• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.492-500
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• 2023

The spectrum of this study was research on the closed hydroponic cultivation of netted melons (Cucumis melo L.) using coir substrate, analyzing the impact of this cultivation method on melon yield, fruit quality, and the efficiency of water and nutrient usage. The experimental results showed that the average fruit weight of the melons grown in a closed system was 71.4 g higher than that of the open system, and the fruit width was on average 0.2 cm larger, showing a statistically significant difference. However, there was no difference in the average sugar content of the fruit flesh and height. Although there is no substantial commercial difference, it is conjectured that the change in the macronutrients ratio in the irrigation has played a role in the statistically significant increase in fruit weight, which is attributed to changes in the crops' nutrient uptake concentrations. This necessitates further research for a more comprehensive understanding. In terms of the productivity of irrigation required to produce the fruit, applying the closed system resulted in an increase of 7.6 kg/ton compared to the open system, saving 31.6% of water resources. Additionally, in terms of nutrients, cultivating in a closed system allowed for savings of approximately 59, 25, 55, 83, 76, and 87% of N, P, K, Ca, Mg, and S, respectively, throughout the entire cultivation period. As the drainage was reused, the ratios of NO₃^- and Ca²⁺ increased up to a maximum of 9.6 and 9.1%, respectively, while the ratios of other ions gradually decreased. In summary, these results suggest that closed hydroponic cultivation can effectively optimize the use of water and fertilizer while maintaining excellent fruit quality in melon cultivation.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.193-200
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• 2000

The object of this study is to investigate the quality change of sweet basil grown with selenium(Se) in hydroponic culture. Sweet basil was cultured with 1 fold herb nutrient solution as suggested by European vegetable R & D Center in Belgium. Before three weeks harvest, sodium selenate(N $a_2$Se $O_4$) was supplied to 2 and 4 mg. $L^{-1}$ in the nutrient solution. Sweet basil was stored at 1$0^{\circ}C$ using 40um ceramic film and PET (polyethylene terephalate) for 15 days in modified atmosphere(MA) storage condition. The weight loss of sweet basil was higher in non-treatment compared to Se treatments in both of two films but it was decreased over 5% in PET treatment. Se concentrations in leaf tissues increased in the response to the treated levels of N $a_2$Se $O_4$concentrations, and this tendency was appeared similar results after storage. There was no significant effect of packing materials on volatilization of Se in sweet basil. The total chlorophyll and essential oil content was increased with increasing N $a_2$Se $O_4$concentration in nutrient solution. The amount of volatilization flavor was not higher at N $a_2$Se $O_4$4mg. $L^{-1}$ treatment compare to others during storage. Se content was 112.73 ug. $g^{-1}$ dry mass at 2 mg. $L^{-1}$ treatment before storage and the decrease of Se content was observed by 50% at 15 days after storage. The condition, which N $a_2$Se $O_4$2mg. $L^{-1}$$^{plement}$ in nutrient solution during growth stage and stored with 40um ceramic film on 1$0^{\circ}C$are acceptable for maintaining of sweet basil quality. Moreover it can be a proper Se concentration for human health. Overall, Se treatment in nutrient solution has effect on promoting and maintaining quality of herb during storage life. Also, there was not significant change of essential oil compounds by volatilization of Se.mpounds by volatilization of Se.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.133-140
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• 2001

This study was conducted to develop a nutrient uptake model in cucumnber (Cucumis sativus L. cv. Eunsung Backdadagi) plants for prediction of the amount of nutrients in drainage solution in a closed perlite culture system. Electrical conductivity (EC) of the nutrient solution was adjusted to 1.5, 1.8, 2.1, 2.4, and 2.7 dS. $m^{-1}$ . The amount of nutrient solution absorbed in different EC treatments was not different until the mid stage of growth. However, after the mid growth stage, a high EC treatment resulted in less solution absorption. The absorption rates of K, N $O_3$$^{[-10]}$ -N, Mg, and P increased continuously for a whole growing period in all treatments, while those of Ca decreased slightly. For S, the decrease was significant after th mid stage of growth. although the amounts of absorbed inorganic ions in different EC treatments were not significantly different at the first stage of growth, they were significantly different after the mid stage of growth and decreased slightly at the end of growth stage. Models for predicting the amounts of each inorganic ion absorbed were developed by using EC and the amount of nutrient solution absorbed per unit radiation(mg.M $J^{-1}$), which proved to be practical with a positive correlation at 1 percent probability between the developed model and practical values..

