• Journal of Korean Society of Steel Construction
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• v.8 no.4 s.29
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• pp.19-29
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• 1996

In this paper, it is presumed that the stress time history was generated by simulation method and investigated compatibility in regard to the reappearance of stress time history. In this procedure, the identified frequency distribution of stress range of the steel railroad bridge varies with the rational values of cut off point and bar width. Thus, we show variable aspect of the equivalent stress range results from change of cut off point and bar width. In addition, we analyze the variable of RMC and RMS model due to the cut off point and bar width of the measured stress history which influencs the prediction of fatigue life in the steel railroad bridge. The simulated stress time history is carried out by the superposition method incorporating the vertical load with rotation moment obtained from the Hermition interpolation function, and compared with developing stress results from measured maxi mum stress. Through this study, we can estimate the remaining fatigue life from a safety point of view and comparative accuracy.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.52-57
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• 1997

국제 열 핵융합로 (International Thermonuclear Experimental Reactor) 의 중앙 솔레노이드(solenoid) 초전도 전자석의 피복관 (conduit) 으로서 가장 유력한 후보 재료인 니켈-철 기저 초합금에 대한 개선된 파괴역학적 거동 예측 모형을 개발하기 위하여 피로균열 성장과 파괴 인성 치의 측정이 사용되었다. 유한 요소법을 사용하는 상용 구조해석 코드인 ANSYS 제 5.2판에 의해 초전도 전자석 피복관 재료에 대한 탄소성 파괴역학적 거동을 살펴보았다. 정확한 파괴 기준을 개발하기 위하여 삼차원 J 적분 인자에 의한 결과를 사용하였다. 얇은 피복관재의 경우에 절대온도 4도에서의 적합한 파괴 인성치는 실제 단면효과를 고려한 표면균열 인장시험 결과를 토대로 J 적분으로 도출한 150 MPaㆍm$^{1}$2/ 로 제시되었다.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.375-388
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• 2021

This paper aims to help prevent the spread of COVID-19 by analyzing confirmed cases of COVID-19 in Daejeon. A high volume of visitors, downtown areas, and psychological fatigue with prolonged social distancing were considered as risk factors associated with the spread of COVID-19. We considered the weekly confirmed cases in each administrative district as a response variable. Explanatory variables were the number of passengers getting off at a bus station in each administrative district and the elapsed time since the Korean government had imposed distancing in daily life. We employed a mixed-effects zero-inflated Poisson regression model because the number of cases was repeatedly measured with excess zero-count data. We conducted k-means clustering to identify three groups of administrative districts having different characteristics in terms of the number of bars, the population size, and the distance to the closest college. Considering that the number of confirmed cases might vary depending on districts' characteristics, the clustering information was incorporated as a categorical explanatory variable. We found that Covid-19 was more prevalent as population size increased and a district is downtown. As the number of passengers getting off at a downtown district increased, the confirmed cases significantly increased.

• Information Systems Review
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• v.16 no.3
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• pp.135-160
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• 2014

Most Social Network Service (SNS) provide online chat, video and file sharing, blogging and others. Because of this advantage, people depend on SNS to communicate with others. However, recently SNS encourage people to reveal too much information broadly so SNS users are concerned about privacy invasion and data spill. They also feel fatigue in process of touching people they don't know while using SNSs. That is the reason why they attempt to switch from opened SNS to Closed SNS. Therefore, the purpose of this study is to empirically investigate and analyze the effect of the factors on the SNS users' switching behavior when using SNS. To accomplish this purpose, this research adopted "Push-Pull-Mooring (PPM)" framework. The PPM is proposed by population geologist, who used it to explain the incentives of demographic migration. Following PPM model, this research empirically examines the three categories of antecedents for SNS switching intention toward closed SNS: push (i.e., weak connection, privacy concern, relative complexity), pull (i.e., enjoyment, belongingness, peer influence), mooring (i.e., SNS fatigue, user resistance) factors. The survey was conducted for 285 users on SNS communities in Korea. The results of this study are as follows; First, wear connection and privacy concern are significantly related to SNS switching intention. Second, enjoyment and belongingness are significantly related to SNS switching intention. Finally, the results show that SNS fatigue has a moderating effect on the links between push factors and SNS switching Intention. Also, user resistance has a moderating effect on the links between pull factors and SNS switching Intention. These findings contribute to the SNS literature both theoretically and practically.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.585-596
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• 2016

