• Korean Journal of Plant Tissue Culture
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• v.28 no.3
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• pp.117-121
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• 2001

Microstructure of abaxial leaf surface and carbohydrate content of propagules grown in different culture conditions such as heterotrophic, mixotrophic and autotrophic carbon source were investigated. In the leaves of propagules which were grown in the green house, autotrophic and mixotrophic conditions, wax layer was observed, but in the leaves of the heterotrophic propagules, it was not observed. Size and number of stomata of the leaves in the heterotrophic condition was larger and more numerous than that of autotrophic propagules. Especially, stomata of the leaves in the autotrophic condition was similar to the leaves of plant grown in green house. Carbohydrate content was higher in photoautotrophic condition than that in mixotrophic and heterotrophic culture. Also, Free sugar content showed higher in photoautotrophic propagules than that in mixotrophic and heterotrophic culture. In all the culture conditions, content of glucose were higher than that of other free sugars.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.73-85
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• 2009

An investigation was conducted to get the basic data for establishing structural safety and environmental management of tomato greenhouses in Chungnam region. The contents of the investigation consisted of actual state of greenhouse structures and environmental control facilities. Most of greenhouses were arch type single-span plastic houses and they had too low height for growing tomatoes. Frameworks of multi-span greenhouses were suitable, but those of single-span were mostly insufficient. Every greenhouse had thermal curtain movable or covering fixed inside the greenhouse for energy saving, and heating facilities were mostly warm air heater. Irrigation facilities were mostly drip tube and controlled by manual operation or timer. Almost all of the greenhouses didn't install high level of environmental control facilities such as ventilator, air circulation fan, $CO_2$ fertilizer, insect screen, supplemental light, and cooling device.

• Environmental and Resource Economics Review
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• v.9 no.1
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• pp.127-153
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• 1999

청정개발체제(CDM)란 '기후변화의 부정적 효과 완화'와 '개도국의 지속 가능한 발전 지원'이라는 기후변화협약의 양대 목표를 비용 효과적으로 이행하기 위해 교토의정서에 마련된 수단이다. CDM은 선진국인 부속서 I 국가와 이에 해당하지 않는 비(非)부속서(non-Annex) I 국가 즉 개도국이 배출감축을 위해 공동으로 노력하고 그 결과 창출된 온실가스 감축 분을 이 두 그룹 국가간에 배분되도록 한 제도다. 즉 선진국은 개도국에 자본과 기술을 투자하여 온실가스 저감사업을 벌이고 이 과정에서 발생한 온실가스 배출감축 분을 자국의 감축실적(credits)으로 인정받게 되고, 개도국은 이 과정에서 기술이전 및 재정지원의 혜택을 받을 수 있게 되어 있다. CDM은 따라서 세계 대다수의 국가가 직 간접으로 영향을 받지 않을 수 없을 것이며, 이로 인해 CDM의 구체적 실천 방안을 둘러싸고 각 국간의 이해 관계가 좀처럼 좁혀지기 어려운 상황이다. 이에 따라 지난해 부에노스 아이레스에서 개체되었던 COP-4에서는 CDM 체제를 비롯한 기후변화협약의 핵심 쟁점사항을 오는 2001년(또는 2002년)에 개체될 COP-6까지 일괄 타결키로 한 부에노스 아이레스 행동계획을 채택하는 데 그쳤다. CDM이 향후 어떤 형태로 결정되는 가에 따라 우리 나라가 받는 영향도 상당한 차이가 날 것이다. 따라서 CDM의 전개 방향을 면밀히 주시하고 이에 대한 대응책 마련이 절실히 요구되고 있다.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.419-428
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• 2021

