• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.45-55
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• 2019

TheCitrus grandis Osbeck is a special product in the Jeju island. The product has been as a remedy for liver damage and hang over. This study demonstrates how to investigate and compare the antioxidant, phenol content, tyrosinase and ${\alpha}$-glucosidase inhibitory activity, antimicrobial, and alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activity with the C. grandis leaves extracted in different ethanol concentrations. From the yield, a 20% ethanol extract demonstrated the highest results among the other extracts. The distilled water extract showed the most abundant in a total phenol content and highest ABTS radical scavenging activity and reducing power assay. In the DPPH radical scavenging activity, ${\alpha}$-glucosidase and tyrosinase inhibitory assay (used ${\text\tiny{L}}$-tyrosine as substrate), the 80% ethanol extract exhibited a higher value than other extracts. The 60% ethanol extract showed prominent activities in the tyrosinase inhibitory (used ${\text\tiny{L}}$-dopa as substrate), ADH and ALDH activity assay. In the minimum inhibitory concentration (MIC) assay, 60% and 80% ethanol extracts inhibited the bacterial growth almost similarly. Moreover, the gram-positive bacteria was more restrained than the gram-negative bacteria. The resultsrevealed that the distilled water and 80% ethanol extract showed a relatively higher antioxidant activity compared to other extracts. The 60 ~ 80% ethanol extracts demonstrated potential tyrosinase, ${\alpha}$-glucosidase inhibitory, antimicrobial, ADH and ALDH activities. Therefore, the C. grandis is suggested to be considered as a functional material for various proposes.

• Structural Engineering and Mechanics
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• v.70 no.1
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• pp.67-80
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• 2019

Strengthening with near surface mounted carbon fibre reinforced polymers (NSM-CFRP) is a strengthening technique that have been used for several decades to increase the load carrying capacity of reinforced concrete members. In Iraq, many concrete buildings and bridges were subjected to a wide range of damage as a result of the last war and many other events. Accordingly, there is a progressive increase in the strengthening of concrete structures, bridges in particular, by using CFRP strengthening techniques. Near-surface mounted carbon fibre polymer has been recently proved as a powerful strengthening technique in which the CFRP strips are sufficiently protected against external environmental conditions especially the high-temperature rates in Iraq. However, this technique has not been examined yet under repeated loading conditions such as traffic loads on bridge girders. The main objective of this research was to investigate the effectiveness of NSM-CFRP strips in reinforced concrete beams under repeated loads. Different parameters such as the number of strips, groove size, and two types of bonding materials (epoxy resin and cement-based adhesive) were considered. Fifteen NSM-CFRP strengthened beams were tested under concentrated monotonic and repeated loadings. Three beams were non-strengthened as reference specimens while the remaining were strengthened with NSM-CFRP strips and divided into three groups. Each group comprises two beams tested under monotonic loads and used as control for those tested under repeated loads in the same group. The experimental results are discussed in terms of load-deflection behavior up to failure, ductility factor, cumulative energy absorption, number of cycles to failure, and the mode of failure. The test results proved that strengthening with NSM-CFRP strips increased both the flexural strength and stiffness of the tested beams. An increase in load carrying capacity was obtained in a range of (1.47 to 4.49) times that for the non-strengthened specimens. Also, the increase in total area of CFRPs showed a slight increase in flexural capacity of (1.02) times the value of the control strengthened one tested under repeated loading. Increasing the total area of CFRP strips resulted in a reduction in ductility factor reached to (0.71) while the cumulative energy absorption increased by (1.22) times the values of the strengthened reference specimens tested under repeated loading. Moreover, the replacement of epoxy resin with cement-based adhesive as a bonding material exhibited higher ductility than specimen with epoxy resin tested under monotonic and repeated loading.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.46-46
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• 2019

