• International Area Studies Review
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• v.15 no.3
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• pp.55-76
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• 2011

In this paper, we estimate a model that incorporates key features of business cycles, co-movement among economic variables and switching between regimes of expansion and recession, to aggregate quarterly data for the NAFTA region. Two common factors reflecting the permanent and transitory components of the business cycle in the region, along with the turning points from one regime to the other, were extracted from the data by using the Kalman filter and maximum likelihood estimation approach of Kim (1994). Estimation results confirm that a typical aspect of business cycles are also observed (i.e., recessions are steeper and shorter than recoveries) in the region, and that both co-movement and that regime switching are found to be important features of the business cycle. The two common factors produce sensible representations of the trend and cycle, and the estimated turning points are in line with independently determined chronologies. It also turns out that the degree of synchronization between the NAFTA region and Korea, has significantly increased since the entry into force of the NAFTA.

• Information and Communications Magazine
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• v.31 no.1
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• pp.71-81
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• 2013

본고에서는 자연계에 존재하는 동조 현상을 이해하고 공학적으로 활용하기 위하여 동조 현상에 관한 대표적인 수학적 모델을 살펴보고 동조의 원리를 분석한다. 또한 동조 현상을 공학적으로 활용한 주요 사례를 살펴봄으로써 자연계를 모방한 동기화 방식의 장단점을 분석하고 자연계 모방 기술의 필요성을 역설한다. 아울러 동조 현상을 공학적으로 활용하는데 필요한 향후 연구 이슈를 제시한다.

• Korea Real Estate Review
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• v.24 no.1
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• pp.39-52
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• 2014

This study examines the degree of global co-movement & spillover effect among the housing price of ten major countries of OECD including Korea, based on the 3 hypothesis. The data used in this study is quarterly house price index of OECD countries from 1975 to 2012. VAR model is used to analyze the co-movement, and Granger causality methodology is used for the analysis of Spillover Effect. It is found that entire period of study is that the global house prices showed the co-movement, but the coefficient was weak. Since 2008 global financial crisis, the co-movement increased significantly and the adjusted R-square of this model increased 78% compared to the entire period (1975-2012). In general, all hypotheses in this study were significant, and the common shock hypothesis were most significant. In case of Korea, the degree of co-movement was weak compared to the other countries and spillover effect was independent since 2008.

• Korea journal of population studies
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• v.33 no.3
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• pp.31-51
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• 2010

This study investigates changes in family values (attitudes toward marriage, children, and traditional sex roles) and examines how the values influence on their intentions of marriage and expected age at first marriage. A sample consists of 5,984 never married men and women drawn from the 2005 and 2009 National Marriage and Fertility Study. The results show that the endorsement on marriage and children has decreased while endorsement on traditional sex role attitude has increased over the past five years. Those who have higher values on marriage, children, and traditional sex role have a higher likelihood of marriage intention. However, the effects of the family values on marriage intention have weakened during the period. The endorsement on marriage lowers the mean ages of the expected first marriage. Comparing the effects of the family values during the period, this study find that normative aspects of the family values have lower effects, whereas individual aspects of the values have stronger effects over time. These findings suggest that the effects of family values vary across sex, time, and the aspect of the values.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.376-390
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• 2009

The objective of this study is to examine the factors affecting adolescents' intention to buy e-Learning web site, expecially focuses on the moderating effect of adolescents's conformity. The main results are as follows. First, teacher's ability, personalized service, easy for service search, interaction between students, service revival for joining e-Learning sites affect intention to buy e-Learning web site through perceptual usefulness, except for entertainment. Second, perceptual usefulness has positive effect on intention to buy. Third, According to conformity, personalized service has different effect on perceptual usefulness. The result shows higher in high conformity group than low conformity group. It means e-Learning companies should focus on reference group or special group to effect their marketing strategy on adolescents. Lately, preceded studies investigated using SERVQUAL or SERVERF which were suit to offline. But, this study found e-Learning factors which are suitable to online. So, the factors and the results are more useful to e-Learning companies.

