• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.465-471
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• 2021

The study investigates the dynamic correlation of cryptocurrencies and equity in Vietnam and tests the safe-haven property of them from the perspective of the stock market in Vietnam during the pandemic crisis by applying the dynamic conditional correlation (DCC) GARCH model and regression with a dummy variable, respectively. This study employs time series data on the daily dataset from September 2014 to September 2021 with the focus on the two most popular cryptocurrencies - Bitcoin and Litecoin. The results show that the dynamic conditional correlations between cryptocurrencies and equity in Vietnam increased during the pandemic, however, in most periods, positive dynamic correlations often dominate. Besides, the regression results also indicate that Bitcoin and Litecoin act as weak safe-haven investments for stocks in Vietnam during the COVID-19 turmoil. They are more suitable for diversification purposes although the dynamic correlations between them and the stock index in Vietnam vary stronger during the pandemic crisis than before. The findings of this study suggest that in the period of pandemic crisis, cryptocurrencies are not concerned as effective safe-haven assets for stock in Vietnam. Instead, cryptocurrencies are only playing a potential role in diversification benefit in this economy.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_2
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• pp.989-998
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• 2020

Recently, demands for large-capacity electronic loads are increasing in various industries such as a reliability test for the performance of a DC power supply device or a dummy-load for improving the stability of an independent microgrid to be actively built in the future. The electronic load required in these various fields requires an operation such as a continuously variable resistance load while minimizing the switching harmonic component generated in the electric load current in order to reduce the influence of interference from the load peripheral device. Electronic loads require a system that minimizes switching current ripple for load control. Therefore, in this paper, we propose a three-level module converter structure to reduce the current ripple of an electronic load, and a multilevel interleaved power converter topology to reduce the current ripple. The validity of the proposed electronic load, 3-level 6 interleaver converter, was verified by simulation and experiment. In addition, the user's convenience was provided by applying the emotional command curve interface method.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.517-525
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• 2021

The study investigates the behavior of Asian banks in response to the subprime mortgage crisis and examines how countries that have experimented with a mix of conventional and Islamic banking managed their balance sheet during that period. The study carries out an independent mean t-test comparing the difference of leverage of 464 conventional commercial Asian banks pre- and post-crisis from the largest twenty-five Asian economies based on GDP (2007). The analysis uses 10-year unbalanced panel data of conventional banks and employs the generalized least squares estimation using a dummy variable event window method to capture the response of Asian banks. The study finds evidence of a structural change in the capital structure of Asian commercial banks in response to the financial crisis. Findings suggest that conventional banks increased their capital position more in countries that have both Islamic and conventional banking than those countries without Islamic banking services. By having Islamic banking in their product portfolio, countries can exert market discipline on conventional banks. The study identifies a significant role of global macroeconomic shocks on banks liability structure decision-making. Evidence shows that this increase in capital positioning by banks was a permanent rather than a temporary response.

• Journal of Korea Planning Association
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• v.54 no.4
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• pp.122-130
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• 2019

The purpose of this study is to analyze effect of climate and urban factors on energy resilience, and to explore policy alternatives to strengthen resilience of energy system. For this purpose, this study used extensive literature review on resilience studies and multiple regression analysis. In this study, blackout time was set as a dependent variable. And the independent variables were divided into climate and urban (robustness, countermeasure capacity) characteristics. As a result of the analysis, in terms of climate characteristics, maximum wind speed and cooling/heating degree-day have statistically significant impact on blackout time. With regard to urban characteristics, number of consumer, ratio of deteriorated housing and coast dummy variables have statistically significant impact on blackout time. And the ratio of government employees and road ratio were found to be the most influencing factors to shorten time taken to restore original level of electricity supply. Based on the study results, several policy suggestions to improve energy resilience were made such as continuous management of vulnerable areas and strengthening disaster response services. This study only considered engineering dimension of resilience. Further studies need to be approached on ecological & social-ecological dimension.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.69-70
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• 2020

Accidents in the construction industry are very high compared to other industries, and the number is also increasing steeply every year. Relevant studies were limited for solving the problems. The purpose of this study is to develop a comprehensive risk prediction process for personnel deployed at construction sites on safety management. First of all, the variables were divided into fixed, real-time and working types variables, and the relevant comprehensive data were collected. Second, the probability of a disaster was derived based on the collected data, and weights for each variable were calculated using the dummy regression analysis method using statistical methodology. Lastly, the resulting weighting and disaster probability equation was constructed, and The Final Risk Calculation Formula was developed. The Final Risk Calculation Formula presented in this study is expected to have a significant impact on the establishment of effective safety management measures to prevent possible safety accidents at construction sites

• Asia pacific journal of information systems
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• v.30 no.3
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• pp.590-613
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• 2020

As a part of advanced technology society, South Korean youth have been accessing the Internet at a very high pace. The Internet overuse could yield addiction where may be a serious psychological disorder of this century. The literature remarks that gender could make a significant difference on internet addiction. Therefore, this study aims to examine the effect of gender variable on internet addiction for a sample of South Korean university students (n = 815; 312 females and 503 males). The instrument had two sections; the demographics and twenty Internet Addiction survey items based on a five level scale; "Rarely, Occasionally, Frequently, Often and Always". The results showed that general tendency among the participants appeared between "Occasionally" and "Frequently" for internet addiction. In order to test five derived study hypotheses, the researchers conducted comparative statistical tests. The t-tests revealed that gender made statistically significant differences on nineteen items where males were higher than females showing that males significantly spend more time on the Internet than females. Additionally, t-tests results showed that seventeen of the survey items showed statistically significant differences with respect to types of technology dominant environment. The researchers created two dummy variables to combine gender and technology dominant environment variables and gender and school year variables, to have a better understanding the gender effect with one-way ANOVA. The gender difference still exists following its merge to technology dominant environment showing that the gender surpasses IT related environment. When school year combines to gender, males show higher scores for certain items, especially for freshman year.

