• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.4
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• pp.35-52
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• 2013

Markowitz's portfolio selection model is used to construct an optimal portfolio which has minimum variance, while satisfying a minimum required expected return. The model uses estimators based on analysis of historical data to estimate the returns, standard deviations, and correlation coefficients of individual stocks being considered for investment. However, due to the inaccuracies involved in estimations, the true optimality of a portfolio constructed using the model is questionable. To investigate the effect of estimation inaccuracy on actual portfolio performance, we study the changes in a portfolio's realized return and standard deviation as the accuracy of the estimations for each stock's return, standard deviation, and correlation coefficient is increased. Furthermore, we empirically analyze the portfolio's performance by comparing it with the performance of active mutual funds that are being traded in the Korean stock market and the KOSPI benchmark index, in terms of portfolio returns, standard deviations of returns, and Sharpe ratios. Our results suggest that, among the three input parameters, the accuracy of the estimated returns of individual stocks has the largest effect on performance, while the accuracy of the estimates of the standard deviation of each stock's returns and the correlation coefficient between different stocks have smaller effects. In addition, it is shown that even a small increase in the accuracy of the estimated return of individual stocks improves the portfolio's performance substantially, suggesting that Markowitz's model can be more effectively applied in real-life investments with just an incremental effort to increase estimation accuracy.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.374-384
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• 2014

In this paper, characteristics of transactions by investors were examined based on the relationship between South Korea's stock market trends and the amount of net purchasing by investors. The study period is from January of 2004 to December of 2011, a total 1,991 days on 96 months. Data used for correlation and regression analysis include the value of the KOSPI index at the end of each month, the monthly net purchase amount of each of the groups, as well the daily volume, the daily price. In this study, the long-term phase of the market divided by refining. and each of the investment position of invest group was investigated. As a result, foreign investors are a net selling position when market was rising phase of the tertiary. And private investors were a net short positions when the market was decline phase of the tertiary. Regardless of the flow changes, the private investors had opposite position to the flow of the mark, also they had opposite position to the position of the foreign investors.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.155-161
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• 2016

In current algorithm trading system, general users need to program their algorithms using programing language and APIs provided from financial companies. Therefore, such environment keeps general personal investors away from using algorithm trading. Therefore, this paper focuses on developing user-friendly algorithm trading system which enables general investors to make their own trading algorithms without knowledge on program language and APIs. In the system, investors input their investment criteria through user interface and this automatically creates their own trading algorithms. The proposed system is composed with two parts: server intercommunicating with financial company server to send and to receive financial informations for trading, and client including user convenience-based user interface representing secondary indexes and strategies, and a part generating algorithm. The proposed system performance is proven through simulated-investment in which user sets up his investment strategy, algorithm is generated, and trading is performed based on the algorithm

• Journal of Industrial Convergence
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• v.20 no.6
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• pp.135-140
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• 2022

In the domestic stock market, the capital market opened in January 1992, and the proportion of foreign capital has steadily increased, accounting for 30% of the domestic market in Overall stock market trend infers that the domestic stock market is more influenced by foreign issues than domestic issues. The trading trend of foreign capital displays a similar flow to exchange rate fluctuations,; thus, preparing an investment strategy by using the Pearson analyzing method the effect of exchange rates of foreign capital trading, fluctuations in exchange rates, and predicting one of the macroeconomic indicators will yield high returns in the stock market. Therefore, this research was conducted to help investment by predicting foreign variables comparing and analyzing exchange rates and foreign capital trading patterns, and predicting appropriate time for buying and selling.

• Journal of Korea Trade
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• v.25 no.2
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• pp.95-110
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• 2021

Purpose - This paper intends to conduct theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI to China on green total factor productivity, so as to provide a new perspective and ideas for the improvement of China's green total factor productivity and promote the high-quality development of China's economy Design/methodology - This paper uses the data of 30 provinces, autonomous regions and municipalities in China from 2004 to 2017 as the research sample, adopts the GML index method of SBM Directional Distance Function to measure GTFP, and analyzes the influence of South Korea-China trade and FDI from South Korea on China's GTFP. Findings - Trade is conducive to promoting technological progress, which has a significant promotion effect on China's green total factor productivity. While FDI has a significant inhibitory effect on China's green total factor productivity, which verifies the "pollution haven" hypothesis. In addition, such influence has certain regional overall heterogeneity. Trade has a more significant promoting effect on GTFP in eastern coastal areas, while FDI has a more significant inhibitory effect on GTFP in central and western inland areas. The interaction between trade and FDI is conducive to the improvement of green total factor productivity, indicating that the benign mechanism of trade and FDI has been formed. Urbanization, industrial structure, human resource level and investment in science and technology are all conducive to the improvement of GTFP. Originality/value - Through theoretical analysis and empirical test on the action mechanism of South Korea-China trade and South Korea's FDI on green total factor productivity, this paper provides a solid theoretical foundation for the further development of China-South Korea economic and trade cooperation in the future.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.25-43
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• 2022

Purpose - This study is to investigate the direct and moderating effect of intangible variable like economic freedom to facilitating factors on FDI(foreign direct investment) inflows and the difference of facilitating factors by the stage of economic development. Design/methodology/approach - Fixed-effect panel regression analysis with 19-year macro economic data from 2000 to 2019 including economic freedom index from Fraser Institute in 13 developed and 15 developing countries was used. Research implications or Originality - In analysis of direct effect of 5 sectors in economic freedom, the influence of economic freedom was shown weaker than other macro economic factors on FDI inflows, which indicates that actual development of economic factors are more important. The effect of economic freedom on FDI inflows at the stage of economic development differed. In developed countries, human capital, GDP, export, free trade and regulation affected FDI inflows in decreasing order, as did human capital, GDP, consumption expenditure, export, investment expenditure, government expenditure, free trade and sound money in developing countries. In analysis of moderating effect of economic freedom, a domestic and international market size, a flexible labor market which can provide a cheaper good human resources and government expenditures for improving social infrastructure under free economic environment facilitated FDI inflows. However, the statistical significance of moderating effect on export was not shown, which indicates that economic freedom policy itself without actual improvement of exports could not attract FDI inflows.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.171-184
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• 2023

