• Journal of Korean Society of Transportation
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• v.32 no.1
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• pp.13-26
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• 2014

Depending most of its energy sources on foreign countries, Korea efforts to reduce energy consumption in transportation. While studies on the relationship between gas price and transportation demand are many in number, most previous studies have focused on automobile and Seoul. This study analyzes the impact of gas price on transit (bus and subway) demand using monthly data and for various metropolitan areas (Seoul, Busan, Daejeon, Daegu and Gwangju). The research utilizes a time-series model and a multiple regression model, and calculates modal demand elasticities of gas price. The result shows that elasticities of subway demand with respect to gas price is higher than those of bus demand. In addition, elasticities of predominantly automobile cities are more likely to be more sensitive to gas price than those of cities with well-structured transit system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8719-8727
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• 2015

The purpose of this study is to examine the production efficiency of Rose farm and to explain the factors of the inefficiency. To analysis the production efficiency, SFA(Stochastic Frontier Analysis) and DEA(Data Envelopment Analysis) methods are measured, and then, Tobit regression model is used to analysis the influential factors on the production efficiency. As a result, first, the production efficiency by SFA is 88.4%, and by DEA, results are 78.5% and 85.2% in the CRS and VRS model, respectively. In particular, the production efficiency of the measurement results of the two methods are complementary, it is described in the same order of efficiency of each management body. Second, the results of tobit model shows that 6 input-factors are significant, and seed/nursery and material costs, which have the largest regression coefficient value and positive effect on production efficiency, are the most influential factors. Therefore, the results of this study indicates Rose farm can enhance their management efficiency by increasing amount of the seed/nursery and material costs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.627-633
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• 2009

Composite has become one of the most frequently used material for a tube of satellite camera due to its attractive characteristics. However, laminated composites can be weakened by delamination which comes from interlaminar stress. Such failure mode cause structural instability of the camera as well as degradation of optical quality. Therefore composite tube should be robust in delamination. Also, composite tube should have high stiffness, sufficient high natural frequency and small coefficient of thermal expansion. The design procedures presented in this paper are based on design of experiments. The experiments for mechanical analysis are designed by the tables of orthogonal arrays. In order to manipulate the various mechanical properties systematically, multiple-attribute decision making(MADM) is employed. Through analysis of variance and F-test, the critical design variables which have dominant influences on mechanical performance are determined. Finally improved ply angles for composite tube are determined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.582-590
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• 2016

This study examined the relationships among smartphone addiction, parenting attitudes and resilience to identify the relevant factors affecting smartphone addiction. Data were collected from a total of 220 middle school students responding to questionnaires in G city and analyzed using descriptive statistics, independent t-test, ANOVA, $Scheff{\acute{e}}$ test, Pearson coefficient correlation, and multiple regression. The results showed that the parenting attitude and resilience were negatively correlated with smartphone addiction. The significant factors affecting smartphone addiction were gender, the time of smartphone usage, parenting attitudes, and resilience. These variables explained 21.9% of smartphone addiction and the highest factor was the parenting attitudes, followed by gender, time of smartphone usage, and resilience. This study indicated that it is important to develop a program to ensure adolescents positively perceive parenting attitudes and increase their resilience to decrease the incidence of smartphone addiction.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1217-1225
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• 2015

Survey research, data is commonly collected through a sample design with complex design features that allow the relative efficiency on the precision of an estimator to be measured using the concept of the design effect compared to simple random sampling as a reference design. This concept is most useful when the design effect can be expressed as a function of various design features. We propose a design effect formula suitable under a stratified multistage sampling by generalizing Gabler et al. (1999, 2006)'s approaches for multistage sampling. Its use can either guide improvement in the design efficiency when in design stage or enable the evaluation of the adopted design features afterwards.

• The Journal of the Korea Contents Association
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• v.17 no.2
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• pp.1-12
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• 2017

This study investigated the effect of parental attachment on interpersonal competence and psychological well-being of college students. 625 college students completed self-administered questionnaires. Reliability test, ANOVA, Duncan ex-post analysis, and hierarchical regression analysis on data were used. Study results showed that parental attachement and interpersonal competence had significant effects on college students' psychological well-being. Results also depicted gender differences in the relationship of study variables; students' interpersonal competence demonstrated partial mediation effect in the relation of attachment with the same-sex parent and psychological well-being, while complete mediation effect in that of attachment with the opposite-sex parent and psychological well-being, These findings suggest that gender-conscious university policies to promote interpersonal competence among students are greatly needed to ensure psychological well-being of the student population.

• Korean Journal of Childcare and Education
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• v.9 no.2
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• pp.5-21
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• 2013

The purpose of this study was to identify the relationship of job stress, parenting stress and parenting behaviors in nurses. This research was carried out targeting 201 nurses in total who have preschool children and work at two university hospitals and three general hospitals in D Metropolitan. For the analysis of the research SPSS 17.0 was used for the data analysis. Regression analysis was the statistical method used for data analysis. There were significant negative correlations for parenting behavior and parenting stress in the mothers. Among daily lived stress, parental role stress and job stress significantly influenced parenting behavior. Therefore, daily life stress, job stress and parental role stress had an influence on the parenting behavior. The results of this study show that parenting stress, job stress are powerful factors for understanding parenting behavior. An important implication of this study is that nurses in future should be considered with the parenting stress and job stress.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.67-81
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• 2006

The present study suggests an analytical method to overcome the spatial problems that traditional hedonic methods have. The concept of overlapping neighborhoods is introduced in order to solve the problems of global parameter estimate methods that treat the whole city by the gross. Moreover, a 3rd party program for the tight coupling of GIS and statistics is developed in order to explore hedonic methods efficiently. By using these, this study analyses the spatial variation of location variables that affect the real estate price. The results show that the influences of urban centers do not reach to the whole city, but only to the catchment areas of them. And the coefficients of location variables are different depending on the space. The tight coupling of GIS and statistics offers a powerful tool in analysing the real estate price efficiently.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.413-424
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• 2015

The purpose of this study was to investigate the effects of leader-member exchange(LMX), participation in the opportunities for competency development, and subjective career success. LMX and participation in the opportunities for competency development were the independent variables and the subjective career success was used as control variable. Based on the data collected from 257 employees of a Korean financial company, correlation analysis and multiple regression analysis were conducted through the using SPSS/WIN 20.0 statistical package program. The results showed the statistically significant correlation between employability and other research variables. Also, results identified that participation in the opportunities had largest influence on the employability and LMX had no significant effects on the employability. The discussion and proposition for the future studied were provided.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.525-540
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• 2012

The purpose of the present study is to examine the causal relationship and invest the difference among isolation, interaction, content satisfaction, achievement and persistence in cyber university education by employment status. For this study, 104 students at A cyber university in Korea completed surveys in the fall semester of 2011. The result of this study indicated that there was a meaningful effect of interaction on isolation. Secondly, there was a meaningful effect of interaction on content satisfaction. Thirdly there was a meaningful effect of interaction on achievement. Lastly there were meaningful effects of isolation and interaction on persistence. In addition, according to multi-group analysis, there were no significant differences of structural path coefficients between two groups. Based on these results, this study suggests instructional design methods and management strategies to improve the quality of learning in cyber universities.