• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.860-877
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• 2013

Cloud computing has become one of the most important technologies for reducing cost and increasing productivity by efficiently using IT resources in various companies. The cloud computing system has mainly been built for private enterprise, but public institutions, such as governments and national institutes, also plans to introduce the system in Korea. Various researches have pointed to security problems as a critical factor to impede the vitalization of cloud computing services, but they only focus on the security threats and their correspondents for addressing the problems. There are no studies that analyze major security issues with regard to introducing the cloud computing system. Accordingly, it is necessary to research the security factors in the cloud computing given to public institutions when adopting cloud computing. This research focuses on the priority of security solutions for the stepwise adoption of cloud computing services in enterprise environments. The cloud computing security area is classified into managerial, physical and technical area in the research, and then derives the detailed factors in each security area. The research derives the influence of security priorities in each area on the importance of security issues according to the identification of workers in private enterprise and public institutions. Ordered probit models are used to analyze the influences and marginal effects of awareness for security importance in each area on the scale of security priority. The results show workers in public institutions regard the technical security as the highest importance, while physical and managerial security are considered as the critical security factors in private enterprise. In addition, the results show workers in public institutions and private enterprise have remarkable differences of awareness for cloud computing security. This research compared the difference in recognition for the security priority in three areas between workers in private enterprise, which use cloud computing services, and workers in public institutions that have never used the services. It contributes to the establishment of strategies, with respect to security, by providing guidelines to enterprise or institutions that want to introduce cloud computing systems.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.471-485
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• 2016

Least squares (LS) regression is a classic method for regression that is optimal under assumptions of regression and usual observations. However, the presence of unusual data in the LS method leads to seriously distorted estimates. Therefore, various robust estimation methods are proposed to circumvent the limitations of traditional LS regression. Among these, there are M-estimators based on maximum likelihood estimation (MLE), L-estimators based on linear combinations of order statistics and R-estimators based on a linear combinations of the ordered residuals. In this paper, robust regression estimators with high breakdown point and/or with high efficiency are compared under several simulated situations. The paper analyses and compares distributions of estimates as well as relative efficiencies calculated from mean squared errors (MSE) in the simulation study. We conclude that MM-estimators or GR-estimators are a good choice for the real data application.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.377-389
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• 2020

This research focuses on identifying and measuring key personality factors affecting the job performance of salesperson working in the machinery industry in Vietnam. A total number of 218 salesperson working in machinery industry were surveyed. After evaluating Cronbach's Alpha and using the regression analysis technique, the results show the impact level of personality trait factors affecting the job performance of salesperson working in machinery industry. Ordered from the highest to the lowest effects on job performance, these factors are: agreeableness, openness to experience, conscientiousness, extraversion, and neuroticism. Five research hypotheses are accepted. Specifically, openness to experience, conscientiousness, extraversion, and agreeableness have positive impacts on job performance of salesperson working in machinery industry in Vietnam. However, neuroticism has a negative impact on job performance of salesperson. This research results indicate the level of impact of personality traits on the sales staff performance in machinery industry. Many people apply to this profession as a career choice. Each occupation is suitable for certain personality trait, which changes very little during adulthood. Research also shows that each personality trait always has its strengths and weaknesses. The educational environment should create conditions for learners to develop their character in a natural way.

• 한국노년학
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• v.40 no.1
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• pp.163-178
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• 2020

The purpose of this study is to analyze leisure factors affect happiness of the elderly by sex in Korea and then to discuss implications for the findings. Data of National Leisure Activity Survey conducted by Korea Culture & Tourism Institute in 2016 were used for this study. From this dataset, 891 male elderly and 970 female elderly aged above 65 were selected for this study. Ordered logistic regression model was used by considering the nature of the dependent variable. The results of this study can be summarized as follows. First, choice proportions of leisure activities classified by four type are different by sex of the elderly. Second, among control variables, household income, residential area, joining a club have different significant effect on happiness of the elderly by sex but volunteering have same significant effect on happiness of the elderly by sex. Third, any type of leisure activity have no significant effect on happiness of both the male elderly and the female elderly. Fourth, cost of leisure has significant positive effect on happiness of both the male elderly and the female elderly but has different significance by sex. Fifth, focus on leisure rather than work has very significant positive effect on happiness of both the male elderly and the female elderly. Sixth, leisure life satisfaction has very significant positive effect on happiness of both the male elderly and the female elderly.