• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.377-382
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• 2010

건물의 대형화 고층화로 고강도 콘크리트의 사용이 증대되면서 고강도 콘크리트의 화재 시 폭열 대책이 필요하다. 본 연구는 전국 화력발전소에서 매립되는 Bottom Ash와 EPS를 재활용하여 건축소재의 내화기준에 만족하고 자원순환 소재의 새로운 개발방향을 제시하고자 난연성이 가미된 경량콘크리트 패널을 개발하여 그 난연 성능 및 벽체로서의 성능을 실험하였다. 실험은 Bottom Ash를 활용한 코팅 경량골재를 2개 Type으로 개발하여 단위중량, Flow, 압축강도, 열전도율, 부착강도, 건조수축, 흡수율, 난연 성능을 평가하였다. 그 결과 대부분의 데이터가 KS기준에 맞게 나왔으며, 난연 성능 또한 1급으로 나왔다. 이로서 폐자재인 Bottom Ash와 EPS를 재활용하여 화재 시 난연성능이 확보됨은 물론 국가성장핵심 사업인 녹색성장에 걸맞은 새로운 경량콘크리트 패널을 개발할 수 있게 되었다.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.256-264
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• 2018

This study performed statistical matching using population census microdata and financial panel data. It generated the national basic data for simulation including income and property. Using this data the basic old-age pension, which is one of the biggest benefits, simulation was performed by applying the micro simulation methodology. In addition, we verified the coherence of the analysis results by comparing simulation basic data and financial panel data, basic old-age pension pilot simulation analysis results and basic old&-age pension actual beneficiary data.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.385-394
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• 2012

This study investigates whether earnings management behavior of chaebol firms differ from that of non-chaebol firms. The ownership structure of chaebol firms is characterized by the dominance of one largest shareholder and his family members who typically participate in the management of the firm directly or indirectly and influence most of the important management decision. This study adopts the random effect model and the hausman and talyor model, using a panel of 5092 firm-year over a period from 1991 to 2010 to control for potential heterogeneity and endogeneity that may cause sever bias. This study finds that there is no difference in accrual based earnings management level between chaebol firms and non-chaebol firms. However, chaebol firms appeared to engage less real earnings management that is known to negatively affect future earnings and share prices. The results are consistent when controlling for potential heterogeneity and endogeneity in the hausman and taylor model. The results may be of interest to various stakeholders, policy makers, standard setters and academic researchers.

• The Journal of Korean Association of Computer Education
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• v.17 no.6
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• pp.103-113
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• 2014

This study designed and implemented a query model for consecutive analyses of dynamic multivariate graph data. First, the query model consists of two procedures; setting the discriminant function, and determining an alteration method. Second, the query model was implemented as a query system that consists of a query panel, a graph visualization panel, and a property panel. A Node-Link Diagram and the Force-Directed Graph Drawing algorithm were used for the visualization of the graph. The results of the queries are visually presented through the graph visualization panel. Finally, this study used the data of worldwide import & export data of small arms to verify our model. The significance of this research is in the fact that, through the model which is able to conduct consecutive analyses on dynamic graph data, it helps overcome the limitations of previous models which can only perform discrete analysis on dynamic data. This research is expected to contribute to future studies such as online decision making and complex network analysis, that use dynamic graph models.

• Environmental and Resource Economics Review
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• v.25 no.1
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• pp.89-112
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• 2016

In this paper, as a determining factor of the Environment Kuznets Curve hypothesis, we analyzed the impact of technological innovation. In this paper, in order to empirically validate the role of technological innovation to an inverted U-shaped Environments Kuznets Curve hypothesis, we utilize the 2SLS considering relationship between R&D and the GDP per capita. Also, using the Panel VAR (Panel Vector Auto Regression) model to analyze with what time lag R&D per capita has impact on the emissions of greenhouse gases per capita. Empirical results show that R&D per capita(proxy of innovation) is a important factor to explain Environmental Kuznets Curve hypothesis, and that the external shock such as R&D per capita reduces greenhouse gas emissions per capita with about 3 time lag.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.77-82
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• 2019

