• Communications of Mathematical Education
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• v.37 no.1
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• pp.21-45
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• 2023

This study presents a machine learning program designed to identify impactful papers in the field of mathematics education. To achieve this objective, we examined the impact of papers from a scientific econometrics perspective, developed a mathematics education research network, and defined the impact of mathematics education research using PageRank, a network centrality index. We developed a machine learning model to determine the impact of mathematics education research and identified the journals with the highest percentage of impactful articles to be the Journal for Research in Mathematics Education (25.66%), Educational Studies in Mathematics (22.12%), Zentralblatt für Didaktik der Mathematik (8.46%), Journal of Mathematics Teacher Education (5.8%), and Journal of Mathematical Behaviour (5.51%). The results of the machine learning program were similar to the findings of previous studies that were read and evaluated qualitatively by experts in mathematics education. Significantly, the AI-assisted impact evaluation of mathematics education research, which typically requires significant human resources and time, was carried out efficiently in this study.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.329-338
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• 2022

As the non-face-to-face economic situation developed due to the COVID-19 pandemic, untact stock groups appeared in the stock market. This study proposed the Korea COVID-19 fear index following the spread of infectious diseases in the COVID-19 pandemic situation and analyzed the influence on the untact stock and contact stock returns. The results of the empirical analysis are as follows. First, as a result of the Granger causality analysis using the Korea COVID-19 fear index, significant causality was found in the return of contact stocks such as Korean Air, Hana Tour, CJ CGV, and Paradise. Second, as a result of stock price prediction based on the LSTM model, Kakao, Korean Air, and Naver's prediction performance was high. Third, the investment performances of the Alexander filter entry rule using the predicted stock price were high in Naver futures and Kakao futures. This study can find a difference from previous studies in that it analyzed the influence of the spread of the COVID-19 pandemic on untact and contact stocks in the COVID-19 situation where the non-face-to-face economy is in full swing.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.04a
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• pp.104-104
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• 2018

• Journal of the Korean Society for information Management
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• v.31 no.3
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• pp.153-179
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• 2014

This study explores the characteristics of centrality measures for analyzing researchers' impact and structural positions in research collaboration networks. We investigate four binary network centrality measures (degree centrality, closeness centrality, betweenness centrality, and PageRank), and seven existing weighted network centrality measures (triangle betweenness centrality, mean association, weighted PageRank, collaboration h-index, collaboration hs-index, complex degree centrality, and c-index) for research collaboration networks. And we propose SSR, which is a new weighted centrality measure for collaboration networks. Using research collaboration data from three different research domains including architecture, library and information science, and marketing, the above twelve centrality measures are calculated and compared each other. Results indicate that the weighted network centrality measures are needed to consider collaboration strength as well as collaboration range in research collaboration networks. We also recommend that when considering both collaboration strength and range, it is appropriate to apply triangle betweenness centrality and SSR to investigate global centrality and local centrality in collaboration networks.

• Land and Housing Review
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• v.4 no.1
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• pp.43-54
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• 2013

This This paper investigates the variation of the factors to determinate housing price in Seoul metropolitan area after sub-prime financial crisis, in Korea, using a VAR model. The model includes housing price and housing rent (Jeonse) in Seoul metropolitan area from 1999 to 2011, and uses interest rate, real GDP, KOSPI, Producer Price Index and practices to impulse response and variance decomposition analysis to grasp the dynamic relation between a variable of macro economy and and a variable of housing price. Data is classified to 2 groups before and after the 3rd quater of 2008, when sub-prime crisis occurred; one is from the 1st quater of 1999 to the 3rd quater of 2008, and the other is from the 2nd quater of 1999 and the 4th quater of 2011. As a result, comparing before and after sub-prime crisis, housing price is more influenced by its own variation or Jeonse price's variation instead of interest rate and KOSPI. Both before and after sub-prime financial crisis, Jeonse price is also influenced by its own variation and housing price. While after sub-prime financial crisis, influences of Producer Price Index, KOSPI and interest rate were weakened, influence of real GDP is expanded. As housing price and housing rent are more influenced by real economy factors such as GDP, its own variation than before sub-prime financial crisis, the recent trend that the house prices is declined is difficult to be converted, considering domestic economic recession and uncertainty, continued by Europe financial crisis. In the future to activate the housing business, it ia necessary to promote purchasing power rather than relaxation of financial and supply regulation.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.135-142
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• 2002

본 연구에서는 2개의 사례지구에 대한 설문조사를 통해 서비스평가 구조모형을 개발하였다. 모형의 가설로서 요인분석과 신뢰성 분석 등을 통해 구성된 '질적서비스에 대한 인식', '이동성에 대한 인식 '환승에 대한 인식', '경제성에 대한 인식'이란 인지서비스(Perceived service)를 나타내는 4개의 잠재변수는 '개인속성'과 '교통특성'이란 잠재변수의 영향을 받으며, 상호 구조적인 관계를 가지고 전반적인 만족도로 대표되는 '서비스평가'에 영향을 미친다고 가정한다. 모형추정결과, 기초적합지수(GFI)가 상인·월성 0.864, 지산·범물 0.807로 나타났고, 조정 적합지수 (AGFI)는 상인·월성 0.823. 지산·범물 0.759로 나타나 적합성은 대체로 양호하다고 할 수 있다. 또한 두 지역 모두에 있어서 잠재변수 간이나 잠재변수와 관측변수간의 인과계수의 유의성도 2, 3개의 인과계수를 제외하면 모두 5% 유의수준에서 유의한 것으로 나타나 전체적으로 모형이 타당하다고 판단된다. 상인·월성의 경우, 운전기사에 대한 인식치가 '서비스평가'에 미치는 영향력이 가장 크며, 요금수준과 더불어 직접적으로 '서비스평가'에 영향을 미치고 있다 기타 편리성, 쾌적성, 시설 및 운영성이 중요한 원인으로 작용하고 있다는 것을 시사하고 있다. 지산·범물의 경우, 쾌적성, 시설 및 운영성, 편리성이 '서비스평가'에 직접적으로 큰 영향력을 미치고 있다. 특히 이러한 '질적서비스에 대한 인식'은 버스의 현행 요금수준과 대기시간에, 그리고 유의성이 높다고 할 수 없지만 이용자의 연령과 버스이용빈도에 영향을 받고 있는 것으로 나타났다.

