• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.1228-1233
• /
• 2002

This study is aimed to evaluate a tunneling effect in association with the measurement of sound transmission loss. Based on the formulation for sound transmission loss of a finite panel in the presence of tunnel, variations of the sound transmission loss with parameters such as the location of panel and tunnel depth are investigated. It can be seen that differences in the sound transmission loss are quite evident below coincidence frequency and the sound transmission loss greatly depends on panel location in the tunnel. In comparison with the case without a tunnel, maximum difference occurs in the case where the panel is placed on the center of the tunnel and the flushing with the end of the tunnel gives the better estimation of transmission loss.

• Proceedings of the KAIS Fall Conference
• /
• 2009.05a
• /
• pp.870-873
• /
• 2009

본 연구에서는 미세 무광부식 패턴을 갖는 HD Switch Panel 부품을 설계하고 금형을 제작하였다. 이를 위하여 사출성형 Simulation(CAE)을 이용하여 사출성형 공정의 문제점과 부품의 변형량을 예측 하였다. 또한 금형표면의 가열온도와 실제 금형온도의 비교함으로써 공정변수 조절을 통한 사출성형 조건의 최적화를 달성할 수 있었다. 한편, 순간금형표면가열을 이용한 성형기술인 E-MOLD를 적용하여 자동차 내장부품용 HD Switch Panel을 제작하였고, 전자현미경과 원자현미경을 이용한 표면 평가를 통하여 무광부식 패턴의 전사율 향상으로 인한 무광 특성이 향상됨(2.5이상$\rightarrow$1.5~1.7)을 확인하였다.

• Health Policy and Management
• /
• v.25 no.3
• /
• pp.152-161
• /
• 2015

We analyze the determinants of obesity and the chronic diseases using the Korea Health Panel data. Also we analyze the effect of obesity and the chronic diseases on the health care expenditures. Through this study, to reduce the health care expenditures, we suggest the policy implication that might curb the obesity and the chronic diseases. We estimate the determinants of obesity, the chronic diseases, and the health care expenditures using 2SLS (two stage least squares) estimation method under the simultaneous equations framework. Result says that obesity and chronic diseases significantly have positive effects on the health care expenditures. Also the determinants of the health care expenditures that have positive effects are age, income and health care utilization variables.

• Korea Trade Review
• /
• v.44 no.2
• /
• pp.173-188
• /
• 2019

The purpose of this study is to investigate the causal relationship between the logistics industry and the economic growth in Korea, and to provide implications for the contribution of the logistics industry to economic growth. Unlike Previous Related Studies, we derive short-term and long-term effects through dynamic panel analysis such as panel Granger causality test and impulse response function estimation using panel vector error correction model. The results of the empirical analysis are as follows: Labor input of the logistics industry has the greatest positive impact on economic growth. And capital input and total sales of the logistics industry have a negative effect on economic growth. This means that Korea's logistics industry features labor-intensive growth. In addition, We have also found that the growth (sales) and capital input of the logistics industry have not yet had a direct positive impact on economic growth. Therefore, the results of this analysis provide implications for the direction of logistics industry policy to enhance contribution of the logistics industry to economic growth.

• Proceedings of the Korean Statistical Society Conference
• /
• 2002.11a
• /
• pp.265-272
• /
• 2002

An Integer-valued autoregressive integrated (INARI) model is introduced to eliminate stochastic trend and seasonality from time series of count data. This INARI extends the previous integer-valued ARMA model. We show that it is stationary and ergodic to establish asymptotic normality for conditional least squares estimator. Optimal estimating equations are used to reflect categorical and serial correlations arising from panel count data and variations arising from three random processes for obtaining observation into estimation. Under regularity conditions for martingale sequence, we show asymptotic normality for estimators from the estimating equations. Using cancer mortality data provided by the U.S. National Center for Health Statistics (NCHS), we apply our results to estimate the probability of cells classified by 4 causes of death and 6 age groups and to forecast death count of each cell. We also investigate impact of three random processes on estimation.

• Journal of Korea Trade
• /
• v.23 no.2
• /
• pp.76-87
• /
• 2019

Purpose - This study empirically analyzes the effects of the European Union-South Korea Free Trade Agreement on Korean exports in major sectors. Design/Methodology - This study is based on the augmented gravity model with a panel data set covering 51 countries between the years 2000 and 2015. Findings - Main findings of the present study is that the agreement has affected the chemical sector the most. Fixed effects estimation predicted a positive trade effect of 38.3%, while Poisson maximum likelihood estimation predicted an impact of 4.75% in the chemical export sector. Regression results for the other sectors only show insignificant effects. Originality/value - The findings imply that the effects of the EU-South Korea free trade agreement on the Korean exports are quite specific compared to the European ones, meaning that the Korean government should focus on sector-specific programs to maximize the welfare benefits of the free trade agreement.

• Journal of Korean society of Dental Hygiene
• /
• v.21 no.3
• /
• pp.245-253
• /
• 2021

Objectives: The objective of this paper was to estimate a South Korean's lifetime dental expenditures for periodontitis. Methods: For our study, we collected data from the Korea Health Panel Survey (KHPS), from 2010 to 2016. The outpatient dental care data of 1,919,608 samples of periodontitis were extracted using R version 3.0 and estimations of lifetime dental expenditures for them were generated using Excel. Results: Over 50% of the lifetime dental expenditure of South Koreans was spent for periodontitis, and incurred after the age of 40. The results showed that an estimate of average per capita lifetime dental expenditure for men (approximately 13 million won) was greater than that for women (approximately 8.8 million won) for periodontitis. Conclusions: Efficient methods for the prevention and management of periodontitis are necessary, and a new paradigm of health care system is required to reduce dental expenditure through its prevention.

• The Korean Journal of Applied Statistics
• /
• v.24 no.1
• /
• pp.11-23
• /
• 2011

Robust unit root tests are developed for dynamic panels consisting of TAR processes. The test statistics are all based on diverse combinations of individual t-type tests for significance of TAR coefficients. Limiting null distributions are established. A Monte-Carlo experiment compares the proposed tests. The tests are applied to a panel data set of Canadian unemployment rates which show asymmetric features as well as having outliers.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.419-420
• /
• 2009

• The Journal of Industrial Distribution & Business
• /
• v.8 no.2
• /
• pp.5-10
• /
• 2017

Purpose - The purpose of this paper was to analyze the Chinese government's announcement of the RMB's appreciation on July 1, 2010, and its aim was to ascertain whether the appreciation has affected Chinese export prices by empirically measuring the degree of the exchange rate pass-tough on those prices. Research design, data, and methodology - Using 73 HS trade categories with cross-industry and time-series data, the panel estimation of a fixed-effects model has been applied to measure the degree and stability of any exchange rate pass-through effects. The estimation results show that the export prices of most trade categories were affected by the exchange rate changes. The pass-through effect was generally small, at about -0.485, and statistically significant in most export prices. Results - The empirical results indicate that China would lose its advantage and competitiveness in export if the RMB were appreciated continuously and rapidly because its export goods would no longer operate under strong monopolistic competition. Conclusions - The implications for China's exchange rate policy suggest that it would be better for the RMB to appreciate slowly and gradually rather than radically. It is clear that it would be allow the capital free flow in Chinese overall economic interest to reduce the continuous appreciation pressure on the currency and pave the way for improvements in export distribution competitiveness.