• Korean Journal of Remote Sensing
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• v.38 no.2
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• pp.153-166
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• 2022

Waterstorage is one of the factorsthat most directly represent the amount of available water resources. Since the effects of drought can be more intuitively expressed, it is also used in variousstudies for drought evaluation. In a recent study, hydrological drought was evaluated through information on observing reservoirs with optical images. The short observation cycle and diversity of optical satellites provide a lot of data. However, there are some limitations because it is vulnerable to the influence of weather or the atmospheric environment. Therefore, thisstudy attempted to conduct a study on estimating the drought index using Synthetic Aperture Radar (SAR) image with relatively little influence from the observation environment. We produced the waterbody of Baekgok and Chopyeong reservoirs using SAR images of Sentinel-1 satellites and calculated the Reservoir Area Drought Index (RADI), a hydrological drought index. In order to validate the applicability of RADI to drought monitoring, it was compared with Reservoir Storage Drought Index (RSDI) based on measured storage. The two indices showed a very high correlation with the correlation coefficient, r=0.87, Area Under curve, AUC=0.97. These results show the possibility of regional-scale hydrological drought monitoring of SAR-based RADI. As the number of available SAR images increases in the future, it is expected that the utilization of drought monitoring will also increase.

• Particle and aerosol research
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• v.18 no.1
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• pp.9-21
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• 2022

In this study, a novel antiviral coating method for the air filtration system of subway station was investigated. Using dry aerosol coating process, we developed a high-performance antiviral air filter with spark discharger and carbon brush type ionizer. Silver nanoparticles were produced by a spark discharge generation system with ion injection system and were used as antiviral agents coated onto a medium grade air filter. The pressure drop, filtration efficiency, and antiviral ability of the filter against aerosolized MS2 virus particles as a surrogate of SARS-CoV-2 virus were tested with dust contamination. Dust contamination caused the increase of the filtration efficiency and pressure drop, while the antiviral agents (in this study, silver nanoparticles) coating did not have any significant effect on the filtration efficiency and pressure drop. Using these properties, we suggested a novel method to maximize the antiviral performance of the antiviral air filter that was contaminated by dust particles. Moreover theoretical analysis of antiviral ability with dust contamination and re-coated antiviral agents was carried out using a mathematical model to calculate the time-dependent antiviral effect of the filter under actual conditions of subway station. Our model can be used to apply on antiviral air filtration system of subway station for prevention of pandemic diffusion, and predict the life cycle of an antiviral filter.

• Journal of Korean society of Dental Hygiene
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• v.22 no.1
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• pp.1-9
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• 2022

Objectives: This study was conducted to find scaling patients' oral health belief and satisfaction by applying Comprehensive Dental Hygiene Care (CDHC) process. Methods: From July 1 to September 20, 2020, the data about 182 patients who had scaling in dental clinics and hospitals had been collected and analyzed. For data analysis, SPSS Statistics 22.0 was applied to conduct frequency analysis, chi-square, t-test, One way ANOVA and Pearson's correlation analysis. Results: Regarding oral health behavior, in the CDHC group 92.4% used oral care products (p<0.001), and 67.4% regularly visited dental clinics for oral care (p<0.001). Regarding the oral health belief according to general characteristics, in the CDHC group, persons aged '50-65' scored 2.4 (the highest), and were significantly different from those aged '20-29' as the result of post-hoc analysis (p<0.001). Regarding the oral health belief of the CDHC group according to oral health behavior, the scaling cycle '3 months' scored the highest (p<0.05). The patients' satisfaction had high correlations with benefit (p<0.01) and Importance (p<0.05) as the sub factors of the oral health belief of the CDHC group. Conclusions: CDHC positively influenced scaling patients' oral health belief and satisfaction. Therefore, it is necessary to expand CDHC, as the medium to improve oral health belief and satisfaction, to clinical settings.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.502-517
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• 2022

As the use of TBM increases, research has recently increased to to analyze TBM data with machine learning techniques to predict the exchange cycle of disc cutters, and predict the advance rate of TBM. In this study, a regression prediction of disc cutte wear of slurry shield TBM site was made by combining machine learning based on the machine data and the geotechnical data obtained during the excavation. The data were divided into 7:3 for training and testing the prediction of disc cutter wear, and the hyper-parameters are optimized by cross-validated grid-search over a parameter grid. As a result, gradient boosting based on the ensemble model showed good performance with a determination coefficient of 0.852 and a root-mean-square-error of 3.111 and especially excellent results in fit times along with learning performance. Based on the results, it is judged that the suitability of the prediction model using data including mechanical data and geotechnical information is high. In addition, research is needed to increase the diversity of ground conditions and the amount of disc cutter data.

• Journal of Veterinary Science
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• v.23 no.6
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• pp.90.01-90.13
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• 2022

Background: Insulin regulates glucose homeostasis and has important effects on metabolism, cell growth, and differentiation. Depending on the cell type and physiological context, insulin signal has specific pathways and biological outcomes in different tissues and cells. For studying the signal pathway of insulin on glycolipid metabolism in porcine embryonic fibroblast (PEF), we used high-throughput sequencing to monitor gene expression patterns regulated by insulin. Objectives: The goal of our research was to see how insulin affected glucose and lipid metabolism in PEFs. Methods: We cultured the PEFs with the addition of insulin and sampled them at 0, 48, and 72 h for RNA-Seq analysis in triplicate for each time point. Results: At 48 and 72 h, 801 and 1,176 genes were differentially expressed, respectively. Of these, 272 up-regulated genes and 264 down-regulated genes were common to both time points. Gene Ontology analysis was used to annotate the functions of the differentially expressed genes (DEGs), the biological processes related to lipid metabolism and cell cycle were dominant. And the DEGs were significantly enriched in interleukin-17 signaling pathway, phosphatidylinositol-3-kinase-protein kinase B signaling pathway, pyruvate metabolism, and others pathways related to lipid metabolism by Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Conclusions: These results elucidate the transcriptomic response to insulin in PEF. The genes and pathways involved in the transcriptome mechanisms provide useful information for further research into the complicated molecular processes of insulin in PEF.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.195-202
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• 2022