The experiments were performed in the Jinan (elevation: 300 meters above sea level), Jeollabuk-do. Seedlings (n = 63 per $3.3m^2$) of ginseng cultivar (Cheonpung, Yeonpung) were planted on April 10, 2015. Shading material of plastic film house was blue-white film. Before the Planting seedling, silicate (3 kg/10 a) or chitosan (40 kg/10 a) was fertilized and foliar sprayed on the leaves 1000 times dilution solution once a month from May to September every year. The growth results of 5-year old ginseng surveyed in 2018 are as follows. The average air temperature in the plastic film house was the highest at $26.6^{\circ}C$ and $26.5^{\circ}C$ in July and August, respectively, and the highest temperature was $40.5^{\circ}C$ in July. The maximum daily temperature of $35^{\circ}C$ or more was 30 days, with the average soil temperature being $24.9^{\circ}C$ in August. The chemical properties of the test soil are as follows. pH was 6.4~6.9 level and EC was 0.35~0.46 dS/m. The organic matter content was 33.5~41.4 g/kg, and available-P content was 251.9~306.8 mg/kg. Exchangeable cations contents, such as K, Ca and Mg were all the appropriate ranges. The soil microbial density surveyed by the dilution plate method was 10~50 times higher than that of control (Non-treatment) and actinomycete density was 3~6 times higher. Pathogens of the genus Fusarium by Metagenome analysis decreased 91.3% and 68.2% respectively in the foliar sprayed of chitosan and soluble-silicate. The light intensity (PAR) in the blue-white film plastic film house gradually increased until July and then decereased, with the average of light intensity in March-October was $120.3umol/m^2/s$. The growth of aerial parts such as plant height and stem length was better than non-sprayed group in silicate or chitosan treatments and Yeonpung cultivar was superior to the Cheonpung cultivar. The SPAD value was higher in Yeonpung cultivar foliar sprayed with soluble-silicate. The growth of underground parts such as root length and taproot length were better in chitosan and soluble-silicate treatment than control, especially in Yeonpung cultivar foliar sprayed with chitosan was good in taproot length and taproot diameter, and fresh weight of root was 60.1 g. Ginsenoside contents were 24.9 mg/g and 22.4 mg/g, in the Cheonpung cultivar foliar sprayed with soluble-silicate or chitosan respectively, 28% and 15% higher than control (19.5 mg/g). The incidence of disease by Alteraria panax and Botrytis cinerea was 3~9% and 4~9%, respectively. High temperature damage rate was 3~5%.

• Journal of Life Science
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• v.31 no.3
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• pp.338-345
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• 2021

Zizania latifolia has long been used as a tea for both edible and medicinal purposes. However, research into the use of Z. latifolia as a high value-added edible material is lacking. In a previous study, we confirmed that tricin is the major component in Z. latifolia. In this study, we investigated the protective effect of a Z. latifolia extract (ZLE). Toxicity tests of ZLE or tricin on HepG2 cells revealed no toxicity due to ZLE or tricin at all concentrations used. The reduction in cell viability by tert-butyl hydroperoxide (t-BHP) was suppressed by treatment with ZLE or tricin. In addition, ZLE or tricin effectively inhibited the production of reactive oxygen species (generation of hydrogen peroxide, alkoxy free radicals, and peroxyl free radicals by t-BHP) and oxidative damage. ZLE or tricin treatments also increased the protein expression of superoxide dismutase 1 (SOD1), catalase, heme oxygenase-1 (HO-1), and nuclear factor erythroid-related factor 2 (Nrf2), which are known as antioxidant enzymes, suggesting that the protective effect of ZLE is related to activation of tricin. Taken together, the results indicate that Z. latifolia can be developed as a functional food material for improving liver function.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.10
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• pp.25-32
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• 2018

The ending of the warranty under the current Multi-Housing Management Act has a lot of problem as it is very disadvantageous to the business entity and it makes hard for the contractor to finish the repair work. It is almost none for the business entity to get the written confirmation of the expiration of warranty liability from the client even though it sincerely completed their warranty obligation. It is because the client asks for the works other than fair repair arising from the defect in the work, such as the upgrade work for the enhancement of the value of their assets and the repair work which the client should take care before it issues the written confirmation of the expiration of warranty liability to the contractor. "So, though there is the law specifying this matter, the parties are relying on the unnecessary civil agreement. This leads to the big social and economic losses. If there is no agreement made between the client and the contractor, that leads to the legal dispute. This research on cases of 10 apartments shows that the types of works which the apartment residents ask for depend on the characteristics and conditions of the apartments and that they ask for various kinds of compensational works. In addition, it was found that there were many cases in which even the civil agreement is not recognized as the ending of the warranty obligation even if the proper procedure is taken for the ending of warranty by the contractor or business entity. If the collateral is to be offered to the client, the contractor would get more hard because there is the additional cost other than the warranty obligation, thus damaging the legal objective of the laws trying to minimize the damage made to the resident of the apartments. It means that the increase in the unnecessary warranty cost would lead to the increase in the selling price of apartment and the ending of the dispute through the civil procedure would make the Multi-Housing Act ineffective.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.337-351
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• 2022