This study was designed to examine the relationships among the levels of perceived stress, dietary behaviors, physical exercise, drinking, smoking, and relief from fatigue through sleep which affect the subjective happiness in adolescents. Based on the study findings, this paper proposes the basic data required for offering practical solutions to improve the subjective happiness of adolescents. IBM SPSS 20 and AMOS 23 were used to conduct frequency and descriptive analyses, in conjunction with Pearson's correlation coefficients, the AMOS bootstrapping method and phantom variables, for the raw data obtained from the 9,599 participants included in the 11th Korea Youth Risk Behavior Web-based Survey. Those factors having a direct effect on the subjective happiness of the adolescents were the level of perceived stress, relief from fatigue through sleep, physical exercise, dietary behavior and smoking. Perceived stress had an indirect effect on subjective happiness, and the analysis of the indirect effect and significance level of multiple mediators by means of phantom variables showed that, as well as perceived stress, relief from fatigue through sleep, physical exercise, dietary behaviors, and smoking also had indirect effects on subjective happiness. Consequently, a multidisciplinary approach is needed to optimize the subjective happiness in adolescents and financial support for environmental improvements is particularly necessary.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.251-258
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• 2018

We study convergent factors to depression(CES-D: Center for Epidemiologic Studies Depression scale) among administrative staff in general hospital. The questionnaire was used using an unregistered self-administered questionnaire for 201 staff from 9 general hospitals located in J area from Jul. 3rd, 2017 to Jul. 29th, 2017. The hierarchical multiple regression analysis shows the following results. The depression of respondents turned out to be significantly higher in following groups: a group in which Rosenberg Self-Esteem Scale(RES) is lower, a group in which Multidimensional Fatigue Scale(MFS) is higher, a group in which Psychosocial Well-being Index Short Form(PWI-SF) are higher. The results show explanatory power of 32.5%. The results of the study indicate that the efforts, to increase RES, and to decrease MFS and PWI, are required to improve the depression among administrative staff in general hospital. These results could be used in organizing human resource management and industrial health education to lower the level of depression in general hospital administration staff. Following studies need to analyze the structural equation model that effects the depression levels of administrative staff in general hospital.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.243-251
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• 2019

This study was undertaken to validate and assess the reliability of the Korean version of professional quality of life scale (K-ProQOL) that measures the compassion satisfaction, compassion fatigue and burnout among clinical nurses in Korea. We conducted an internal consistency reliability and construct validity by applying confirmatory factor analysis using SPSS WIN (24.0) and AMOS (18.0). Survey data were collected from 210 nurses working at three tertiary hospitals located in Seoul. Reliable internal consistency was achieved for the K-ProQOL, with a Cronbach's alpha for the total scale and three sub scale values of 0.72-0.90. Factor loadings on three subscales of the 30 items considered ranged from 0.25 to 0.82. The model was validated by confirmatory factor analysis (RMSEA 0.05-0.1, GFI >0.7, CFI >0.7). The findings of this study demonstrate that the K-ProQOL has satisfactory construct validity and reliability to measure compassion satisfaction, compassion fatigue and burnout among clinical nurses in Korea. This is the first study assessing the validity and reliability of the Korean version of professional quality of life scale for clinical nurses in Korea.

