• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5906-5913
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• 2015

This paper analyzes the effect of adoption and complementarity of production technology bundles in horticultural greenhouse - more than 10m vinyl greenhouse ($T_1$), polyolefin film ($T_2$), winding branch ventilation ($T_3$), and more than 15 ounce lagging cover ($T_4$). The results are as follows: First, only using $T_1$, only using $T_2$, only using $T_3$, only using $T_4$, using $T_1$ and $T_3$, and using $T_1$ and $T_4$, have a higher net return. Second, when $T_3$ is used, $T_1$ and $T_2$ are complementary. Third, $T_1$ and $T_3$ are always complementary. Fourth, when $T_2$ and $T_3$ are not used, $T_1$ and $T_4$ are complementary. The results of this paper could contribute to government's technology diffusion policies and subsequent studies.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.391-399
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• 2018

In this paper, experimental study performed on steel-pipe connections for structural members of a greenhouse is presented. By those experiments performed, bending moment, deformation and stress distribution of specimens were investigated under four point bending test. The bending performance according to connection method using pin and the stretching is also investigated. The results of bending performance of the no connection specimen were compared to those of other connection specimens. The pin and stretching connection specimens showed lower banding performance than the no connection specimen. The stretching connection method was relatively higher bending performance than the pin connection specimens. According to the results, we proposed the connection method with good bending performance that can be applied to steel-pipe connection in greenhouse.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.203-206
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• 2003

우리나라 시설원예 면적은 '95년 43,093ha에서 '01년 말 현재 52,125ha로 연평균 3.2%의 증가율을 보인 반면 난방면적은 연평균 10.8%씩 증가하여 12,710ha로 전체 시설재배 면적의 24.4%를 차지하고 있다. 또한 난방연료의 95% 이상이 경유이며, 최근 국제정세 불안 등으로 유가가 급등하여 시설재배농가의 연료비 부담은 더욱 가중되고 있다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.11a
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• pp.86-89
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• 2004

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.10a
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• pp.187-191
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• 2003

• Journal of Biosystems Engineering
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• v.29 no.2
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• pp.159-166
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• 2004

In this study, we have developed a web-based management system for greenhouse teleoperation. The remote control system consisted of a database, a web-server, a controller in greenhouse, and clients. The database in the server stored user's information and greenhouse conditions was used to manage user's login and conditioning data. The management system developed by using Java applet, which was a client program for effective and easy management of greenhouse, monitored the greenhouse in real time. Master and driver boards were installed in the greenhouse control unit. Database on flowering to collect and analyze data exchanged data with the server. The master board could be managed effectively by timer routine, repeat control within setting time, and algorithm of setting points. Also, the greenhouse conditions could be controlled by manual or remote controller(PC) through a web browser in internet. Furthermore, all of the control devices of the greenhouse were managed by remote control of using PC and checked via camera installed in greenhouse. Finally, we showed the experimental results of the system which was installed in Pusan Horticultural Experiment Station.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.342-344
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• 2012

A new grafted cactus cultivar, called 'Hwangseon', Gymnocalycium mihanovichii, is a hybrid crossed between two orange color cultivars 'Geoseong' and 'Huhwang'. Mating was performed in the greenhouse of National Institute of Horticultural & Herbal Science (NIHHS) in 2005. The harvested seeds were sown at 100 mL volumetric flasks filled with 'Kyoto' medium. Seedling had been grafted into a young rootstock, Hylocereus trigonus, and cultured in vitro in 100 mL test tube for more than six months. After re-grafting and planting in the green house in 2006, their characteristics were evaluated three times until 2009. The new cultivar has a flat round shape and bright yellow skin color. In addition, it has 7 to 9 ribs with gray and straight spines on the body and produces an average of 12.3 offsets.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.501-508
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• 2012

Reducing carbon dioxide ($CO_2$) exhaust has become a major issue for society in the last few years, especially since the initial release of the Kyoto Protocol in 1997 that strictly limited the emissions of greenhouse gas for each country. One of the primary sectors affecting the levels of atmospheric greenhouse gases is agriculture where $CO_2$ is not only consumed by plants but also produced from various types of soil and agricultural ecosystems including greenhouses. In greenhouse cultivation, $CO_2$ concentration plays an essential role in the photosynthesis process of crops. Optimum control of greenhouse $CO_2$ enrichment based on accurate monitoring of the added $CO_2$ can improve profitability through efficient crop production and reduce environmental impact, compared to traditional management practices. In this study, a sensor-based control system that could estimate the required $CO_2$ concentration considering emission from soil for cucumber greenhouses was developed and evaluated. The relative profitability index (RPI) was defined by the ratio of growth rate to supplied $CO_2$. RPI for a greenhouse controlled at lower set point of $CO_2$ concentration (500 ${\mu}mol{\cdot}mol^{-1}$) was greater than that of greenhouse at higher set point (800 ${\mu}mol{\cdot}mol^{-1}$). Evaluation tests to optimize $CO_2$ enrichment concluded that the developed control system would be applicable not only to minimize over-exhaust of $CO_2$ but also to maintain the crop profitability.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.350-351
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• 1998

This study was conducted to investigate the effect of reflective film(RF) mulching on the growth and flowering of snapdragon 'Fujinoyuki' in greenhouse cultivation. On the spectroradiometry of mulching materials in the wavelength zone of 300nm to 1100nm, 85% of total light source was reflected from RF, while over 95% was absorbed into black polyethylene film(BL). Under plant canopy, light, air temperature, and leaf temperature were higher on the RF mulching than BL, but soil temperature and soil heat flux were higher under the BL. Primary plant growth such as dry weight, stem hardness, lodging, and transpiration was superior when using RF mulching. RF mulching accelerated the plants to bloom about 12 days earlier with admirable cut flower quality.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.402-410
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• 2017

The effect of the steel pipe member joint on the design performance of a plastic multi-span greenhouse was analysed through the comparing full-scale experiment and numerical analysis. The design performance of the greenhouse is generally evaluated through numerical analysis, but it is rare to consider the characteristics of the connections or joints of the members. In this study, the effect of the column-gutter beam-rafter-wind break wall joint on the design performance of the whole structure of a plastic multi-span greenhouse was analysed. The numerical results with assuming that the member joint are rigid condition were compared with the full-scale load test results using member joints used in the field. The stiffness of the entire structure was compared using the load-displacement relationship and the change of the load sharing ratio that the main members such as column, rafters, and wind break wall was analysed. The results of the load test were about 40% larger than the numerical result and the member stress was more than twice as large as those of the loaded columns. In order to increase the reliability of the design performance of the greenhouse, it is necessary to develop a numerical analysis model which can consider the characteristics of various joints.