• Journal of Energy Engineering
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• v.26 no.2
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• pp.80-92
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• 2017

This paper attempts to estimate the diesel fuel demand function in Korea using panel data panel data of 16 major cities or provinces which consist of diesel demands, diesel market prices and gross value added from the year 1998 to 2015. I apply panel GLS(generalized least square) model, fixed effect model, random effect model and dynamic panel model to estimating the parameters of the diesel fuel demand function. The results show that short-run price elasticities of the diesel fuel demand are estimated to be -0.2146(panel GLS), -0.2886(fixed effect), -0.2854(random effect), -0.1905(dynamic panel) respectively. And short-run income elasticities of the diesel fuel demand are estimated to be 0.7379(panel GLS), 0.4119(fixed effect), 0.7260(random effect), 0.4166(dynamic panel) respectively. The short-run price and income elasticities explain that demand for diesel fuel is price- and income-inelastic. The long-run price and income elasticities are estimated to be -0.4784, 1.0461 by dynamic panel model, which means that demand for diesel fuel is price-inelastic but income-elastic in the long run. In addition I apply dummy variable model to estimate the effect of 16 major cities or provinces on diesel demands. The results show that diesel demands is affected 10 regions on the basis of Seoul.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.1-13
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• 2020

In the event of fire, it is necessary to put out the fire within a golden time to minimize personal and property damages. To this end, it is necessary for fire engines to arrive at the site quickly. This study established a fire engine travel time estimation model to secure the golden time by identifying road and environmental factors that influence fire engine travel time in the case of fire by examining data on fire occurrence with GIS DB. The study model for the estimation of fire engine travel time (model 1) covers variables by applying correlation analysis and regression analysis with dummy variables and predicts travel time for different types of places where fire may occur (models 2, 3, 4). Analysis results showed that 17 siginificant independent variables are derived in model 1 and the fire engine travel time differs depending on the types of places where fire occurs. Key variables(travel distance, number of lane, type of road) that are included commonly in the 4 models were identified. Variables identified in this study can be utilized as indicators for research related to travel time of emergency vehicles and contribute to securing the golden time for emergency vehicles.

• Journal of Families and Better Life
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• v.23 no.2 s.74
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• pp.137-148
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• 2005

This study compared one-child households' economic structures between those who determined not to have more children and those who have a birth plan. This study examined the demographic characteristics and economic variables such as income, consumption expenditures, assets. debt, and a subjective evaluation of future economic status. Especially, it compared the effects of socioeconomic variables on expenditures on a child between low-fertility and birth-planned households. From a questionnaire completed by a husband or wife of one-child households, 154 low-fertility households and 201 birth-planned households were obtained. A t-test, chi-square test, multiple regression analysis and a dummy variable interaction technique were used. The findings of this study are as follows: First, low-fertility households were older, had higher income, and had more educated, employed wives. Their marital duration was longer, and their child was older than those of birth-planned households. Second, low-fertility households had higher consumption expenditures than did birth-planned households. Especially, expenditures of apparel and shoes, health care, education, and entertainment were significantly higher for low-fertility households. Also, low-fertility households spent more than did birth-planned households on a child. However, low-fertility households had significantly more debt than did their counterparts, and their expectation level of future economic status were lower than that of birth-planned households. Third, the effects of socioeconomic variables on expenditures on a child were different between low-fertility and birth-planned households. Age, education level, husband's occupation, wife's employment status, income, net asset, and subjective evaluation of future economic status showed significant differences. Income elasticity of expenditure on a child was significantly higher for low-fertility households than their counterparts.

• Journal of Korean Clinical Health Science
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• v.2 no.2
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• pp.148-157
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• 2014

Purpose. This study compares and analyzes customer service on customer satisfaction and customer royalty on customer satisfaction targeting the customers visiting a hospital or a clinic which is franchised or not. And it aims at helping business rationalization for a medical institution. Methods. This paper conducts a survey and selects a sample of 670 customers except the missing value targeting the customers of 4 primary health care institutions and 4 bigger health care institutions in Seoul and Gyeonggi province. It conducts frequency analysis for the purpose of investigating the respondents' generic characteristic and factor of their medical institution selection, and factor analysis, reliability analysis and regression analysis for the hypothesis testing. Results. The first hypothesis testing result is significant in level of significance of 0.01. The second one is the same as the first one, but the dummy variable shows a negative regression coefficient(-0.479). The third one is significant in level of significance of 0.01, but the forth one is not significant. And the respondents prioritize website(Home page) and convenience in use of a hospital procedure for selecting a hospital or a clinic. Conclusions. The additional analysis finds that the franchised group has more satisfaction than none franchised group. But in case of their royalty, the average of franchised and none franchised groups are not significantly different. Therefore, the results of this paper reveal to support the results of the advanced researches.