• Journal of KIISE:Software and Applications
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• v.31 no.4
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• pp.467-477
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• 2004

While recommender systems were used by a few E-commerce sites former days, they are now becoming serious business tools that are re-shaping the world of I-commerce. And collaborative filtering has been a very successful recommendation technique in both research and practice. But there are two problems in personalized recommender systems, it is First-Rating problem and Sparsity problem. In this paper, we solve these problems using the associative relation clustering and “Lift” of association rules. We produce “Lift” between items using user's rating data. And we apply Threshold by -cut to the association between items. To make an efficiency of associative relation cluster higher, we use not only the existing Hypergraph Clique Clustering algorithm but also the suggested Split Cluster method. If the cluster is completed, we calculate a similarity iten in each inner cluster. And the index is saved in the database for the fast access. We apply the creating index to predict the preference for new items. To estimate the Performance, the suggested method is compared with existing collaborative filtering techniques. As a result, the proposed method is efficient for improving the accuracy of prediction through solving problems of existing collaborative filtering techniques.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.11-21
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• 2022

All-solid-state batteries are one of the promising candidates for next-generation batteries and are drawing attention as a key component that will lead the future electric vehicle industry. This study analyzes 10,280 comments on Reddit, which is a global social media, in order to identify policy issues and public interest related to all-solid-state batteries from 2016 to 2021. Text mining such as frequency analysis, association rule analysis, and topic modeling, and sentiment analysis are applied to the collected global data to grasp global trends, compare them with the South Korean government's all-solid-state battery development strategy, and suggest policy directions for its national research and development. As a result, the overall sentiment toward all-solid-state battery issues was positive with 50.5% positive and 39.5% negative comments. In addition, as a result of analyzing detailed emotions, it was found that the public had trust and expectation for all-solid-state batteries. However, feelings of concern about unresolved problems coexisted. This study has an academic and practical contribution in that it presented a text mining analysis method for deriving key issues related to all-solid-state batteries, and a more comprehensive trend analysis by employing both a top-down approach based on government policy analysis and a bottom-up approach that analyzes public perception.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.39-54
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• 2013

Recent explosive increase of electronic commerce provides many advantageous purchase opportunities to customers. In this situation, customers who do not have enough knowledge about their purchases, may accept product recommendations. Product recommender systems automatically reflect user's preference and provide recommendation list to the users. Thus, product recommender system in online shopping store has been known as one of the most popular tools for one-to-one marketing. However, recommender systems which do not properly reflect user's preference cause user's disappointment and waste of time. In this study, we propose a novel recommender system which uses data mining and multi-model ensemble techniques to enhance the recommendation performance through reflecting the precise user's preference. The research data is collected from the real-world online shopping store, which deals products from famous art galleries and museums in Korea. The data initially contain 5759 transaction data, but finally remain 3167 transaction data after deletion of null data. In this study, we transform the categorical variables into dummy variables and exclude outlier data. The proposed model consists of two steps. The first step predicts customers who have high likelihood to purchase products in the online shopping store. In this step, we first use logistic regression, decision trees, and artificial neural networks to predict customers who have high likelihood to purchase products in each product group. We perform above data mining techniques using SAS E-Miner software. In this study, we partition datasets into two sets as modeling and validation sets for the logistic regression and decision trees. We also partition datasets into three sets as training, test, and validation sets for the artificial neural network model. The validation dataset is equal for the all experiments. Then we composite the results of each predictor using the multi-model ensemble techniques such as bagging and bumping. Bagging is the abbreviation of "Bootstrap Aggregation" and it composite outputs from several machine learning techniques for raising the performance and stability of prediction or classification. This technique is special form of the averaging method. Bumping is the abbreviation of "Bootstrap Umbrella of Model Parameter," and it only considers the model which has the lowest error value. The results show that bumping outperforms bagging and the other predictors except for "Poster" product group. For the "Poster" product group, artificial neural network model performs better than the other models. In the second step, we use the market basket analysis to extract association rules for co-purchased products. We can extract thirty one association rules according to values of Lift, Support, and Confidence measure. We set the minimum transaction frequency to support associations as 5%, maximum number of items in an association as 4, and minimum confidence for rule generation as 10%. This study also excludes the extracted association rules below 1 of lift value. We finally get fifteen association rules by excluding duplicate rules. Among the fifteen association rules, eleven rules contain association between products in "Office Supplies" product group, one rules include the association between "Office Supplies" and "Fashion" product groups, and other three rules contain association between "Office Supplies" and "Home Decoration" product groups. Finally, the proposed product recommender systems provides list of recommendations to the proper customers. We test the usability of the proposed system by using prototype and real-world transaction and profile data. For this end, we construct the prototype system by using the ASP, Java Script and Microsoft Access. In addition, we survey about user satisfaction for the recommended product list from the proposed system and the randomly selected product lists. The participants for the survey are 173 persons who use MSN Messenger, Daum Caf$\acute{e}$, and P2P services. We evaluate the user satisfaction using five-scale Likert measure. This study also performs "Paired Sample T-test" for the results of the survey. The results show that the proposed model outperforms the random selection model with 1% statistical significance level. It means that the users satisfied the recommended product list significantly. The results also show that the proposed system may be useful in real-world online shopping store.

• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.127-138
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• 2011

The core service of most research portal sites is providing relevant research papers to various researchers that match their research interests. This kind of service may only be effective and easy to use when a user can provide correct and concrete information about a paper such as the title, authors, and keywords. However, unfortunately, most users of this service are not acquainted with concrete bibliographic information. It implies that most users inevitably experience repeated trial and error attempts of keyword-based search. Especially, retrieving a relevant research paper is more difficult when a user is novice in the research domain and does not know appropriate keywords. In this case, a user should perform iterative searches as follows : i) perform an initial search with an arbitrary keyword, ii) acquire related keywords from the retrieved papers, and iii) perform another search again with the acquired keywords. This usage pattern implies that the level of service quality and user satisfaction of a portal site are strongly affected by the level of keyword management and searching mechanism. To overcome this kind of inefficiency, some leading research portal sites adopt the association rule mining-based keyword recommendation service that is similar to the product recommendation of online shopping malls. However, keyword recommendation only based on association analysis has limitation that it can show only a simple and direct relationship between two keywords. In other words, the association analysis itself is unable to present the complex relationships among many keywords in some adjacent research areas. To overcome this limitation, we propose the hybrid approach for establishing association network among keywords used in research papers. The keyword association network can be established by the following phases : i) a set of keywords specified in a certain paper are regarded as co-purchased items, ii) perform association analysis for the keywords and extract frequent patterns of keywords that satisfy predefined thresholds of confidence, support, and lift, and iii) schematize the frequent keyword patterns as a network to show the core keywords of each research area and connecting keywords among two or more research areas. To estimate the practical application of our approach, we performed a simple experiment with 600 keywords. The keywords are extracted from 131 research papers published in five prominent Korean journals in 2009. In the experiment, we used the SAS Enterprise Miner for association analysis and the R software for social network analysis. As the final outcome, we presented a network diagram and a cluster dendrogram for the keyword association network. We summarized the results in Section 4 of this paper. The main contribution of our proposed approach can be found in the following aspects : i) the keyword network can provide an initial roadmap of a research area to researchers who are novice in the domain, ii) a researcher can grasp the distribution of many keywords neighboring to a certain keyword, and iii) researchers can get some idea for converging different research areas by observing connecting keywords in the keyword association network. Further studies should include the following. First, the current version of our approach does not implement a standard meta-dictionary. For practical use, homonyms, synonyms, and multilingual problems should be resolved with a standard meta-dictionary. Additionally, more clear guidelines for clustering research areas and defining core and connecting keywords should be provided. Finally, intensive experiments not only on Korean research papers but also on international papers should be performed in further studies.

