• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.13-17
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• 2015

There are many vinyl houses in rural areas. These vinyl houses have occasionally been collapsed due to heavy snow load in winter. If these vinyl houses are collapsed, many farmers get a lot of economical damages. So it is very important to built safe vinyl house that is able to withstand the applied heavy snow load. In this study, compressive buckling and flexural tests were performed to investigate the strength increase of circular mortar filled pipes. The results showed that buckling load and flexural moment of mortar filled pipes were increased 42 % ~ 82 %, 40 % ~ 44 % respectively more than only pipe without mortar. It is recommended that mortar filled pipes as main members of vinyl house have to be used to prevent collapsing due to the severe snow load.

• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.3
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• pp.4483-4491
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• 1977

The results obtained are as follows; 1. The variation of the temperature in a vinyl house without heating system is similar to that of air temperature in a day. The difference of maximum temperature and minimum one in a day is 27$^{\circ}C$ which is two times greater than the daily difference of air temperature. 2. When the length of the duct is increased, the high temperature zone is built up in the direction of warm air discharge from the duct, and the low temperature zone is built up in the opposite direction of warm air discharge. But, in case of the duct length is short (0.05 L), the temperature distrubution in a vinyl house become uniform. It is concluded that the shorter length of the duct, the better the distribution of the temperature in a vinyl house is. 3. When the duct is installed at high position, the high temperature zone is built up in the upper zone of the vinyl house and the low temperature zone is built up in the lower zone. And when the position of the duct is low, the rate of temperature variation along the vertical direction become high, and the direct contact of warm air with the plant in the house is occured. It is concluded that the duct should be installed at the position of slightly higher than the plant height. 4. When the fuel consumption rate is fixed at the 101/hr, the lowest temperature warming rate in the vinyl house is 5$^{\circ}C$ without regard to the air temperature.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.3
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• pp.27-34
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• 2010

Unbraced vinyl house frame that is economically installed is certainly easy to collapse under the influence of excess snow load. To make it more cheaply in putting up as well as more efficiently in withstanding the applied snow load, it is essential to insert additional bracing into the existing unbraced vinyl house frame. On the other hand, there are varieties of possible bracing shapes that can be formed. However, their efficiencies are different. Therefore, it is important to identify the most effective bracing shape. In this study, 2 different kinds of bracing shapes, horizontal and inclined bracing, are used to additionally install in the ordinary single frames in order to show the effect of the bracing resisting the applied snow load and compare the bending moment, axial force, combined stress and vertical displacement of the vinyl house frame.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.2
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• pp.23-29
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• 2010

Vinyl house is a simple agricultural structure that is installed economically and easily. In contrast, every year the farmers have spent a lot of money because of the collapse of this structure caused by the external forces such as strong wind and heavy snow. To prevent this damage due to frequent heavy snow and strong wind, it would be necessary to design it again. But getting rid of former vinyl house and reconstructing is unreasonable. It would be very economic if the former vinyl house is strengthened simply. This paper covers the investigation of the effect of the bracing systems that are additionally inserted inside the ordinary single frames as well as unbraced multiple frames that resisting only the strong wind load.

• Journal of Korean Association for Spatial Structures
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• v.14 no.4
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• pp.81-88
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• 2014

Construction of vinyl house structures is increasing because they do not have a large cross section as non-permanent structures. Vinyl house structures are apt to collapse by snow load because they have a small size member as a temporary building. Therefore, it is very important to ensure not only the stiffness of the individual member, but also the overall stability of three-dimensional arch-type vinyl house structures. The purpose of this study is to estimate the stability of arch-type vinyl house structures that have a various curvature under the vertical load such as snow load. As a result of the study, the buckling load of V27 model is the largest, and the values of buckling load have a tendency to increase with increasing H(height of arch) in the case of $H{\leq}2.75m$, but to decrease with increasing H in the case of $H{\geq}2.75m$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.351-354
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• 2003

The appearances of growth and yield according to the cultivation types were investigated in chalok 1. The days to harvest under double vinyl house, open mulching and open cultivation were 87.7, 95.8, and 101.8 days, respectively and significantly different in each cultivation types. The branched ears of open mulching, double vinyl house and open cultivation were started at 7,8, and 13 days after silking, respectively. The frequency of branched ear per total plants to double vinyl house, open cultivation and open mulching were 10%, 13%, and 19%, respectively. The ear weight of open mulching and open cultivation was superior to branched ear weight. The yields (kg/10a) of double vinyl house, open mulching and open cultivation were 755.7kg, 740.7kg, and 530.0kg, respectively. The yields(kg/10a) of double vinyl house and open mulching were significantly different to that of open cultivation and LSD(5%) was 133.42. Thus, early cultivations in double vinyl house were more beneficial than other cultivation types because of the highest yield and the lowest branched ear.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.757-766
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• 2015

