• Journal of applied mathematics & informatics
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• v.5 no.3
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• pp.805-810
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• 1998

In this paper we set the stock price model in security market when the price process is a continuous semartingale and find a unigue solution of price process model.

• Journal of Distribution Science
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• v.13 no.5
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• pp.71-82
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• 2015

Purpose - The purpose of this study is to investigate risk price implied from the pricing kernel of Korean stock distribution market. Recently, it is considered that the quantitative easing programs of major developed countries are contributing to a reduction in global uncertainty caused by the 2007~2009 financial crisis. If true, the risk premium as compensation for global systemic risk or economic uncertainty should show a decrease. We examine whether the risk price in the Korean stock distribution market has declined in recent years, and attempt to provide practical implications for investors to manage their portfolios more efficiently, as well as academic implications. Research design, data and methodology - To estimate the risk price, we adopt a non-parametric method; the minimum norm pricing kernel method under the LOP (Law of One Price) constraint. For the estimation, we use 17 industry sorted portfolios provided by the KRX (Korea Exchange). Additionally, the monthly returns of the 17 industry sorted portfolios, from July 2000 to June 2014, are utilized as data samples. We set 120 months (10 years) as the estimation window, and estimate the risk prices from July 2010 to June 2014 by month. Moreover, we analyze correlation between any of the two industry portfolios within the 17 industry portfolios to suggest further economic implications of the risk price we estimate. Results - According to our results, the risk price in the Korean stock distribution market shows a decline over the period of July 2010 to June 2014 with statistical significance. During the period of the declining risk price, the average correlation level between any of the two industry portfolios also shows a decrease, whereas the standard deviation of the average correlation shows an increase. The results imply that the amount of systematic risk in the Korea stock distribution market has decreased, whereas the amount of industry-specific risk has increased. It is one of the well known empirical results that correlation and uncertainty are positively correlated, therefore, the declining correlation may be the result of decreased global economic uncertainty. Meanwhile, less asset correlation enables investors to build portfolios with less systematic risk, therefore the investors require lower risk premiums for the efficient portfolio, resulting in the declining risk price. Conclusions - Our results may provide evidence of reduction in global systemic risk or economic uncertainty in the Korean stock distribution market. However, to defend the argument, further analysis should be done. For instance, the change of global uncertainty could be measured with funding costs in the global money market; subsequently, the relation between global uncertainty and the price of risk might be directly observable. In addition, as time goes by, observations of the risk price could be extended, enabling us to confirm the relation between the global uncertainty and the effect of quantitative easing. These topics are beyond our scope here, therefore we reserve them for future research.

• Journal of Navigation and Port Research
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• v.47 no.2
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• pp.100-105
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• 2023

This study investigated determinants of stock betas of shipping companies in Korea. Beta is a measurement of sensitivity of an individual stock to the movement of the whole stock market. It is widely accepted that stock betas are not constant, but time-varying, which implies that they are affected by other factors. In this regard, this study examined betas of six shipping companies listed on the Korea Exchange for the period of 2000-2021 and their relationship with financial leverage, operating leverage, and cyclicality in the shipping market. Empirical analysis showed that betas of Korean shipping companies were positively associated with financial and operating leverages but negatively with cyclicality.

• The Journal of Information Technology
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• v.8 no.3
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• pp.57-71
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• 2005

This thesis is to explore the relaxation of restrictions at the acquisition of own stock, and to get the results from this system many countries' legislations were alluded as model cases for Korean system. In comparing with America, Japan, Europe(EC 2nd Commercial Law), and England, the final suggestion for Korean companies law as follows: The solution of problems which is derived from the acquisition at own stock in enterprise is to make the optimum situation for the economic development and stability of stock market. So, to solve these problems needs the relaxation of restrictions for this system and by the relaxation of restrictions can get the distribution of its profit to stockholder, and the compensation for employers and employees. Furthermore, through this system the company can achieve the protection against M&A and the supply of company funds. In conclusion the relaxation of restrictions at the acquisition of own stock is acknowledged the necessity, but the problems that would be followed must be necessarily minimized, and to do so, the legal system has to be molded for this purpose and the its procedure(that is, accounting deal of own stock, the fictitious dividend, and non-appliance of tendency control) has to be prior to the legal system.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.4
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• pp.213-224
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• 1998

