• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.285-292
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• 2020

Because the inner environment of greenhouse has a direct impact on crop production, many studies have been performed to develop technologies for controlling the environment in the greenhouse. However, it is difficult to apply the technology developed to all greenhouses because those studies were conducted through empirical experiments in specific greenhouses. It takes a lot of time and cost to develop the models that can be applicable to all greenhouse in real situation. Therefore studies are underway to solve this problem using computer-based simulation techniques. In this study, a model was developed to predict the inner environment of glass greenhouse using CFD simulation method. The developed model was validated using primary and secondary heating experiment and daytime greenhouse inner temperature data. As a result of comparing the measured and predicted value, the mean temperature and uniformity were 2.62℃ and 2.92%p higher in the predicted value, respectively. R² was 0.9628, confirming that the measured and the predicted values showed similar tendency. In the future, the model needs to improve by applying the shape of the greenhouse and the position of the inner heat exchanger for efficient thermal energy management of the greenhouse.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.403-412
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• 2017

To investigate the control effect of insect pests by natural enemies, sticky traps were used in commercial tomato greenhouses in Chun-cheon and the experiment fields of Gangwon-do Agricultural Research and Extension Services, Republic of Korea using semi-forcing culture (February to June). We selected low toxicity pesticides, environment-friendly agricultural materials (EFAM), and natural enemies of the study species, combinations of which have been previously used in farms to control insect pests. In this study, Trialeurodes vaporariorum and thrips, which are major agricultural insect pests, were studied in experimental greenhouses. The adult T. vaporariorum population was observed in mid-April and the population of thrips showed occurrences in early April. Regarding seasonal fluctuation, T. vaporariorum peaked in mid-May and thrips peaked after June. one insecticide, spiromesifen suspension concentrate (SC); one fungicide, cyazofamid SC; and two EFAMs containing neem tree extract were shown to be slightly toxic to Encarsia formosa and Orius laevigatus. The results of this study could be used to develop management models using natural enemies of control the insect pests; T. vaporariorum and thrips in semi-forcing culture of tomato.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.71-77
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• 2011

This study was conducted to predict the yield loss of red pepper and to determine the economic weed thresholds levels for red pepper cultivation field from competition with the most serious weeds, Echinochlor crus-galli (L.) P. beauv. (barnyard grass) and Chenopodium album L. (goosefoot) in Youngyang of Korea. Crop yield as a function of weed density was predicted by using a rectangular hyperbola, and their economic threshold levels were determined by using the equation developed by Cousens (1987). The red pepper yield loss models of weeds were predicted as y=317.0 kg/ (1+0.1707x), $R^2$=0.895 in E. crus-galli and y=323.2 kg/(1+0.2900x), $R^2$=0.896 in C. album L.. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. Economic thresholds of each weed were calculated as 6.5 plant $100m^{-2}$ in E. crus-galli, and 3.7 plant $100m^{-2}$ in C. album L..

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.38-43
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• 2012

This study was conducted to predict the yield response of red pepper and to determine the economic weed threshold levels for red pepper cultivation field from competition with the most serious weeds, Amaranthus patulus and Digitaria ciliaris in Youngyang of Korea. Crop yield as a function of weed density was predicted by using a rectangular hyperbola, and their economic threshold levels were determined by using the equation developed by Cousens (1987). The red pepper yield loss models of weeds were predicted as y=304.7/(1+0.063x), $R^2$=0.967 in D. ciliaris and y=281.3/(1+0.1723x), $R^2$=0.952 in A. patulus. Economic thresholds calculated using Cousens' equation were negatively related with the competitiveness of weed. Economic thresholds of each weed were calculated as 18.2 plant $100m^{-2}$ in D ciliaris, and 7.2 plant $100m^{-2}$ in A. patulus.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.1-13
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• 2021

The concept of integrated pest management (IPM) first developed in the 1950s, and the concept of economic control via pest management was established in the 1960s. Research on IPM began in the United States and Europe, and IPM studies in Korea started with citrus insects and paddy field pests following the distribution of high-yield varieties of rice. Apple IPM in Korea began with research on pest control using chemical pesticides and pesticides resistant to insect pests, studies on the ecology of insect pests and their natural enemies, and the exploitation of sex pheromones on insect pests. Since the 1990s, IPM research and field projects have been carried out simultaneously for farming households. In the 2000s, the development of pest monitoring and forecasting models centered on mating disturbances, database programs for pests, and networks for sharing information. IPM technology has expanded via the development of unmanned forecasting systems and automation technologies in the 2010s.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.1
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• pp.37-47
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• 2023

The black cutworm, Agrotis ipsilon (Hufnagel), is an important crop pest worldwide that feeds more than 80 plant species including cabbage, potato, maize, wheat and bean, and this moth is a typical pest attacking underground parts of crops. It has been known in farm booklets that the larvae of A. ipsilon overwinter in the soil in Korea, but no definitive data exist yet. This study was conducted to evaluate that the specific appearance time of A. ipsilon observed actually in the field could be explained when we assumed that this pest overwinters in a form of larvae or pupae. Degree day-based phenology models were applied for tracking forward or backward to find the predicted developmental stage which developed at a specific stage found in the field. As a result of the analysis, it was confirmed that an initial population could be established in a group that does not overwinter as larvae or pupae in Korea. In other words, the appearance of adults in early March to April could not be explained by the presence of domestic overwintering populations. Populations that overwinter as larvae or pupae in Korea were able to emerge as adults in June to July at the earliest. Therefore, the group of adults appearing in early spring is highly likely to be a population that migrated from outside Korea. Taken together, it was estimated that the colony of A. ipsilon in Korea would be formed by a mixture of a migrant population through long-distance migration and a overwintering population.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.5
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• pp.1-14
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• 2023