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.75-76
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• 2001

순환식 펄라이트재배에서 배액 재사용을 위한 양분흡수 모델링을 작성하고자 EC 처리(1.5, 1.8, 2.1, 2.4, 2.7 dSㆍm-1)를 수행하였다. 생육 중기까지 EC 수준에 따른 양액흡수량은 차이가 없었지만 중기 이후 EC가 높을수록 흡수량이 감소되는 경항을 보였다(Fig. 1). NO$_3$-N, P 및 K의 흡수량은 생육기간 동안 처리간 차이를 유지하였는데 N과 K는 생육 중기 이후 일정 수준을 유지하였으나 P는 생육기간 동안 다소 증가되는 경향을 보였다. S의 흡수량은 생육 중기 이후 모든 처리에서 급격한 감소를 보였으며 생육 후기에는 처리간에 차이가 없었다(Fig. 2). 오이의 무기이온 흡수율에서와 같이 흡수량에서도 EC간 차이를 보여 EC를 무기이온 흡수량을 추정하는 요소로 이용할 수 있을 것으로 생각되었다. 무기이온 흡수량은 모든 EC 처리간에 생육 초기에는 차이를 보이지 않았으나 생육중기 이후에는 뚜렷한 차이를 보인 후 생육 후기의 높은 농도에서 그 차이가 다소 감소되는 경향을 보였다. 단위일사량에 따른 양액흡수량과 EC를 주된 변수로 한 오이의 이온 흡수량 예측 회귀식을 작성하였는데 모든 무기이온 흡수량 추정식의 상관계수는 S를 제외한 모든 이온에서 높게 나타났는데 특히 N, P, K 및 Ca에서 높았다. S이온에서의 상관계수는 0.47로 낮게 나타났으나 각 이온들의 회귀식에 대한 상관계수는 모두 1% 수준에서 유의성을 보여 위의 모델식을 순환식 양액재배에서 무기이온 추정식으로 사용이 가능할 것으로 생각되었다(Table 1). 이를 이용한 실측치와의 비교는 신뢰구간 1%내에서 높은 정의상관을 보여 실제적인 적용이 가능할 것으로 생각되었다(Fig 3)..ble 3D)를 바탕으로 MPEG-4 시스템의 특징들을 수용하여 구성되고 BIFS와 일대일로 대응된다. 반면에 XMT-0는 멀티미디어 문서를 웹문서로 표현하는 SMIL 2.0 을 그 기반으로 하였기에 MPEG-4 시스템의 특징보다는 컨텐츠를 저작하는 제작자의 초점에 맞추어 개발된 형태이다. XMT를 이용하여 컨텐츠를 저작하기 위해서는 사용자 인터페이스를 통해 입력되는 저작 정보들을 손쉽게 저장하고 조작할 수 있으며, 또한 XMT 파일 형태로 출력하기 위한 API 가 필요하다. 이에, 본 논문에서는 XMT 형태의 중간 자료형으로의 저장 및 조작을 위하여 XML 에서 표준 인터페이스로 사용하고 있는 DOM(Document Object Model)을 기반으로 하여 XMT 문법에 적합하게 API를 정의하였으며, 또한, XMT 파일을 생성하기 위한 API를 구현하였다. 본 논문에서 제공된 API는 객체기반 제작/편집 도구에 응용되어 다양한 멀티미디어 컨텐츠 제작에 사용되었다.x factorization (NMF), generative topographic mapping (GTM)의 구조와 학습 및 추론알고리즘을소개하고 이를 DNA칩 데이터 분석 평가 대회인 CAMDA-2000과 CAMDA-2001에서 사용된cancer diagnosis 문제와 gene-drug dependency analysis 문제에 적용한 결과를 살펴본다.0$\mu$M이 적당하며, 초기배발달을 유기할 때의 효과적인 cysteamine의 농도는 25~50$\mu$M인 것으로 판단된다.N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%

