• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.19-20
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• 2000

We have developed the 12.1" SVGA reflective type color TFT-LCD(Thin Film Transistor - Liquid Crystal Display) with the high aperture ratio and well designed reflector for the applications such as mini note PC, Note PC and electronic book. The panel shows the high reflectance(30%) and contrast ratio(20:1) resulted from optimizing the optical films and designing the embossing shaped reflector. By improving the chromacity, the color reproducibility was increased up to 20%. As removing the backlight unit, we reduced the power consumption, thickness and weight of the panel to 0.8W, 2.2mm, and 250gram, respectively. According to the above performances, we have obtained fabrication process for mass production, and furthermore, could have access to fast market launching.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.157-177
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• 2022

Investors are trading stocks by keeping a close watch on the order information submitted by domestic and foreign investors in real time through Limit Order Book information, so-called price current provided by securities firms. Will order information released in the Limit Order Book be useful in stock price prediction? This study analyzes whether it is significant as a predictor of future stock price up or down when order imbalances appear as investors' buying and selling orders are concentrated to one side during intra-day trading time. Using classification algorithms, this study improved the prediction accuracy of the order imbalance information on the short-term price up and down trend, that is the closing price up and down of the day. Day trading strategies are proposed using the predicted price trends of the classification algorithms and the trading performances are analyzed through empirical analysis. The 5-minute KOSPI200 Index Futures data were analyzed for 4,564 days from January 19, 2004 to June 30, 2022. The results of the empirical analysis are as follows. First, order imbalance information has a significant impact on the current stock prices. Second, the order imbalance information observed in the early morning has a significant forecasting power on the price trends from the early morning to the market closing time. Third, the Support Vector Machines algorithm showed the highest prediction accuracy on the day's closing price trends using the order imbalance information at 54.1%. Fourth, the order imbalance information measured at an early time of day had higher prediction accuracy than the order imbalance information measured at a later time of day. Fifth, the trading performances of the day trading strategies using the prediction results of the classification algorithms on the price up and down trends were higher than that of the benchmark trading strategy. Sixth, except for the K-Nearest Neighbor algorithm, all investment performances using the classification algorithms showed average higher total profits than that of the benchmark strategy. Seventh, the trading performances using the predictive results of the Logical Regression, Random Forest, Support Vector Machines, and XGBoost algorithms showed higher results than the benchmark strategy in the Sharpe Ratio, which evaluates both profitability and risk. This study has an academic difference from existing studies in that it documented the economic value of the total buy & sell order volume information among the Limit Order Book information. The empirical results of this study are also valuable to the market participants from a trading perspective. In future studies, it is necessary to improve the performance of the trading strategy using more accurate price prediction results by expanding to deep learning models which are actively being studied for predicting stock prices recently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.216-221
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• 2011

After the year of 2000, the Korean government has abolished the limit on foreign investments. Foreign investments in the domestic market have been thriving since. In domestic stock market, the proportion of market value held by foreign investors reaches over 40%. There are many followers in the markets, asking about what kinds of the firm that foreign investors prefer. Prior researches show that foreign investors in the American and European markets prefer stocks of the firm which are well known and are geographically closer. In this paper, we attempt to define the financial characteristics of the firms in which foreigners invest in the Korean market. The result shows that foreign investors in the domestic market tend to prefer firms with high market value of capital and dividend yield. It also shows that foreign investors in the Korean market choose firms with high book value to market value over others, while the firms with high debt ratio and the portion of the largest stock holders are shunned. This research suggests that foreign portfolio investments in the Korean market have contributed to liquidity of stock market and changed the governance structure of domestic firms in a positive way.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1654-1662
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• 2011

