• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.485-492
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• 2021

The wind turbines with a rated capacity of 50kW or less are generally considered as small class. Small wind turbines are an attractive alternative for off-grid power system and electric home appliances, both as stand-alone application and in combination with other energy technologies such as energy storage system, photovoltaic, small hydro or diesel engines. The research objective is to develop the 50kW scale wind turbine blades in ways that resemble as closely as possible with the construction and methods of utility scale turbine blade manufacturing. The mold process based on wooden form is employed to create a hollow, multi-piece, lightweight design using carbon fiber and fiberglass with an epoxy based resin. A hand layup prototyping method is developed using high density foam molds that allows short cycle time between design iterations of aerodynamic platforms. A production process of five blades is manufactured and key components of the blade are tested by IEC 61400-23 to verify the appropriateness of the design. Also, wind system with developed blades is tested by IEC 61400-12 to verify the performance characteristics. The results of blade and turbine system test showed the available design conditions for commercial operation.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.83-98
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• 2021

This study identified the influence of employees' hybrid start-up intention (intention to start a business while maintaining a job) on the employees' self-determination motivation (intrinsic motivation, extrinsic motivation) and prior knowledge through the Model of Goal-directed Behavior (MGB). We used a PLS-SEM called SmartPLS 3.0 for 126 valid samples collected by judgement extraction for office workers throughout June 13, 2020 to July 3, 2020, and empirically evaluated the measurement model (internal consistency reliability, convergent and discriminant validity) and the structural model (multicollinearity, determination coefficient, effect size, predictive relevance, etc.). Only the intrinsic motivation for realizing the hybrid start-up goal of office workers had a significant impact on the hybrid start-up attitude and subjective norms, and the prior knowledge of hybrid start-up had a significant impact on the hybrid start-up desire and the hybrid start-up intention. In order to induce hybrid start-ups for workers with unstable employment, we need systems and programs that can inspire employees with intrinsic motivation and knowledge about hybrid start-up, so follow-up researches are necessary to analyze about government systems and consulting support that can promote hybrid start-up.

• Journal of fish pathology
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• v.34 no.1
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• pp.39-46
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• 2021

Tetracycline (TC) is one of the antibiotics used for treatment of bacterial infection in Korea. Inadequate usage and abuse cause the resistance to antibiotics, like Tetracycline, Erythromycin, and Fluoroquinolone. It can also affect severe economic loss in aquaculture field in Korea. We isolated 101 bacterial samples from diseased fish at aquaculture sites in Gyeonggi-do during 2015~2018. Minimum inhibitory concentration (MIC) method has been used to determine distribution and to identify bacterial isolates resistant to antibiotics including Oxytetracycline (OTC), Ampicillin (AMP), Clindamycin (CLI), Enrofloxacin (ENRO), Gentamycin (GEN). TC resistant isolates were confirmed antibiotic resistant genes by conventional PCR. Bacterial isolates were identified as Aeromonas spp. (43.5%), Pseudomonas spp. (4.0%) and Vibrio spp. (5.0%). It was confirmed that multi-resistant isolates (77.2%) were predominant over single-resistant one (22.8%). TC resistant genes like tet(A), tet(D), tet(E), tet(G), tet(M), and tet(S) were detected and tet(A) was the most prevalent. Aeromonas spp. is a dominant strain in bacterial infections in fishes of aquaculture sites, and further investigation on various antibiotic resistance genes will be needed for clear understanding of aquaculture sites in Gyeonggi-do.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.1-8
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• 2020

The purpose of this study was to identify the factors that influence the organizational commitment of clinical dental hygienists to contribute to manpower management. The subject of the study was 195, and the following results were obtained as a result of collecting and analyzing data using a self-filling questionnaire from March 10 to April 20, 2020. The degree of organizational commitment, job satisfaction, and internal marketing according to general characteristics were analyzed by t-test and one-way ANOVA, and post-test was set to'Scheffe'. The correlation between organizational commitment, job satisfaction, and internal marketing showed a significant positive correlation with job satisfaction (r=0.689) and internal marketing (r=0.678). The factors influencing organizational commitment were multiple regression analysis, and the influencing factors for organizational commitment were internal marketing and job satisfaction. The most influential factor was job satisfaction, and the explanatory power was 56.1%.As a result, the internal marketing of clinical dental hygienists was found to be related to job satisfaction and organizational commitment, and the factor that most affected was job satisfaction. Therefore, institutional and administrative support from dental medical institutions is needed to improve job satisfaction, which has an impact on organizational commitment of clinical dental hygienists.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.80-86
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• 2021

The purpose of this study was to determine the optimal sowing date for the spring sowing cultivation of rapeseed (Brassica napus L.). To determine suitable rapeseed sowing dates for spring sowing cultivation, changes in growth, flowering characteristics, and seed production were investigated in Muan, South Korea between 2019 and 2020. 'Jungmo7001' is the suitable variety for spring sowing because of its early flowering characteristics, high seed yield, and the fact that it occupies the highest cultivation area in South Korea. When the yield of 'Jungmo7001' was investigated in 2019 and 2020, the highest yields recorded were 243 kg/10a in February 28, 2019, and 294 kg/10a in February 18, 2020. As a result, the optimal rapeseed seeding period is considered to be mid-to-late February in the southern region. There was no statistically significant difference in seed crude oil content. The content of oleic acid (C18:1) decreased, but that of linoleic acid (C18:2) and of linolenic acid (C18:3) increased significantly depending on the sowing date.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.415-423
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• 2021