In order to develope a mobile-based greenhouse energy calculation program, firstly, the overall thermal transmittance of 10 types of major covers and 16 types of insulation materials were measured. In addition, to estimate the overall thermal transmittance when the cover and insulation materials were installed in double or triple layers, 24 combinations of double installations and 59 combinations of triple installations were measured using the hotbox. Also, the overall thermal transmittance value for a single material and the thermal resistance value were used to calculate the overall thermal transmittance value at the time of multi-layer installation of covering and insulating materials, and the linear regression equation was derived to correct the error with the measured values. As a result of developing the model for estimating thermal transmittance when installing multiple layers of coverings and insulating materials based on the value of overall thermal transmittance of a single-material, the model evaluation index was 0.90 (good when it is 0.5 or more), indicating that the estimated value was very close to the actual value. In addition, as a result of the on-site test, it was evaluated that the estimated heat saving rate was smaller than the actual value with a relative error of 2%. Based on these results, a mobile-based greenhouse energy calculation program was developed that was implemented as an HTML5 standard web-based mobile web application and was designed to work with various mobile device and PC browsers with N-Screen support. It had functions to provides the overall thermal transmittance(heating load coefficient) for each combination of greenhouse coverings and thermal insulation materials and to evaluate the energy consumption during a specific period of the target greenhouse. It was estimated that an energy-saving greenhouse design would be possible with the optimal selection of coverings and insulation materials according to the region and shape of the greenhouse.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.273-281
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• 2016

In this study, after carrying out a bending test that targeted the frames of plastic film greenhouse, the load-displacement relationship was analyzed to be used as basic data to develop greenhouse construction and maintenance guidelines. As a result, regardless of the shapes of the specimen, the yield and the maximum load increased as the size of the specimen increased. The displacement also showed the same pattern. A steel pipe showed lower yield and maximum load than a square pipe, and the displacement was large. In the steel pipe case, the displacement under the yield and maximum load was in the range of approximately 1.42-4.20mm and 5.80-24.13mm, respectively. In the square pipe case, the displacement under the yield and maximum load was in the range of approximately 1.62-3.00mm and 3.13-8.01mm, respectively. Further, a large difference was observed between the result of this test and the values calculated by a conventionally provided standard. In particular, not much difference was found from the result of this test in the case of a purlin member from the values provided by previous researches. However, a large difference was observed in the column or main rafter members. Furthermore, when a wide-span and venlo type, which is a glasshouse, was used as a target(h/100 and h/80), the displacement under the yield and maximum load was approximately 28.0mm and 35.0mm, respectively, which showed a large difference compared with the Netherlands standard(14.0mm) of a glasshouse. Further, in the main rafter case, a large difference was observed in the displacement limit according to the width(i.e., span) of the greenhouse where members are used. Therefore, because the displacement limit can vary depending on various factors such as type, form, and size of a greenhouse, we determined that studies or tests that consider these factors should be carried out to reflect them in the construction and maintenance of greenhouses.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.308-316
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• 2015

This study was conducted to investigate the situation of ICT apply to plastic greenhouse, and the results be apply to design of new one. A CFD analysis were conducted to monitering the ventilation and energy saving of the single span greenhouse newly designed. The causes of delay to apply ICT to plastic greenhouse are the high cost for installation(24%), insufficiency of after services(19%), often disorder(16%), unskillful management of soft ware(15%), insufficient ICT efficiency(13%) and unsatisfying of income increase(12%). The parts of problem occurred in ICT plastic greenhouse are the structure, actuator, environmental control system and sensor(approximate 14%, respectively), remote control technique(13%), plant management technique(12%), energy saving technique(10%) and utilization of software(8%). In the condition of lateral window closed, the average wind speed changed to slow, but it was faster in the condition of leeward side window opened than in the condition of lee and winward side window opened. The air movement in the condition of lateral window closed occur by air moving fan not by out air. It is not affect the room temperature but effective the uniformity of room temperature. The average temperature of low height greenhouse was uniform than high height one. The average temperature in condition of 3rd curtain opened become same with outside temperature after 2 hours, but take more 5 hours in condition of 3rd curtain closed.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.73-79
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• 2020

