• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.50-60
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• 1987

Sensitivity, expressed in the $96h-LC_{50}$ determined with continuous flow system, was compared for eight developmental stages of Oryzias latipes with butachlor, diazinon and fenitrothion. Significance of the laboratory determined $96h-LC_{50}$ in real field situation was evaluated for butachlor using outdoor model agrosystem. In the laboratory tests, the most sensitive stage was post-larva stage IV(7 days after hatching) with $96h-LC_{50}$ of 0.14, 1.4, and 1.6ppm for butachlor, diazinon and fenitrothion, respectively, whereas the least sensitive stage was early embryo stage(1 day after fertilization), and then the susceptibility was somewhat stable after 21days after hatching. In the model agrosystem test, the highest concentration of 0.53ppm of butachlor in water was obtained at the 2nd day after application. The stages IV and VIII showed mortality of over 50% at 96 hours after application. It is concluded that the conventional use of butachlor in the field would cause significant adverse effect on O. latipes. It is suggested that sensitivity test at the early life stages with fish is an important part of the ecotoxicological assessment of chemicals.

• Smart Media Journal
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• v.11 no.2
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• pp.53-62
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• 2022

Due to the accelerated global warming phenomenon after industrialization, the frequency of changes in the existing environment and abnormal climate is increasing. Agriculture is an industry that is very sensitive to climate change, and global warming causes problems such as reducing crop yields and changing growing regions. In addition, environmental changes make the growth period of crops irregular, making it difficult for even experienced farmers to easily estimate the growth stage of crops, thereby causing various problems. Therefore, in this paper, we propose a CNN model for estimating the growth stage of crops. The proposed model was a model that modified the pooling layer of ResNet, and confirmed the accuracy of higher performance than the growth stage estimation of the ResNet and DenseNet models.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.279-285
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• 2022

This study was carried out to establish proper irrigation standards by growth stages using integrated solar radiation (ISR) for strawberry hydroponics cultivation. The irrigation methods were automatically controlled when it reached ISR values based on the external solar irradiance. The ISR standards were set at 150 J·cm^-2 and 200 J·cm^-2, and as the last treatment, ISR value was changed from 200 J·cm^-2 to 150 J·cm^-2 according to growth stage. The timer-automated irrigation system was applied as a control. The monthly average irrigation frequency of 150 J·cm^-2, growth stages (150 J·cm^-2) treatment in March were 5.6 times, that of 200 J·cm^-2, growth stages (200 J·cm^-2) treatment in December were 2.7 times, and that of timer system was 3.6-3.8 times. The water use efficiency (WUE) of timer was 19.8 g·L^-1 lower than ISR. There was no significant difference in growth and fruit characteristics between ISR and timer. The total yield and rate of marketable fruit of treatments by growth stages was the highest 328 g/10 a and 85.3 %, respectively. Therefore, in case of strawberry hydroponic cultivation, controlling ISR by growth stages was more helpful to improve yield rather than applying same ISR standard during cultivation.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.113-120
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• 2023

Smart farms are steadily increasing in research to minimize labor, energy, and quantity put into crops as IoT technology and artificial intelligence technology are combined. However, research on efficiently managing crop growth information in smart farms has been insufficient to date. In this paper, we propose a management technique that can efficiently monitor crop growth information by applying autonomous sensors to smart farms. The proposed technique focuses on collecting crop growth information through autonomous sensors and then recycling the growth information to crop cultivation. In particular, the proposed technique allocates crop growth information to one slot and then weights each crop to perform load balancing, minimizing interference between crop growth information. In addition, when processing crop growth information in four stages (sensing detection stage, sensing transmission stage, application processing stage, data management stage, etc.), the proposed technique computerizes important crop management points in real time, so an immediate warning system works outside of the management criteria. As a result of the performance evaluation, the accuracy of the autonomous sensor was improved by 22.9% on average compared to the existing technique, and the efficiency was improved by 16.4% on average compared to the existing technique.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.23-28
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• 2009

This study was conducted to evaluate the effect of optimized environment conditions with growth stage in photoautotrophic micropropagation on the growth of potato (Solanum tuberosum L. cv. Dejima) plantlets and energy efficiency. Optimum environment conditions at each stage were decided in our previous study. For the evaluation of optimized environment control, potato plantlets were cultured under four different conditions: photoautotrophic optimum conditions of photosynthetic photon flux density (PPFD) and $CO_2$ levels with growth stage (POG), photoautotrophic constant condition with average PPFD and $CO_2$ levels (PCA), photoauototrophic constant condition with maximum PPFD and $CO_2$ levels (PCM), and photomixotrophic conventional condition with 3% sucrose (PMC) as control. As a result, environment control with growth stage (POG) significantly promoted all the growth characteristics such as the number of nodes and unfolded leaves, shoot height, shoot diameter, and fresh and dry weights of potato grown in vitro. In addition, based on dry weight consumed electricity and $CO_2$ were the lowest in POG suggesting the highest energy efficiency among the treatments. After transferring potato plantlets to greenhouse, the plantlets under POG showed vigorous growth, which was pretty similar with those under PMC. The accumulations of dry matter in POG were 4.7 times in vitro and 3.8 times in greenhouse as much as those in the conventional control (PCM). Thus, we concluded that in vitro environment control with growth stage induced vigorous growth of potato plantlets both in vitro and in greenhouse with less energy consumption.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.548-556
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• 2013