Since the late 1980s, an Increasing number of neural network models have been studied in the areas of financial prediction and analysis. The purpose of this study is to Investigate the possibility of building a neural network model that is able to construct a profitable trading strategy in the Korean Stock Market. This study classifies stocks into the future market winners and losers from the publicly available accounting information and builds portfolios based on this information. The performances of the winner portfolios and the loser portfolios are compared with each other and against the market index. The empirical result of this research is consistent with the traditional fundamental analysis where it is claimed that the financial statements contain firm values that may not be fully reflected In stock prices without delay. Despite the supporting empirical evidence. It is somewhat Inconclusive as to whether or not the abnormal return in excess of market return is the result of the extra knowledge obtained in the neural network models derived from the historical accounting data. This research attempts to open another avenue using neural network models for searching for evidence against market efficiency where statistics and intuition have played a major role.

• The Korean Journal of Financial Management
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• v.24 no.4
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• pp.201-232
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• 2007

In this study, we investigated public announcements of stock splits using the Korean Stock Market data from 2000 through 2007. The purposes of this study are to examine whether stock splits have the information contents in the Korean capital markets, and to investigate the possible cause of the market reactions. We measured the market reactions with abnormal returns, cumulative abnormal returns and cumulative average abnormal returns. For the purpose, two specific hypotheses were tested. One is 'Signalling Effects' where stock splits function as a signal through which managers transmit a favorable information for investors. The other is 'Liquidity Effects' where stock splits increase the trading convenience. We have th following results. Firstly, positive market effects were found when stock splits were announced. Secondly, there was difference in trading convenience between the high and the low split ratios. Finally, the long term performance through stock splits in the Korean capital markets was not significant.

• Asia pacific journal of information systems
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• v.16 no.1
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• pp.71-84
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• 2006

Case-based reasoning (CBR) is a reasoning technique that reuses past cases to find a solution to the new problem. It often shows significant promise for improving effectiveness of complex and unstructured decision making. It has been applied to various problem-solving areas including manufacturing, finance and marketing for the reason. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still a challenging issue. Most of the previous studies on CBR have focused on the similarity function or optimization of case features and their weights. According to some of the prior research, however, finding the optimal k parameter for the k-nearest neighbor (k-NN) is also crucial for improving the performance of the CBR system. In spite of the fact, there have been few attempts to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors to combine. This study applies the novel approach to Korean stock market. Experimental results show that the GA-optimized k-NN approach outperforms other AI techniques for stock market prediction.

• East Asian Economic Review
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• v.20 no.2
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• pp.169-190
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• 2016

This paper tests the weak-form efficient market hypothesis for Korean industry-sorted portfolios. Based on a panel variance ratio approach, we find significant mean reversion of stock returns over long horizons in the pre Asian currency crisis period but little evidence in the post-crisis period. Our empirical findings are consistent with the fact that Korea accelerated its integration with international financial market by implementing extensive capital liberalization since the crisis.

• The Pure and Applied Mathematics
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• v.24 no.4
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• pp.227-241
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• 2017

The study investigates the stock market using emotion index calculated from SMD based on investors' emotion. In the VAR anlaysis, we find that the correlation between the KOSPI200 return and emotion score sum is highest in 2- or 3- day lag. This study concludes that explanatory power of the SMD emotion index is limited in explaining the Korean stock market yet.

• KDI Journal of Economic Policy
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• v.40 no.1
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• pp.45-66
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• 2018

This paper measures the extent of comovements in stock returns between Korea and three major countries (China, Japan and the U.S.) using industry-level data for Korea from 2003 to 2016 in the spirit of the international capital asset pricing model. It also examines what drives the comovements between Korea and the three countries. We find that the comovements of Korean stock returns with those of the U.S. and Japan became smaller after the global financial crisis. In contrast, the comovement in stock returns between Korea and China became larger after the crisis. After an additional analysis, we conclude that trade linkage is the main driver of the comovements between Korea and the three countries.