The objective of this study is to analyze the heat transfer loss of covering materials in a single-span plastic greenhouse under the steady-state wind environment. To achieve this objective, the following were conducted: (1) design of a small-scaled wind tunnel (SCWT) to analyze heat losses of the greenhouse and its performance; (2) determination of the overall heat transfer coefficient (OHTC) for the covering materials using a small-scaled greenhouse model. The SCWT consists of the blowing, dispersion, steady flow, reduction and testing areas. Each part of the SCWT was customized and designed to maintain air flow at steady state and to minimize the variances in the SCWT test. In this study, the OHTCs of the covering materials were calculated by separating each with the roof, side wall, front and back of the small-scaled greenhouse model. The results of this study show that the OHTC of the roof increases as wind speed increases but the zones in which the increase rate of the OHTC decreased, were distinguished by wind tunnel wing speed of 2 ms^-1. For the side wall, the increase rate of the OHTC was particularly higher in the 0-1 ms^-1 zone.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.187-195
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• 2015

In this study, a field test of uplift load was carried out using 15 greenhouse foundations fabricated in full scale on a sand soil to examine the uplift capacity of plastic film greenhouse and glasshouse foundations for disasterproof standard. As a result, the maximum uplift capacity of the target greenhouse foundations was shown to be in the range from 11.6kN to 82.4kN according to the differences between the forms and sizes of the foundation. As a result of the examination of the applicability using the field uplift load test result of the theoretical equation proposed for maximum uplift capacity calculation of greenhouse foundations, we found that in general, the conventional theoretical equation for the calculation provided numerical values close to the field test results. However, the soil considered in this study was a sand; thus, in the future, verifying the conventional theoretical equation for the uplift capacity calculation of a cohesive soil would be necessary.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.89-93
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• 1998

농가보급형 비닐온실(1-2W형)은 농촌진흥청에서 '92년 4월에 폭 7m, 측고 2.7m, 동고 4.8m로 개발하여 각 시ㆍ군에 설계서를 배포하였으며 '95년 3월 자재일부와 동고의 높이를 수정하였고, 개량아치단동형(1-lS)과 '94년 6월에 개발된 한국형 유리온실과 함께 농민들이 가장 선호하는 시설형태 중 하나이다. (중략)

• 월간 기계설비
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• s.236
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• pp.54-65
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• 2010

지구 대기 중 온실가스 농도와 지구의 지표 온도가 매년 증가하고 있으며 21세기에는 기후변화의 가속도가 훨씬 심해질 것으로 전망되고 있다. 산업혁명 이후부터 급격하게 늘어난 온실가스의 영향으로 기후변화가 일어나고 있다는 것은 새삼스러운 이슈가 아니며, 어느 한 지역에 그치는 것이 아니라 지구환경적 문제이기 때문에 모든 국가의 공동 대책 수립이 불가피하다는 논의가 진행된 지 오래다. 지난 1992년 브라질에서 열린 '리우환경회의'에서 본격적으로 지구온난화 방안을 논의한 이래, 1997년 일본에서 '교토의정서' 채택에 관한 회의가 열렸으며, 매년 협약이행 당사국 총회를 개최해 오고 있다. 범지구적 구속력을 갖는 '교토의정서'의 탄소배출 협의내용은 2012년까지 효력을 갖는데 우리나라는 의무대상국이 아니었지만 앞으로 열릴 회의를 통해 어떤 형태로든 의무감축 대상국이 될 공산이 크다. 우리나라도 국회에 계류 중인 '녹색성장기본법'이 통과되면 탄소감축이 본격적으로 시행될 예정이며 현재 시범실시중인 탄소배출권 거래제도 구체화될 계획이다. 이번호에서는 국제 탄소배출권 논의에 대한 전반적인 사항과 이와 관련한 우리나라 정책 및 현황 등을 점검해보고 기업 및 가정에서 실행할 수 있는 대책 등에 대해 알아본다.