• Korean Management Science Review
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• v.28 no.2
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• pp.1-16
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• 2011

In this study we suggested two optimization models to answer a question from an investor standpoint : how many convertible bonds should one convert, and how many keep? One model minimizes certain risk to the minimum required expected return, the other maximizes the expected return subject to the maximum acceptable risk. In comparison with Markowitz portfolio models, which use the variance of return, our models used Conditional Value-at-Risk(CVaR) for risk measurement. As a coherent measurement, CVaR overcomes the shortcomings of Value-at-Risk(VaR). But there are still difficulties in solving CVaR including optimization models. For this reason, we adopted Rockafellar and Uryasev's[18, 19] approach. Then we could approximate the models as linear programming problems with scenarios. We also suggested to extend the models with credit risk, and applied examples of our models to Hynix 207CB, a convertible bond issued by the global semiconductor company Hynix.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.99.5-99
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• 2001

This study presents a simulation of the traction return current based on $2{\times}25kV$ power supply system in order to determine the impedance bond intensity of impulse type track circuit on the electrified Gyeongbu line. The results of the simulation enables us to measure the precise intensity of catenary current that returns to the substation through KTX (Korean Train Express) operated by $2{\times}25kV$ power supply system with common earth network. The combination of $2{\times}25kV$ and common earth network established on the electrified Gyeongbu line for the first time in Korea. We show that the relationships among the traction return current, earth current, and catenary current, and catenary current can be applied to this line in order to determine the optimal impedance bond intensity ...

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.123-126
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• 2001

This study presents the simulation of the traction return current based on 2${\times}$25kV power supply system in order to determine the impedance bond intensity of impulse type track circuit on the Kyoungbo electrification line. The results of simulation enables us to measure the precise intensity of catenary current, returning to the substation through KTX (Korean Train Express) operated by 2${\times}$25kV power supply system with common earth network. In the wake of establishing 2${\times}$25kV and common earth network used in Korea for the first time, in particular, it is possible to determine the impedance bond intensity of impulse type track circuit, which is applicable to the Kyoungbo electrification line by specifying the relations among the traction return current, earth current, and catenary current.

• Textile Coloration and Finishing
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• v.10 no.4
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• pp.53-61
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• 1998

The absorptions of ultraviolet rays of benzophenone derivatives were investigated in terms of the position of substituent, especially hydroxyl group. When the derivatives were added to the aqueous solution of Rhodamin B, which has very low light-fastness, all of them delayed the photofading of Rhodamin B solution. But on the fabrics, only the derivatives with the hydroxyl group at 2-position showed the good ability of ultraviolet rays absorption. The benzophenone derivatives absorb ultraviolet rays to form a hydrogen bond between hydroxyl group and carbonyl group, and return to their original structure by releasing heat energy. In solution, the derivatives can form a intermolecular hydrogen bond, and absorb the ultraviolet rays. But on the fabric, the intermolecular hydrogen bond is impossible, only hydroxyl group of 2-position forms a intramolecular hydrogen bond, and that makes the derivatives on the fabric absorb ultraviolet rays.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.15-25
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• 2020

This empirical research aims to identify the relationship between fiscal and financial macroeconomic fundamentals and the volatility of government bonds' borrowing cost in an emerging country - Vietnam. The study covers the period from July 2006 to December 2019 and it is based on a sample of 1-year, 3-year, and 5-year government bonds, which represent short-term, medium-term and long-term sovereign bonds in Vietnam, respectively. The Generalized AutoRegressive Conditional Heteroskedasticity (GARCH) model and its derivatives such as EGARCH and TGARCH are applied on monthly dataset to examine and suggest a significant effect of fiscal and financial determinants of bond yield volatility. The findings of this study indicate that the variation of Vietnam government bond yields is in compliance with the theories of term structure of interest rate. The results also show that a proportion of the variation in the yields on Vietnam government bonds is attributed to the interest rate itself in the previous period, base rate, foreign interest rate, return of the stock market, fiscal deficit, public debt, and current account balance. Our results could be helpful in the macroeconomic policy formulation for policy-makers and in the investment practice for investors regarding the prediction of bond yield volatility.