With the full spread and rapid development of social media, the trend of decentralization of social media information propagation is becoming clearer day by day, and the segmentation of time by audiences using social media information is clearly progressing. Therefore, this study aims to study the influence relationship between social media attitudes toward fake news, social capital, risk perception, and discriminant intentions based on existing studies. Accordingly, the research model presented related research questions and organized a questionnaire to collect a total of 500 valid surveys. The SPSS 26.0 program and the AMOS 24.0 program were used to analyze the data. The research results are as follows. First, the more positive the user's attitude towards the fake news identification intention of social media, the more they want to use various methods or tools to identify the authenticity of online information. Second, the more positive the user's attitude towards social media fake news, the more aware of the potential threats social media fake news poses to their own physical, psychological, financial and so on. At the same time, by raising one's own awareness of the dangers, counterintelligence intentions against fake news on social media will also increase. Third, the richer the social capital the user has, the stronger the information literacy, and therefore the stronger the identification intention of social media fake news. Fourth, the higher the value of social capital Chinese users have, the greater the damage they have suffered from fake news, and the higher the risk awareness of fake news to protect their interests. Fifth, it means that Chinese users recognized information suspected of social media and took corresponding measures.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.155-162
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• 2022

This study investigated the immunostimulatory effect of enzymatic porcine placental hydrolyzate (EPPH) in cyclophosphamide (Cy)-treated rats. This effect of EPPH prevented Cy-induced decreases in body, spleen, and thymus weights and natural killer (NK) cell activity. The numbers of immune cells, such as white blood cells, granulocytes, and lymphocytes, and mid-range absolute counts were significantly higher compared to the control group. The levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-2, IL-12, and immunoglobulin G (IgG) were notably reduced by Cy, while EPPH prevented these effects. Histopathological analysis of spleen samples revealed the protective effect of EPPH against Cy-induced immunosuppression. The findings demonstrate that EPPH can alleviate immunosuppression by cell viability, tissue damage, and regulation of the levels of cytokines. EPPH may have value as a component of immunostimulatory agents or an ingredient in functional foods.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.27-37
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• 2022

With the recent increase in the spread of ESS (Electric Storage System), the damage to human life and property is also rapidly increasing due to continuous fires caused by ESS. In the manufacture of urethane sandwich panels used in ESS, it is necessary to improve the flame retardant performance. In this study, in order to realize the flame retardant properties of flexible polyurethane foam, the effect of the tissue density of the product due to the change of the isocyanate functional group parameter that changes the physical properties of the product on the fire performance was studied. The product was manufactured by changing the density of the urethane structure, and combustion performance tests, gas toxicity tests, and smoke density tests were performed. As a result, it was confirmed that the total amount of heat released had excellent performance when the isocyanate functional group was high, and had no correlation with the maximum heat release rate. When the value of the isocyanate functional group was 2.7 or more, the collapse of the shape could be prevented. In the gas hazard test, the performance was increased when the isocyanate functional group was relatively high, so a flame retardant for the Char system, which had a dense structure and easy to form a carbonized film, was added. confirmed to be. Therefore, as a result of this study, it is thought that it will be possible to lay the foundation for the development of a flame retardant to replace the cheap urethane sandwich panel used in the past.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1709-1722
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• 2022

The rise in temperature induced by global warming caused in El Nino and La Nina, and abnormally changed the temperature of seawater. Rainfall concentrates in some locations due to abnormal variations in seawater temperature, causing frequent abnormal floods. It is important to rapidly detect flooded regions to recover and prevent human and property damage caused by floods. This is possible with synthetic aperture radar. This study aims to generate a model that directly derives flood-damaged areas by using modified U-NET and TerraSAR-X images based on Multi Kernel to reduce the effect of speckle noise through various characteristic map extraction and using two images before and after flooding as input data. To that purpose, two synthetic aperture radar (SAR) images were preprocessed to generate the model's input data, which was then applied to the modified U-NET structure to train the flood detection deep learning model. Through this method, the flood area could be detected at a high level with an average F1 score value of 0.966. This result is expected to contribute to the rapid recovery of flood-stricken areas and the derivation of flood-prevention measures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.10
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• pp.701-708
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• 2022

Since the propellant tank structure of the projectile is mainly subjected to a compressive force, there is a high risk of damage due to buckling. Large and lightweight structures such as propellant tank have a complex manufacturing process. So it requires a non-destructive test method to predict buckling load to use the structure after testing. Many studies have been conducted on Vibration Correlation Technique(VCT), which predicts buckling load using the relationship between compressive load and natural frequency, but it requires a large compressive load to predict the buckling load accurately, and it tends to decrease prediction accuracy with increasing internal pressure in structure. In this paper, we analyzed the causes of the decrease in prediction accuracy when internal pressure increases and proposed a method increasing prediction accuracy under the low compressive load for being usable after testing, through VCT combined testing and FEA result. The prediction value by the proposed method was very consistent with the measured actual buckling load.