• Journal of Korean Association for Spatial Structures
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• v.6 no.3 s.21
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• pp.59-67
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• 2006

A conventional passive TMD is only effective when it is tuned properly. In many practical applications, inevitable off-tuning of a TMD occurs because the mass in a building floor could change by moving furnishings, people gathering, etc. when TMDs are offtuned, TMDs their effectiveness is sharply reduced. Moreover, the off-tuned nTMDs can excessively amplify the vibration levels of the primary structures. This paper discusses the application of a new class of MR damper, for the reduction of floor vibrations due to machine and human movements. The STMD introduced uses a MR damper called to semi-active damper to achieve reduction in the floor vibration. Here, the STMD and the groundhook algorithm are applied to a single degree of freedom system representative of building floors. The performance or the STMD is compared to that or the equivalent passive TMD. In addition, the effects of off-tuning due to variations in the mass of the floor system. Comparison of the results demonstrates the efficiency and robustness or STMD with respect to equivalent TMD.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.965-972
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• 2014

Attitudes and behavior within the store congestion of the store is a store in any manner affect the formation process of investigating synchronism in the control of the consumer appears to analyze the influence of enemy has its purpose. Store and spatial congestion factor of social behavioral factors also revisit the help of word-of-mouth is. Consumer groups with high and low groups of synchronism suggested. Social attitudes towards the store congestion significantly positive effect that I've shown, it was not significant spatial congestion. During a revisit of action is a statistically significant relationship that I've shown, is a significant effect of word-of-mouth relationship was not significant. Investigating the moderating effects of consumer synchronism result of high consumer groups a significant impact on the social congestion showed, at low spatial influence congestion.

• Journal of Korean Society of Steel Construction
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• v.26 no.3
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• pp.177-189
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• 2014

When floor vibration problems occur in existing buildings, TMD (tuned mass damper) can be a viable alternative to resolving the problem. Only when TMD has been exactly tuned to the natural frequency of the floor, it can control the vibration as intended in design. However, TMD gets inefficient in the situation where the natural frequency changes as a result of the uncontrollable variation of the floor mass weight. This physical phenomenon is often called as TMD-off-tuning. This study proposes asymmetric TMD for enhancing the robustness of floor vibration control against uncertain natural frequencies. The proposed TMD features two asymmetric linear springs such that the floor vibrational energy can be dissipated through both the translational and rotational motion. An easy-to-use graphical optimization method was developed in this study. The asymmetric TMD proposed outperformed in vibration control by 28% compared to that of conventional TMD. The robustness of asymmetric TMD of this study was two times higher than that of conventional TMD.

• The Journal of Society for e-Business Studies
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• v.25 no.4
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• pp.125-141
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• 2020

Recent Studies emphasize the effect of investors attention, recognition and sentiment on the trading behavior of retail investors and stock price variation. In this study, we use Naver Trend to measure investors'attention and investigate the relation between investor attention and price synchronicity, total risk and systematic risk of stocks. Using various research methodologies such as portfolio analysis, fixed effect regression and dynamic panel analysis, we find consistent results. First, stock price synchronicity is increased with lager average search volume, but with less search variability. Second, both average search volume and its variability are positively related to total risk and beta of stocks. These results can be interpreted that search volume sharply increases only when stock-related event occurs.

• The Journal of the Korea Contents Association
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• v.16 no.9
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• pp.339-348
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• 2016

This research attempted to identify factors associated with SNS peer bullying and analyzed the moderating effect of moral disengagement in the relationship between peer conformity and SNS peer bullying. We used multiple regression analysis to test our hypotheses. Results indicated that antisocial peer conformity is positively related with SNS peer-bullying. The effect of antisocial conformity on SNS peer-bullying was higher for those who have higher moral disengagement. Based on these results, this study suggests providing educational programs that target moral disengagement as a strategy to decrease the negative role of antisocial conformity on SNS peer-bullying.