• Journal of Korea Technology Innovation Society
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• v.16 no.2
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• pp.424-443
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• 2013

National Research Foundation of Korea (NRF) provides underpinning to boost international and domestic competitiveness in basic science and engineering (S&E) research. In 2012, NRF came up with the idea about implementing koreanized grant funding system and a NRF grant funding mechanism on basic research was applied to General Researcher program. The main components of the mechanism are 1) no final evaluation, instead intensive evaluation for next proposal submission, 2) no paper account report, instead reporting it online, 3) no lengthy final report, instead unloading a brief overview of research achievements. For successful establishment of the NRF grant funding mechanism, the quality and quantity-based quantitative guidelines of research achievement for various research areas are essential. In this study, we suggest 3 quantitative indexes and these quantitative guidelines provides a supplementary tool for researcher's capability review. These guidelines will be also useful to elevate the reliability and objectivity of peer review.

• International Area Studies Review
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• v.13 no.2
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• pp.255-276
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• 2009

This article has examined the international transmission of returns among S&P500, Nikkei225 and SENSEX stock index cash markets using the daily closing prices covered from January 4, 2002 to February 6, 2009. For this purpose we employed dynamic time series models such as the Granger causality analysis and variance decomposition analysis based on VAR model. The main empirical results are as follows; First, according to Granger causality tests we find that S&P500 stock index has a significant prediction power on the changes of SENSEX and Nikkei225 stock index market and vice versa. However, US stock market's influence is dominant to the other stock markets at a significant level statistically. Second, according to variance decomposition, SENSEX stock index is more sensitive to the movement of S&P500 than that of Nikkei225 stock index. These kinds of empirical results shows that the three stock markets are integrated over times and these results will be informative for the international investors to build the world-wide investment portfolio and risk management strategies, etc.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.47-47
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• 2021

글로벌 물산업의 규모는 2019년 기준 약 1,000조원 수준으로 2024년까지 연평균 3.5%의 성장률을 달성할 것으로 예측하고 있다. 특히 코로나 19의 영향으로 디지털 물산업에 대한 투자가 증가하고 있으며 4차산업혁명 등으로 지속 성장이 예상되고 있다. 이러한 디지털 물산업 시장의 성장은 물산업분야의 기술경쟁력의 중요도가 더욱 높아질 것을 예상하게 한다. 우리나라의 물산업에 있어서 기술경쟁력 분석을 위해 많은 연구가 진행되어왔으나 대부분 설문조사에 근거한 정석적 분석에 의존하여 왔다. 정성적인 분석에 의존한 연구의 경우, 대상 응답자들이 특정 분야에 치중되어 분석되거나 긍정적으로 판단하는 경향이 있어 우리나라의 물산업 기술의 현재 상황을 과대평가할 가능성이 있다. 또한 연구시점, 설문분야에 따라 결과가 상이할 수 있어 결과의 신뢰성 및 시계열적 추이분석이 어려워 물산업정책 수립을 위해 활용되는데 한계가 존재하였다. 본연구에서는 기존의 정성적 분석에서 벗어나 정량적인 자료에 근거하여 우리나라의 물산업 기술수준과 시장지배를 동시에 고려하여 분석하였다. 물산업의 기술영향력지수(Cites per Patent)와 시장지배력지수(Patent Family Size)를 기준으로 선도국가와 국내 물산업 기술수준 및 시장영향력을 비교하고 평가하였다. 연구결과의 정책적 활용을 위해 물기술과 물시장의 상이한 분류체계를 물시장 중심으로 재분류하여 물산업 기술경쟁력을 분석하여 제시하였다. 연구결과 우리나라의 국내 기술영향력 중 가장 낮은 분야는 하수도 디지털 분야로 선도국가 대비 30% 수준이었으며 시장지배력분야 또한 하수분야로 7% 수준으로 파악되었다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.810-811
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• 2007

기온의 변화에 따라 전력수요는 상관성을 가지고 밀접하게 움직이는데, 최근에 와서 상관성이 약화되는 경향을 보이면서 불확실성이 증가되고 있다. 이러한 현상이 나타나는 원인은 기온을 분포함수화하여 접근하지 못하고, 누적기온 영향력과 실질적 기온분포를 반영하지 못했기 때문이다. 따라서 이를 보완하기 위해 전력기온지수라는 개념을 새로 창출하였으며, 여기에 누적기온반응도, 유효기온분포 및 실질기온 효과를 반영하였다. 따라서 종합적 전력기상요인인 전력기온지수를 통해 전력소비자의 자발적 수요관리 유도 및 안정적 전력수급의 토대를 마련할 수 있다는 결론을 얻었다.