• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.132-138
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• 2023

The Gymnocalycium mihanovichii has been an important export item of Korean flower industry for a long time. Although there is a high demand for grafted cactus from overseas, its production for export is limited. In this study, the growth and marketable yield characteristics of Gymnocalycium mihanovichii 'I-Hong' were compared between soil culture and ebb-and-flow hydroponic system with single- or double-tier bench. As a result, hydroponic methods with single-tier bench resulted in higher fresh weight and glove diameter compared to other cultivation methods. In the ebb-and-flow hydroponic system, hydroponic system with double-tier bench of grafted cactus traits has a lower growth rate than other cultivations. However, the hydroponic system with double-tier bench of grafted cactus significantly increased the yield. In conclusion, the yield from hydroponic system with double-tier bench was better than soil cultivation method. Although there were some differences in color depending on the cultivation method, it was considered that there was no difference in appearance of Gymnocalycium mihanovichii 'I-Hong'. Our results suggest the cultivation methods to overcome production constraints, expand their exports, and improve the value-added characteristics of grafted cactus.

• Computational Structural Engineering
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• v.12 no.1
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• pp.86-94
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• 1999

예비구조설계에서는 구조시스템 대안의 생성과 발전, 여러 방법과 대상에 따른 해석과 설계 다양한 요구조건과 구조적 특성을 고려한 여러 구조시스템 대안의 비교 및 선택 과정을 거친다. 그리고, 이러한 각 과정은 구조설계자의 경험적 지식을 바탕으로 하는 종합적인 사고와 판단에 따라서 단계적, 반복적으로 이루어진다. 그러므로, 예비구조설계에서는 정형화된 자료와 작어뿐 아니라 비정형화된 자료와 작업도 처리해야 한다. 따라서, 컴퓨터는 정형화된 자료와 작업을, 구조설계자는 비정형화된 자료와 작업을 직접 처리하고 이를 상호작용을 통하여 교환 및 지시하는 방식, 즉 구조설계자와 컴퓨터의 역할분담에 기초한 상호작용방식을 통하여 예비구조설계에 컴퓨터를 효율적으로 활용할 수 있을 것이다. 구조설계자와 컴퓨터의 역할분담에 기초한 상호작용을 원활히 지원하기 위해서는 구조시스템 대안의 기하학적 향상, 재료에 대한 자료를 효과적으로 제시할 수 있는 3차원 관점, 각 구조시스템 대안을 검토하고 비교하는 사항이 되는 다양한 요구조건에 대한 자료들을 관리하고 제시할수 있는 요구조건 관점이 필요하다. 그리고 예비 구조설계가 진행되어 온 과정, 방향, 설계의도등의 파악을 위한 바탕이 될 수 있는 작업과정관점, 구조시스템 대안 발전 관점이 필요하다. 예비구조설계의 프로세스 조절을 위한 상호작용을 효과적으로 지원하기 위해서는 컴퓨터가 수행 할 수 있는 정형화된 작업들을 예비구조설계의 진행순서인 구조시스템 대안의 생성과 발전, 구조시스템 대안의 해석과 설계, 구조시스템 대안의 선택에 따라서 나열하여 제시할 필요가 있다. 이를 통해서 구조설계자는 자신의 판단에 따라서 다음에 수행해야 할 작업을 결정하고, 그에 해당하는 정형화된 작업을 컴퓨터가 제시한 작업 중에서 선택하고 그 수행을 지시하여 자신의 경험적 지식과 설계의도에 맞추어 예비구조설계의 프로세스를 조절할 수 있다.정조합력은 유의차가 컸으나, 상반조합 능력은 없었다. 교배친의 우성효과는 컸다. 잡종강세 환경변이 및 상가적 작용도 컸다. 우성의 방향은 정의 방향이었으므로 우성귀전자가 크게 작용하였다. 이들 형질들의 귀전자들은 초우성을 나타내었다. 교배친의 자견층중의 우성순서는 잠120>잠114>잠108>잠119>잠118>잠107>잠117>잠113 순이었고, 웅견층중에서는 잠114>잠108>잠120>잠117>잠118>잠107>잠119>잠119>잠113 순이었다. 자견층 비율에서는 광의의 귀전력이 협의의 귀전력보다 컸고, 웅견층 비율에서는 같았다, 견층 비율에서는 일반조합 능력은 크게 나타났으나, 특정조합 능력과 상반조직 능력은 나타나지 않았다. 자견층 비율에서 교배친의 우성효과는 컸다. 자견층 비율에서는 교배친의 우성효과는 적었다. 자웅견층 비율의 잡종 강세는 적게 나타났다. 환경변이와 상가적 작계는 자웅견층 비율에서는 크게 나타났다. 우성의 방향은 자견층 비율에서는 정의 방향으로 우성 귀전자가 크게 작용하였으며, 자견층 비율에서는 정의 방향으로 우성 귀전자가 부분적으로 작용하였다. 교배친의 자견층 비율의 우성순서는 잠117>잠114>잠108>잠120>잠118>잠119>잠107>잠113 순이었고, 자견층 비율에서는 잠114>잠117>잠108>잠118>잠107>잠119>잠113>잠120의 순이었다.지방산의 조성이 많은 차이를 보였다.{2+}$ 26 및 $Na^+$ 26 mg $L^{-1}$이었다. 양액 재배 후 버려지는 폐양액 중의 무기성분 함량은 양액재배에 이용되는 원수에 비해 상당히 높아졌다.료로서 응용 가능성이 있음을 시사한다.약재료인 약초류 등을 이용하였는데 오랫동안 푹 삶아 그물에 곡류 등을 넣어 죽이나 밥으로 조리하였으며 면으로도 조리하였다. 이상과 같이 조선시대 주식류의 종류 및 조리방법에 대한

