• 지능정보연구
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• 제22권2호
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• pp.81-96
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• 2016

최근 인터넷의 보편화와 정보통신 기술의 발달로 인해 인터넷을 통한 정보검색이 일상화 됨에 따라 주식에 관한 정보 역시 검색엔진, 소셜네트워크서비스, 인터넷 커뮤니티 등을 통해 획득하는 경우가 잦아졌다. 특정 단어에 대한 키워드 검색량은 사용자의 관심도를 반영하기 때문에 다양한 연구에서 개별 기업에 대한 인터넷 검색량은 투자자의 관심도에 대한 척도로서의 사용가능성을 각광받았다. 특정 주식에 대한 투자자의 관심이 증가할 때 일시적으로 주가가 상승하였다가 회복하는 반전현상은 여러 연구를 통해 검증되어 왔지만 그 동안 투자자의 관심도는 주로 주식거래량, 광고 비용 등을 사용해 간접적으로 측정되었다. 본 연구에서는 국내 코스닥 시장에 상장된 기업에 대한 인터넷 검색량을 투자자의 관심의 척도로 사용하여 투자자의 관심에 근거한 주가변동성의 변화를 전체 시장 측면과 산업별 측면에서 관찰한다. 또한 투자자 관심이 야기한 가격압박에 의한 주가 반전현상의 존재를 코스닥 시장에서 검증하고 산업 간의 반전정도의 차이를 비교한다. 실증분석 결과 비정상적인 인터넷 검색량 증가는 주가변동성의 유의적인 증가를 가져왔고 이러한 현상은 IT S/W, 건설, 유통 산업군에서 특히 강하게 나타났다. 비정상적인 인터넷 검색량의 증가 이후 2주 간 주가변동성이 증가하였고 3~4주 후에는 오히려 변동성이 감소하는 것을 확인하였다. 이러한 주가 반전현상 역시 IT S/W, 건설, 유통 산업군에서 보다 극단적으로 발생하는 것으로 나타난다.

• 산경연구논집
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• 제10권6호
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• pp.51-58
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• 2019

Purpose - Prior studies reported that the opacity of information caused stock price crash. If managers fail to disclose unfavorable information about the firm over a long period of time, the stock price is overvalued compared to its original value. If the accumulated information reaches a critical point and spreads quickly to the market, the stock price plunges. Information management by management's disclosure policy can cause information uncertainty, which will lead to a plunge in stock prices in the future. Thus, this study aims at examining the impact of disclosure quality on crash risk by focusing on the unfaithful disclosure firms. Research design, data, and methodology - This study covers firms listed on KOSPI and KOSDAQ from 2004 to 2013. Firms excluded from the sample are non-December firms, capital-eroding firms, and financial firms. The financial data used in the research was extracted from the KIS-Value and TS2000 database. Unfaithful disclosure firm designation data was collected from the Korea Exchange's electronic disclosure system (kind.krx.co.kr). Stock crash is measured as a dummy variable that equals one if a firm experiences at least one crash week over the fiscal year, and zero otherwise. Results - Empirical results as to the relation between unfaithful disclosure corporation designation and stock price crashes are as follows: There was a significant positive association between unfaithful disclosure corporation designation and stock price crash. This result supports the hypothesis that firms that have previously exhibited unfaithful disclosure behavior are more likely to suffer stock price plunges due to information asymmetry. Second, stock price crashes due to unfaithful disclosures are more likely to occur in Chaebol firms. Conclusions - While previous studies used estimates as a proxy for information opacity, this study used an objective measure such as unfaithful disclosure corporation designation. The designation by Korea Exchange is an objective evidence that the firm attempted to conceal and distort information in the previous year. The results of this study suggest that capital market investors need to investigate firms' disclosure behaviors.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.543-553
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• 2020

This paper examines the effect of COVID-19 pandemic on the Philippine stock exchange, peso-dollar rate and retail price of diesel using robust least squares regression and vector autoregression (VAR). The robust least squares regression using MM-estimation method concluded that COVID-19 daily infection has negative and statistically significant effect on the Philippine stock exchange index, peso-dollar exchange rate and retail pump price of diesel. This is consistent with the results of correlation diagnostics. As for the VAR model, the lag values of the independent variable disclose significance in explaining the Philippine stock exchange index, peso-dollar exchange rate and retail pump price of diesel. Moreover, in the short run, the impulse response function confirmed relative effect of COVID-19 daily infections and the variance decomposition divulge that COVID-19 daily infections have accounted for only minor portion in explaining fluctuations of the Philippine stock exchange index, peso-dollar exchange and retail pump price of diesel. In the long term, the influence levels off. The Granger causality test suggests that COVID-19 daily infections cause changes in the Philippine stock exchange index and peso-dollar exchange rate in the short run. However, COVID-19 infection has no causal link with retail pump price of diesel.

• 산경연구논집
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• 제4권2호
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• pp.13-19
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• 2013

Purpose - The paper tested the relationship between the stock markets of the Middle East and the USA with the oil price and US dollar index as threshold variables. Research design, data, and methodology - The stock price indices of the USA, the Middle East (Abu Dhabi, Jordan), WTI spot crude oil price, and US dollar index were daily returns in the research period from May 21, 2001 to August 9, 2012. Following Hansen (1999), the panel threshold regression model was used. Results - With the US dollar index as the threshold variable, a negative relationship existed between the stock price indices of Jordan and the USA but no significant result was found between the stock price indices of Abu Dhabi and the USA. Conclusions - The USA is an economic power today:even if it has a closer relationship with the US stock market, the dynamic US economy can learn about subsequent developments and plan in advance. Conversely, if it has an estranged relationship with the US stock market, thinking in a different direction and different investment strategies will achieve good results.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.1-9
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• 2021

