• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.55-64
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• 2020

Since the European Union-South Korea Free Trade Agreement entered into force in 2011, the Korean automobile market has grown rapidly, resulting in intensifying competition among companies in the market. European automakers gained price competitiveness, which intensified competition with Korean automakers. In such a situation, various studies on the Korean automobile market have been conducted, but studies such as market influencing factor analysis and consumer analysis have mainly been conducted, and there is no research on the analysis of competitive dynamics in the market. In this study, the competitive dynamics between Hyundai Motors, Kia Motors, Mercedes-Benz, and BMW, which are major automakers in the Korean automobile market, are analyzed. The competitive relationship between major automakers are modeled using the Lotka-Volterra (LV) model and the competitive dynamics over time are analyzed by applying the Moving Window. In order to explain the competitive dynamics effectively, we analyze it by subdividing it based on various influencing factors.

• Journal of the Korean Geotechnical Society
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• v.39 no.9
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• pp.5-11
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• 2023

In analyzing geotechnical structures, the analysis fields are becoming increasingly diversified. In particular, the need for predicting the thermal behavior of ground materials has become important in fields related to soil freezing. To ensure a reliable assessment of the freezing behavior of the ground, considering the variation in the effective thermal conductivity of soil specimens under various conditions is crucial. In this study, probe experiments were conducted by varying the porosity, initial degree of saturation, and read time settings of the meter. Next, the factors influencing the effective thermal conductivity of the frozen sandy soil were evaluated. The experimental results conducted under different porosity conditions showed a tendency for the effective thermal conductivity of frozen soil to increase as the specimen's porosity decreased. However, as the degree of saturation of the specimen increased, the effective thermal conductivity also increased. The sensitivity of the meter's read time setting to the measurement of effective thermal conductivity was observed. When the read time was set to 1 min, the measured values were in a range similar to that obtained in previous studies conducted in Korea with the same soil specimen.

• Communications for Statistical Applications and Methods
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• v.26 no.3
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• pp.325-336
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• 2019

In this article we extend the discrete Weibull regression model in the presence of missing data. Discrete Weibull regression models can be adapted to various type of dispersion data however, it is not widely used. Recently Yoo (Journal of the Korean Data and Information Science Society, 30, 11-22, 2019) adapted the discrete Weibull regression model using single imputation. We extend their studies by using multiple imputation also with several various settings and compare the results. The purpose of this study is to address the merit of using multiple imputation in the presence of missing data in discrete count data. We analyzed the seventh Korean National Health and Nutrition Examination Survey (KNHANES VII), from 2016 to assess the factors influencing the variable, 1 month hospital stay, and we compared the results using discrete Weibull regression model with those of Poisson, negative Binomial and zero-inflated Poisson regression models, which are widely used in count data analyses. The results showed that the discrete Weibull regression model using multiple imputation provided the best fit. We also performed simulation studies to show the accuracy of the discrete Weibull regression using multiple imputation given both under- and over-dispersed distribution, as well as varying missing rates and sample size. Sensitivity analysis showed the influence of mis-specification and the robustness of the discrete Weibull model. Using imputation with discrete Weibull regression to analyze discrete data will increase explanatory power and is widely applicable to various types of dispersion data with a unified model.

• Journal of East-West Nursing Research
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• v.29 no.1
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• pp.49-58
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• 2023

Purpose: This study aimed to investigate the effects of personality, ego-resilience, and commitment to career choice on the adaptation to college among new nursing students residing in various regions. Methods: The participants were 175 freshmen in nursing departments at 7 universities located in D Metropolitan city. Data were collected through an online questionnaire from June 20, 2022 to July 1, 2022. The collected data were analyzed using descriptive statistics, t-test, one-way ANOVA, Scheffe's test, Pearson's correlation coefficient, and stepwise multiple regression analysis using IBM SPSS/WIN 28.0 software. Results: The average scores of participants were as follows: personality (4.10±0.41), ego-resilience (3.55±0.62), commitment to career choice (3.36±0.59), and adaptation to college (3.63±0.58). The factors influencing college adaptation were ego-resilience, personality, satisfaction with nursing major, and commitment to career choice. The combined explanatory power of these variables for college adaptation was 64.8%. Conclusion: This study highlights the necessity for developing educational programs, training initiatives, and curricular activities to enhance ego-resilience, foster appropriate personality, increase satisfaction with nursing major, and improve commitment to career choice levels among new nursing students residing in various regions.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.55-62
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• 2023

For proper socialization of children the psychological and emotional state of parents that affect children is very important. Recently, while interest in various psychological behavioral problems of children has increased, various studies have been conducted on parental psychology that affects children's emotions. In particular, due to COVID-19, stress has increased throughout society, and it has made parental psychology and childrearing more difficult. Therefore, we aim to investigate the effects of psychological factors, among the variables of various parents that affect children's problem behavior in this study. As a result of this study, it can be confirmed that there is a difference in the effect of parental depression on children's internalizing and externalizing behaviors. Parental depression had a significant positive effect on children's internalizing behavior with 𝛽 =.34, p<.001. In other words, the higher the parents' depression, the higher the child's internalization behavior. And parental depression was found to have a significant effect on children's externalizing behavior, with 𝛽 =.81, p<.001. This also means that the higher the parents' depression, the higher the child's externalizing behavior. Therefore, it can be seen that parental depression is an important factor influencing both children's internalizing and externalizing behaviors.

