• Asia pacific journal of information systems
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• v.30 no.1
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• pp.31-52
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• 2020

Stock markets are popular investment avenues to people who plan to receive premium returns compared to other financial instruments, but they are highly volatile and risky due to the complex financial dynamics and poor understanding of the market forces involved in the price determination. A system that can forecast, predict the stock prices and automatically create a portfolio of top performing stocks is of great value to individual investors who do not have sufficient knowledge to understand the complex dynamics involved in evaluating and predicting stock prices. In this paper the authors propose a Stock prediction, Portfolio Generation and Selection model based on Machine learning algorithms, Artificial neural networks (ANNs) are used for stock price prediction, Mathematical and Statistical techniques are used for Portfolio generation and Un-Supervised Machine learning based on K-Means Clustering algorithms are used for Portfolio Evaluation and Selection which take in to account the Portfolio Return and Risk in to consideration. The model presented here is limited to predicting stock prices on a long term basis as the inputs to the model are based on fundamental attributes and intrinsic value of the stock. The results of this study are quite encouraging as the stock prediction models are able predict stock prices at least a financial quarter in advance with an accuracy of around 90 percent and the portfolio selection classifiers are giving returns in excess of average market returns.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.199-217
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• 1992

The purpose of this study was to examine changes in the household investment planning according to the family life cycle, to improve the household investment planning process, and to develop research model. The results were as follows : Household investment planning varied with stages of the family life cycle because the stock of resources shifted and financial goals changed as the family life cycle stage changed. The main financial goals of family in each stage of the life cycle were the purchasing of house in the establishing stage, children's education and marriage in the extending stage, and the elderly's economic welfare in the diminishing stage. Also, in the Ⅰ & Ⅱ stage the most important investment goals were the purchasing of house, children's education in the Ⅲ stage, children's marriage in the Ⅳ stage, and the elderly's economic welfare in the Ⅴ stage. Therefore, the financial goals were recognized as the important goals underlain the investment-planning goals, and alternatives for the accomplishment of investment-planning goals were determined. The results of this study can contribute to establish the long-run investment planning process and improve the level of household's financial well-being.

• Korean Management Science Review
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• v.32 no.1
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• pp.15-33
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• 2015

Under complete information, introducing additional constraints to a portfolio will have a negative impact on performance. However, real-life investments inevitably involve use of error-prone estimations, such as expected stock returns. In addition to the reality of incomplete data, investments of most Korean domestic equity funds are regulated externally by the government, as well as internally, resulting in limited maximum investment allocation to single stocks and risk free assets. This paper presents an investment framework, which takes such real-life situations into account, based on a newly developed portfolio selection model considering realistic constraints under incomplete information. Additionally, we examined the effects of additional constraints on portfolio's performance under incomplete information, taking the well-known Samsung and SK group stocks as performance benchmarks during the period beginning from the launch of each commercial fund, 2005 and 2007 respectively, up to 2013. The empirical study shows that an investment model, built under incomplete information with additional constraints, outperformed a model built without any constraints, and benchmarks, in terms of rate of return, standard deviation of returns, and Sharpe ratio.

• The Korean Journal of Financial Management
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• v.22 no.2
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• pp.135-164
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• 2005

We analyze trade and balance records of 10,000 stock investment accounts of individual investors for the period of 1998 to 2003. Individual investors em an annual gross return of 12.3% while the KOSPI and the value weighted composite including KOSDAQ stocks yield 13.6% and 9.7% respectively during the same period. Net return performance is 8.3%, a drop of 5.3% mainly due to heavy trading. Individual investors' annual turnover amounts to over 270 percent. In an analysis of groups formed on the month's end position value, the performance of the top quintile is found comparable to the market while the rest yield significantly lower risk-adjusted returns than the market. We also find evidence rejecting the rational expectation model while supporting the overconfidence hypothesis which states overconfidence leads to a higher level of trading, resulting in poor performance. Individuals tilt their stock investment toward high-beta, small, and value stocks.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.157-165
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• 2022

As the stock market is affected by various circumstances including economic and political variables, predicting the stock market is considered a still open problem. When combined with corporate financial statement data analysis, which is used as fundamental analysis, and technical analysis with a short data generation cycle, there is a problem that the time domain does not match. Our proposed method, LSTE the operating profit and market outlook of a petrochemical company and estimates the sales and operating profit of the company, it was possible to solve the above-mentioned problems and improve the accuracy of stock price prediction. Extensive experiments on real-world stock data show that our method outperforms the 8.58% relative improvements on average w.r.t. accuracy.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.165-173
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• 2021