UAE has rapidly developed into one of the leading global financial hubs, with significant transformations in its stock exchanges. In its attempt at economic diversification in the last two decades, the country has also taken a lead in the GCC region in introducing extensive reforms to attract FDI to the Emirates. However, oil price volatilities have posed a significant challenge to all oil-exporting countries. The main aim of this study is to explore the impact of economic diversification and oil price on the UAE stock market. The study applies Granger Causality and Vector Autoregressive Model on monthly Abu Dhabi stock exchange index, Dubai Fateh crude oil spot price, and FDI inflows during 2001-19. The short-term interbank rate has been included as a monetary policy variable. The results show a substantial difference between the two phases of reforms. Oil price and Abu Dhabi stock index show bidirectional relationship during 2001-09 but no causality was found during 2010-19. Furthermore, the second phase was characterized by unidirectional causation from FDI to ADX index. This study highlights FDI inflows as a key driver of stock market performance during the last decade and emphasizes the success of the intense reforms in the UAE initiated for the diversification of its economy.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1113-1119
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• 2021

This study aims to determine the impact of the news coverage of the COVID-19 pandemic on the composite stocks' movement (IHSG) in Indonesia. This study used secondary data of daily time series with an observation range of March 2020-June 2020. This study used three main variables, namely, COVID-19 news, the daily price of a composite stock market index (IHSG), and interest rate. This study clarifies pandemic news into two forms to facilitate quantitative analysis, namely, good news and bad news. Both pandemic news conditions, which have been clarified, are then processed into the index and reprocessed along with two other variables using vector autoregressive (VAR). The results showed that the good news have a dominant effect on developing the composite stock price index (IHSG) in Indonesia during the COVID-19 pandemic. Although the good news dominates the composite stock price index (IHSG) movement in Indonesia, the bad news must also be anticipated. By implementing a series of macroeconomic policies that follow the conditions of the composite stock price index (IHSG) movements on the stock exchange floor, the bad news response can decrease the potential for a decline in investor confidence, so that the financial system's macroeconomic stability is maintained.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.601-611
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• 2021

There are many asset prices which are interlinked and have a bearing on the stock market index. Studies have shown that the interrelationship among these asset prices vary and are inconsistent. The ultimate aim of this study is to examine the dynamic relationship between gold price, oil price, exchange rate and stock index. Monthly time series data has been utilized by the researcher to examine the interrelationship between four variables. The relationship among stock exchange rate index, oil price and gold price have been undertaken using regression and granger causality test. The results indicate that the exchange rate and oil price have an indirect influence on NIFTY; whereas gold price had a direct impact on NIFTY. It is evident from the results that volatility in the price of gold is mainly dependent on the exchange rate and vice versa. All the variables affect NIFTY in some way or the other. However, gold has a direct and vital relationship. From the study findings, it can be concluded that macroeconomic variables like commodity prices and foreign exchange rate, gold and oil, have a strong relationship on the return on securities at the national stock exchange of India.

• 경영과학
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• 제28권1호
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• pp.53-60
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• 2011

Time series analysis methods have been traditionally used in stock price prediction. However, most of the existing methods represent some methodological limitations in reflecting influence from external factors that affect the fluctuation of stock prices, such as oil prices, exchange rates, money interest rates, and the stock price indexes of other countries. To overcome the limitations, we propose a network based method incorporating the relations between the individual company stock prices and the external factors by using a graph-based semi-supervised learning algorithm. For verifying the significance of the proposed method, it was applied to the prediction problems of company stock prices listed in the KOSPI from January 2007 to August 2008.

• 대한산업공학회지
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• 제39권6호
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• pp.535-545
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• 2013

The goal of stock investment is earning high rate or return with stability. To accomplish this goal, using a portfolio that distributes stocks with high rate of return with less variability and a stock price prediction model with high accuracy is required. In this paper, three methods are suggested to require these conditions. First of all, in portfolio re-balance part, Max-Return and Min-Risk (MRMR) model is suggested to earn the largest rate of return with stability. Secondly, Entering/Leaving Rule (E/L) is suggested to upgrade portfolio when particular stock's rate of return is low. Finally, to use outstanding stock price prediction model, a model based on Semi-Supervised Learning (SSL) which was suggested in last research was applied. The suggested methods were validated and applied on stocks which are listed in KOSPI200 from January 2007 to August 2008.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제23권11호
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• pp.625-631
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• 2017

과거부터 현재까지 주식시장에 대한 주가 변동 예측은 풀리지 않는 난제이다. 주가를 과학적으로 예측하기 위해 다양한 시도 및 연구들이 있어왔지만, 아직까지 정확한 미래를 예측하는 것은 불가능하다. 하지만, 주가 예측은 경제, 수학, 물리 그리고 전산학 등 여러 관련 분야에서 오랜 관심의 대상이 되어왔다. 본 논문에서는 최근 각광 받고 있는 딥러닝(Deep-Learning)을 이용하여 주가의 변동패턴을 학습하고 미래를 예측하고자한다. 본 연구에서는 오픈소스 딥러닝 프레임워크인 텐서플로우를 이용하여 총 3가지 학습 모델을 제시하였으며, 각 학습모델은 각기 다른 입력 피쳐들을 받아들여 학습을 진행한다. 입력 피쳐는 이전 연구에서 사용한 단순 가격 데이터를 확장해 입력 피쳐 개수를 증가시켜가며 실험을 하였다. 세 가지 예측 모델의 학습 성능을 측정했으며, 이를 통해 가격-기반 입력 피쳐에 따라 달라지는 예측 모델의 성능 변화 비교 분석하여 가격-기반 입력 피쳐가 주가예측에 미치는 영향을 평가하였다.