• Title/Summary/Keyword: co-occurrence frequency

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A Study on Technology Forecasting based on Co-occurrence Network of Keyword in Multidisciplinary Journals (다학제 분야 학술지의 주제어 동시발생 네트워크를 활용한 기술예측 연구)

  • Kim, Hyunuk;Ahn, Sang-Jin;Jung, Woo-Sung
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.4
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    • pp.49-63
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    • 2015
  • Keyword indexed in multidisciplinary journals show trends about science and technology innovation. Nature and Science were selected as multidisciplinary journals for our analysis. In order to reduce the effect of plurality of keyword, stemming algorithm were implemented. After this process, we fitted growth curve of keyword (stem) following bass model, which is a well-known model in diffusion process. Bass model is useful for expressing growth pattern by assuming innovative and imitative activities in innovation spreading. In addition, we construct keyword co-occurrence network and calculate network measures such as centrality indices and local clustering coefficient. Based on network metrics and yearly frequency of keyword, time series analysis was conducted for obtaining statistical causality between these measures. For some cases, local clustering coefficient seems to Granger-cause yearly frequency of keyword. We expect that local clustering coefficient could be a supportive indicator of emerging science and technology.

Text-Mining Analyses of News Articles on Schizophrenia (조현병 관련 주요 일간지 기사에 대한 텍스트 마이닝 분석)

  • Nam, Hee Jung;Ryu, Seunghyong
    • Korean Journal of Schizophrenia Research
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    • v.23 no.2
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    • pp.58-64
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    • 2020
  • Objectives: In this study, we conducted an exploratory analysis of the current media trends on schizophrenia using text-mining methods. Methods: First, web-crawling techniques extracted text data from 575 news articles in 10 major newspapers between 2018 and 2019, which were selected by searching "schizophrenia" in the Naver News. We had developed document-term matrix (DTM) and/or term-document matrix (TDM) through pre-processing techniques. Through the use of DTM and TDM, frequency analysis, co-occurrence network analysis, and topic model analysis were conducted. Results: Frequency analysis showed that keywords such as "police," "mental illness," "admission," "patient," "crime," "apartment," "lethal weapon," "treatment," "Jinju," and "residents" were frequently mentioned in news articles on schizophrenia. Within the article text, many of these keywords were highly correlated with the term "schizophrenia" and were also interconnected with each other in the co-occurrence network. The latent Dirichlet allocation model presented 10 topics comprising a combination of keywords: "police-Jinju," "hospital-admission," "research-finding," "care-center," "schizophrenia-symptom," "society-issue," "family-mind," "woman-school," and "disabled-facilities." Conclusion: The results of the present study highlight that in recent years, the media has been reporting violence in patients with schizophrenia, thereby raising an important issue of hospitalization and community management of patients with schizophrenia.

On the Change of Flood and Drought Occurrence Frequency due to Global Warming : 2. Estimation of the Change in Daily Rainfall Depth Distribution due to Global Warming (지구온난화에 따른 홍수 및 가뭄 발생빈도의 변화와 관련하여 : 2. 지구 온난화에 따른 일강수량 분포의 변화 추정)

  • Yun, Yong-Nam;Yu, Cheol-Sang;Lee, Jae-Su;An, Jae-Hyeon
    • Journal of Korea Water Resources Association
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    • v.32 no.6
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    • pp.627-636
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    • 1999
  • In 60 years when the double $CO_2$concentration is anticipated the average annual rainfall depth is expected to be increased by 5 10% due to global warming. However, in the water resources area the frequency change of meteorological extremes such as droughts and floods attracts more interests than the increase of annual rainfall amount. Even though recent frequent occurrences of this kind of meteorological extremes are assumed as an indirect proof of global warming, the prediction of its overall tendency has not yet been made. Thus, in this research we propose a possible methodology to be used for its prediction. The methodology proposed is based on the frequency distribution of daily rainfall be Todorovie and Woolhiser(1975), and Katz(1977), where the input parameters are modified to consider the change of monthly or annual rainfall depth and, thus, to result in the change of frequency distribution. We adopt two values(10mm, 50mm) as thresholds and investigate the change of occurrence probability due to the change monthly and annual rainfall depth. these changes do not directly indicate the changes of occurrence probability of floods and droughts, but it may still be a very useful information for their prediction. Finally, the changes of occurrence probability were found to be greater when considering the monthly rainfall rather than the annual rainfall, and those in rainy season than those in dry season.