• Horticultural Science & Technology
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• v.17 no.3
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• pp.355-360
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• 1999

This study was carried out to investigate the effect of irrigation frequency, particle size and depth of perlite medium on the growth of Dendranthema grandiflorum (Ramat.) Kitamura 'Shuhouno-chikara' grown on recycling system. In Exp 1, the irrigation frequency (IF) was designed as 3 (IF3), 9 (IF9), and 18 (IF18) times a day. Fine and coarse particle size (PS) of perlite was used as a media, and depth of media (DM) was 15 and 10 cm contained in $34{\times}120{\times}15cm$ styrofoam bed. In Exp 2, the IF was 3 (IF3), 6 (IF6), and 9 (IF9) times a day with the same amount of nutrient solution. Fine and coarse PS were used, and DM was 15 and 7.5 cm. In this study, high IF and fine PS was favorable for plant growth. However, as the IF became frequent, difference of plant growth between fine and coarse PS became smaller. Also, shallow media showed little difference with deep media in plant growth. Thus, decreasing the amount of media was recommended to reduce the production cost.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.347-349
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• 1998

Slow sand filtration was modified and applied for the determination of eliminating efficacy of various fungi and for recommending an easy approach to growers. After 1,500 liter filtration, Fusarium oxysporum was eliminated by several substrates such as activated charcoal (92.5% elimination), silica (90.8%), vermiculite (90.5%), sand (82.3%), perlite (50.4%), and hydroball (21.2%). Silica was able to eliminate several fungi by maximal ratio, which was corresponded to Fusarium oxysporum 120 cfu/mL. Collectotrichum lagenarium 98 cfu/mL. Phytophthora capsici 82 cfu/mL, Botrytis cinerea 62 cfu/mL, Pythium spp. 42 cfu/mL, and Sclerotinia ssp. 52 cfu/mL. In this case, the change of EC was minor and pH was maintained to about 7. In deep flow culture of 'Ddooksum Cheokchookmyeon' lettuce and 'Seokwang' tomato, silica-, activated charcoal-, and vermiculite-based filtration system successfully eliminated Fusarium oxysporum and Phytophthora capsici from the nutrient solution. As a result, these plants were not diseased by ten weeks after inoculation. With this system, growers can easily control the root-zone fungi in the recirculating hydroponic system.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.43-54
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• 1998

This experiment was conducted to develop optimal nutrient solution for tomato plants, according to the plant growth stages in closed system. Perlite substrate was supplied with 1/2 and 1 strength of the solution of National Horticultural Research Station in Japan. Plants grew better and the nutrient_contents in the leaves were also proper in 1 strength. Based on these results, optimal nutrient solution in perlite was composed by n/w of 1 strength according to the plant growth rates ： N 13.5, P 3.3, K 7.0, Ca 7.0, Mg 3.5 me.L$^{-1}$ in seedling stage, N 14.2, P 3.3, K 8.0, Ca 7.5, Mg 4.0 me.L$^{-1}$ in vegetative stage and N 10.0, P 3.0, K 7.0, Ca 6.0, Mg 3.0 me.L$^{-1}$ in reproductive stage. To examine the suitability of the nutrient solution developed in this experiment, tomato plants were grown in rockwool and supplied with two different composition and concentration of nutrient solution composed by n/w of 1 strength in perlite (SCUT) and by Research Station for Greenhouse Vegetable and Floriculture on the Netherlands (PBG). PH and EC in SCUT were changed little in 1 strength but a significant change of PH was shown in 1/2 strength. Later, drained solutions in rockwool were also analyzed according to the Plant growth stages. Low concentrations of N and P in root zone were shown in early growth stage but N was increased in reproductive stage, while, K, Ca, Mg concentration was consistent through the whole growth stage. Considering these results, we found that the rebalance of N and P was needed, that is, reduction of N concentration in reproductive stage and increasing of P concentration in vegetative stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.251-255
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• 2008