Purpose: First, this paper suggests an alternative approach to find optimal portfolio (stocks, bonds and ESG stocks) under the maximizing utility of investors. Second, we include ESG stocks in our optimal portfolio, and compare improvement of welfares in the case with and without ESG stocks in portfolio. Methods: Our main method of analysis follows Brennan et al(2002), designed under the continuous time framework. We assume that the dynamics of stock price follow the Geometric Brownian Motion (GBM) while the short rate have the Vasicek model. For the utility function of investors, we use the Power Utility Function, which commonly used in financial studies. The optimal portfolio and welfares are derived in the partial equilibrium. The parameters are estimated by using Kalman filter and ordinary least square method. Results: During the overall analysis period, the portfolio including ESG, did not show clear welfare improvement. In 2017, it has slightly exceeded this benchmark 1, showing the possibility of improvement, but the ESG stocks we selected have not strongly shown statistically significant welfare improvement results. This paper showed that the factors affecting optimal asset allocation and welfare improvement were different each other. We also found that the proportion of optimal asset allocation was affected by factors such as asset return, volatility, and inverse correlation between stocks and bonds, similar to traditional financial theory. Conclusion: The portfolio with ESG investment did not show significant results in welfare improvement is due to that 1) the KRX ESG Leaders 150 selected in our study is an index based on ESG integrated scores, which are designed to affect stability rather than profitability. And 2) Korea has a short history of ESG investment. During the limited analysis period, the performance of stock-related assets was inferior to bond assets at the time of the interest rate drop.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.691-702
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• 2022

This study verifies the diversification effect when non-financial asset such as fractional music royalties investment which is recently get interest from masses, is included in traditional global asset allocation portfolio. From Jan 2019 when Music Royalties index is announced to Jun 2022, compared traditional global asset allocation portfolio and the portfolio included with music royalties. To eliminate the enhancement effect from portfolio strategy itself rather than including non-financial asset, used the four basic portfolio strategy such as buy & hold, constant rebalanced, mean variance, risk parity. As a result, all the portfolios included with music royalties shows less risk with higher returns. This means the sharpe ratio has enhanced and that results the portfolio diversification effect is placed. The empirical analysis of the study found academic significance in that the portfolio included with music royalties investment has diversification effect, and show the possibilities the not only on the music royalties, other non-financial asset can be shown the portfolio diversification effect.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.133-145
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• 2023

This paper examines whether investors have adapted to the venture capital(VC) investment style. VC firms invest in privately held companies and generate returns by selling them after the lock-up period expires. We analyze the impact on stock prices before and after the lock-up period expiration, and compare the Cumulative Abnormal Return(CAR) between the past period(2015-2017) and the recent period(2020-2022) to investigate the effect of the second venture boom. The main findings are as follows. First, unlike in the past, stock price returns around the lock-up period expiration have been lower than the KOSDAQ index in recent years. Second, the impact on stock prices is significant for both 1-month and 12-month lock-up periods. Specifically, it is confirmed that stocks held by venture capital and professional investors with a 1-month lock-up period respond in advance to their information after the second venture boom. Finally, we find that there is a difference in CAR depending on whether or not the company received VC investment after the second venture boom. Based on our findings, we suggest that VC firms need to revise their exit strategies to improve performance. This includes finding ways to reduce information asymmetry and fees, as well as developing strategies to mitigate market volatility. Additionally, the current lock-up period for VCs should be reconsidered as it may increase the risk of stock price decline. We recommend that the government revise the scope and duration of lock-up periods to protect investors after IPO.

• Journal of Korean Society of Rural Planning
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• v.22 no.2
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• pp.121-129
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• 2016

A disaster can be defined in many ways based on perspectives, in addition, its types are able to classify differently by various standards. Considering the different perspectives, the disaster can be occurred by natural phenomenon that is like typhoon, earthquake, flood, and drought, and by the accident that is like collapse of facilities, traffic accidents, and environmental pollution, etc. Into the modern society, moreover, the disaster includes the damages by diffusion of epidemic and infectious disease in domestic animals. The disaster was defined by natural and man-made hazards in the past. As societies grew with changes of paradigm, social factors have been included in the concept of the disaster according to new types unexpected by new disease and scientific technology. Change the concept of social disasters, Ministry of Public Safety and Security (MPSS) has provided the regional safety index, which measures the safety level of a local government. However, this regional safety index has some limitation to use because this index provides the information for city unit which is a unit of administrative districts of urban. Since these administrative districts units are on a different level with urban and rural areas, the regional safety index provided by MPSS is not be able to direct apply to the rural areas. The purpose of this study is to determine the regional safety index targeting rural areas. To estimate the safety index, we was used for 3 indicators of the MPSS, a fire, a crime, and an infectious disease which are evaluable the regional safety index using an accessibility analysis. For determining the regional safety index using accessibility from community centers to public facilities, the safety index of fire, crime, and infectious disease used access time to fire station, police office, and medical facility, respectively. An integrated Cheongju, targeting areas in this study, is mixed region with urban and rural areas. The results of regional safety index about urban and rural areas, the safety index in rural area is relatively higher than in the urban. Neverthless the investment would be needed to improve the safety in the rural areas.