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Research Trends Analysis on ESG Using Unsupervised Learning

  • Woo-Ryeong YANG;Hoe-Chang YANG
    • The Journal of Economics, Marketing and Management
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    • v.11 no.3
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    • pp.47-66
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    • 2023
  • Purpose: The purpose of this study is to identify research trends related to ESG by domestic and overseas researchers so far, and to present research directions and clues for the possibility of applying ESG to Korean companies in the future and ESG practice through comparison of derived topics. Research design, data and methodology: In this study, as of October 20, 2022, after searching for the keyword 'ESG' in 'scienceON', 341 domestic papers with English abstracts and 1,173 overseas papers were extracted. For analysis, word frequency analysis, word co-occurrence frequency analysis, BERTopic, LDA, and OLS regression analysis were performed to confirm trends for each topic using Python 3.7. Results: As a result of word frequency analysis, It was found that words such as management, company, performance, and value were commonly used in both domestic and overseas papers. In domestic papers, words such as activity and responsibility, and in overseas papers, words such as sustainability, impact, and development were included in the top 20 words. As a result of analyzing the co-occurrence frequency of words, it was confirmed that domestic papers were related mainly to words such as company, management, and activity, and overseas papers were related to words such as investment, sustainability, and performance. As a result of topic modeling, 3 topics such as named ESG from the corporate perspective were derived for domestic papers, and a total of 7 topics such as named sustainable investment for overseas papers were derived. As a result of the annual trend analysis, each topic did not show a relatively increasing or decreasing tendency, confirming that all topics were neutral. Conclusions: The results of this study confirmed that although it is desirable that domestic papers have recently started research on consumers, the subject diversity is lower than that of overseas papers. Therefore, it is suggested that future research needs to approach various topics such as forecasting future risks related to ESG and corporate evaluation methods.

Analysis of Mission, Vision and Core values in Korean Tertiary General Hospitals Through Text Mining (텍스트 마이닝을 통한 상급종합병원의 미션, 비전, 핵심가치 분석 연구)

  • Ji-Hoon Lee
    • Korea Journal of Hospital Management
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    • v.28 no.2
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    • pp.32-43
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    • 2023
  • Purposes: This research is conducted to identify main features and trends of mission, vision and core values in Korean tertiary general hospitals by using text-mining. Methodology: For the study, 45 mission, 112 vision and 190 core values are collected from 45 tertiary general hospitals' homepages in 2022 and use word frequency analysis and Leyword co-occurrence analysis. Findings: In the tertiary general hospitals' mission, there are high frequency words such as 'health', 'humanity', 'medical treatment', 'education', 'research', 'happiness', 'love', 'best', 'spirit', and mission mainly includes the content of contributing humanity's health and happiness with these words. In case of vision, high frequency words are 'hospital', 'medical treatment', 'research', 'lead', 'trust', 'centered', 'patient', 'best', 'future'. By using these words in vision, it represents the definition and characteristics of vision such as ideal organizations in the future, goals and targets. As a result of the Leyword co-occurrence analysis, vision includes the content of 'high-tech medical treatment', 'special care for patients', 'leading education and research', 'the highest trust with customer', 'creative talents training'. -astly, the high frequency word-pairs in core values are 'social distribution', 'innovation pursuit', 'cooperation and harmony', and it defines standards of behavior for organizations. Practical Implication: To correct the problems of vision, mission and core values from findings, firstly, it needs for Korean tertiary general hospitals to use the words that can explain organization's identity and differentiate others in their mission. Secondly, considering strengthening the role of hospitals in their community and the importance of members in organizations, it is necessary to establish vision with considering community and members to activate vision effectively. Thirdly, because there are no specific guidelines of establishing mission, vision and core values for healthcare organizations, this research concepts and results could be utilized when other organizations establish mission, vision and core values.

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Consideration of Structural Damage of Fresh Water Tank for 2,600 TEU Container Vessel (2,600 TEU Container Vessel 의 Fresh Water Tank 구조손상 사례 고찰)

  • Shin Sung-Kwang;Ahn Hyung-Joon;Choi Eui-keol;Koh Myeong-Seob;Leem Hyo-Kwan
    • Special Issue of the Society of Naval Architects of Korea
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    • 2005.06a
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    • pp.216-221
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    • 2005
  • Many tanks such as a fresh water tank, an aft peak tank and oil tanks are arranged in the engine room and aft part areas of the ship. By added mass effect of the fluid inside the tanks, the natural frequency will be changed according to filling height of the tank. For this reason, there is possibility of occurrence of excessive vibration by resonance between natural frequencies of local structure and excitation frequencies of the propeller or main engine. Therefore, calculation of natural frequencies is required for structure for many types of tank which are contacting with water or oil to consider added mass effect for anti-resonance design at design stage. In this study, a case of structure damage on the fresh water tank for 2600 TEU container vessel is introduced. In addition, natural frequency analysis and vibration measurement have been performed to investigate vibration characteristics for excessive vibration control.