• Journal of Bio-Environment Control
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• v.9 no.3
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• pp.171-178
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• 2000

Gross photosynthetic rats of leaves of hydroponically grown cucumber plants(Cucumis sativus L. cv. Guwoosalichungjang) were measured under various conditions of photosynthetic photon flux(PPF), ambient $CO_2$ concentration, air temperature and leaf nitrogen contents. Light compensation point of leaf photosynthesis appeared to be in the range of 10~20$\mu$mol.m$^{-2}$ .s$^{-1}$ and light saturation point be above 1000$\mu$mol.m$^{-2}$ .s$^{-1}$ . Gross photosynthetic rates increased persistently and asymptotically as air temperature rose from 12$^{\circ}C$ to 32$^{\circ}C$. However, there were only small differences in gross photosynthetic rates in the range of 24-32$^{\circ}C$, so that the range seemed to be optimal for photosynthesis of cucumber plants at the condition of $CO_2$ concentration of 400$\mu$mol.mol$^{-1}$ and PPF of around 400$\mu$mol.m$^{-2}$ .s$^{-1}$ . $CO_2$ compensation point of leaf photosynthesis appeared to be in the range of 20-40$\mu$mol.mol$^{-1}$ and $CO_2$ saturation point be above 1200$\mu$mol.mol$^{-1}$ . Gross photosynthetic rates increased sigmoidally as leaf nitrogen content increased. These environmental factors interacted synergistically to enhance gross photosynthetic rate, so that the rate increased multiplicatively s level of one factor increased progressively with higher levels of he other factors. Mathematical models wer developed to estimate the gross photosynthetic rate in accordance with the variations of these environmental factors. These modes can be used not only to explain he variation of growth or yield of cucumber plants under different environmental conditions but also as building blocks of plant growth model or expert system of cucumber plants.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.7-14
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• 2005

This study was conducted to develop a chain conveyor-type, row-spacing system for a plant factory. The developed system was evaluated for its practical use in growing plants. Results are intended to provide technical suggestions on the row spacing for hydroponically grown vegetables in a plant factory. The designed row-spacing system for a plant factory could be adjusted by four stages with a conveying speed range of $5.3\~15.8cm{\cdot}s^{-1}$ and with a row-space range of 10-25cm. The torque of driving shaft was measured with a torque range of 11.7-33.3 N$\cdot$m according as a trough weight changes with a range of $17\~935$ N. A measured value was $5.9\~9.8\;N{\cdot}m$ lower than a theoretical value. Travel reduction rate was shown up $1.6\~1.9\%$. The conveying time of trough was shown up 2.24 seconds in case that the designed value was 2.26 seconds. The system was evaluated to be functioning effectively according to the initial design factors in the test.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.28-37
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• 2019

