• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.375-380
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• 2017

This paper reports the results of an acceleration test to predict the contact-induced failure that could occur at the cylinder-to-hole joint for the fuel rod of a sodium-cooled fast reactor (SFR). To incorporate the fuel life of the SFR currently under development at KAERI (around 35,000 h), the acceleration test method of reliability engineering was adopted in this work. A finite element method was used to evaluate the flow-induced vibration frequency and amplitude for the test parameter values. Five specimens were tested. The failure criterion during the life of the SFR fuel was applied. The S-N curve of the HT-9, the material of concern, was used to obtain the acceleration factor. As a result, a test time of 16.5 h was obtained for each specimen. It was concluded that the $B_{0.004}$ life would be guaranteed for the SFR fuel rods with 99％ confidence if no failure was observed at any of the contact surfaces of the five specimens.

• Korean Journal of Cognitive Science
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• v.32 no.3
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• pp.141-167
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• 2021

Authenticity is the opposite of hypocrisy or deceitful living in philosophy. While various positive factors that humans experience in life based on authenticity have been studied abroad, most of the studies in Korea that tried to measure authenticity did not take into account the characteristics of Korean culture or were developed only for the purpose of use in a limited domain or specific purpose. In this study, based on the specificity of Korean culture, we developed a measure of authenticity that researchers can use universally. To this end, the items constituting the existing authenticity scale and the items reflecting the cultural value of Korean society, which value social relationships, are integrated. The results of exploratory factor analysis and confirmatory factor analysis indicated that authenticity consists of three factors: self-awareness, behavioral authenticity, and relationship authenticity. In addition, criterion validity was verified based on correlations with life satisfaction, mindfulness, self-esteem, HEXACO, social desirability, self-regulation focus, and emotional diversity. These results suggest that the authenticity scale of this study is a reliable and valid measure, and is expected to be an important tool for empirical individual differences research on authenticity in everyday life in Korean population.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.151-162
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• 2012

Analysis for back fat thickness (BFAT) and daily body weight gains from birth to the end of a performance test were conducted to find an optimal method for estimation of weaning age effects and to ascertain impacts of weaning age on the growth performance of purebred Berkshire pigs from a closed population in Korea. Individual body weights were measured at birth (B), at weaning (W: mean, 22.9 d), at the beginning of the performance test (P: mean, 72.7 d), and at the end of the performance test (T: mean, 152.4 d). Further, the average daily gains in body weight (ADG) of 3,713 pigs were analyzed for the following periods: B to W (DGBW), W to P (DGWP), P to T (DGPT), B to P (DGBP), B to T (DGBT), and W to T (DGWT). Weaning ages ranged from 17 to 34 d, and were treated as fixed (WF), random with (WC) and random without (WU) consideration of an empirical relationship between weaning ages in the models. WF and WC produced the lowest AIC (Akaike Information Criterion) and least fractions of error variance components in multi-traits analysis, respectively. The fractions of variances due to diverse weaning age and the weaning age correlations among ADGs of different stages (when no overlapping allowed) by WC ranged from 0.09 to 0.35 and from -0.03 to 0.44, respectively. The maximum weaning age effects and optimal back fat thicknesses were attained at weaning ages of 27 to 32 d. With the exception of DGBW, the effects of weaning age on the ADGs increased (ranging from 1.50 g/d to 7.14 g/d) with increased weaning age. In addition, BFAT was reduced by 0.106 mm per increased day in weaning age. In conclusion, WC produced reasonable weaning age correlations, and improved the fitness of the model. Weaning age was one of crucial factors (comparable with heritability) influencing growth performance in Berkshire pigs. Further, these studies suggest that increasing weaning age up to 32 d can be an effective management strategy to improve growth performance. However, additional investigations of the costs and losses related to extension of the suckling period and on the extended range of weaning age are necessary to determine the productivity and safety of this practice in a commercial herd and production system.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.1
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• pp.53-63
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• 2020

The purpose of this study is to analyze the current status of the second year of application of Integrated Science and Science Laboratory Experiments, which are common courses of high school, and to explore suggestions for curriculum development in the future. To this end, the results of the survey of a total of 244 science-core and general high schools were compared with the survey result of 2018 school year. In addition, in-depth interviews were conducted with nine science teachers of the focus group to discuss the current state of curriculum implementation. According to the results, as in the first year, most of the Integrated Science courses were implemented in 6-8 units, and in most schools the number of teachers in charge of Integrated Science per class were 3-4. In the teacher's focus group interview, teachers insisted that Integrated Science requires integrated teaching approaches and is good for generating students' interest, but it is difficult to implement process-based assessment due to issues such as ensuring fairness of assessment. Most of Science Laboratory Experiments courses were implemented in two semesters, one unit per semester, and there was little link between Integrated Science and Science Laboratory Experiments because of the different teaching staff. The school life record entry method of Science Laboratory Experiments has been changed to criterion-based assessment starting in 2019, so students' satisfaction or flow of classes is much better than expected, and teachers can teach without burden. Based on the research results, ways to support the settlement of Integrated Science and Science Laboratory Experiments as common subjects, and ways to improve those subjects in the next curriculum revision were suggested.

• The Korean Journal of Coaching Psychology
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• v.8 no.1
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• pp.1-50
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• 2024

The purpose of this study is to identify career barrier factors experienced by career interruption women, develop a tool to measure career barrier, and verify their validity. To this end, preliminary questions were developed by reviewing literature, conducting one-on-one in-depth interviews with 10 women on career interruption, and conducting an open questionnaire with 100 women on career interruption. The subjects of the study were married women aged 20 to 54 who had past employment experience, wanted to be re-employed, and experienced retirement due to marriage, pregnancy, childbirth, childcare, and family care, and the period of career interruption was selected for more than one year. After that, 63 questions were selected for 7 factors. A preliminary survey was conducted on 300 women with career interruption in Korea, and as a result, 63 questions of 6 factors were derived through exploratory factor analysis. The main survey was conducted with 44 questions of 6 factors by partially modifying the questions reflecting the important concepts in each factor. In this survey of 600 people, in order to verify the validity of the constituent concept of this test, the entire sample was divided into two groups, and group 1 (G1, N=309) conducted exploratory factor analysis and group 2 (G2, N=291) conducted confirmatory factor analysis. As a result of exploratory factor analysis for Group 1, 34 questions of 6 factors were finally derived, and a confirmatory factor analysis of Group 2(G2) was conducted to confirm the model fit of the derived factors, and it was confirmed that the model fit criteria were met. In order to verify the convergence validity of the developed career barrier scale, a correlation analysis was conducted with the career barrier test for female college students, and as a result of the analysis, the career barrier scale for women with career interruption and the career barrier test for female college students showed statistically significant correlation. In order to verify the validity of the criterion, the results of a correlation analysis with variables of job preparation behavior, job stress, state anxiety, and life satisfaction were all found to be statistically significant. Finally, the academic, practical, and policy significance and limitations of this study and future research directions were presented.