The purpose of this study was to report the changes in underwater anxiety, physical self-efficacy, and water safety consciousness in elementary school students through participation in survival swimming education, and the relationship between variables. For this purpose, 300 out of 312 elementary school students who participated in survival swimming education in Busan were used as valid samples. The collected data were analyzed through exploratory factor analysis, reliability analysis, correspondence sample t-test, and multiple regression analysis using the SPSS 25.0 statistical program, and the results are as follows. First, the underwater anxiety of elementary school students before and after participating in survival swimming education decreased, and the physical self-efficacy and water safety awareness increased. Second, underwater anxiety of elementary school students who participated in survival swimming education partially negatively affected physical self-efficacy and water safety consciousness, and physical self-efficacy partially positively affected water safety consciousness. Based on these results, the effectiveness of survival swimming education could be confirmed, and the direction of qualitative expansion of the program could be reconsidered.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.211-225
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• 2021

The purpose of this study was to investigate the effect of academic self-efficacy, task value, behavioral participation, cognitive participation, emotional participation, and initiative participation on learning satisfaction in 462 college students who took a flip learning class. Results, As for the direct effect of variables affecting learning satisfaction, behavioral participation was the largest factor, followed by initiative participation, task value, emotional participation, and academic self-efficacy. These variables explained 86% of learning satisfaction. Academic self-efficacy and task value had an indirect effect on learning satisfaction through behavioral, emotional, and proactive participation. In the multi-group moderating effect with the upper-middle class (B+ or higher) and the lower-middle class (below B) group as the moderating variables, there was a partial moderating effect because the path coefficients of leading participation and learning satisfaction differed between the groups. It is necessary to seek various ways to increase the degree of participation in learning and to develop an intervention strategy through a program tailored to each individual.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.1
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• pp.7-15
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• 2022

Objectives : The purpose of this study is to identify the effect of office workers' stress level and stress vulnerability on heart rate variability (HRV), confirm the significance of objective stress indicators obtained through subjective stress and heart rate variability devices, and examine their effectiveness as an integrated stress measurement tool in community mental health projects. Methods : From June to July in 2020, 929 workers participated in the stress management and mental health promotion project carried out by K hospital, and their recorded database was used for study analysis with their agreements. Multiple linear regression analysis was performed to find out the effects of general stress level, and stress vulnerability on heart rate variability. Results : All general characteristics were found to have a significant effect on SDNN (ln), RMSSD (ln), LF (ln), and HF (ln), but work experience did not significantly affect RMSSD (ln). Stress level and stress vulnerability did not significantly affect heart rate variability, but stress perception, a sub-factor of stress level, was found to have a significant effect on RMSSD (ln) (β=0.118, p=0.023). Conclusions : In this study, stress perception, a sub-factor of stress level, was found to be a factor affecting RMSSD (ln). This indicates an association with the activity of parasympathetic nerves in stressful situations, and more follow-up studies are needed to use it as a direct indicator of chronic stress and integrated stress in the community mental health field.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.611-618
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• 2022

The purpose of this study was to confirm the degree of other behaviors among university students in the department of radiology(science) who experienced online classes in the COVID-19 situation and to investigate the effect of self-directed learning ability, flow and academic achievement on other behaviors. The research method was descriptive research. Data were 200 students collected from June 1 to 30 in 2022 using structured questionnaires as students in the Department of Radiology(science). Collected data were analyzed using descriptive statistics, t-test, ANOVA, Cronbach's pearson's correlation, multiple regression analysis with SPSS/WIN 21.0. The result of the study showed that the other behaviors were in the order of 'having s different thought, and 'sending text messages'. other behaviors was 1.75, self-directed learning ability was 3.60, flow was 3.23 and academic achievement was 4.29. There was a significant negative correlation between other behaviors and self-directed learning ability, flow, academic achievement. Factors influencing other behaviors were academic achievement, age, flow, self-directed learning ability in that order. As a result of the above research. it is expected that specific measures and various teaching methods to be flowed in the class are need as the way to lower the other behaviors of university students in the Department of Radiology(science) is to increase academic achievement.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.408-415
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• 2021

This study was conducted to evaluate various beneficial functions of soaked and germinated Robusta coffee beans. Vietnam Robusta coffee beans were soaked in purified water or Salicornia extract for 12 h. The total polyphenol content of non-germinated coffee (NGC), Salicornia extract-germinated coffee (SGC), and water-germinated coffee (WGC) was found to be 16.71-20.17%. First, NGC, SGC, and WGC at concentrations of 25-100 ㎍/mL showed significant anti-oxidant effects on DPPH radical scavenging and xanthine oxidase activity. NGC, SGC, and WGC also inhibited tyrosinase activity and melanin formation in α-MSH-induced B16F10 cells. In addition, the anti-obesity property of germinated coffees was tested by the Oil Red O staining method. NGC, SGC, and WGC inhibited adipogenesis in 3T3-L1 cells without cytotoxicity. Taken together, germinated Robusta coffees with enhanced flavor showed beneficial multifunctional effects, such as anti-oxidant, anti-melanogenesis, and anti-adipogenesis effects.