We designed a system that can automatically collect, convey, and control cool air of $15^{\circ}C-20^{\circ}C$ containing carbon dioxide from a mushroom cultivation house to a strawberry plastic house. We recorded the temperature at various positions from July to August 2017. The average temperature of the green house during day and at night was maintained at $33^{\circ}C$ and $26^{\circ}C$, respectively. In the moveable three-tier cylindrical bed, the average temperature around root was maintained at $26^{\circ}C$ and $21^{\circ}C$ during day and at night, respectively. On the high-bench in the green house, the temperature was maintained at $32^{\circ}C$ and $30^{\circ}C$ during day and at night, respectively. The carbon dioxide concentration was maintained around 800-1,600 ppm in the mushroom cultivation system and 400-800 ppm in the strawberry plastic house. The growth characteristics of the strawberry treated with moveable three-tier cylindrical bed were significantly different from those of the untreated high-bench bed. In addition, during the summer season, moveable three-tier cylindrical bed showed more tendency to increase in normal fruit number (NFN) and to decrease in defective fruit number (DFN) compare to the high-bench bed. Therefore, the moveable three-tier cylindrical bed showed a tendency to be more than 2 times higher yields than that of the high-bench bed. It was confirmed that ever-bearing strawberry cultivars could be cultivated in green house due to the cool air supply from the mushroom cultivation system in the summer season.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.169-174
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• 1992

This experiment was carried out to investigate the possibility of practical use of intermittent soaking system(ISS) in hydroponicaly growing tomato. There were four treatments which were NFT, Aeroponics, and ISS with 10 and 15 minute soaking intervals. 1. Plant height is highest in NFT, but main root length is longest in ISS. While stem diameter and leaf number were not significantly difference. 2. Fresh and dry weight were heavier in NFT than those of other systems at early growth stage, but the heavier in ISS system, the growth more develop. 3. In 43 days after treatment, the number of flowerlet was largest in aeroponics, and then ISS and NFT in order. Fruit weight per plant was also heaviest in aeroponics. 4. Average yield per plant were 1929.1g in aeroponics, 1475.2g in ISS with 10 minute soaking interval, 1276.2g in NFT and 1084.8g in ISS with 15 minute soaking interval. 5. Average fruit number per plant were 11.0 in aeroponics, 9.7 in NFT, 8.3 in ISS with 15 minute soaking interval, and 7.7 in ISS with 10 minute soaking interval. Average fruit weight were 192.9g in aeroponics, 172.4g in ISS with 10 minute soaking interval, 134.0g in NFT and 126.0g in ISS with 15 minute soaking interval. 6. Average fruit length was longer in aeroponics and ISS with 10 minute soaking interval than in the NFT and ISS with 15 minute soaking interval. Average fruit width was similarly wider in NFT, aeroponics and ISS with 10 minute soaking interval than in ISS with 15 minute soaking interval.

• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.234-241
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• 2023

This study was conducted to investigate the growth of lettuce (Lactuca sativa L.) and Korean mint (Agastache rugosa Kuntze) with microbubble in a closed-type plant production system (CPPS) with a deep flow technique (DFT). Lettuce and Korean mint were grown in CPPS for 23 days. Microbubble was treated for 5 minutes daily at 9:00, 13:00, and 17:00 for 16 days. The leaf length, leaf width, leaf area, and fresh and dry weights of lettuce and Korean mint were significantly lower in microbubble than in the control. The total root length, root surface area, and the number of root tips of lettuce and Korean mint were significantly lower in the microbubble than in the control. In the case of average root diameter, there was no difference between the treatments of lettuce. However, Korean mint significantly increased in thickness in the microbubble treatment, indicating variations among the different crops. The results of the research indicated that microbubble treatment in the DFT inhibited plant growth by inducing abiotic stress in lettuce and Korean mint.

