• Journal of Chest Surgery
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• v.24 no.3
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• pp.296-302
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• 1991

Coronary artery involvement and myocardial ischemic symptom in Takayasu`s arteritis is uncommon Its presentation as coronary artery narrowing is a potentially lethal but correctable problem. In this case report, a 17-year-old woman of Takayasu`s arteritis with unstable anginal and moderate heart failure is presented. Her coronary angiogram showed that the main trunk of the left coronary artery was moderately narrowed and the proximal portion of the circumflex branch was severely obstructed and the right coronary artery was also narrowed diffusely. Simultaneously the patient had the moderate degree of mitral regurgitation. In order to save her life, the coronary bypass surgery using the saphenous veins and the modified Wooler`s mitral annuloplasty were done urgently, Immediate recovery was uneventful and the postoperative exercise capacity was markedly improved. But the long-term prognosis seems to be uncertain because of 3 reasons: 1] natural progress and complication of Takayasu`s arthritis; 2] fate of the saphenous vein grafts in a relatively young patient with aortitis; 3] residual mitral regurgitation. So long-term follow-up should be needed.

• Journal of Technology Innovation
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• v.25 no.1
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• pp.61-89
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• 2017

This study aims to estimate empirically the respective impacts of R&D expenditure, R&D labor, overseas direct investment, commodity trade balance, and technology trade openness on technology balance of payments. To examine the presence of co-integration between them, this paper employed the ARDL-bounds test using time series data from 1981 to 2014, and the result shows that there is a stable long-run equilibrium relationship among them. Furthermore, we estimated long- and short-run coefficients of the technology balance of payments with respect to each variables based on long-run equilibrium equation and error correction model. As a result, the technology balance of payments respond negatively to R&D labor and technology trade openness, and R&D expenditure does produce positive effects in the long-run, while coefficients of overseas direct investment and commodity trade balance in the long-run are not statistically significant. Besides, according to results of error correction model, overseas direct investment only has clearly a positive effects in the short-run, in contrast, the short-term relationships between the other variables and the technology balance of payments could not definitively derived. This implies that it is necessary to procure and cultivate talented personnel, as well as to enlarge gradually technology trade size in order to improve technology balance of payments from a long-term point of view.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.23-34
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• 2020

The paper revisits the author's previous paper to examine short-run and long-run dynamic relationships between macroeconomic variables and stock prices in Korea. The data is updated to the period for which monthly data are available from January 1986 to June 2018 (390 observations) retrieved from the Bank of Korea. The results of Johansen cointegration test indicate that at least one cointegrating equation exists, confirming there is a long-run equilibrium relationship between macroeconomic variables and stock prices in Korea. The results of vector error correction estimates confirm that: 1) the coefficient of the error correction term is significant with a negative sign, which is, a long-run dynamic relationship is observed between macroeconomic variables and stock prices; 2) for short-run dynamics, the nominal exchange rate of the Korean won per the US dollar is positively related to stock prices, while interest rates are negatively related to stock prices in the short-run; 3) the coefficient of global financial crises is insignificant, that is, the changes of stock prices are determined largely by their own dynamics in the model. The results suggest only that the global financial crises neither cause instability in the cointegrating vector, nor affect significant changes in the endogenous variables in the model.

• Korean Journal of Remote Sensing
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• v.26 no.4
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• pp.403-410
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• 2010

NDVI(Normalized Difference Vegetation Index), which is broadly used as short-term data composite, is an important parameter for climate change and long-term land surface monitoring. Although atmospheric correction is performed, NDVI dramatically appears several low peak noise in the long-term time series. They are related to various contaminated sources, such as cloud masking problem and wet ground condition. This study suggests a simple method through harmonic analysis for reducing NDVI noise using SPOT/VGT NDVI 10-day MVC data. The harmonic analysis method is compared with the polynomial regression method suggested previously. The polynomial regression method overestimates the NDVI values in the time series. The proposed method showed an improvement in NDVI correction of low peak and overestimation.

• International Area Studies Review
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• v.15 no.2
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• pp.101-123
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• 2011

The paper is basically attempted to reveal the factor price equalization(FPE) on Korea, United States, and Japan by the ARDL-bounds testing. Wage-rental ratio and relative commodity prices between Korea, United States, and Japan are analyzed by employing equality and convergence frameworks. Empirical evidences are shown that necessary and sufficient conditions for the FPE seems to be easily satisfied in a small country such as Korea rather than large ones as like United States and Japan. And, the FPE is more easily achieved by a nominal term rather than the real term. Due to the fact that an error correction term in the Error Correction Model is insignificant, direct mobility of labor and capital between the countries is not that effective to a short run adjustment. It implies that the FPE is in general going through a long run path. It also has to be mentioned that a trade policy has to selectively implemented depending on the weight of trading volumes and it has to be build up by a long run basis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.321-329
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• 2013

