• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3025-3035
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• 2018

This study investigates the momentum phenomena of stocks listed on the taiwan stock exchange. The purpose of this study is to examine the differences in momentum phenomena among firm size, foreign investor ownership, individual investor ownership, and institutional investor ownership. The empirical results of the momentum phenomenon in the Taiwanese stock market are as follows. First, there is no momentum phenomenon during the whole sample period. Second, momentum profitability does not exist even if this study divides by firm size. However, the results are different if this study divides it by the investor ownership. Third, there is a significant positive momentum for firms with high individual ownership. Fourth, on the contrary, positive momentum was observed in firms with low institutional ownership. Finally, there was no momentum phenomenon when dividing by foreign ownership. This study has academic contribution in analyzing the momentum phenomenon in Taiwanese stock market considering the investor's ownership.

• Journal of Intelligence and Information Systems
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• v.27 no.1
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• pp.65-82
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• 2021

Stock market investors are generally split into foreign investors, institutional investors, and individual investors. Compared to individual investor groups, professional investor groups such as foreign investors have an advantage in information and financial power and, as a result, foreign investors are known to show good investment performance among market participants. The purpose of this study is to propose an investment strategy that combines investor-specific transaction information and machine learning, and to analyze the portfolio investment performance of the proposed model using actual stock price and investor-specific transaction data. The Korea Exchange offers daily information on the volume of purchase and sale of each investor to securities firms. We developed a data collection program in C# programming language using an API provided by Daishin Securities Cybosplus, and collected 151 out of 200 KOSPI stocks with daily opening price, closing price and investor-specific net purchase data from January 2, 2007 to July 31, 2017. The self-organizing map model is an artificial neural network that performs clustering by unsupervised learning and has been introduced by Teuvo Kohonen since 1984. We implement competition among intra-surface artificial neurons, and all connections are non-recursive artificial neural networks that go from bottom to top. It can also be expanded to multiple layers, although many fault layers are commonly used. Linear functions are used by active functions of artificial nerve cells, and learning rules use Instar rules as well as general competitive learning. The core of the backpropagation model is the model that performs classification by supervised learning as an artificial neural network. We grouped and transformed investor-specific transaction volume data to learn backpropagation models through the self-organizing map model of artificial neural networks. As a result of the estimation of verification data through training, the portfolios were rebalanced monthly. For performance analysis, a passive portfolio was designated and the KOSPI 200 and KOSPI index returns for proxies on market returns were also obtained. Performance analysis was conducted using the equally-weighted portfolio return, compound interest rate, annual return, Maximum Draw Down, standard deviation, and Sharpe Ratio. Buy and hold returns of the top 10 market capitalization stocks are designated as a benchmark. Buy and hold strategy is the best strategy under the efficient market hypothesis. The prediction rate of learning data using backpropagation model was significantly high at 96.61%, while the prediction rate of verification data was also relatively high in the results of the 57.1% verification data. The performance evaluation of self-organizing map grouping can be determined as a result of a backpropagation model. This is because if the grouping results of the self-organizing map model had been poor, the learning results of the backpropagation model would have been poor. In this way, the performance assessment of machine learning is judged to be better learned than previous studies. Our portfolio doubled the return on the benchmark and performed better than the market returns on the KOSPI and KOSPI 200 indexes. In contrast to the benchmark, the MDD and standard deviation for portfolio risk indicators also showed better results. The Sharpe Ratio performed higher than benchmarks and stock market indexes. Through this, we presented the direction of portfolio composition program using machine learning and investor-specific transaction information and showed that it can be used to develop programs for real stock investment. The return is the result of monthly portfolio composition and asset rebalancing to the same proportion. Better outcomes are predicted when forming a monthly portfolio if the system is enforced by rebalancing the suggested stocks continuously without selling and re-buying it. Therefore, real transactions appear to be relevant.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1087-1093
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• 2017

The purpose of this study is to present an empirical analysis of determinants of the amount of orders received in construction technology engineering industry sector. Regression model was applied for 5 years from 2010 to 2014 to find out how the factors affecting the amount of orders received each year are different and what trends are observed. Although common significant variables were identified that there is a difference in the impact on their orders received. Specifically, the increase in the number of orders received while reducing the impact on orders received from 2010 to 2013, 2014 showed a slight tendency to increase. And increase in the number of employees shows that the influence of order received is higher in 2014 than in 2010. In addition, the gap between the metropolitan area and the non-metropolitan area has doubled in 2014 compared to 2010, but it is also confirmed that the metropolitan area is still strong. On the other hand, in the case of licensed technology, the only statistically significant variable was the negative correlation between the amount of orders received. Although the influence declined in 2014 compared to 2011, it still had a large impact on the amount of orders received.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.4
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• pp.312-320
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• 2016