• Communications for Statistical Applications and Methods
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• v.21 no.5
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• pp.445-459
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• 2014

This paper investigates the dependence structure of Korean financial markets (stock, foreign exchange (FX) rates and bond) using copula-GARCH and dynamic conditional correlation (DCC) models. We examine GJR-GARCH with skewed elliptical distributions and four copulas (Gaussian, Student's t, Clayton and Gumbel) to model dependence among returns, and then employ DCC model to describe system-wide correlation dynamics. We analyze the daily returns of KOSPI, FX (WON/USD) and KRX bond index (Gross Price Index) from $2^{nd}$ May 2006 to $30^{th}$ June 2014 with 2,063 observations. Empirical result shows that there is significant asymmetry and fat-tail of individual return, and strong tail-dependence among returns, especially between KOSPI and FX returns, during the 2008 Global Financial Crisis period. Focused only on recent 30 months, we find that the correlation between stock and bond markets shows dramatic increase, and system-wide correlation wanders around zero, which possibly indicates market tranquility from a systemic perspective.

• Journal of Service Research and Studies
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• v.10 no.4
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• pp.71-88
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• 2020

CB(Convertible bond) is mezzanine security that have the characteristics of bonds and stocks. From the perspective of investors, the purpose of the research is to empirically investigate the degree of investment efficiency of CB and to suggest efficient investment plans. The research method investigated the maturity interest rate, conversion price, and conversion date for CB, and then linked it with daily stock price fluctuations after the conversion date to determine the degree of investment efficiency and stock conversion effect of CB. As a result of the study, it was analyzed that the ratio of the conversion price exceeded days was only about 1/4 of the conversion date, so the investment efficiency was low. The conversion day yield was -6.3% on average and the maturity day yield was -5.2% on average, showing a minus return on average, which was calculated differently from investor expectations. It was analyzed that the number of stocks with a minus conversion day is 2.4 times greater than the number of plus stocks and 3.7 times more than the number of plus stocks with a minus maturity return, so the expected return on stock conversion of CB is low. The research contribution was derived from the problem that the expected rate of return of CB is not high, and it is that the investor's point of view when purchasing CB was established.

• Plant Journal
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• v.11 no.1
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• pp.30-38
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• 2015

This study is about whether the new Project Finance scheme called "Asset Backed Short Term Bond(ABSTB)" with Project Finance Guarantee Cover provided by Korean Exim Bank(KEXIM) is an appropriate and valid financing structure, through close examinations on domestic and overseas IPP case studies. This study clearly indicates that (i) the interest rate of ABSTB with KEXIM's Project Finance Guarantee is relatively more competitive than the interest rate of other ABSTB guaranteed by EPC Companies (ii) the lower credit rated EPC companies make higher ROE(Return on Equity) through this financing structure. Lastly, Korean EPC Companies can secure profitability through this innovative financing scheme which will also lead to winning more power plant Contracts and become globally competitive.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.113-124
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• 2021

The study investigates how financial markets respond to a shock to tone and semantic similarity of the Bank of Thailand press releases. The techniques in natural language processing are employed to quantify the tone and the semantic similarity of 69 press releases from 2010 to 2018. The corpus of the press releases is accessible to the general public. Stock market returns and bond yields are measured by logged return on SET50 and short-term and long-term government bonds, respectively. Data are daily from January 4, 2010, to August 8, 2019. The study uses the Structural Vector Auto Regressive model (SVAR) to analyze the effects of unanticipated and temporary shocks to the tone and the semantic similarity on bond yields and stock market returns. Impulse response functions are also constructed for the analysis. The results show that 1-month, 3-month, 6-month and 1-year bond yields significantly increase in response to a positive shock to the tone of press releases and 1-month, 3-month, 6-month, 1-year and 25-year bond yields significantly increase in response to a positive shock to the semantic similarity. Interestingly, stock market returns obtained from the SET50 index insignificantly respond to the shocks from the tone and the semantic similarity of the press releases.

• Journal of the Korean Data and Information Science Society
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• v.14 no.4
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• pp.805-815
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• 2003

This study examines two hypothesis regarding return generating process of corporate bonds: the trading day hypothesis and calendar day hypothesis. To differentiate two hypothesis ANOVA(analysis of variance) and regression analysis were used. If the statistical result can not reject calendar day hypothesis, it implies that there is weekend effect. The statistical result didn't support any particular hypothesis for the period of September 7th, 1999 through December 31, 2002. However, corporate bonds were supporting calendar day hypothesis for the period of October 9, 2000 through December 31, 2002. The result indicates that the Korean corporate bond market got through the impact of IMF.