Despite the advantage of unlimited access, there are insufficient studies for the accuracy and stability of FKP that blocks the spread of the system for various applications. Therefore, we performed a long-term analysis from continuous real-time positioning, and investigated the error characteristics dependent on the size and the surrounding environment. The FKP shows significant changes in the positioning accuracy at different times of day, where the accuracy during daytime is worse than that of nighttime. In addition, the size and deviation of FKP correction may change with the ionospheric conditions, and high correlation between ambiguity resolution rate and the deviation of correction was observed. The receivers continuously request the correction information in order to cope with sudden variability of ionosphere. On the other hand, the correction information was not received up to an hour in case of stable ionospheric condition. It is noteworthy that the outliers of FKP are clustered in their position with some biases. Since several meters of errors can be occurred for kinematic positioning with FKP, therefore, it is necessary to make appropriate preparation for real-time applications.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1541-1551
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• 2023

Radiometric calibration is a fundamental step in ocean color remote sensing since the step to derive solar radiance spectrum in visible to near-infrared wavelengths from the sensor-observed electromagnetic signals. Generally, satellite sensor suffers from degradation over the mission period, which results in biases/uncertainties in radiometric calibration and the final ocean products such as water-leaving radiance, chlorophyll-a concentration, and colored dissolved organic matter. Therefore, the importance of radiometric calibration for the continuity of ocean color satellites has been emphasized internationally. This study introduces an approach to improve the radiometric calibration algorithm for the visible bands of the Geostationary Ocean Color Imager-II (GOCI-II) satellite with a focus on stability. Solar Diffuser (SD) measurements were employed as an on-orbit radiometric calibration reference, to obtain the continuous monitoring of absolute gain values. Time series analysis of GOCI-II absolute gains revealed seasonal variations depending on the azimuth angle, as well as long-term trends by possible sensor degradation effects. To resolve the complexities in gain variability, an azimuth angle correction model was developed to eliminate seasonal periodicity, and a sensor degradation correction model was applied to estimate nonlinear trends in the absolute gain parameters. The results demonstrate the effects of the azimuth angle correction and sensor degradation correction model on the spectrum of Top of Atmosphere (TOA) radiance, confirming the capability for improving the long-term stability of GOCI-II data.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.583-615
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• 2019

This paper investigates the level of decoupling between greenhouse gas emissions and economic growth in Korea. Despite previous studies mainly stressed the existence of the Environmental Kuznets Curve, the lack of investigations in the level of decoupling constraints further policy suggestions. This study analyzes the level of decoupling in the short- and long-term, focusing on short-term volatility of GHG emissions income elasticity. In the long run, there is no decoupling in Korea because a robust causal relationship exists between GHGs, GDP, and fossil fuels. However, the short-term volatility is clearly identified under the long-term equilibrium(coupling), indicating there is the relative decoupling in the short run. The results show that fossil fuel dependence is a significant factor that increases short-term volatility(decoupling) and breaks the causal link(coupling) between GHGs and GDP.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.11-17
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• 2021

This study aims to know the contribution of external debt to Indonesia's economic growth. The data used a source from the Central Bank of Indonesia from 2011 to 2020. This empirical study uses a quantitative approach with Error Correction Model as the regression method. Government expenditure, government revenue, export, import, inflation, and exchange rate are control variables. The result of the descriptive statistic shows economic growth in Indonesia increased gradually from 2011 to 2020. The increase in economic growth occurred regardless of the contribution of external debt. It does, however, inform the public that Indonesia's economic system has seen successful investments. The result of the study is classified into long-term and short-term. External debt contributes to growth in the long term and has a significant impact. The study's findings will give Indonesia optimism that it can manage external debt as a source of domestic investment. This research may also persuade Indonesia to maintain its economic potency in the future. In the future, this research can be perfected, by adding a threshold level on the amount of Indonesia's external debt.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.561-572
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• 2021

This study aims to analyze the causality between GDP per capita, urbanization, and education. This also aims to determine the long-term and short-term relationships between economic urbanization, education, and GDP per capita by applying Vector Error Correction Model (VECM). Data was obtained from the World Bank and UNDP from 1990 to 2018. The estimation results showed that economic growth and education on urbanization have the strongest causality in VECM. Therefore, they are pull factors with a significant effect in the long and the short term. Some suggestions concerning policy implications were stated, and they include: forming area-based urbanization, where cities within one area are integrated, to get the impact of an agglomeration economy. Also, the government needs to accelerate the distribution of infrastructure and public facilities in various regions to avoid population density in one area due to urbanization, and government needs to pay attention to easier access to education and more equitable ones in various regions. On the contrary, after education is evenly distributed in all regions, the government needs to pay attention to transportation access and infrastructure.