The purpose of this study is to analyze the relationship between the controlling shareholding ratio and the business diversification of savings banks The difference in this study is the analysis of the relationship between the controlling shareholding ratio of the savings bank and the business diversification using panel data. In this study, the semi-annual financial statements for the period 2014-2018 were used on the basis of a sample of 79 saving banks. The research model is analyzed using random effects generalized linear square (GLS) model considering the autocorrelation problem. As a result of the empirical analysis, it is estimated that the relationship between the controlling shareholding ratio of the savings bank and the business diversification is significant (+). This is the result of supporting the hedging hypothesis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.491-497
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• 2018

This study analyzes the relationship between R&D input and performance using panel data from the defense industry. A research model is established based on the R&D logic model, and the study sample consists of a strongly balanced panel data (n=351) empirically analyzed using panel linear regression. Results identified that defense improvement expenditure has a positive influence on the R&D input, and R&D input positively affected patents using a 5-year time lag. In addition, R&D input positively impacts economic performance, including sales and profit. Hence, the major finding includes R&D inputs have statistically significant effects on economic outcome and the R&D logic model featuring a time-lag.

• Journal of Convergence for Information Technology
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• v.12 no.4
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• pp.286-302
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• 2022

This study examined the dynamic role that automation has had upon employment, productivity, and profitability. For the analysis, 342 companies of the Workplace Panel Survey of the Korea Labor Institute conducted from 2005 to 2015 was used. For analytical models, the fixed effect model, which is capable of controlling the endogeneity problems of variables, was used. According to the analysis results, the increased ratio of automation in Korean companies (1) resulted in the increase of turnover in the short and long terms, a temporary decrease in employment, and (2) a decrease of productivity in the short and medium terms, and thereby (3) failing to change profitability in a positive manner.

• The Korean Journal of Applied Statistics
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• v.35 no.6
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• pp.703-724
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• 2022

Although longitudinal studies mainly produce multivariate longitudinal data, most of existing statistical models analyze univariate longitudinal data and there is a limitation to explain complex correlations properly. Therefore, this paper describes various methods of modeling the covariance matrix to explain the complex correlations. Among them, modified Cholesky decomposition, modified Cholesky block decomposition, and hypersphere decomposition are reviewed. In this paper, we review these methods and analyze Korean children and youth panel (KCYP) data are analyzed using the Bayesian method. The KCYP data are multivariate longitudinal data that have response variables: School adaptation, academic achievement, and dependence on mobile phones. Assuming that the correlation structure and the innovation standard deviation structure are different, several models are compared. For the most suitable model, all explanatory variables are significant for school adaptation, and academic achievement and only household income appears as insignificant variables when cell phone dependence is a response variable.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.253-261
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• 2001

화장품의 사용감은 개개인에 따라 다양한 기호를 나타내며 상대적이고 감성적인 개념들이 우선하게 된다. 이러한 관능특성들을 보다 객관적이며, 과학적으로 고찰하고자 하는 연구분야가 바로 관능평가이다. 본 연구에서는 메이크업 단계 중 베이스 메이크업에 속하는 제품인 파운데이션의 관능 특성을 보다 객관적이며 신뢰성 있게 평가, 분석하는 전문패널 평가 시스템을 구축하기 위하여 사내 여성을 대상으로 discriminative 및 descriptive 테스트를 실시하였다. 이를 통해 적합한 패널을 선정하였고 일정하게 규정된 일련의 교육과정들을 통해 패널을 훈련시킴으로써 베이스 메이크업 전문 패널 평가 시스템을 구축하였다. 그 후 파운데이션에 대해 질감별 제품을 평가하도록 한 후 이러한 방법으로 수집된 데이터를 신뢰성 있는 통계적 분석법을 이용하여 제품의 사용감 특성이 위치되니 2차원적 공간영역과 제품별 사용감의 특성을 분석하였다. 그 후 분석된 결과를 자사 브랜드 메이크업 라인의 파운데이션 제품에 응용하여 제품을 차별화 시키도록 설계하고 질감별 특징적 사용감과 적합한 특성강도를 제시한 후 이를 나타내는 처방의 제품을 결정하였다. 최종적으로 출시된 제품을 실제 소비자들을 통해 기호형 관능평가를 다시 한번 실시하였으며, 그 결과 실제 느끼는 사용감각 특성과 상품개발 계획 시 소구하고자 했던 관능특성이 일치하게 나타나 사용감 설계의 객관성을 검증하였다. 따라서, 본 연구는 이와 같은 결과를 통해 관능평가를 제품개발에 응용한 활용방안으로 보고자 하였다.