• Journal of agriculture & life science
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• v.52 no.6
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• pp.27-36
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• 2018

Recently, the demand for new cultivar of oriental mustard(Brassica juncea) is increased as the consumption of oriental mustard has increased dramatically in the market due to Kimchi is attracting the world's attention. However, absence of seed supply system can cause many problems including inbreeding depression due to self seed production, deterioration of the seed purity and heterogeneity of commercial seed. To establish the $F_1$ variety breeding system of oriental mustard, pure line and inbred lines were screened from inbreeding genetic resources. Male-sterile line was also selected from breeding combinations for the quality improvement of mustard. The combining ability from(Indojasai ${\times}$ Goheungdamyang) combinations and isolation line of(MS910 ${\times}$ Japan red mustard 8 ${\times}$ Ganghwa mustard 9) was highest, thus these lines were selected as parental lines. PCR(Polymerase Chain Reaction) and gene sequence analysis revealed that the genes related to CMS(orf263, orf220, and orf288) were distributed in mitochondria. The isolated lines from this study also showed good performance in yield test and farmhouse prove test.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.83-91
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• 2021

BACKGROUND: Cultivation area using agricultural plastic film facilities in Korea is rapidly increasing every year; however, it accelerates the salt accumulation in soils due to repeated cultivation and excessive use of chemical fertilizers. Coal ash contains various trace elements and has high potential to be used in agricultural purposes. This research was aimed to improve the quality of salts-accumulated soils and crop growth grown in the plastic film facilities using the soil amendment derived from coal ash and zero-valent iron powder. METHODS AND RESULTS: Soil amendment used in the study was manufactured using coal ash with iron powder and subjected to a typical upland soil for soil quality enhancement and two salts-accumulated soils for crop growth. After one month incubation of the salts-accumulated soils treated with the soil amendment, soil pH increased significantly and soil EC decreased by approximately 50%, compared to the control or the treatment without the soil amendment. Since the soil salts' concentration is proportional to EC, the subjected soil amendment can be proposed as an effective way to overcome soil salts accumulation in agricultural plastic film facilities. For crop growth, the length of roots and stems increased by approximately 10% and the dry weight also increased by a maximum of 75%, compared to the control. CONCLUSION: The soil amendment made from waste resources such as coal ash and zero-valent iron was found to not only be effective in improving salt-accumulated soils and crop yield but also be safe against harmful heavy metals.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.41-48
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• 2021

As the rural population continues to decline and aging, the improvement of agricultural productivity is becoming more important. Early prediction of crop quality can play an important role in improving agricultural productivity and profitability. Although many researches have been conducted recently to classify diseases and predict crop yield using CNN based deep learning and transfer learning technology, there are few studies which predict postharvest crop quality early in the planting stage. In this study, a early quality prediction model is proposed for sprout ginseng, which is drawing attention as a healthy functional foods. For this end, we took pictures of ginseng seedlings in the planting stage and cultivated them through hydroponic cultivation. After harvest, quality data were labeled by classifying the quality of ginseng sprout. With this data, we build early quality prediction models using several pre-trained CNN models through transfer learning technology. And we compare the prediction performance such as learning period and accuracy between each model. The results show more than 80% prediction accuracy in all proposed models, especially ResNet152V2 based model shows the highest accuracy. Through this study, it is expected that it will be able to contribute to production and profitability by automating the existing seedling screening works, which primarily rely on manpower.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.111-118
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• 2020