In this study, when cardiopulmonary resuscitation continued for a long time, the rescuer's blood lactic acid concentration, heart rate, and rating of perceived exertion were measured to identify the change in the rescuer's fatigue. Data collection was conducted from July 5 to July 9, 2021, with a total of 24 students, 12 students department of special warfare medical non-commissioned officer, and 12 students department of emergency medical technology at D University, undergoing a two-person alternative chest compression resuscitation for 60 minutes. As a result of the study, the rescuer's blood lactic acid concentration, heart rate, rating of perceived exertion, and chest compression speed were significantly changed according to the duration of CPR (p<.001, p<.001, p<.001, p<.001). blood lactic acid concentrations at every measurement cycle (30 minutes, 40 minutes, 50 minutes, 60 minutes) showed a significant positive correlation with heart rate (r=.696, p<.001, r=.672, p<.001, r=.709, p<.001, r=.782, p<.001), there was also a significant positive correlation with the rating of perceived exertion (r=.476, p<).05, r=.426, p<.05, r=.470, p<.05, r=.470, p<.05). Therefore, monitoring the fatigue of rescuers using heart rate and rating of perceived exertion will be useful for maintaining high-quality chest compression in situations where cardiopulmonary resuscitation is required for a long time.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.327-333
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• 2022

In this study, silicon/carbon nanotube/carbon (Si/CNT/C) composites for anode were prepared to improve the volume expansion of silicon used as a high-capacity anode material. Si/CNT were prepared by electrostatic attraction of the positively charged Si and negatively charged CNT and then hydrothermal synthesis was performed to obtain the spherical Si/CNT/C composites. Poly(vinylidene fluoride) (PVDF), polyacrylic acid (PAA), and styrene butadiene rubber (SBR) were used as binders for electrode preparation, and coin cell was assembled using 1.0 M LiPF₆ (EC:DMC:EMC = 1:1:1 vol%) electrolyte and fluoroethylene carbonate (FEC) additive. The physical properties of Si/CNT/C anode materials were analyzed using SEM, EDS, XRD and TGA, and the electrochemical performances of lithium-ion batteries were investigated by charge-discharge cycle, rate performance, dQ/dV and electrochemical impedance spectroscopy tests. Also, it was confirmed that both capacity and rate performance were significantly improved using the PAA/SBR binder and 10 wt% FEC-added electrolyte. It is found that Si/CNT/C have the reversible capacity of 914 mAh/g, the capacity retention ratio of 83% during 50 cycles and the rate performance of 70% in 2 C/0.1 C.

• Journal of Christian Education in Korea
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• v.70
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• pp.11-35
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• 2022

The purpose of this article is to suggest nine types of educational ministry based on the practical theology in Christian Education. For the purpose this article emphasizes an individual dimension including church, society dimensions. An individual dimension is based on the spirit of post digital era within sociocultural area in different with personal-existential area of the philosophical and theological perspective and life cycle theology area of the developmental psychological perspective. Post digital era means the humanization of digital, digital friendly, and emotional digital cultural characteristics. Post digital generation means child, youth, young adults those who are accustomed with post digital cultural of the post digital era. The educational ministry for the post digital generations categorized into nine types according to correlation with individual, church, and society as a field of ministry and critical scientific method, critical confessional method, and critical correlational method as an interdisciplinary which are composed of Christian tradition and contemporary science. Representative key competencies of nine types in the educational ministry are media literacy, relational identity, communication, high touch, discipleship, making and using media, integrative vocation, collaboration abilities, and home, school, and social resilience in relation with multicultural generations.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.32-42
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• 2022

The strategy to develop a launch vehicle family by bundling multiple rocket engines of a single type has been proven by SpaceX and their reusable fleet comprised of Falcon 9 and Falcon Heavy. In this study, we revisit a potential launch vehicle family out of a 35 tonf-class methalox staged combustion cycle engine and evaluate their utility and performance in various space missions. For example, a Korean version of Falcon 9 can deliver 4.7 tons of payload into 500 km SSO in an expendable mode while the payload is reduced to 2.16 tons in a sea-landing reusable mode. A Korean version of Falcon Heavy can deliver 4.4 tons into GTO when launched from the Naro Space Center, indicating that this common booster core configuration can handle Cheollian 2 albeit the high inclination. Once developed, the same methaloax engine can power the first-stage of smallsat launch vehicles and air launch vehicles.

• Journal of Korean Library and Information Science Society
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• v.53 no.4
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• pp.189-209
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• 2022

The purpose of this study is to analyze the content of the online book curation services and recommended books list by public libraries in Korea and to identify their properties. The case for analysis is a list of 11,447 recommended books provided by 35 online book curation services collected from 23 public libraries and the main results of the study are as follows. Only few case libraries were presenting recommendation themes, and recommendation targets were most often not specific, and the recommendation cycle of books was the most monthly. In general, books recommended for book curation do not overlap with each other, but there was overlap in the field of literature (novels) published in 2019~2021. For recommended books, the proportion of books published by some publishers was high, and books published in 2019~2021 were the most common. The subject areas analyzed based on the KDC 6th ed were literature the most. Readers analyzed by ISBN were of in the order of cultural books and children's books, and the type of publication was in the order of books, pucture books, and comics. Based on these research results, it was required to develop guidelines for online book curation service for public libraries and build a platform to share with libraries.