This study examined the effect of Debt Equity Ratio (DER), Net Profit Margin (NPM), and Size on stock prices with company performance as measured by Return on Assets (ROA) as a mediating variable. The sample used is 136 manufacturing companies listed on the Indonesia Stock Exchange (IDX) in the 2014-2018 period. This research was tested using a Warp PLS statistical test tool to prove the proposed hypothesis. The results showed that DER has a significant negative effect on ROA and a significant positive effect on Stock Price. NPM has a significant positive effect on ROA as well as a significant positive effect on Stock Price. While Size has a significant positive effect on ROA but has no effect on Stock Price. ROA has a significant positive effect on Stock Price. ROA does not act as a mediating variable in the relationship between Size and Stock Price; however, ROA acts as a mediating variable in the DER and Stock Price relationship, as well as, in the relationship between NPM and Stock Price. The implications of the results of this study can be used by investors in making investment decisions, paying attention to the company's financial aspects, namely DER, NPM, Size, and ROA.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.9
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• pp.837-848
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• 2012

This study has conducted the economic effects of R&D investment in the IT industry using multi-regression analysis with three independent variables; capital stock, labor input and R&D stock. In this study, the IT industry has been categorized into three sub-industries; broadcasting communication appliances, information appliances and electronic components industry. Our analysis has found that auto-correlation shows considerable levels whereas figures of t-value and R-square show significant levels among all the IT sub-industries. Meanwhile, the values of R&D stock in the information appliances industry and that of labor input coefficients in the electronic components industry were minus, thus multi-collinearity was suspected. We have solved the problems regarding auto-correlation and multi-collinearity through Cochrane-Orcutt estimation and principal components analysis. This paper has derived the implications that R&D investment in the broadcasting communication industry is much more influential than any other IT sub-industry.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.2
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• pp.75-93
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• 2013

In applying Markowitz's portfolio selection model to the stock market, we developed a comprehensive investment decision-making framework including key inputs for portfolio theory (i.e., individual stocks' expected rate of return and covariance) and minimum required expected return. For estimating the key inputs of our decision-making framework, we utilized an exponentially weighted moving average (EWMA) which places more emphasis on recent data than the conventional simple moving average (SMA). We empirically analyzed the investment results of the decision-making framework with the same 15 stocks in Samsung Group Funds found in the Korean stock market between 2007 and 2011. This five-year investment horizon is marked by global financial crises including the U.S. subprime mortgage crisis, the collapse of Lehman Brothers, and the European sovereign-debt crisis. We measure portfolio performance in terms of rate of return, standard deviation of returns, and Sharpe ratio. Results are compared with the following benchmarks : 1) KOSPI, 2) Samsung Group Funds, 3) Talmudic portfolio based on the na$\ddot{i}$ve 1/N rule, and 4) Markowitz's model with SMA. We performed sensitivity analyses on all the input parameters that are necessary for designing an investment decision-making framework : smoothing constant for EWMA, minimum required expected return for the portfolio, and portfolio rebalancing period. In conclusion, appropriate use of the comprehensive investment decision-making framework based on the Markowitz's model integrated with EWMA proves to achieve outstanding performance compared to the benchmarks.

• East Asian Economic Review
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• v.23 no.4
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• pp.353-379
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• 2019

This paper aims to determine factors causing the stagnation of Korean firms' fixed investment after the global financial crisis, using panel data for the period of 1999-2016. Fixed investment remained sensitive to cash flow and Tobin's q although their effects decreased after the global financial crisis. A decreasing trend of cash flow and an increase in Tobin's q since the early 2000's imply that the worsening cash flow was a major factor behind the sluggish investment after the crisis. Meanwhile, debt-equity ratio remained significant for non-chaebol affiliated firms, reflecting disparity in access to external financing. Volatility of stock returns also became insignificant after the crisis, casting doubt on the argument that uncertainty was a major factor contributing to the decline of fixed investment. Analysis of financial investment confirmed the significant effect of cash flow, larger than that on financial investment than on fixed investment. In particular, debt repayment and other financial investment, except share repurchase, were sensitive to cash flow. However, the substitution of fixed investment by financial investment is a consequence, rather than a cause of declining fixed investment.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.629-639
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• 2020

The current study explains how corruption, terrorism, political stability and oil price has an effect on on the Iraq stock exchange utilizing corruption perception index as a proxy of corruption, global terrorism index as proxy for terrorism, political stability and oil price with ISX60 index as proxy of stock market for the period (2005-2019) using Ordinary Least Square method. The results show that the level of corruption, terrorism activities and political stability coefficient is significantly positive with Iraq stock exchange. In contrast, the oil price coefficient is significantly negative with Iraq stock exchange, which means that lower levels of corruption, less terrorism activities and more stability in political system have strong influence on stock market development in Iraq. The study concludes that the explanatory variables are important for Iraq stock exchange. Hence, the study suggests the policy makers to develop stock market by implementing policies and strategies to overcome high level of corruption, terrorism activities especially after ISIS/ISIL announcement has been made public. There is a need for transparency and creating stable political environment through good governance practices in order to attract more foreign investment and promote economic development. Factors like terrorism and corruption make economic and political systems unstable and has an adverse effect on on Iraq's stock exchange performance.