Soybeans are one of the world's top five staple crops and a major source of plant-based protein. Due to their susceptibility to climate change, which can significantly impact grain production, the National Agricultural Science Institute is conducting research on crop phenotypes through growth analysis of various soybean varieties. While the process of capturing growth progression photos of soybeans is automated, the verification, recording, and analysis of growth stages are currently done manually. In this paper, we designed and trained a YOLOv5s model to detect soybean leaf objects from image data of soybean plants and a Convolution Neural Network (CNN) model to judgement the unfolding status of the detected soybean leaves. We combined these two models and implemented an algorithm that distinguishes layers based on the coordinates of detected soybean leaves. As a result, we developed a program that takes time-series data of soybeans as input and performs growth analysis. The program can accurately determine the growth stages of soybeans up to the second or third compound leaves.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.2
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• pp.71-82
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• 2024

It would be advantageous to grow legume forage crops in order to increase the productivity and sustainability of sloped croplands in Hamkyongbukdo. In particular, the identification of potential cultivation areas for alfalfa in the given region could aid decision-making on policies and management related to forage crop production in the future. This study aimed to analyze the climate suitability of alfalfa in Hamkyongbukdo under current and future climate conditions using the Fuzzy Union model. The climate suitability predicted by the Fuzzy Union model was compared with the actual alfalfa cultivation area in the northern United States. Climate data obtained from 11 global climate models were used as input data for calculation of climate suitability in the study region to examine the uncertainty of projections under future climate conditions. The area where the climate suitability index was greater than a threshold value (22.6) explained about 44% of the variation in actual alfalfa cultivation areas by state in the northern United States. The climatic suitability of alfalfa was projected to decrease in most areas of Hamkyongbukdo under future climate scenarios. The climatic suitability in Onseong and Gyeongwon County was analyzed to be over 88 in the current climate conditions. However, it was projected to decrease by about 66% in the given areas by the 2090s. Our study illustrated that the impact of climate change on suitable cultivation areas was highly variable when different climate data were used as inputs to the Fuzzy Union model. Still, the ensemble of the climate suitability projections for alfalfa was projected to decrease considerably due to summer depression in Hamkyongbukdo. It would be advantageous to predict suitable cultivation areas by adding soil conditions or to predict the climate suitability of other leguminous crops such as hairy vetch, which merits further studies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1662-1667
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• 2011

Anthocyanins belong to a group of flavonoid compounds and are well known for their various health beneficial effects, which include antioxidative activities. Among them, the major anthocyanins isolated from seed coat of black soybean (Glycine max L.) were previously characterized as glycosides containing glucopyranose. Asthma is an allergic disease that is strongly associated with various immune cells, including basophils and mast cells. Eosinophils, basophils, and mast cells play important roles in allergic asthma through the release of inflammatory mediators such as asthma-specific T-helper 2 (Th2) cytokines and subsequent amplification of asthma symptoms via degranulation. Rat basophilic leukemia RBL-2H3 cells are the most common in vitro models for evaluating allergic reactions. In this study, we examined the effects of anthocyanin from seed coat of black soybean on antigen-stimulated degranulation and Th2 cytokine production in RBL-2H3 cells. Cell degranulation was evaluated by measuring the release of ${\beta}$-hexosaminidase. ${\beta}$-Hexosaminidase release and Th2 cytokine production in RBL-2H3 cells was much higher upon stimulation with IgE-antigen complex than those in untreated control cells. Anthocyanins significantly suppressed IgE-antigen complex-induced degranulation of RBL-2H3 cells and inhibited IgE-antigen complex-mediated interleukin (IL)-4, IL-13, and tumor necrosis factor ${\alpha}$ (TNF-${\alpha}$) production in RBL-2H3 cells. These findings suggest that anthocyanins from seed coat of black soybean effectively inhibit allergic reactions and may have beneficial effects against allergic asthma.

• Korean Journal of Medicinal Crop Science
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• v.13 no.3
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• pp.93-100
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• 2005

This research was performed to investigate the possibilities of industrial usage of camellia (Camellia japonica L.) by examining the antioxidant and antimicrobial effects of methanol extract with different sections. Content of total phenolics, DPPH radical scavenging activities and antibacterial activity of young leaf, mature leaf, flower bud, flower, bark, and seed of camellia were compared in vitro experimental models. Total phenolics was contained the higher in young leaf (74.62 mg), flower bud (65.02 mg) and flower (62.42 mg) but less than 20.95 mg per 100 g of dry weight in other parts of Camellia japonica L. And effects of antioxidant measured by DPPH radical scavenger activity ($RC_{50}$, reduce concentration 50%), was shown higher $7.16{\sim}18.14\;{\mu}g/m{\ell}$ in methanol extract of young leaf, flower bud and flower than $61.23\;{\mu}g/m{\ell}$ of BHT as a chemical oxidant. Also, the antimicrobial activity of Camellia japonica L. extracts determined using a paper disc method against food-borne pathogen and food spoilage bacteria, the young leaves extracts showed the most active antimicrobial activity against 7 kinds of harmful microorganisms. Flower bud extracts showed the highest antibacterial activity against P. aeruginosa and Enterobacter spp. C1036. In addition, the minimum inhibitory concentration (MIC) of young leaf extract against B. subtillis,S. fradiae,S. aureus,E. coli,P. aeruginosa, Enterobacter spp. C1036, and S. typhimurium were revealed 1 to 15 ${\mu}g/m{\ell}$. As a result, antimicrobial activity of camellia extracts was shown higher gram positive bacteria than gram negative bacteria.