• Knowledge Management Research
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• v.21 no.3
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• pp.177-195
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• 2020

The social consciousness on fake reviews has triggered researchers to suggest ways to cope with them by analyzing contents of fake reviews or finding ways to discover them by means of structural characteristics of them. This research tried to collect data from blog posts in Naver and detect habitual patterns users use unconsciously by variables extracted from blogs and blog posts by a machine learning model and wanted to use the technique in predicting fake reviews. Data analysis showed that there was a very high relationship between the number of all the posts registered in the blog of the writer of the related writing and the date when it was registered. And, it was found that, as model to detect advertising reviews, Random Forest is the most suitable. If a review is predicted to be an advertising one by the model suggested in this research, it is very likely that it is fake review, and that it violates the guidelines on investigation into markings and advertising regarding recommendation and guarantee in the Law of Marking and Advertising. The fact that, instead of using analysis of morphemes in contents of writings, this research adopts behavior analysis of the writer, and, based on such an approach, collects characteristic data of blogs and blog posts not by manual works, but by automated system, and discerns whether a certain writing is advertising or not is expected to have positive effects on improving efficiency and effectiveness in detecting fake reviews.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.589-598
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• 2019

This study was conducted to build a structural equation model explaining factors that affect hemodialysis patients' quality of life to test the goodness of fit of the model and identify directly and indirectly significant paths. To accomplish this, 230 patients receiving hemodialysis registered at study hospitals in G Metropolitan City and M City were randomly selected, and 201 were used in the final analysis. Data were collected using a self reporting questionnaire from February 1 to March 31, 2014. SPSS WIN 18.0 was used for descriptive statistics and correlation analysis of the general characteristics and for reliability analysis of the research tools. In addition, AMOS 18.0 was used for confirmatory factor analysis of latent variables, to determine the goodness of fit of the hypothetic model, and hypotheses testing. The results of this study were as follows: the fit of the modified model was 41.32, GFI = .96, AGFI = .92, RMR = .04, NFI = .96, CFI = .91 and TLI = .95. Twelve out of the 22 research hypotheses that were improved and improved were statistically significant. The results indicated that hemodialysis patients' quality of life was influenced directly by self-efficacy, depression, and self-care behavior, and indirectly by sleep disturbance, stress, fatigue, and family support. These variables explained 58.6% of the variation in quality of life. Overall, these findings suggest that nursing interventions for hemodialysis patients require strategies for managing patient depression and for increasing self-efficacy and self-care behavior to improve quality of life.

• Journal of Korean society of Dental Hygiene
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• v.10 no.4
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• pp.595-605
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• 2010

Objectives : A precedent research has documented that occupational stress is closely associated with increased the risk of fatigue and decreased in job satisfaction. This study was conducted in an effort to assess the relationship of occupational stress to self-perceived fatigue and job satisfaction by using job strain model. Methods : The number of respondents was 122 dental hygienist who work in dental clinic and period of the investigation was July 2009 through september 2009. A structured questionnaire was employed to evaluate the participants' sociodemographics, job-related factors, health-related behaviors, occupational stress, job satisfaction and self-perceived fatigue. Occupational stress and self-perceived fatigue were assessed using the Korean Occupational Stress Scale-Short form (KOSS-SF) and the Multidimensional Fatigue Scale (MFS), respectively. Results : In job strain model, the ratio of Q2(High Strain Job) group that more susceptible to disease by stress than other group was 16% and the proportion of high fatigue group(Q3, Q4 group) and low job satisfaction group(Q3, Q4 group) was 48%, 45% respectively. In logistic regression analyses, a High Strain Job group was associated with higher odds of react factor(fatigue, job satisfaction) and the odds was down by 3.3%~7.5% after adjustment for age, smoking, alcohol drinking, regular exercise. So the effective strategy for fatigue, job satisfaction reduction for dental hygienist requires additional program focusing on innovated work environment that provide a enough leisure time and exercise program considering the personality traits. Conclusions : The results of this study suggest that occupational stress is a determinant predictor of self perceived fatigue and job satisfaction. Thus, a stress management program for the reduction of occupational stress, and the promotion of dental hygienist impact assessment health and quality of life is strongly recommended.