This study analyzed the distribution of the blood glucose level according to the fasting status. Moreover, a relationship was analyzed between fasting blood glucose level and glycemic control indicators. A total of 707 outpatients, who visited Dankook University Hospital, were included and classified into either the fasting group and the non-fasting group. The mean blood glucose level of each group was calculated and analyzed by sex, age, and clinic. In addition, blood glucose, HbA1c, fructosamine, and 1,5-AG were measured in 153 fasting health check-up patients, and the correlation between the blood glucose level and glycemic control indicators was evaluated. Blood glucose averages between the two groups (non-fasting 111.9 vs. fasting 103.6 mg/dL) were different (p<0.05); and the mean difference was lower in women (4.8 mg/dL) than in men (12.2 mg/dL). A significant difference of the median glucose values among the age groups was only observed in the non-fasting group (Kruskal-Wallis test, p<0.01), and not in the fasting group. A 1,5-Anhydroglucitol was estimated to be significantly correlated with the fast blood glucose level in the range of the criteria of impaired fasting glucose (IFG). We presented an assessment of the distribution of blood glucose level in accordance with the fasting status among outpatients, and estimated that 1,5-anhydroglucitol was well correlated with the fasting blood glucose than fructosamine and HbA1c, through the analysis of results of health screening subjects. It is suggested that the use of glycemic indicators that reflect short-term blood glucose control can be used together with the blood glucose measurement in the screening of diabetes mellitus.

• Journal of KIISE:Databases
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• v.34 no.3
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• pp.179-192
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• 2007

This paper addresses an approach that recommends investment types for stock investors by discovering useful rules from past changing patterns of stock prices in databases. First, we define a new rule model for recommending stock investment types. For a frequent pattern of stock prices, if its subsequent stock prices are matched to a condition of an investor, the model recommends a corresponding investment type for this stock. The frequent pattern is regarded as a rule head, and the subsequent part a rule body. We observed that the conditions on rule bodies are quite different depending on dispositions of investors while rule heads are independent of characteristics of investors in most cases. With this observation, we propose a new method that discovers and stores only the rule heads rather than the whole rules in a rule discovery process. This allows investors to define various conditions on rule bodies flexibly, and also improves the performance of a rule discovery process by reducing the number of rules. For efficient discovery and matching of rules, we propose methods for discovering frequent patterns, constructing a frequent pattern base, and indexing them. We also suggest a method that finds the rules matched to a query issued by an investor from a frequent pattern base, and a method that recommends an investment type using the rules. Finally, we verify the superiority of our approach via various experiments using real-life stock data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.294-299
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• 2019

Korean hospitals implement external quality assessment (EQA) schemes to improve the quality of clinical tests. However, smaller hospital do not implement EQA due to lack of appreciation and cost burdens. The purpose of this study was to analyze the results of EQA from the perspective of clinical chemistry carried out at a small-to-medium sized hospital (SMH) and to investigate factors influencing quality control. The medical institution concerned had performed EQA on 21 items annually for three years and had analyzed measurement methods, variation coefficients, and anomalous results as defined by the SMH. No significant change in test methods or variation coefficients, which exhibited a high level of variation, were observed for any test item over the 3-year period. The results obtained showed that anomalous test results were significantly more frequent when EQA was not conducted (p<0.05), internal quality control was not conducted daily (p<0.01), and when tests were less frequently performed (p<0.01). Small-to-medium sized hospitals need to be more aware of the benefits of EQA and provide tailored education to staff.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.165-190
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• 2008

The degree of informational asymmetry relating to the expiration of index derivatives is usually increased as an expiration day of index derivatives approaches. The increase in the degree of informational asymmetry may have some effects on trading behavior of investors. To examine what the effects look like, 'life cycle of index derivatives' in this study is defined as three adjacent periods around expiration day: pre-expiration period(a week before the expiration day), post-expiration period(a week after the expiration day), and remaining period. It is inspected whether stock investor's trading behavior is changed according to the life cycle of KOSPI200 derivatives and what the reason of the changing behavior is. We have four results. First, trading behavior of each investor group is categorized into three patterns: ㄱ-pattern, L-pattern and U-pattern. The level of trading activity is low for pre-expiration period and normal for other periods in the ㄱ-pattern. L-pattern means that the level of trading activity is high for post-expiration period and normal for other periods. In the U-pattern, the trading activity is reduced for remaining period compared to other periods. Second, individual investors have ㄱ-pattern of trading large stocks according to the life cycle of KOSPI200 index futures while they show U-pattern according to the life cycle of KOSPI200 index options. Their trading behavior is consistent with the prediction of Foster and Viswanathan(1990)'s model for strategic liquidity investors. Third, trading pattern of foreign investors in relation to life cycle of index derivatives is partially explained by the model, but trading pattern of institutional investors has nothing to do with the predictions of the model.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.575-583
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• 2021

