• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.20-29
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• 2022

The operational modal analysis (OMA) technique, which extracts the modal parameters of a structural system using ambient vibrations, has been actively developed as a field of structural health monitoring of cable-supported bridges. In this paper, the short and long-term modal parameters of a cable-stayed bridge were evaluated using the acceleration data obtained from the two ambient vibration tests (AVTs) and three years of continuous measurements. A total of 27 vertical modes and 1 lateral mode in the range 0.1 ~ 2.5 Hz were extracted from the high-resolution AVTs which were conducted in the 6th and 19th years after its completion. Existing OMA methods such as Peak-Picking (PP), Eigensystem Realization Algorithm with Data Correlation (ERADC), Frequency Domain Decomposition (FDD) and Time Domain Decomposition (TDD) were applied for modal parameters extraction, and it was confirmed that there was no significant difference between the applied methods. From the correlation analysis between long-term natural frequencies and environmental factors, it was confirmed that temperature change is the dominant factor influencing natural frequency fluctuations. It was revealed that the decreased natural frequencies of the bridge were not due to changes in structural performance and integrity, but to the environmental effects caused by the temperature difference between the two AVTs. In addition, when the TDD technique is applied, the accuracy of extracted mode shapes is improved by adding a proposed algorithm that normalizes the sequence so that the autocorrelations at zero lag equal 1.

• 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.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.217-233
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• 2022

This study was conducted with the purpose of deriving a revitalization plan by analyzing the factors influencing the characteristics and perception of self-employment and self-employment selection of young people. To this end, discussions on self-employment and the size of workers were reviewed, and the characteristics, determinants, and difficulties of self-employment youth were analyzed based on data from a survey of youth in Seoul and Gyeonggi-do. The support plan proposed through the analysis should first strengthen the program so that the government, local governments, and schools can all gain experience in the practice of developing ideas, producing, and selling based on aptitude and competency to solve youth employment problems. Next, compared to support for technology-based start-ups, there are no suitable programs in the fields of knowledge, manufacturing, and distribution, and there is almost no support for freelancers in which the majority of young people are engaged. Therefore, it is necessary to diversify support projects so that the diversity of young people can be expressed in self-employment. Finally, it was found that entrepreneurship had an important influence on self-employment. However, Korean teenagers do not know what entrepreneurship is and have no experience in education, so they should focus on cultivating entrepreneurship in the regular curriculum and establishing a cultural foundation to foster young leaders with creative ideas and execution.

• Journal of the Korean Wood Science and Technology
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• v.49 no.3
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• pp.234-253
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• 2021

The Quercus mongolica has a high utilization value in industrial economic sector. The species is distributed throughout Korea, however, the damage caused by deterioration such as discoloration and decay is severe. For this reason, the deterioration of Q. mongolica is an obstacle to its use as wood, but research on deterioration factors is insufficient. In this study, we focused on fungi as a factor influencing the deterioration of Q. mongolica, and isolated and identified the fungi from the deteriorated Q. mongolica. In additions, in order to confirm whether the identified fungi actually affects wood deterioration, enzyme activities of the identified fungi were evaluated and related mass loss of wood treated with the fungi was measured by wood decay test. As a result of sequencing analysis using the ITS region of the genomic DNA of the fungi isolated from Q. mongolica, Mucor circinelloides, Cunninghamella elegans, and Umbelopsis isabellina 3 species belonging to Mucoromycota phylum, and Ophiostoma piceae and Aureobasidium melanogenum 2 species belonging to Ascomycota phylum were identified. These five fungi had enzyme (i.e. cellulase, laccase) activities related to wood decay and reduced the mass of heartwood and sapwood of Q. mongolica in practice. In particular, O. piceae and A. melanogenum, which have both cellulase and laccase activities, showed 6.9% and 1.5% mass loss, respectively. These results indicated that five fungi identified in this study influence the deterioration of Q. mongolica and are wood decaying fungi for Q. mongolica potentially.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.361-370
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• 2021

The purpose of this study was to identify the factors influencing college life stress and life satisfaction of nursing students. The subjects included nursing students from some select areas. The research was conducted in November and December 2020. The data of a total of 227 nursing students were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlations, and stepwise multiple regression analysis. The findings show that college life stress, economic conditions, and interpersonal relationships had significant effects on life satisfaction of the nursing students with an explanatory power of 27.1%. The study examined life satisfaction based on general characteristics and found variations according to college life satisfaction (F=5.88, p=.003), grades (F=7.07, p=.001), interpersonal relationships (F=8.80, p=.000), and economic conditions (F=10.53, p=.000). There was a statistically significant negative correlation between their college life stress and life satisfaction (r=-.436, p<.001). To summarize, these findings raise a need to provide nursing students with a strategy to address economic issues by reducing their academic stress through an improved educational environment, help them keep positive interpersonal relationships through effective communication, and offer them active information such as counseling so that they can achieve life satisfaction.