The U-shaped composite beam used in this study consist of a reinforced concrete structure, a beam steel structure supporting the slab, a reinforced concrete structure, and a U-shaped steel plate. The U-shaped composite beam was developed for the purpose of using it as a parking lot because it is highly constructible and has low floor height and long span. For the improvement of constructivity, the U-shaped composite beam ends are planned with standardized H-shaped steel and connected directly to the columns, and the middle of the U-shaped composite beam consists of U-shaped steel plates folded in U-shaped form using thin steel plates (t=6) instead of H-shaped steel. In the middle of the composite beam, where U-shaped steel plates are located, the depth of U-shaped beam may be planned to be small so as to satisfy the height limit of the parking lot. It is important to grasp the structural performance according to the change of depth because low beam depth is advantageous for the reduction of the floor height, but it is a inhibitor to the structural behaviors of U-shaped composite beam. In addition, since U-shaped composite beams are a mixture of steel frame structures, reinforced concrete structures and U-shaped steel plates, securing unity has a great influence on securing structural performance. Therefore, in this study, a structural experiment was conducted to understand the structural performance according to the depth change for U-shaped composite beam. A total of three specimens were planned, including two specimens that changed the depth using a criteria specimen planned for a general parking lot. The results of the experiment showed that the specimens who planned the depth greatly had better structural performance such as yield strength, maximum strength, and energy than the standard specimen.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.116-122
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• 2021

This study quantitatively evaluated the performance improvement of a circular reinforced concrete pier under dynamic load with strengthening using a steel plate. Various three-dimensional elements were applied using the finite element program ABAQUS. The analytical parameters included the ratios of the steel cover length to the pier's total height and the ratios of the steel cover thickness to the pier diameter for inelastic-nonlinear analysis. The lower part of the pier had fixed boundary conditions, and lateral repetitive loads were applied at the top of the pier. The pier was investigated to evaluate the dynamic performance based on the load-displacement curve, stress-strain curve, ductility, energy absorption capability, and energy ratio. The yield and ultimate loads of piers with steel covers increased by 3.76 times, and the energy absorption capability increased by 4 times due to the confinement effects caused by the steel plate. A plastic hinge part of the column with a steel plate improved the ductility, and the thicker the steel plate was, the greater the energy absorption capacity. This study shows that the reinforced pier should be improved in terms of the seismic performance.

• Journal of Animal Science and Technology
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• v.62 no.6
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• pp.777-789
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• 2020

Intense artificial selection has been imposed to Luzhong mutton sheep population in the past years. Improvements on growth and reproductive performance are two breeding goals in the present herd. Although some progresses were phenotypically observed possibly due to inbreeding induced by strong selection in terms of these traits, the genomic evaluation was poorly understood. Therefore, a high-density SNP array was used to characterize the pattern of runs of homozygosity (ROH), estimate inbreeding and inbreeding depressions on early growth performance and litter size based upon ROH, and scan positive selection signatures of recent population. Consequently, a low inbreeding level was observed which had negative effects on litter size, but not on early growth performance. And 160 genes were under selection, of which some were reported to be linked to several traits of sheep including body weight, litter size, carcass and meat quality, milk yield and composition, fiber quality and health, and the top genes were associated with growth (growth hormone [GH]- growth hormone receptor [GHR]- Insulin-like growth factor 1 [IGF1] axis) and litter size (bone morphogenic proteins [BMPs]-associated). The effectiveness of previous breeding measures was highlighted, but purging selection was proposed to alleviate the inbreeding depression on litter size, providing some genomic insights to breeding management of Luzhong mutton sheep.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1301-1314
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• 2022

Normalized Difference Vegetation Index (NDVI) is utilized as an indicator to represent the vegetation condition on the land surface in various applications such as land cover, crop yield, agricultural drought, soil moisture, and forest disaster. However, satellite optical sensors for visible and infrared rays cannot see through the clouds, so the NDVI of the cloud pixel is not a valid value for the land surface. This study proposed a real-time correction of the underestimation noise for GEO-KOMPSAT-2A (GK2A) daily NDVI and made sure its feasibility through the quantitative comparisons with Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI and the qualitative interpretation of time-series changes. The underestimation noise was effectively corrected by the procedures such as the time-series correction considering vegetation phenology, the outlier removal using long-term climatology, and the gap filling using rigorous statistical methods. The correlation with MODIS NDVI was higher, and the difference was lower, showing a 32.7% improvement compared to the original NDVI product. The proposed method has an extensibility for use in other satellite products with some modification.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.126-132
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• 2022

