• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.885-889
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• 2004

Fast and high-quality document clustering algorithms play an important role in providing data exploration by organizing large amounts of information into a small number of meaningful clusters. Hierarchical clustering improves the performance of retrieval and makes that users can understand easily. For outperforming of clustering, we implemented hierarchical structure with variety and readability, by careful selection of cluster topic words and deciding the number of clusters dynamically. It is important to select topic words because hierarchical clustering structure is summarizes result of searching. We made choice of noun word as a cluster topic word. The quality of topic words is increased $33\%$ as follows. As the topic word of each cluster, the only noun word is extracted for the top-level cluster and the used topic words for the children clusters were not reused.

• The Korean Journal of Applied Statistics
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• v.35 no.6
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• pp.739-754
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• 2022

Usually, text data consists of many variables, and some of them are closely correlated. Such multi-collinearity often results in inefficient or inaccurate statistical analysis. For supervised learning, one can select features by examining the relationship between target variables and explanatory variables. On the other hand, for unsupervised learning, since target variables are absent, one cannot use such a feature selection procedure as in supervised learning. In this study, we propose a word selection procedure that employs topic models to find latent topics. We substitute topics for the target variables and select terms which show high relevance for each topic. Applying the procedure to real data, we found that the proposed word selection procedure can give clear topic interpretation by removing high-frequency words prevalent in various topics. In addition, we observed that, by applying the selected variables to the classifiers such as naïve Bayes classifiers and support vector machines, the proposed feature selection procedure gives results comparable to those obtained by using class label information.

• Journal of Korean Elementary Science Education
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• v.28 no.4
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• pp.404-414
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• 2009

The revised curriculum in 2007 includes open inquiry approach to increase students' interest in science and to build up creativity. So teachers and pre-service teachers should be equipped with the ability of open inquiry performance. In order to investigate pre-service teachers' readiness to perform open inquiry tasks, we analyzed reports written as homework by a group of 71 juniors in a national university of education. The investigation tool was composed of four domains: topic selection, the inquiry process, the conclusion, and reporting. Each domain had three or four sub-domains. By using the framework, four raters scored the students' inquiry reports. The findings reveal that the pre-service elementary school teachers have difficulty in the domain of 'topic selection' and the 'conclusion' compared with the other domains. Under the topic selection domain, they showed weaknesses in 'creativity' and 'scientific topic' and under the conclusion domain, they had difficulty in 'recognizing limits' and 'value of conclusion'. The finding suggests that pre-service teaching program should provide with opportunities to perform open inquiry continually.

• Journal of Engineering Education Research
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• v.21 no.1
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• pp.14-26
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• 2018

The goal of this study was to explore topic defining patterns of students in interdisciplinary Capstone Design Class. Thematic analysis methodology was used to examine 85 Korean college students' lived experience of project topic generation which is for interdisciplinary capstone design class and Individual open-ended survey for constituted the data sources. Findings show four contexts of student's topic defining patterns using thematic analysis including (a) one leader's directed problem representation, (b) team common decision making after brainstorming, (c) empathy with professor proposed issue, (d) problems offered to students by corporate or research competitions. Based on research result, I could suggest instructional strategies of Capstone Design Class of teacher for helping their students' topic defining. It was necessary to minimize the opinions of the instructors at the beginning of class and minimize the number of team members. And also it provided a lot of opportunities to collaborate with companies in the topic selection process, it will help to develop the students' ability to determine the valuable topic in project.

• Women's Health Nursing
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• v.29 no.2
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• pp.128-136
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• 2023

Purpose: Topic modeling is a text mining technique that extracts concepts from textual data and uncovers semantic structures and potential knowledge frameworks within context. This study aimed to identify major keywords and network structures for each major topic to discern research trends in women's health nursing published in the Korean Journal of Women Health Nursing (KJWHN) using text network analysis and topic modeling. Methods: The study targeted papers with English abstracts among 373 articles published in KJWHN from January 2011 to December 2021. Text network analysis and topic modeling were employed, and the analysis consisted of five steps: (1) data collection, (2) word extraction and refinement, (3) extraction of keywords and creation of networks, (4) network centrality analysis and key topic selection, and (5) topic modeling. Results: Six major keywords, each corresponding to a topic, were extracted through topic modeling analysis: "gynecologic neoplasms," "menopausal health," "health behavior," "infertility," "women's health in transition," and "nursing education for women." Conclusion: The latent topics from the target studies primarily focused on the health of women across all age groups. Research related to women's health is evolving with changing times and warrants further progress in the future. Future research on women's health nursing should explore various topics that reflect changes in social trends, and research methods should be diversified accordingly.