This paper investigates how does cash holdings have effect on investment-cash flow sensitivity in korea firms over the period 1981-2009. According to $\"{O}$.Arslan et al.(2006), I expect that financially constrained firms have more cash holdings. and financially constrained cash-rich firms are likely to have less investment-cash flow sensitivity especially in the financial crisis period. Using financial constraint classification variables(firm size, dividend, cash holdings), we divide whole sample firms into financially constrained firms and financially unconstrained firms, and then I compare investment-cash flow sensitivity in pre-financial crisis(1981-1996), financial crisis(1997-1998) and after-financial crisis(1999-2009) period. This paper's findings are as follows: First, under no financial constraint classification conditions, cash-poor firms exhibit greater investment-cash flow sensitivity than cash-rich firms do during 1981-2009 period except financial crisis period. These findings support the hypothesis that firms have more cash holdings less investment-cash flow sensitivity except in financial crisis period. In financial crisis period, cash holdings have no effect on investment-cash flow sensitivity. Second, this paper findings are somewhat different as $\"{O}$.Arslan et al.(2006)'s. Under the financial constraint classification conditions, financially unconstrained firms have more investment-cash flow sensitivity rather than constrained firms have. The reason is that both dividend and firm size are not a complete classification criteria variables. And there exists other possible determinants of investment-cash flow sensitivity. Finally, this paper find that there are common determinants of corporate cash holdings in all periods. This paper suggests that cash flow and market to book ratio are positive determinants of corporate cash holdings but short-term debt, investment and firm size are negative determinants of corporate cash holdings.

• The Journal of Asian Finance, Economics and Business
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• v.10 no.2
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• pp.153-161
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• 2023

This study's principal goal is to find the interrelation between transparency & disclosure (TD) and the healthcare sector's firm valuation (FV). The paper uses the market-to-book (MTB) ratio and market capitalization as proxies, where sales measure act as a control variable. Dynamic panel data regression (PD) is the method applied for analyzing data. Data pertains to 10 healthcare companies gathered over five years (2016-2020). Results imply that TD has a negative and significant influence on the FV, where market capitalization acts as a proxy for valuation. This association indicates that a greater degree of TD diminishes FV. TD is also reported to have a negative and insignificant association with MTB. Therefore, TD does not influence FV. The findings of this paper have significant practical implications. Results can help policymakers determine mandatory disclosure levels that are not detrimental to the healthcare sector. Managers and analysts must also analyze the dimensions of disclosure that can negatively impact the firm's valuation and make decisions regarding TD accordingly. This is the first study to assess the influence of TD on the FV of the Indian healthcare sector, which makes it unique. This study is limited to the healthcare sector, which is its shortcoming.

• Journal of Information Technology Applications and Management
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• v.29 no.1
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• pp.47-57
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• 2022

The purpose of this study is to analyze the current status of augmented reality picture books, which have been steadily developed since 2010, as a genre of electronic picture books, and to reveal how children's immersion in augmented reality picture books differs from paper picture books. To this end, 30 augmented reality picture books on the market were analyzed according to genre, life theme, implementation method, and augmented reality scene ratio. As a result of the study, it was found that the genre of picture books was in the order of information fairy tales, daily fairy tales, and historical fairy tales, and there were no traditional or fantasy fairy tales. Animals and plants accounted for about half of the life topics, and in some cases, there were only a few or no other life topics. In the augmented reality implementation scene, it consisted of only one page in the early days, but all pages are now possible to implement augmented reality due to technology development, production cost reduction, and improved hardware performance of smartphones. It was found that the augmented reality implementation method used CD-ROM in the early days, but gradually became possible to implement using only mobile phones and tablets that were easy for readers to access. In addition, after presenting four picture books to eight 5-year-old infants, the immersion time was measured and the immersion behavior was observed. As a result, augmented reality picture books showed higher immersion[immersion time, immersion behavior] than paper picture books, but compared by literature genre, life fairy tales were higher in paper picture books and natural fairy tales in augmented reality picture books. It was higher when presenting augmented reality picture books after presenting paper picture books according to the order of presentation of picture book types. The results of this study suggest that more diverse life topics and augmented reality picture books in the genre of children's literature should be developed to increase the utilization of augmented reality picture books. In addition, considering that there are differences in immersion between types, literary genres, and reading experience [presentation order], it is expected to increase the educational effect by using picture books complementarily.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.745-760
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• 2021