Alkaline fuel cells using liquid fuels such as hydrazine and ammonia are gaining great attention as a clean and renewable energy solution possibly owing to advantages such as excellent energy density, simple structure, compact size in fuel container, and ease of storage and transportation. However, common shortcomings including cathode flooding, fuel crossover, side yield reactions, and fuel security and toxicity are still challenging issues. Real time monitoring of fuel concentrations integrated into a fuel cell device can help improving fuel cell performance via predicting any loss of fuels used at a cathode for efficient energy production. There have been extensive research efforts made on developing real-time sensing platforms for hydrazine and ammonia. Among these, recent advancements in electrochemical sensors offering high sensitivity and selectivity, easy fabrication, and fast monitoring capability for analysis of hydrazine and ammonia concentrations will be introduced. In particular, research trend on the integration of metallic and metal oxide nanoparticles and also their hybrids with carbon-based nanomaterials into electrochemical sensing platforms for improvement in sensitivity and selectivity will be highlighted.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.31-31
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• 2023

Mung bean(Vigna radiata (L.) R. Wilczek var. radiata) is a legume that originated in India. It is the third most cultivated legume in Korea after soybean and adzuki bean. Recently, the use of mung bean seeds and sprouts in trendy foods such as rice noodles and Chinese-style stir-fry is expanding thereby increasing its demand. Subsequently, improvement of mung bean varieties is also being actively conducted. In this study, the important agricultural characteristics of 324 mung bean germplasm were recorded and statistically investigated. Seeds of the mung bean germplasm were cultivated at an experimental field located in the National Agrobiodiversity Center (Jeonju, Korea) and 10 quantitative agricultural traits were investigated. Basic statistics, correlation analysis, and principal component analysis were then performed. The results showed significant variations of the quantitative traits among the germplasms (p < 0.05). The days to flowering, maturity, and growth were in the ranges of 31~80, 22~72, and 57~110 days with means of 45, 47, and 92 days, respectively. The highest frequency (f = 192) was for lodging score with 11~50%, while simultaneous maturity (f = 182) was below 50%. Other quantitative traits related to yield including the number of seeds per pod (CV = 10.9%), number of pods per plant (CV = 41.2%), and one-hundred seeds weight (CV = 36.6%) also showed significant variations. Correlation analysis showed positive correlations between the days to maturity and one-hundred seeds weight (r = 0.41) and the days to growth and simultaneous maturity (r = 0.39). In contrast, one-hundred seeds weight was negatively correlated to the number of pods per plant (r = -0.41) and the days to flowering (r = -0.29). Similarly, the days to growth and the number of pods per plant had a negative association with each other (r = -0.29). The principal component analysis revealed the number of days to maturity as the most influential variable along the first principal component (23.7%). In general, this study revealed wide variations in quantitative traits among the studied mung bean germplasm, which could provide several options for cultivar development.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.131-142
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• 2024

The purpose of this study was to estimate the optimal stand density criteria for each growth stage of Chamaecyparis obtusa (Siebold & Zucc.) Endl. to achieve the timber production goal for cypress forests and develop an optimal silvicultural system for forest thinning. A relative yield index (Ry) value of 0.75, presented as a stand density management criterion index, was estimated by analyzing the relationship characteristics between the composition ratio and stand density of slender trees from 216 sample plots of the recruited cypress forests. The analysis of the feasibility of achieving each production target in the existing silvicultural system for C. obtusa revealed that the growth rate according to the parameters of forest land productivity, such as site index and thinning intensity according to the increase in age, was not properly reflected. In the thinning system for each timber production target analyzed in this study, 353 high-quality large hardwoods from 498.1 m³/ha, 703 high-quality medium hardwoods from 376.2 m³/ha, and 1,758 small-diameter hardwoods from 249.5 m³/ha could be harvested. Although the silvicultural system prepared on the basis of the results of this study cannot be uniformly applied according to various management goals, this study is meaningful in that it presents empirical reference standards based on the stand density management diagram that reflects the growth characteristics of cypress forests in South Korea.