• Journal of Environmental Science International
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• v.28 no.5
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• pp.495-502
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• 2019

This study was conducted to investigated the possibility of inactivating wilt germs (Fusarium oxysporum f. sp. radicis lycopersici) using Dielectric Barrier Discharge (DBD) plasma in a hydroponic system. Recirculating hydroponic cultivation system for inactivation was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic and DBD plasma reactor. Two experiments were conducted: batch and intermittent continuous process. The effect of plasma treatment on Total Residual Oxidants (TRO) concentration change, Fusarium inactivation and growth of lettuce were investigated. In the batch experiment, most of the Fusarium was inactivated at a TRO concentration of 0.15 mg/L or more at four-day intervals. There was no change in lettuce growth after two times of plasma treatment for one week. The intermittent continuous experiment consisted of 30-minute, 60-minute, and 90-minute plasma treatment in 2 day intervals and 30-minute treatment a one-day; most of the Fusarium was inactivated only by treatment for 30-minute every two days. However, if inactivation under $10^1CFU/mL$ is required, it will be necessary to treat for 60 minutes in 2 day intervals. The plasma treatment caused no damage to the lettuce, except the 30 min plasma treatment ay the one-day interval. It was considered that the residual TRO concentration was higher than that of the other treatments.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.393-401
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• 2017

The nitrate ($NO_3{^-}$) accumulation of hydroponically grown leafy vegetables may increase in the condition of a closed-type plant production system with low light intensity due to low activity of enzymes involved in nitrogen assimilation and the use of $NO_3-N$ as major nitrogen source. The objective of this study is to investigate the effects of light intensities, nutrient solution compositions and the time of nutrient solution removal before harvest on nitrate contents of hydroponically-grown lettuces in a closed plant production system. The reduction of nitrate contents in leafy lettuces 'Cheongchima' was higher in the treatments of 'TW' (nutrient solution removal) and '$(NH_4)_2CO_3$' (use of ammonium carbonate as nitrogen source) than those in other treatments, which significantly lowered fresh weight and leaf area of the plants. In the light intensity of $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the nitrate content was effectively reduced without causing any growth retardation, by substitution of the nutrient solution composition that $NO_3-N$ was removed ('$NO_3-N$ removal' treatment) or the half strength of standard nutrient solution was applied ('1/2 S' treatment), for 7days before harvest. The effects of light intensity and the time of nutrient solution removal before harvest on growth and nitrate contents in leafy lettuces were investigated. The nitrate contents in leaves under the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ before nutrient solution removal were lower than those of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The removal of nutrient solution for 7 days before harvest quickly reduced the amount of nitrates in leaves in all the light intensities with a greater degree under the $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light condition, while the 7 days-removal with both 200 and $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light conditions caused decrease in 16~31% of leaf area and 20~35% of fresh weight, compared to the 3 days-removal treatment. The nitrate contents were greatly reduced from 3,018 to 1,035 in $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and 2,021 to 480 ppm in the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, with the nutrient solution removal for 3 days before harvest, without causing any deterioration in growth and product quality. The vitamin C contents in leaves were higher in the treatment of nutrient solution removal for both 3 and 5 days before harvest with the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ than those in the light condition of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.228-235
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• 2016

This study was conducted to determine the yield of cherry tomato (Solanum lycopersicum Mill.) grown at three planting times during the uncultivated period of strawberry. Cherry tomato was planted under condition filled with strawberry dedicated culture medium on a two-story bed with April 20, April 30, and May 10 at 2015. Fruit harvest was completed on July 31. The supply concentration of nutrient solution at the time of transplanting was started as EC $1.2dS{\cdot}m^{-1}$ and it was gradually increased to EC $2.5dS{\cdot}m^{-1}$ after blooming of the first flower cluster. Netherlands PBG solution was supplied for one minute six times per day. The heights of cherry tomato plants planted at earlier were significantly greater than those of tomato plants planted later. The heights of cherry tomato plants grown at the bottom of the bed were greater than those grown in the upper bed. The yield of cherry tomatoes planted on April 20 at the bottom of the bed was greatest with an average of 2,954 g of tomatoes per plant. There were no significant differences in the average weight and sugar content of fruit according to planting times and bed position. The yield of cherry tomato plants planted on April 20 was 18% and 34% higher than that of plants planted on April 30 and May 10. We confirmed to increase the yield of the cherry tomato when early plants planted on two-story bed. These results indicate that farmers can choose the best period of producing cherry tomato during the un-cultivated period of strawberry under two-story bed conditions.