• Journal of the Korean earth science society
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• v.42 no.2
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• pp.164-174
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• 2021

The study examines the shearing and crushing characteristics of land-derived subaqueous granular materials in a gravel-bed river. A series of large-sized ring shear tests were performed to examine the effect of shear time and shear velocity on the shear stress characteristics of aquarium gravels with a 6-mm mean grain size. Three different shear velocities (i.e., 0.01, 0.1, and 1 mm/sec) were applied to measure the shear stress under the drained (long-term shearing) and undrained (short-term shearing) conditions. Different initial shear velocities, i.e., 0.01→0.1→1 mm/sec and 0.1→0.01→1 mm/sec, were considered in this study. The test results show that the grain crushing effect is significant regardless of drainage conditions. The shear stress of coarse-grained materials is influenced by initial shear velocities, regardless of the drainage conditions. In particular, particle breakage increases as grain size increases. The shearing time and initial shear velocity are the primary influencing factors determining the shear stress of gravels. The granular materials may be broken easily into particles through frictional resistance, such as abrasion, interlocking and fracture due to the particle-particle interaction, resulting in the high mobility of granular materials in a subaqueous environment.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.221-233
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• 2021

The purpose of this study is to analyze the effects of determinants of innovation performance on innovation performance in industry-research institute(IR) cooperation for researchers of government-funded research institutes in Daedeok Innopolis. We reviewed the existing literature on the determinants of innovation performance through cooperation, and established a conceptual framework to analyze the combinatorial effect of the determinants of innovation performance on innovation performance in IR cooperation. Data for empirical analysis were collected through a questionnaire survey targeting researchers at a government-funded research institute in Daedeok Innopolis. The fuzzy-set qualitative comparative analysis (fsQCA) was used to analyze the combined effect of determinants of innovation performance. The fsQCA results show that the configuration of high motivation, high trust, high commitment and high satisfaction of researchers of government-funded research institutes improve innovation performance. On the other hand, it shows that the configuration of high motivation, high trust, low commitment and low satisfaction of the researcher improves innovation performance.

• Korean Association of Arts Management
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• no.55
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• pp.115-154
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• 2020

This paper examines the professional qualifications of the directors of important public art museums in Korea in comparison to museums outside Korea through analysis of the directors' primary qualifications, including academic background, major, career experience, and study abroad experience, as well as secondary qualifications, including length of tenure, age, gender, and alma mater, which can indirectly the hiring process for directors. The museums examined in this study are separated into three geographical categories - 1. Seoul, 2. the Seoul Metropolitan Area, and 3. locations in Korea outside the Seoul Metropolitan Area - to analyze how the influence of primary and secondary qualifications differs across geographies. Additionally, this study looks at how the professional qualifications of directors in Korea compare to the qualifications of directors outside Korea to identify the idiosyncrasies of the Korean system. It finds that directors in Korea, in general, have a shorter length of tenure, are older, are more likely to be female, and are less likely to be foreign than the directors of overseas museums. Experience-wise, directors in Korea often have experience working as art experts, artists, and art professors, but their backgrounds differ depending on the region in which they are working. Although directors in Korea have, across the board, studied abroad and graduated from prestigious universities, there are noticeable differences across the three geographical locations looked at. Notably, in Korea, the proportion of directors who majored in practical skills is high, while in the case of directors overseas, the proportion of those who majored in art history is high. In addition, while a high percentage of directors are graduates of Hongik University regardless of their museum's location, graduates of Seoul University are mainly concentrated in the Seoul and Seoul Metropolitan Areas. Museums outside the Seoul Metropolitan Area, on the other hand, often hire directors who have graduated from a nearby university. These differences mark a contrast between Korean museums and museums overseas, which generally hire directors who have graduated from prestigious universities, regardless of geographical location.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.457-467
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• 2020

This study aimed to investigate the relationship of life stress, self-esteem, social support, and marital conflict coping, and to identify the factors influencing marital conflict coping in middle-aged adults. The data were collected using questionnaires from 324 middle-aged adults who were in J city, from April to July 2019. The collected data was analyzed using descriptive statistics, t-test, ANOVA, Scheffe test, pearson's correlation coefficient, and multiple regression with SPSS/WIN 24.0 version program. The study results showed that life stress and self-esteem affected negative marital conflict coping, which was 10.1% of the overall explanatory power. The self-esteem and social support affected positive marital conflict coping, which was 20.1% of the overall explanatory power. In other words, it has been confirmed that the higher level of life stress and the lower the level of social support, the more tend to act negative marital conflict coping. Also, the higher level of social support, the more tend to act positive marital conflict coping. Based on this study, it is necessary to develop and apply various programs for couples to participate together in order for middle-aged adults to avoid negative conflict coping and purse positive conflict coping action in a conflict situation that occurs during their married lives.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.315-322
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• 2020

This study was carried out to provide basic data for prevention of burnout by measuring levels of self-efficacy, social support and burnout that nursing students experienced during clinical practice and identifying factors influencing burnout. This is a descriptive research targeting 173 junior- and senior-year nursing students in Y area, and data were collected from October 15^th to November 4^th 2019. For data analysis, frequencies and percentages were calculated, and t-test and ANOVA were conducted along with the Scheffé test as a post-test. In addition, Pearson's correlation coefficients and multiple regression analysis were employed. The study results are as follows. There were significant differences in self-efficacy, social support and burnout depending on grades(t= -2.20, p=.029) and major satisfaction(F=3.62, p=.029) among general characteristics of nursing students. When analyzing correlations among self-efficacy, social support and burnout of nursing students, there was a positive correlation between self-efficacy and social support(r=.214, p=.005), a negative correlation between burnout and self-efficacy(r=-.253, p<.001) and a negative correlation between burnout and social support(r=-.175, p=.021). Major satisfaction(β= -.21, p=.006) had the biggest influence on burnout, and it was followed by self-efficacy(β= -.16, p=.032) and social support(β= -.15, p=.047). The explanatory power of the model was 13.8 percent. In conclusion, it is required to improve university life satisfaction and clinical practice satisfaction and develop programs, which enhance social support and self-efficacy, for preventing burnout of nursing students during clinical practice.