• Journal of KIISE:Software and Applications
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• v.35 no.8
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• pp.522-528
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• 2008

Topic map typically provide information to user through the selection of topics, that is using only topic, association, occurrence on the first topicmap which is made by domain expert without regard to individual interests or context, for the purpose of supplementation for the weakness which is providing personalized topic map information, personalization has been studied for supporting user preference through preseting of customize, filtering, scope, etc in topic map. Nevertheless, personalization in current topicmap is not enough to user so far. In this paper, we propose a design of PTRS(personalized topicmap ranking system) & algorithm, using both user profile(click through data) and basic element of topic map(topic, association) on knowledge layer in specific domain topicmap, therefore User has strong point that is improvement of personal facilities to user through representation of ranked topicmap information in consideration of user preference using PTRS.

• The Korean Journal of Franchise Management
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• v.12 no.4
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• pp.13-23
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• 2021

Purpose: This study aimed to derive clues for the franchise industry to overcome difficulties such as various legal regulations and social responsibility demands and to continuously develop by analyzing the research trends related to franchises published in Korea. Research design, data and methodology: As a result of searching for 'franchise' in ScienceON, abstracts were collected from papers published in domestic academic journals from 1994 to June 2021. Keywords were extracted from the abstracts of 1,110 valid papers, and after preprocessing, keyword analysis, TF-IDF analysis, and topic modeling using LDA algorithm, along with trend analysis of the top 20 words in TF-IDF by year group was carried out using the R-package. Results: As a result of keyword analysis, it was found that businesses and brands were the subjects of research related to franchises, and interest in service and satisfaction was considerable, and food and coffee were prominently studied as industries. As a result of TF-IDF calculation, it was found that brand, satisfaction, franchisor, and coffee were ranked at the top. As a result of LDA-based topic modeling, a total of 12 topics including "growth strategy" were derived and visualized with LDAvis. On the other hand, the areas of Topic 1 (growth strategy) and Topic 9 (organizational culture), Topic 4 (consumption experience) and Topic 6 (contribution and loyalty), Topic 7 (brand image) and Topic 10 (commercial area) overlap significantly. Finally, the trend analysis results for the top 20 keywords with high TF-IDF showed that 10 keywords such as quality, brand, food, and trust would be more utilized overall. Conclusions: Through the results of this study, the direction of interest in the franchise industry was confirmed, and it was found that it was necessary to find a clue for continuous growth through research in more diverse fields. And it was also considered an important finding to suggest a technique that can supplement the problems of topic trend analysis. Therefore, the results of this study show that researchers will gain significant insights from the perspectives related to the selection of research topics, and practitioners from the perspectives related to future franchise changes.

• Journal of The Korean Association For Science Education
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• v.31 no.8
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• pp.1199-1213
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• 2011

The purpose of this study was to investigate the difficulties in engaging in open-inquiry activities - especially finding inquiry topics for student themselves. Data were collected from in-depth interviews with 11 middle school students and their open-inquiry worksheets from 4 months of activities. The investigation tools were composed of three domains for topic choice: selecting subjects, making 10 questions, and choosing a topic with the 10 questions. The study revealed that middle school students have difficulties in the domain of 'object selection' and 'finding inquiry topic.' Under the object selection domain, they showed burden of selection of unlimited subject, lack of knowledge on the science object, and lack of interest in object. Under the domain of finding inquiry topic, they have difficulties from their selected topics that were non-scientific, focus only on interest, lack of background information or those that could be resolved by short answers. Each student has difficulty in doing open-inquiry with relatively different seriousness. The findings suggested that an open inquiry program should be provided along with a systematic guide program on finding inquiry topic for open-inquiry activities to be a successful and continual performance gauge.

• The Korean Journal of Applied Statistics
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• v.32 no.3
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• pp.423-434
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• 2019

An important issues in Korea society in 2018 was the revision of the university entrance examination system. Among the discussions, in order to grasp what the issue of admission officer system is, attention was focused on the function of media such as monitoring and criticism as well as the tried topic analysis of related news articles. As a result, the reorganization of the College Scholastic Ability Test (CSAT) was derived and showed the sensitivity of Korean society towards the CSAT. Topics directly related to the admission officer system were the selection factor and fairness of the university entrance examination system in relation to the selection factor.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5592-5609
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• 2017

JPEG steganography detection is an active research topic in the field of information hiding due to the wide use of JPEG image in social network, image-sharing websites, and Internet communication, etc. In this paper, a new steganalysis method for content-adaptive JPEG steganography is proposed by integrating the evolutionary feature selection and classifier ensemble selection. First, the whole framework of the proposed steganalysis method is presented and then the characteristic of the proposed method is analyzed. Second, the feature selection method based on genetic algorithm is given and the implement process is described in detail. Third, the method of classifier ensemble selection is proposed based on Pareto evolutionary optimization. The experimental results indicate the proposed steganalysis method can achieve a competitive detection performance by compared with the state-of-the-art steganalysis methods when used for the detection of the latest content-adaptive JPEG steganography algorithms.