• Journal of Information Technology Services
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• v.12 no.4
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• pp.41-57
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• 2013

As the usage of SNS has grown dramatically over the last years, it has been used in various sectors not just a tool for communication. In particular, corporate companies actively use Facebook as a tool for corporate marketing. Corporate companies communicate with their customers by providing service or events information. In this study, empirical analysis was carried out on corporate companies that are using Facebook as a marketing tool, thus finding out the influencing factors in continued usage of Facebook Fan Page users. In addition, analysis of the factors will be investigated according to continued usage of the users, where the user's intention will differ depending on how corporate companies operate and deal with the Facebook Fan Page. Factors affecting the user's satisfaction, perceived usefulness, and perceived playfulness were deducted through the analysis of the existing literature study on corporate company's continued intention on the usage of Facebook Fan Page. Accordingly, factor affecting this such as relationship, speed, content diversity, which are the media characteristics of the Facebook were deducted and finally hypothesized. In addition, the type of corporate company's Facebook Fan Page was divided into event type, communication type, information service type. And hence investigated the factors that differed from the continued usage depending on the type. Results analysis shows that perceived usefulness affected only relationship, speed, content diversity. Furthermore, analysis shows that corporate company's Fan Page of communication and event types are the factors that affect the usage intention which meant it only affected the perceived enjoyment. On the basis of this study, we are able to present an implication of value where corporate company use it as a marketing tool, through factors from continued usage of coroporate company's Facebook Fan Page users.

• Journal of the Korea Institute of Building Construction
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• v.18 no.4
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• pp.385-394
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• 2018

There have been frequent reports of schedule delays due to various risks of remodeling projects, which are different from new construction. Therefore, this study was carried out to analyze the risk factors inherent in the remodeling project and the likelihood of schedule delay occurrence in the remodeling construction work. To analyze the relationship between the risk factors and the likelihood of schedule delays of remodeling projects, (1) a prototype of the office building remodeling work was developed through the analysis of existing case and literature, (2) a questionnaire survey was conducted on 29 construction managers who have been or are currently conducting remodeling projects, and (3) after evaluating the reliability of the collected questionnaire results, the relationship between the two elements, which denotes (i) likelihood of schedule delays per each work, (ii) importance of risk factors, and (iii) risk factors affecting schedule delay in remodeling work, was suggested. Using the results of this study, it is expected to develop a plan for preventing the schedule delay of the office building remodeling work through control the risk factors that may cause schedule delays.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.46-57
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• 2020

The dissemination of smart devices has made a lot of changes in overall social activities. In particular, people use various types of smart devices in their spare time, such as watching video clips, but there is a lack of research on external factors influencing the attitude toward using such devices. Therefore, in this study, the effects of video viewing environmental factors (e.g. screen size and video length) and personal factors (e.g. gender and need for entertainment) on perceived ease of use, perceived usefulness, and attitude to use devices based on technology acceptance model. As a result of analyzing 660 users having different smart devices, the attitude to use smart devices is more positive as the screen size increases, but there is no difference according to gender. In addition, while the length of video clips does not affect the attitude to use, the need for entertainment positively affects the attitude to use. Based on the results of this study, we expect that it can be used for optimized customer marketing and management strategy that integrates product development and video content production in consideration of factors such as video viewing environmental factors and personal factors.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.248-255
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• 2013

The objective of this study is to optimize the Metal Injection Molding(MIM) process with design of experiments(DOE) and numerical analysis. To derive the optimal process condition, experiment or numerical analysis was performed under various process conditions. To analyze the interaction among influential factors contributing to the temperature at flow front and response surface in MIM, both central point and axial point were added to the full factorial design with 2 levels and 5 factors and then their impacts on response variable in 43 experimental conditions were analyzed and the significance was evaluated. As a result, sprue, runner, and gate were completely filled in about 0.247 seconds after injection, the front part of the green body was filled in about 0.3344 seconds, the green body except gate, etc changed to almost solid state in about 3.29 seconds, the Packinging pressure was completed in about 6.29 seconds, and the green body inside and outside and sprue, etc became solid in 13.2 seconds. The impact of individual or reciprocal action of factors on the temperature at flow front was analyzed through regular probability, test statistics, main effect, and interaction effect. As a result, of a total of 31 combinations of factors, 9 unit factors and reciprocal actions were significant, and the screening was also possible. A proper regression equation was drawn with regression analysis and response surface design on the response variable of temperature at flow front, and the applicability could be verified.

• Management & Information Systems Review
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• v.29 no.4
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• pp.245-266
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• 2010

So far the study on college graduates has been concentrated on employment and wages. But if college graduates get a job, this study want expanding to the study of the suitability of their level to the job or the job satisfaction. For this study, structural equation model was built up to verify the influencing factors on the job suitability and job satisfaction of college graduates by using data of '2007 Graduates Occupational Mobility Survey(GOMS)'. To put it concretely, job suitability and job satisfaction were analysed based on the leading factors such as vocational value of graduates and the participation of employment supporting program in university. Analyses showed that the vocational value has a positive influence on the job suitability and the job satisfaction as well as the participation of employment support program. And the participation of employment supporting program influenced positively on the job satisfaction and the job suitability while in work. Besides we found that the job suitability has a positive impact on the job satisfaction. These confirmed that the vocational value while in school is very important and plays an important role in the job suitability and the job satisfaction with their jobs while in work. Also those who have a higher vocational value take part in the various employment supporting programs and experience the job satisfaction and the job suitability while in work. Therefore we found that the various employment supporting programs play an important role for the graduates. Accordingly, the school authorities and job centers have to strengthen the value education for the enrolled student to plant a vocational value and improve and reinforce the employment supporting program in university.