This study aims to analyze Taekwondo trends according to news articles by year by applying topic modeling. In order to examine the Taekwondo trend through media reports, articles including news articles and Taekwondo specialized media articles were collected through Big Kinds of the Korea Press Foundation. The search period was divided into three sections: before 2000, 2001~2010, and 2011~2020. A total of 12,124 items were selected as research data. For topic analysis, pre-processing was performed, and topic analysis was performed using the LDA algorithm. In this case, python 3 was applied for all analysis. First, as a result of analyzing the topics of media articles by year, 'World' was the most common keyword before 2000. 'South and North Korea' was next common and 'Olympic' was the third commonest topic. From 2001 to 2010, 'World' was the most common topic, followed by 'Association' and 'World Taekwondo'. From 2011 to 2020, 'World', 'Demonstration', and 'Kukkiwon' was the most common topic in that order. Second, as a result of analyzing news articles before 2000 by topic modeling, topics were divided into two categories. Specifically, Topic 1 was selected as 'South-North Korea sports exchange' and Topic 2 was selected as 'Adoption of Olympic demonstration events'. Third, as a result of analyzing news articles from 2001 to 2010 by topic modeling, three topics were selected. Topic 1 was selected as 'Taekwondo Demonstration Performance and Corruption', Topic 2 was selected as 'Muju Taekwondo Park Creation', and Topic 3 was selected as 'World Taekwondo Festival'. Fourth, as a result of analyzing news articles from 2011 to 2020 by topic modeling, three topics were selected. Topic 1 was selected as 'Successful Hosting of the 2018 Pyeongchang Winter Olympics', Topic 2 was selected as 'North-South Korea Taekwondo Joint Demonstration Performance', and Topic 3 was selected as '2017 Muju World Taekwondo Championships'.

• The Korean Journal of Financial Management
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• v.24 no.3
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• pp.91-131
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• 2007

In the paper, the effects of sidecar on index arbitrage trading and non-index arbitrage trading in the Korean stock market are examined. The analyses of return, volatility, and liquidity dynamics illustrate that there are no distinct differences for index arbitrage group and non-index arbitrage group surrounding the sidecar events. For further analysis, we construct pseudo-sidecar sample and analyse the effects of the actual sidecar and pseudo-sidecar on arbitrage sample and non-index arbitrage sample. The result of analysis using pseudo-sidecar shows that the differences between index arbitrage group and non-index arbitrage group are larger in pseudo-sidecar sample than in actual sidecar sample. This means that former results can be explained by temporary order clustering in one side before and after the event. Sidecar has little effect on non-index arbitrage group, however, it has relatively large effect on arbitrage group. These results imply that it needs to redesign the sidecar system of the Korean stock market which applies for all program trading including arbitrage and non-index arbitrage trading.

• Archives of design research
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• v.14
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• pp.163-178
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• 1996

"Color" education aimed at cultivating creativeness and expressive techniques in the education of visual art, in the college of art and design, should be balanced with "form" education; nevertheless, the present situation at Korean universities is such that the overall environments of "color" education are far too inferior to those of "form" education.The problem is, among other things, that the curriculum of visual art education is centered around formal education; in addition, color education courses consist mostly of theoretical issues, not experimental, first-hand-experience-oriented activities that are best suited for the characteristics of the language of color as a visual language, thereby making it difficult to expect the efficiency of education.Particularly, it is a serious problem that the courses dealing with color are not offered in a step by step fashion, from the most elementary, to the intermediate, working up to the most advanced level. Another problem is that those people involved in color education seldom have an expertise in their area; furthermore, the educational environment, educational tools, and the content of the texbooks are far from being ideal.Moreover, it is a grim reality that most color theory courses that have been offered end up being a lecture of "general, basic" color theories, ignoring the students' diverse specialization areas.As a way of normalizing color education, rationalizing the curriculum and initiating the professorship exclusively teaching color education have to be introduced, so that we can increase the depth of color education and individualize the contents of color education according to the students' needs. It is believed that the introduction of the "color-education-only" professorship will greatly facilitate our effort to devise an efficient educational method, to determine the scope of individualized color education, and to improve the ovarial educational environment (such as facilities, instruments, and teaching materials) necessary for an in-depth education.ments, and teaching materials) necessary for an in-depth education.