multi-span greenhouse was well ventilated by the natural ventilation system during the typical summer weather conditions. The maximum recorded air temperature difference between inside and outside the greenhouse was 3.5$^{\circ}C$ during the hottest (34.7$^{\circ}C$) recorded sunny day; the air temperatures in the greenhouse were very uniform with the maximum temperature difference between six widely dispersed locations being only 1.7$^{\circ}C$. The CFD models predicted that air exchange rates were as high as 0.9 volume per minute (A.C. .min$^{-1}$ ) with 2.5m.s$^{-1}$ winds from the west as designed.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.78-86
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• 2017

Humans are provided with a wide range of public benefits from ecosystems and agricultural ecosystems, but the establishment of the horticulture complex could be a space that hampers the public function of the agricultural ecosystem. In this study, we sought to focus the function of landscape creation of agricultural landscape and tried to analyze the landscape of the horticulture complex. Therefore, This study aims to suggest ways to build a greenhouse complex which is being indiscreetly introduced in the agriculture landscape through environmentally-friendly manner and minimize the function of the ecosystem service. We divided the greenhouse complex into two categories of Plastic Greenhouse(v) and Glass Greenhouse(g), and compared them to the Netherland and Japan counterparts. Each image of research areas was selected by 3 pics and polled by a total of 101 people. The results of the Evaluation of Landscape Image are as shown in the figure. Netherland Glass Greenhouse scored 1.80 in terms of 'Neat' which is one of the given 15 adjectives. Study results shows that Korean Plastic Greenhouse landscapes need to endeavor Japanese vinly greenhouses and Dutch glasshouses. Consequently, an analysis on the elements of landscapes including green area, variant elements, separation distance is essential in order to improve our country's greenhouse complex landscapes. In this regard, continuous research is required to improve rural landscapes and harmonize large-scale horticultural facilities into the existing agricultural ecosystem.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.181-186
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• 2001

During the growth of fruit vegetables such as pepper, cucumber and tomato, there are light deficiency under the plant canopy. This study was conducted to clarify the effect of light diffusion film on the stem growth, canopy, flowering and fruiting of green pepper in greenhouse. The transmittance of total solar radiation into greenhouse under woven and double films were 90% and 75% of polyethylene film. And the transmittance of photosynthetically active radiation into greenhouse under woven and double films were 96% and 81% of polyethylene film. However, the light diffusions under woven, double and polyethylene films were 46%, 31% and 9%, respectively. The plant height under polyethylene film covered greenhouse was 96.9% cm, taller than those under woven and double films by 6.5, 13.9 cm. And the third node length under woven film covered greenhouse was 8.6 cm, shorter than those under double and polyethylene films by 2.5, 5.7 cm. Also the first branch angle under woven film covered greenhouse was 61.0$^{\circ}$, larger than those under double and polyethylene films by 2.3, 10.3$^{\circ}$. But there was no clear difference in the node numbers among the covering materials. The rate of curved and sterile fruit under woven film covered greenhouse was smaller than those under double and polyethylene films by 4.6, 5.5% and 1.2, 3.6%. But the contents of vitamin C showed no difference among the covering materials and plant densities.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.1
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• pp.14-19
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• 2023

In summer, the natural ventilation performance for varying greenhouse width is very important in the glasshouses for year round cultivation. The effect of the side openings and greenhouse width on natural ventilation performance was analyzed by simulation. The necessary ventilation rate with different solar radiation transmittance increased significantly when the outside temperature grows higher. The necessary ventilation rate of 40% transmittance was about half of that of 90% transmittance. In consequence, shading effect on temperature control in greenhouse is significant in summer. When the total area of the openings for ventilation is constant, the maximum ventilation rate happens when the area of roof openings is equal to the area of side openings. This maximum ventilation rate is about 3 times of that of the greenhouse with roof openings and without side openings. Therefore, the side openings are advantageous to improve the natural ventilation in greenhouses. As the greenhouse width increases, the influence of side openings on the ventilation rate is becoming smaller. If the natural ventilation rate of the greenhouse with roof and side openings is to become double of that of the roof openings only, the width should be narrower than 38.4m for the Venlo type and 64m for Wide span type.

• Environmental Engineering Research
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• v.21 no.4
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• pp.420-426
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• 2016

Climate change imposes a huge treat on the sustainability of our environment. One of the major reasons for the increasing impacts of climate change is the emission of greenhouse gases. Therefore, cooperative greenhouse gas emission reduction schemes with a general consensus are needed in order to reduce the impacts of climate change. Due to the strong link between greenhouse gas emission and economic development there is disagreement among countries on the designing and implementation of emission reduction plans. In this paper the authors proposed a two-stage concession game to analyze emission reduction plans and determine a balanced emission range that improves the utilities of the bargaining parties. Furthermore the game was applied to a hypothetical example. Our results from the case study indicated that even though the utilities of the bargaining parties is highly affected by emission reductions, after making concessions their utilities can be improved given their emission reductions are within in a certain desirable range. The authors hope that this article provides insights which could be useful for understanding emission reduction plans and their consequences on the negotiating parties.

