• 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.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.3
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• pp.45-52
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• 2018

Currently, apartments have become an important research subject for the overall area of politics, economics, and culture as well as urban architectural study. However, there are few analyses of the research trends related to the current interest in the apartment research and prediction of the future changes of an apartment in politics and industry. In this study, the research information related to the apartment has classified, and the changes in the research trends have analyzed. Based on the classified data, the first thesis and dissertation related to the apartment and changes of academic notation have discovered. In addition, future interests and future research directions through Frequency of Appearance, Degree Centrality Analysis, and Betweenness Centrality Analysis of author keywords were predicted. As a result of the analysis, 'Space,' 'Residential Mobility' and 'Apartment Complex' studies were found to be important research topics throughout the entire period. 'Han Gang Apartment,' 'Small Size Apartment,' 'Civic Apartments,' 'Jamsil,' and 'Child' were newly interested topics until 70's era. '(Super) High-rise Apartment,' 'Perception,' 'Jugong Apartment,' 'Housing Environment,' 'Housewife,' 'Apartment Layout,' and 'Busan' were newly interested topics during the 80's and 90's era. 'Apartment Price,' 'Energy,' 'Remodeling,' 'Noise,' 'Resident Satisfaction,' 'Community,' and 'Apartment Lotting-out' were newly interested topics after the year 2000. New concerns for last decade are found to be 'Super High-rise Apartment', 'Remodeling', 'Indoor'(2007), 'Apartment Reconstruction Project', 'Brand', 'AHP', 'Housing Environment'(2008), 'Ventilation'(2009), 'Apartment Lotting-out'(2010), 'Economic Assessment'(2011), 'Cost'(2012), 'Green Building', 'Apartment Sales', 'Law', 'Society'(2013), 'Floor Impact Noise', 'Seoul'(2014), 'Noise'(2015), 'Hedonic Model'(2016). In addition, following research topics are expected to be active in the future: In maturity stage of the research development is going to be 'Apartment Price', 'Space', 'Management of Apartment Housing'; the hedonic model, which is research growth and development stage, is going to be '(Floor Impact) Noise', 'Community', 'Energy.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.21-28
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• 2020

In this study, we reviewed the main strategies and contents of the work style innovation promoted by the Moon Jae-in government, and analyzed the contents and success factors of the work innovation based on the case of a specific local government. In particular, this study analyzes the case of innovation in the way of working through simplification of work, and the local governments, which were the subject of the study, received excellent evaluation in the government innovation evaluation of the Ministry of Public Administration and Security in 2019. In this study, we conducted in-depth interviews with employees of local governments to examine the problems, achievements, and success factors related to business simplification. First, it was found that it is very important to form consensus so that the members of the organization can participate in the change in order to simplify the task. Second, incentives, such as HR, were needed to induce active participation of members in the innovation project called Simplification of Work. Third, in order to induce and support organizational change, it was found that the interest and support of middle managers and directors were the most important factors. The results of this study will help to prepare the policy for innovation in the public sector's working style.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.1-13
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• 2020

With the advent of an intelligent information society, research toward artificial intelligence education was conducted. In previous studies, the subject of research is biased, and studies that analyze attitudes toward artificial intelligence are insufficient. So, in this study developed a test tool to measure the artificial intelligence of high school students and analyze their attitudes toward artificial intelligence. To develop the test tool, 229 high school students completed a preliminary test, of which the results were analyzed via exploratory factor analysis. To analyze the students' attitudes toward artificial intelligence, the resulting test tool was applied to 481 high school students, and their test results were analyzed according to factors. From the study's results, there was no difference according to gender in the students' attitudes toward artificial intelligence, but there was a significant difference per grade. In addition, there was a significant difference in attitudes according to artificial intelligence-related experiences: the high school students who had direct and indirect experience with artificial intelligence, programming, and more frequently used it had more positive attitudes toward artificial intelligence than students without this experience. However, artificial intelligence education experience negatively influenced the students' attitudes toward artificial intelligence. Overall, the higher their interest in artificial intelligence, the more positive the high school students' attitudes toward artificial intelligence.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.47-52
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• 2021

Recently, the share of wind power in energy markets has sharply increased with the active development of renewable energy internationally. In particular, large-scale wind farms are being developed far from the coast to make use of abundant wind resources and to reduce noise pollution. In addition to the electromagnetic interference (EMI) caused by offshore wind farms to coastal or air surveillance radars, it is necessary to investigate the EMI on global maritime distress and safety system (GMDSS) communications between ship and coastal stations. For this purpose, this study investigates whether the transmitted field of MF/HF band from a ship would be subject to interference or attenuation below the threshold at a coastal receiver. First, using geographic information system digital maps and 3D CAD models of wind turbines, the area of interest is electromagnetically modeled with patch models. Although high frequency analysis methods like Physical Optics are appropriate to analyze wide areas compared to its wavelength, the high frequency analysis method is first verified with an accurate low frequency analysis method by simplifying the surrounding area and turbines. As a result, the received wave power is almost the same regardless of whether the wind farms are located between ships and coastal stations. From this result, although wind turbines are large structures, the size is only a few wavelengths, so it does not interfere with the electric field of MF/HF distress communications.

