• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.447-454
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• 2001

The automatic document classification is a method that assigns unlabeled documents to the existing classes. The automatic document classification can be applied to a classification of news group articles, a classification of web documents, showing more precise results of Information Retrieval using a learning of users. In this paper, we use the weighted Bayesian classifier that weights with keywords of a document to improve the classification accuracy. If the system cant classify a document properly because of the lack of the number of words as the feature of a document, it uses relevance word cluster to supplement the feature of a document. The clusters are made by the automatic word clustering from the corpus. As the result, the proposed system outperformed existing classification system in the classification accuracy on Korean documents.

• 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.

• The KIPS Transactions:PartB
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• v.8B no.2
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• pp.144-154
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• 2001

협력적 여과 시스템은 사용자가 검색하고 읽었던 웹문서를 기반으로 사용자 군집을 생성하여 웹문서의 정확한 추천을 가능하게 한다. 이러한 목적으로 설계된 다양한 알고리즘이 있으나 속도가 느리거나 정확도가 낮다는 등의 단점이 있다. 본 논문에서는 이러한 단점을 보완하기 위하여 협력적 여과 시스템을 위한 효과적인 사용자 군집 알고리즘인 CUG알고리즘은 사용자 군집을 생성하기 위해 Apriori 알고리즘, Native Bayes 알고리즘을 이용한다. Apriori 알고리즘은 연관 단어 지식 베이스를 구축하고, Native Bayes 알고리즘은 구축된 연관 단어 지식 베이스에 가중치를 추가하며, 사용자가 검색하여 읽은 웹문서를 클래스별로 분류한다. CUG 알고리즘은 분류된 웹문서를 기반으로 하여 사용자 군집을 만든다. 이러한 방법으로 설계된 CUG 알고리즘은 사용자들이 사용할 문서를 미리 검색하여 저장함에 의해 정보검색의 효율성을 향상시키는데 사용될 수 있다. 본 논문에서 설계한 CUG 알고리즘의 선능을 평가하기 위하여 기존의 K-means 방법과 Gibbs샘플링 방법에 의한 군집과 비교한다.

• Journal of KIISE
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• v.44 no.11
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• pp.1236-1243
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• 2017

In this paper, we propose a novel way of producing keyword networks, named LSI-based ClusterTextRank, which extracts significant key words from a set of clusters with a mutual information metric, and constructs an association network using latent semantic indexing (LSI). The proposed method reduces the dimension of documents through LSI, decomposes documents into multiple clusters through k-means clustering, and expresses the words within each cluster as a maximal spanning tree graph. The significant key words are identified by evaluating their mutual information within clusters. Then, the method calculates the similarities between the extracted key words using the term-concept matrix, and the results are represented as a keyword association network. To evaluate the performance of the proposed method, we used travel-related blog data and showed that the proposed method outperforms the existing TextRank algorithm by about 14% in terms of accuracy.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.282-289
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• 2008

Although there were some technological developments in improving the collaborative filtering, they have yet to fully reflect the actual relation of the items. In this paper, we propose the recommendation system using associative web document classification by word frequency and ${\alpha}$-cut to address the short comings of the collaborative filtering. The proposed method extracts words from web documents through the morpheme analysis and accumulates the weight of term frequency. It makes associative rules and applies the weight of term frequency to its confidence by using Apriori algorithm. And it calculates the similarity among the words using the hypergraph partition. Lastly, it classifies related web document by using ${\alpha}$-cut and calculates similarity by using adjusted cosine similarity. The results show that the proposed method significantly outperforms the existing methods.

• Journal of Korea Multimedia Society
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• v.4 no.2
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• pp.171-181
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• 2001

The previous Bayesian document categorization method has problems that it requires a lot of time and effort in word clustering and it hardly reflects the semantic information between words. In this paper, we propose a weighted Bayesian document categorizing method based on association word knowledge base acquired by mining technique. The proposed method constructs weighted association word knowledge base using documents in training set. Then, classifier using Bayesian probability categorizes documents based on the constructed association word knowledge base. In order to evaluate performance of the proposed method, we compare our experimental results with those of weighted Bayesian document categorizing method using vocabulary dictionary by mutual information, weighted Bayesian document categorizing method, and simple Bayesian document categorizing method. The experimental result shows that weighted Bayesian categorizing method using association word knowledge base has improved performance 0.87% and 2.77% and 5.09% over weighted Bayesian categorizing method using vocabulary dictionary by mutual information and weighted Bayesian method and simple Bayesian method, respectively.