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of cucumber grown greenhouse. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging, nitrite scavenging ability activity and ABTS radical scavenging ability. The DPPH free radical scavenging activity of Jangjukcheongjang was the highest in most of the growth stage. The Nitrite scavenging ability at pH 1.2 was more than 40% in all cultivars and growth stages. The ABTS radical scavenging ability of Jangjukcheongjang and Nulpureuncheongjang showed relatively little higher than Janghyeongnakhap and Sinjoeunbaekdadagi. The SOD activity showed higher activity than 95% in all cultivars and growth stages. The activity of CAT was highest in the Nulpureuncheongjang of 2 (12~16cm) growth stage, and the APX activity of Nulpureuncheongjang and Janghyeongnakhap showed a relatively high activity. The POX activity showed distinctly different trends depending on the growth stage, and that is, the activity at harvest stage was significantly reduced. These results suggest that the cucumber had the potent biological activities, and that in the future, the availability of cucumber will be increase in the field of high-value cosmetic and food products.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.47-59
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• 1994

This study was conducted to estimate the growth stages(DVS) and plant developmental rate(DVS) of rape by using climatic data. Daily average air temperature and day length were analyzed in correspond to growth stages of rape. Each growth stage was clasified by seeding, heading, flowering maturing stage respectively. Growing days of each stage were closely related with average air temperature and accumulated air temperature. Plant development rate increased fastly in condition on high temperature and long day length. Especially winter season the DVR increased linearly. DVR fluctuated from 0 to 0.026 upto heading date. In stages from heading to flowering, and to maturing DVR showed in range 0.018-0.048 and 0.005-0.018 respectively. Prediction of plant growth stage has high correlation with obserbed value, r=0.772-0.948, most highest of them were from heading to maturing.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.645-651
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• 2013

The contents of total phenolics and flavonoids, antimicrobial and tyrosinase inhibition activities of five growth stages with four greenhouse-grown cucumber extracts were investigated. Total phenolic content was high in Jangjukcheongjang, Janghyeongnakhap and five growth stage(24~27 cm). The content of total flavonoid did not differ between cultivar or growth stages. Among the four cucumber cultivars, the extract of Janghyeongnakhap showed a relatively strong antimicrobial effect against Staphylococcus aureus. The inhibition zone against Staphylococcus epidermidis of the samples tested in this experiment was 8~12 mm. And the antimicrobial effects against Malassezia furfur was high in Jangjukcheongjang, and showed the highest by the inhibition zone of 14mm in three(17~20 cm) growth stage. The tyrosinase inhibition activity of cucumber extracts showed relatively high activity in Jangjukcheongjang and Sinjoeunbaekdadagi, followed by Janghyeongnakhap. From these results, we confirmed that the extract of cucumber has high antimicrobial and whitening efficacy, and that in the future, the cucumber will be increase the availability in the field of high-value cosmetic materials.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.15-22
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• 2009

Adequate environment conditions with growth stage of potato were decided in a photoautotrophic micropropagation system using models. Total 20 day-period of growth were divided into three growth periods such as 6 (stage 1), 7(stage 2), and 7(stage 3) days. At the 1st stage, no significant differences were observed in the growth of potato plantlets at various photosynthetic photon flux density (PPFD) and $CO_2$ conditions. Considering damaged leaves, $80\;mmol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and ambient $CO_2$ level were adequate in this stage. At the 2nd stage, significant differences were partly observed in several growth characteristics including dry weight. Based on the dry matter model, over $240\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD was too high to cultivate potato plantlets at this stage due to the occurrence of damaged leaves. Considering both plant growth and energy efficiency, $160\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $700\;mol{\cdot}mol^{-1}\;CO_2$ were selected for the adequate combination. At the 3rd stage, the biomass accumulation was significantly induced in potato plantlets under higher levels of PPFD and $CO_2$ concentration as suggested by increased fresh and dry weights. However, we could not find the saturated point with regard to dry matter due to continuous increase of dry mater even under maximum PPFD ($320\;mmol{\cdot}m^{-2}{\cdot}s^{-1})$. Thus, $320\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $1800\;mol{\cdot}mol^{-1}\;CO_2$ were considered as the best choice at final stage in this study. In conclusion, even though the growth period of micropropagated potato plantlets was quite a short, favorable environmental conditions required at each growth stage were different. This technique could improve the growth of micropropagated plantlets compared to the conventional micropropagation and apply to other agriculturally important crops as well as potato in the future.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.192-195
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• 1999

작물은 생육단계에 따라 양분의 흡수특성이 다르기 때문에 생육단계별로 적정 양액농도를 구명해야만 영양생장과 생식생장이 병행된 과채류에 있어서 균형을 유지할 수 있다. 노 등(1995)은 토마토의 펄라이트경 양액재배시 육묘기 때에 양액농도를 EC 0.5mS/cm에서 3.0mS/cm로 높임에 따라 유묘의 광합성속도가 증가하였으나 그 이상의 범위에서는 오히려 감소하였으며, 초장, 엽장, 엽폭, 경경 및 지상부 건물중은 양액농도를 0.5mS/cm에서 5.0mS/cm로 높임에 따라 계속 증가한다고 보고하였다. (중략)