• The Korean Journal of Applied Statistics
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• v.35 no.2
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• pp.251-263
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• 2022

Phase I clinical trial is called 'Dose finding study'. It is first step of experimenting on humans with new drugs developed through animal experiments or vitro experiments. The important area of interest in designing Phase I clinical trial is determining the dose that acceptable level to the patients and provides the greatest efficacy. In this paper, we explain about methods to determine the maximum tolerated dose using various stopping rules. The SM3, NM, Rim, J3, BSM methods are compared through simulation. And we consider how the methods might be reformed. As a result of the simulation, BSM estimated the MTD closest to the target toxicity probability. J3 method required the least number of subjects. These results are due to the feature of the stopping rules of both methods. The BSM adds 2 or 1 subject at the same dose level when there is a toxic reaction. In addition, the J3 method has a smaller number of subjects than the other methods. If the methods are improved by combining these features, MTD can be estimated more efficiently. If the total number of subjects can be reduced while using the stopping rule of the BSM, accurate estimation is possible for a small number of subjects.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.51-59
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• 2020

Although social interest is high in relation to the provision of disease codes to games, it is still insufficient to identify the damages caused by games. The purpose of this study is to examine the research trends related to game using of preschoolers to understand the implications of the precedent researches. According to the purpose, the research period, contents, types, data collection, statistical analysis, research/investigation subjects, and academic fields of the precedent researches were examined. The subject were 69 articles published in Korea from 2010 to 2019. As a result, first, a large number of researches related to preschoolers' game using were conducted in 2010-2011, 2014-2016, and the number has decreased sharply since 2017. Second, the contents of the study were mainly about the negative influences of the game and the program development. Third, quantitative and qualitative researches were conducted evenly. Fourth, the data collection methods was mostly questionnaire and other survey methods, and statistical analysis was mostly descriptive statistics, difference verification, and regression analysis. Fifth, the study subjects were focused on preschoolers, and there were many indirect investigation through parents and teachers. Sixth, the academic fields were largely divided into educational and game fields, and there was a distinct difference in the trend of research topics between the fields. Based on the results, this study aimed to provide basic information and data that can be the basis for further research on the game using and to suggest directions for future research.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.117-129
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• 2021

Nowadays, the trend of early childhood education has focused on finding educational activities to enhance quality of learning with integrative, learner-centered experience by combining each subject and domain. Pre-service early childhood teacher's music drama activity is a sort of integrated education including literature, instrumental music, play, art and movement that are included in the culture and art for preschoolers to help them understand role and value of the art and directly influence personality and creativity and motive to arouse interest in various learning directly. It's expected to see that development of creative teaching plan for the music drama using piano ensemble could support basic research in integrated educational activity in the teacher training course and also, activate the music drama activity. Research findings and suggestion are as follows. First, the music drama activities are systematically and step-by-step implemented according to the audience according to the cooperative learning and creative plans of pre-service early childhood teachers. Second, if understanding characteristics of casts in the music drama and assigning their roles efficiently, it enhances approach of pre-service early childhood teacher music drama activity and activate it. Third, making music in music drama activities can be composed and arranged to suit the musical literacy and level of pre-service early childhood teacher. Fourth, pre-service early childhood teachers could have integrated experience and evaluation efficiently in the short term to use as reference for the teaching plan and data for the music drama.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.354-360
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• 2021

People hope to live a healthy and happy life achieving satisfaction by striking a good work-life balance. Therefore, there is a growing interest in well-aging which means living happily to a healthy old age without worry. This study identified important factors related to well-aging by analyzing news articles published in Korea. Using Python-based web crawling, 1,199 articles were collected on the news service of portal site Daum till November 2020, and 374 articles were selected which matched the subject of the study. The frequency analysis results of text mining showed keywords such as 'elderly', 'health', 'skin', 'well-aging', 'product', 'person', 'aging', 'female', 'domestic' and 'retirement' as important keywords. Besides, a social network analysis with 45 important keywords revealed strong connections in the order of 'skin-wrinkle', 'skin-aging' and 'old-health'. The result of the CONCOR analysis showed that 45 main keywords were composed of eight clusters of 'life and happiness', 'disease and death', 'nutrition and exercise', 'healing', 'health', and 'elderly services'.

• Korean Association of Arts Management
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• no.57
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• pp.59-84
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• 2021

This study examined the structure of YouTube video network and the factors for the diffusion of Chinese creator's videos through the case of famous Chinese creator Fengtimo. There is few interest to the diffusion of Chinese contents among Korean researchers, while they have been studied the consumption of Hallyu(Korean wave) contents overseas. Using the data that YouTube Data API offers, this study analysed the video network that the comments of which are same users with NodeXL tools and the regression model with JASP tools. The study found that there are three groups of the YouTube channels of that network. They are domestic official accounts of Fengtimo, foreign officail accounts of Fengtimo and individual creators' accounts. The official accounts share the videos of Fengtimo's songs and entertainment contents for the fans, where the individual creators share their own meme videos(UGC). The significant factors for the diffusion in the YouTube video network are comments, likes, out-degree, dislikes, in-degree and betweenness centrality. There are significant difference between official channel and indivisual groups on the views. And degree and betweenness centrality have mediating effect. It is necessary to conduct more research on that subject with many other cases if we want to get to know the generalized explanation.