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Semantic Network Analysis on the MIS Research Keywords: APJIS and MIS Quarterly 2005~2009

  • Lee, Sung-Joon;Choi, Jun-Ho;Kim, Hee-Woong
    • Asia pacific journal of information systems
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    • v.20 no.4
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    • pp.25-51
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    • 2010
  • This study compares and contrasts the intellectual development of the MIS field in Korea from 2005 to 2009 to that of international trends by using a keyword co-occurrence network analysis of the two flagship journals: APJIS and MIS Quarterly. From 316 research articles in these two journals, 132 unique and most frequently co-occurred keywords were put into analysis. The results of structural equivalence show a mild correlation between APJIS and MIS Quarterly. The e-commerce, trust, and technology adoption are the high frequency keywords in both journals. In Korea e-learning, purchasing, and recommendation systems turn out to be important keywords while outsourcing, research method, quantitative method, design research, information theory, and empirical research are in average international journals. This connotes that the Korean scholarship tends to focus more on practically oriented topics, but the clustering and relational mapping of research topics in each journal show a mild level of overlap with distinctive orientations due to intrinsic disparities depending on the concerned journals' geographical scopes, namely domestic or global.

Analysis of Reference Inquiries in the Field of Social Science in the Collaborative Reference Service Using the Co-Word Technique

  • Cho, Jane
    • Journal of the Korean Society for Library and Information Science
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    • v.49 no.1
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    • pp.129-148
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    • 2015
  • This study grasped the true nature of the inquiry domain by analysing the requests for collaborative reference service in the social science field using the co-word technique, and schematized the intellectual structure. First, this study extracted 748 uncontrolled keywords from inquiries for reference in the field of social science. Second, calculated similarity indices between the words on the basis of co-occurrence frequency, and performed not only clustering but also MDS mapping. Third, to grasp the difference in inquiries for reference by period, dividing the period into two parts, and performed comparative analysis. As a result, there formed 5 clusters and "Korea Education" showed an overwhelming size with 40.3% among those clusters. The result of the analysis through the period division showed there were many questions about "Education" during the first half, while a lot of inquiries with focus on "welfare and business information" during the second half.

Effects of Smoking, Drinking and Drug use on the Adolescent's Suicidal Ideation by using the Data of the Korea Youth Risk Behavior Web-based Survey through from 2008 to 2014 (2008~2014년까지 청소년건강행태 온라인조사를 활용하여 흡연·음주·약물사용이 청소년 자살생각에 미치는 영향)

  • Jeon, Hae Seong
    • Journal of the Korean Society of School Health
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    • v.28 no.2
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    • pp.99-110
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    • 2015
  • Purpose: This study aims to investigate the association between suicidal thoughts and the co-occurrence of alcohol, tobacco, and drug use among adolescents. Methods: This study used the data of the Korea Youth Risk Behavior Web-based Survey from 2008 through 2014. The subjects of this study were 517,866 students, in total (Male 266,500, Female 251,366). Frequency analysis was conducted on the data about the subjects' general characteristics and their experience of smoking, drinking, and drug use. The relationship between suicidal thoughts and the co-occurrence of alcohol, tobacco, and drug use was analyzed through ${\chi}^2-test$ and logistic regression. The analyses were done using SAS 9.4. Results: According to the study, adolescents who used alcohol, cigarettes, and drugs at the same time engaged in suicidal ideation 3.69 times more than their peers who didn't use such substances (95% CI: 3.40~4.00, p<.001). Also, adolescents who used only tobacco, only alcohol, and only drugs engaged in suicidal ideation 1.49 times (95% CI: 1.43~1.56, p<.001), 1.28 times (95% CI: 1.26~1.31, p<.001) and 2.34 times (95% CI: 2.04~2.69, p<.001) more than the students who didn't use any substances, respectively. Conclusion: Adolescents' suicidal ideation and the co-occurrence of alcohol, tobacco, and drug use had a statistically significant relationship.

Association rule thresholds of similarity measures considering negative co-occurrence frequencies (동시 비 발생 빈도를 고려한 유사성 측도의 연관성 규칙 평가 기준 활용 방안)

  • Park, Hee-Chang
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.6
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    • pp.1113-1121
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    • 2011
  • Recently, a variety of data mining techniques has been applied in various fields like healthcare, insurance, and internet shopping mall. Association rule mining is a popular and well researched method for discovering interesting relations among large set of data items. Association rule mining is the method to quantify the relationship between each set of items in very huge database based on the association thresholds. There are three primary quality measures for association rules; support and confidence and lift. In this paper we consider some similarity measures with negative co-occurrence frequencies which is widely used in cluster analysis or multi-dimensional analysis as association thresholds. The comparative studies with support, confidence and some similarity measures are shown by numerical example.