This study was carried out in 2002 to determine the usefulness of Jeju scoria for a component of a growth medium and optimum planting density of 'Dejima' seed potatoes (Solanum tuberosum L.) grown in a wick hydroponic system. The minitubers ($7.0{\pm}0.2\;g$) produced in an aeroponics system were planted at five planting densities (3 to 15 tubers/box; 19 to $95\;tubers/m^2$) in polystyrene boxes (51 cm long $\times$ 31 cm wide $\times$ 20 cm high) containing two media (perlite + peatmoss and Jeju scoria + peatmoss 1:2, v/v mixtures). There were no significant interactions between medium and planting density for the growth and tuber yield traits. Shoot growth and the number of tubers per plant were not significantly affected by the media. However, tuber yield was higher in the perlite + peatmoss mixture than in the Jeju scoria + peatmoss mixture. The percentage of underdeveloped plants ranged from 8.3 to 14.7% at four lower planting densities (3 to 12 tubers/ box), and was 25.8% at the highest planting density (15 tubers/box). As planting density was increased from 3 to 15 tubers per box, seed potato (${\geq}5\;g$ tuber) number increased from 101 to 269 and yield from 6.3 to $11.6\;kg/m^2$. These results indicate that the perlite + peatmoss mixture might be more suitable for seed potato production in the wick hydroponic system, and considering the percentage of underdeveloped plants and tuber yield, optimum planting density would be 56 to $76\;tubers/m^2$ in the system depending on availability of seed potatoes.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.240-244
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• 2004

This study was conducted to evaluate the effect of different surfactants on the fertilizer reduction and increase of the mineral nutrients uptake of lettuce (Latuca sativa L. 'Hanbatchungchima') in deep flow technique culture. The measured items from lettuce leaves expanded fully were growth, photosynthetic and transpiration rate, and mineral nutrient content K, Ca and Mg, respectively. The highest growth were observed at $0.3mg{\cdot}L^{-1}$ polyvinyl alcohol (PV4-95) treatment, including lettuce grown in the half strength of nutrient solution. The highest photosynthetic rate, transpiration rate and mineral nutrient content were observed at $0.3mg{\cdot}L^{-1}$ calcium lignosulfate (CLS) treatment. Therefore, high-quality leaf lettuce production could be achieved by apply proper surfactants PVA-95 and CLS, which can cut down the total amount of fertilizer and increase uptake of mineral nutrients.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.183-189
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• 2018

This study was carried out to investigate the effect of plant growth and production of tomato (Lycopersicon Esculentum Mill cv. Tefunis) according to the water content of non-recycled rockwool culture in high-rise tomato greenhouse. Daily irrigation amount was 3.8 times higher in the irrigation control by Integrated Solar Radiation (ISR) than in the Frequency Domain Reflectometry (FDR) sensor. Water content of ISR and FDR was 90-95 and 60-65%, respectively. Plant height and weight of tomato fruit was 1.2-1.9 times longer and 1.2-2.0 times heavier in the ISR than in the FDR sensor, respectively. No significantly differed to sugar content of tomato by treatments. Marketable fruits were the higher 1.3 times in the ISR compared with the FDR sensor. Cracking percentage in the ISR was also the higher 2.0 times compared with FDR sensor. Therefore, Irrigation control by ISR was appropriate to improve of plant growth and production of tomato with non-recycled rockwool culture in greenhouse during long-term cultivation.