This study was considered chances of additional income, if farmers raised silkworms in unused mulberry leaves, after harvesting mulberry, investigated yields of mulberry leaves in vinyl-house and optimal amount in raised silkworms, First, the results was investigated productions of mulberry leaves in the mulberry tree-shape of vinyl-house, T-shape harvested 7.07 kg, Y-shape was 6.55 kg, in comparison with convention of it was harvested 4.75 kg mulberry leaves/1 mulberry tree, was harvested 49%, 38% more each. Also, yields of mulberry leaves was used 302 kg when was raised 1box of silkworms in the mulberry tree-shape of vinyl-house. In other hand, yields of raising silkworms was analysed in the mulberry tree-shapes of vinyl-house, mulberry leaves of $1,000m^2$ vinyl-house mulberry tree was raised average of 3.74 boxs silkworms, in the concrete conventional-shape was 3.24 boxs, T-shape did 4.17 boxs and Y-shape was 3.83 boxs, Consequently, if the farmers of $1,000m^2$ vinyl-house mulberry tree raised silkworms with unused mulberry leaves, could get 1~1.2 million won additionally.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2727-2733
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• 2010

Existing and developed models of vinyl house are simulated by 3 dimensional and analysis program. When heavy snow lays 250 mm deep, this paper aims to investigate how its load affects the vinyl house and what deformation happens with structural analysis. Its maximum deformation is decreased to more than 50 % by developing this model in comparison with the existing model. Its developed model is more safe than existing model and its manufacturing expense can be reduced.

• Journal of agricultural medicine and community health
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• v.24 no.1
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• pp.145-159
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• 1999

To find the association, between vinyl house work and the prevalence of low back pain, a questionnaire survey was made toward 215 vinyl house farmers and 228 general farmers without vinyl house who are cared by Jungjung Community health Practioners at Soobuk Myun, Damyang-gun, Chollanamdo. 1. Vinyl house farmers were significantly younger in age, higher in educational status higher survival rate of spouse, higher economic state and less cared by medical aid than general farmers. 2. Vinyl house farmers showed shorter career for agricultural work, used modern farming instrument more frequently and worked with sitting position. 3. During unbusy season in general agriculture, vinyl house farmers consumed significantly more time in agricultural work and general activity, but no significant difference of time of the above activity among busy season. 4. During the last spring season when most vinyl house work was performed, vinyl house farmers showed significantly higher prevalence of low back pain than general farmers, but no significant difference of prevalence among the two groups for the last one week. 5. By the simple analysis statistical significant related variables with low back pain was found to be sex(p<0.001), educational status(p<0.05), work posture(p<0.001) and use of modern agricultural machine(p<0.05). 6. By the multiple logistic regression the odds ratio for low back pain among vinyl house farmers were 2.08(95% confidence interval 1.31-3.00) compared to general farmers, the odds ratio among female was 2.35(95% confidence interval 1.24-4.47) to male, the odds ratio among illiterate persons were 2.60(95% confidence interval 1.24-4.47) to high school graduate, and the odds ration among primary school graduate was 2.19(95% confidence interval 1.04-4.47) to high school graduate. In conclusion because vinyl house farmers showed significantly higher rates of low back pain compared to farmers without vinyl house, continuous study to find the true cause of low back pain among vinyl-house farmers and active effort to prevent low back pain are necessary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.443-447
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• 2002

This study was carried out to determine the differences in the growth, grain yield, and seed quality of sesame plant according to seeding date between P,E. vinyl-house and outdoor cultures. Reproductive growth period in vinyl-house culture was shorter than in outdoor culture. Stem length and capsule setting length of sesame were much longer in vinyl-house culture than in outdoor culture. Also, number of capsules per plant and 1,000 grain weight in vinyl-house culture were higher, specially the grain yield was approximately 57% more than in outdoor culture. In vinyl house culture, sesame plants sown on June 8 had longer capsule setting length, more capsules per plant, higher 1,000 grain weight, and higher percent ripened grain at the upper part of the capsule settings than those sown in May 9. They also had higher 1,000 grain weight at the middle and lower part of the capsule settings compared to May 9 seeding. However, no difference in grain yield of in seeding dates was observed. In outdoor culture, sesame plants, which was sown on May 9, had more effective branch number and capsule number and plant compared to those sown on June 8. Though sesame plants sown on May 9 had lower percent ripened grain at the upper and middle part of the capsule settings and lower 1,000 grain weight, the seed yield was similar to those sown on June 8. No difference in chromaticity value $L^*$ of sesame seeds between two culture conditions was observed. The $a^*$ value was higher in vinyl-house culture than outdoor culture while $b^*$ value was higher in outdoor culture. Sesaminol triglucoside content of sesame seeds was higher in vinyl-house culture than in outdoor culture. On the other hand, the content of sesamin and sesamolin from sesame seeds in vinyl-house culture were lower than in outdoor culture.