Prediction of a stock price has been a subject of interest for a long time in financial markets, and thus, many studies have been conducted in various directions. As the efficient market hypothesis introduced in the 1970s acquired supports, it came to be the majority opinion that it was impossible to predict stock prices. However, recent advances in predictive models have led to new attempts to predict the future prices. Here, we summarize past studies on the price prediction by evaluation measures, and predict the direction of stock prices of Samsung Electronics, LG Chem, and NAVER by applying various machine learning models. In addition to widely used technical indicator variables, accounting indicators such as Price Earning Ratio and Price Book-value Ratio and outputs of the hidden Markov Model are used as predictors. From the results of our analysis, we conclude that no models show significantly better accuracy and it is not possible to predict the direction of stock prices with models used. Considering that the models with extra predictors show relatively high test accuracy, we may expect the possibility of a meaningful improvement in prediction accuracy if proper variables that reflect the opinions and sentiments of investors would be utilized.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.1
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• pp.29-36
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• 2020

Stock price multiple is one of the most well-known equity valuation technique used to forecast equity price. It measures by multiplying "the ratio of stock price to a value driver" by a value driver. The value driver can be earning per share (EPS), sales or other financial measurements. The objective of price multiple technique is to evaluate the value of assets and compare how similar assets are priced in the market. Although stock price multiple technique is common in financial filed, studies on the application of the technique in Thailand is still limited. The present study is conducted to serve three major objectives. The first objective is to apply the technique to measure value of firms in banking sector in the Stock Exchange of Thailand. The second objective is to develop composite price multiple index to forecast equity prices. The third objective is to compare valuation accuracy of different value drivers of price multiple (i.e. EPS, Earnings Growth, Earnings Before Interest Taxes Depreciation and Amortization, Sales, Book Value and Composite Index) in forecasting equity prices. Results indicated that EPS is the most accurate value drivers of price multiple used to forecast equity price of firms in baking sector.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.9
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• pp.189-199
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• 2021

This study attempts to examine the relationship between corporate social responsibility (CSR) disclosure and earnings management practices in the context of Saudi Arabia after mandatory IFRS adoption. It is carried out on an unbalanced panel of 277 observations over the period 2017-2019. For this purpose, CSR disclosure is measured by Bloomberg ESG scores, while the residuals from the modified Jones model are considered for earnings management. As control variables, we have retained the firm performance, market-to-book ratio, firm size, financial leverage, board independence, ownership concentration, managerial ownership, and lagged discretionary accruals. Using the system GMM estimator in the dynamic panel, the results show a positive association between CSR disclosure and earnings management practices, thus supporting the perspective of agency theory. Managers engage in socially responsible activities beforehand to conceal their wrongdoing and convince stakeholders that the organization is transparent. They probably use ethical codes as a tool to achieve their own goals rather than the firm's goals. Our contribution is the use of recent data (2017-2019) taking into account the mandatory adoption of IFRS in Saudi Arabia. Additionally, to our knowledge, this study is the first to address CSR disclosure and earnings management practices using GMM system estimates.

• Journal of Distribution Science
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• v.21 no.6
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• pp.83-89
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• 2023

Purpose: This paper considers the issue of corporate tax avoidance (CTA) in the distribution of the tax burden across companies in Vietnam because the high level of CTA leads to unfairness in taxation. In particular, we aim for discussing the way to measure the extent of CTA and explore the determinants of CTA that reflect the features of high-tax risk-taking companies. Research design, data and methodology: The study investigates factors influencing the CTA behavior of legal entities listed on the Vietnam stock market between 2012 and 2018 to fill the empirical research vacuum in the country. we employ the dynamic GMM estimate method. Interestingly, CTA is considered through three approaches, including two effective-tax-rate-based methods and especially accrual earnings Results: The results highlight tax - accounting book disparities have significant effects on CTA. In addition, firm size, net asset value, debt leverage, and tax-accounting books are related to CTA. Conclusions: Tax avoidance is shown to have a positive correlation with financial distress in this case. The higher a company's capital adequacy ratio, the fewer tax avoidance opportunities it has. The paper draws some recommendations to deal with tax avoidance that improves the fairness in the distribution of the tax burden among corporations.