• Agribusiness and Information Management
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• v.7 no.2
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• pp.12-18
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• 2015

Since 2000s, proper utilization of IoT (Internet of Things) technology is a key factor for a firm to become more competitive, and this stream is not exceptional for the food and agriculture industry. Along with this stream, Korea government organization, for example MAFRA (Ministry of Agriculture, Food and Rural Affairs), elected to adopt IoT technology, such as USN and RFID technologies, in the food and agriculture industry. Based on the IoT technology, MAFARA launched six "IoT based farm" project in 2007. IoT based farm project includes IoT based greenhouse system project, and it shows drastic efficiency in terms of cost reduction. When it comes to the productivity, however, the effect of IoT based greenhouse system is still ambiguous. In this regard, this study conducted systems analysis and design for IoT based tomato greenhouse in order to help farmers' decision making related to the productivity by establishing standardized database structure and designing output form to analyze productivity indices. Proposed systems analysis and design can be utilized as a data analysis tools by farmers. Productivity data from the proposed systems is can be used by researchers to identify the relationship among environment, plant growth and productivity. Policy makers also can refer to the data and output forms to predict the quantity of fruit during certain period and to revise production guideline more precisely.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.1-11
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• 2023

This study analyzed the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes. The groundwater observation data in the Miryang study area were used and classified into greenhouse and field cultivation areas to compare the groundwater impact of water curtain cultivation in the greenhouse complex. We identified the characteristics of the groundwater time series data by the terrain of the study area and selected the optimal model through time series analysis. We analyzed the time series data for each terrain's two representative groundwater observation wells. The Seasonal ARIMA model was chosen as the optimal model for riverside well, and for plain and mountain well, the ARIMA model and Seasonal ARIMA model were selected as the optimal model. A suitable prediction model is not limited to one model due to a change in a groundwater level fluctuation pattern caused by a surrounding environment change but may change over time. Therefore, it is necessary to periodically check and revise the optimal model rather than continuously applying one selected ARIMA model. Groundwater forecasting results through time series analysis can be used for sustainable groundwater resource management.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.427-432
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• 2016

Nitrous oxide is one of the main sources of greenhouse gases and its concentration has increased from 273 ppb in 1,750 to 315 ppb in 2005. Specially, nitrogen fertilizer used in agricultural soils is considered as an important source of atmospheric $N_2O$ emission. This study was conducted to estimate the difference of nitrous oxide emission as chamber position on furrow and ridge and crop existence in gas sampling chamber on upland. Four treatments used in this experiment were (1) no-fertilizer without crop in chamber on ridge, (2) fertilizer application without crop in chamber on ridge, (3) fertilizer application with crop in chamber on ridge, (4) fertilizer application without crop in chamber on ridge and furrow. Nitrous oxide emission at fertilizer application with crop in chamber on ridge were the highest while were the lowest at no-fertilizer without crop in chamber on ridge. There was no significant difference of nitrous oxide emission by chamber position, but total emission by crop existence in chamber was significant difference. Therefore, in order to estimate greenhouse gases emission using chamber method in upland, it should be considered in correlation with crop existence in chamber and characteristic changes like as the soil moisture, microbial flora by crop growth stage.

• Research in Plant Disease
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• v.20 no.4
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• pp.264-269
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• 2014

The effect of biological control of the root-knot nematode, Meloidogyne incognita, on cucumber and lettuce was evaluated with green manure crop species in greenhouse. Nematicidal effect of sudan grass cultivation in cucumber greenhouse was comparable to that of chemical treatment with fosthiazate GR, showing the high activity of 88.6%. Sudan grass cultivation in lettuce greenhouse significantly reduced the number of M. incognita in soil, showing 93.5% of nematiidal activity. In addition, since growth of sudan grass was superior to other green manure crop species, it is considered that cultivation of sudan grass is proper to control M. incognita in greenhouse.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.215-224
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• 2009

A survey on the actual state of heating, cooling, ventilation, and air-flow and experimental measurement of temperature and humidity distribution in tomato greenhouse were performed to provide fundamental data required in the development of air-flow control technology. In single-span plastic houses, which account for most of 136 tomato greenhouses surveyed, roof windows, ventilation and air-flow fans were installed in a low rate, and installation specs of those facilities showed a very large deviation. There were no farms installed greenhouse cooling facilities. In the hot air heating system, which account for most of heating type, installation specs of hot air duct showed also a large deviation. The exhaust air temperature and wind speed in hot air duct also were measured to have a big difference depending on the distance from the heater. We are using the maximum difference as indicator to determine whether temperature distribution is uniform. However if the temperature slope is not identical in greenhouse, it can't represent the uniformity. We analyzed relation between the maximum difference and the uniformity of temperature and humidity distribution. The uniformity was calculated using the mean and standard deviation of data from 12 measuring points. They showed high correlation but were represented differently by linear in the daytime and quadratic in the nighttime. It could see that the uniformity of temperature and humidity distribution was much different according to greenhouse type and heating method. The installation guidelines for ventilation and air-flow fan, the spread of greenhouse cooling technology for year-round stable production, and improvement of air duct and heating system, etc. are needed.