• Journal of the Korean Society for information Management
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• v.35 no.1
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• pp.231-250
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• 2018

In this paper, we propose a new methodology for extracting and formalizing subjective topics at a specific time using a set of keywords extracted automatically from online news articles. To do this, we first extracted a set of keywords by applying TF-IDF methods selected by a series of comparative experiments on various statistical weighting schemes that can measure the importance of individual words in a large set of texts. In order to effectively calculate the semantic relation between extracted keywords, a set of word embedding vectors was constructed by using about 1,000,000 news articles collected separately. Individual keywords extracted were quantified in the form of numerical vectors and clustered by K-means algorithm. As a result of qualitative in-depth analysis of each keyword cluster finally obtained, we witnessed that most of the clusters were evaluated as appropriate topics with sufficient semantic concentration for us to easily assign labels to them.

• Therapeutic Science for Rehabilitation
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• v.11 no.2
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• pp.25-37
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• 2022

Objective : Through the bibliographic analysis method, the flow of research is grasped from a macroscopic point of view and the connection system of key words is conducted. The purpose of this is to provide basic data for conducting research on aging anxiety and lifestyle. Methods : Among the bibliographic analysis methods, a citation analysis method that identifies the association based on the number of citations and a simultaneous appearance word analysis method that identifies the association based on the number of keywords appeared was used. VOSviewer was used to cluster and chart the analyzed information. Results : The frequency of occurrence of papers by year showed a gradual increase until 2017 and a rapid increase from 2018. In the field of research paper study, research was most actively conducted in the field of psychiatry. In the citation analysis, the United States, Australia, and the United Kingdom showed high correlation with each other, and as a result of conducting simultaneous word analysis on major keywords, words with high association with aging anxiety were found to be depression. Conclusion : This study is meaningful in that it grasped the flow of aging anxiety and lifestyle research from a macroscopic point of view using a bibliographic analysis method. Based on this, it is expected to understand the importance of lifestyle from the preventive point of view of aging and to be used as basic data for intervention and related education.

• Journal of the Korean Society for information Management
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• v.30 no.4
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• pp.195-213
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• 2013

This study aims at establishing the identity of teaching Korean as a Foreign Language (KFL) domain by using journal profiling and co-word analysis in comparison with the relevant and adjacent domains. Firstly, by extracting and comparing topic terms, we calculate the similarity of academic journals of the three domains, KFL, teaching Korean as a Native Language (KNL), and Korean Linguistics (KL). The result shows that the journals of KFL form a distinct cluster from the others. The profiling analysis and co-word analysis are then conducted to visualize the relationship among all the three domains in order to uncover the characteristics of KFL. The findings show that KFL is more similar to KNL than to KL. Finally, the comparison of knowledge structures of these three domains based on the co-word analysis demonstrates the uniqueness of KFL as an independent domain in relation with the other relevant domains.

• Journal of the Korean Society for information Management
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• v.35 no.3
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• pp.11-39
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• 2018

The study examines the research trends of doctoral dissertations in Library Science and Information Science published in the U.S. for the last 5 years. Data collected from PQDT Global includes 1,016 doctoral dissertations containing "Library Science" or "Information Science" as subject headings, and keywords extracted from those dissertations were used for a network analysis, which helps identifying the intellectual structure of the dissertations. Also, the analysis using 103 subject heading keywords resulted in various centrality measures, including triangle betweenness centrality and nearest neighbor centrality, as well as 26 clusters of associated subject headings. The most frequently studied subjects include computer-related subjects, education-related subjects, and communication-related subjects, and a cluster with information science as the most central subject contains most of the computer-related keywords, while a cluster with library science as the most central subject contains many of the education-related keywords. Other related subjects include various user groups for user studies, and subjects related to information systems such as management, economics, geography, and biomedical engineering.