• Journal of the Korean Professional Engineers Association
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• v.29 no.2
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• pp.80-90
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• 1996

This research aimed at investigating the changes of volatile basic nitrogen, amino nitrogen and lipids during the fermentation of 6 month Anchovy cured under room temperature with various treatments(20, 30 and 40% salted) and examing the optimum condition of Anchovy sauce. The results are summerized as the V.B.N which increased with the curing period of anchovy from 14 mg% to 90～107mg% in 180 days curing at 20% salt level. Amino nitrogen in minced anchovy was higher than in whole anchovy during fermentation and the content of Extractive Nitrogen in the curing anchovy containing 20% of salt, kept the highest amount in 60 curing days. As a rule, minced anchovy showed more rapidly increased than whole anchovy. The lipid in curing anchovy containing 20% and 30% of salt has already been oxidized in 30 days while the lipid of anchovy cured with 40% salt prolonged the initial stage to 45 days. During fermentation, peroxide value and acid value showed constant increasing, while thiobarbituric acid began to decrease after 120 days curing. Among the non-polar lipids, linolenic acid, linoleic acid and erucic acid was decomposed by 24.5%, 22.2%, and 20.0%, respectively. It was noticed that the decomposition of polar lipid was retarded by higher salt content.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.456-466
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• 2014

This is a study of George Lindbeck's postliberalism that views religion as a cultural-linguistic approach. Knowing that the conceptual-propositional approach of the traditional Christian theology and the experiential-expressive approach of liberalism cannot be a solution for the post-modem religious phenomenon, George Lindbeck proposes an alternative. He proposes a cultural-linguistic approach to overcome the previous approaches. The first insight of Lindbeck's postliberalism is to understand religion as culture or language, because human beings become acquainted with a religion as they learn a language. The second insight comes out of the first, to understand doctrine as grammar. If we understand religion and doctrine this way the troubles and conflicts among religions will be resolved naturally, because each religion can be interpreted in its own system just as a language cannot be said to be good or bad, right or wrong. This approach makes several contributions as follows: it promotes a dialogue among religions, it emphasizes practice; and it preserves the Bible as an authoritative theological text. However it also brings many limitations as follows: it emphasizes the church's interpretation rather than the text's own interpretation; it views the truth simply as coherence; it promotes radical relativism and elitism; and through theological eschatology he makes his theory return to a propositionalism. Accordingly, the researcher concludes that Lindbeck's cultural-linguistic theory of religion is not an alternative that overcomes the limitations of theological conservativism and liberalism.

• Journal of Korea Water Resources Association
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• v.45 no.4
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• pp.361-371
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• 2012

For a basin with existing reservoirs, the necessity of additional water demands has been proposed, as well as a reevaluation of existing reservoir yield has been proposed. The objective of this study is to reevaluate a multipurpose reservoir yield and to assess the possibility of additional water supply according to increase of downstream water demands. Andong and Imha Reservoirs are selected for reevaluation. The standard reservoir operation rule model and the HEC-ResSim model were used for reservoir simulation for 30 years (1979~2008). In this study, water supply reliability was set up as 96.7% and 95.0% with yearly and monthly evaluating unit. In case of 95% water supply reliability with yearly evaluating unit, water supply capability of Andong reservoir was evaluated as 893MCM and water supply capability of Imha reservoir was evaluated as 382MCM, and that results showed that water yields for both reservoirs are less than the original designed yields.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.555-559
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• 2006

This paper will intend to contribute to extracting and storing various form of information on user interests by using structural rules user makes and XML-based word document converting techniques. The system named PPE consists of three essential element. One is converting element which converts word documents like HWP, DOC into XML documents, another is extracting element to prepare structural rules and extract concerned information from XML document by structural rules, and the other is storing element to make final XML document or store it into database system. For word document converting, we developed OCX based word converting daemon. Helping user to extracting information, we developed script language having native function/variable processing engine extended from XSLT. This system can be used in the area of constructing word document contents DB or providing various information service based on RAW word documents. We really applied it to project management system and project result management system.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.400-409
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• 2009

The Broadcasting Law amended in January 2007 declared to adopt universal right to view(known more widely as Universal Access Right, UAR), the right to access broadcasting programs on such major sports or other events that are likely to catch the gaze of the public television viewers. Then its implementation rule was issued in February 2008, and under the regulations the Committee of Ensuring Universal Access Right has been established, where detailed action measures and guidelines are currently in the process of preparing. However, it is no question that an effectiveness of the implementation system of Universal Access Right presupposes sufficient amount of discussion and social consensus. At present, the major focus in this issue is on the matters including which type of events is subject to UAR and what criteria are desirable in determining which broadcasting company has priority. In this context, this study aims at identifying implications for policy by examining the precedent cases of Europe, Australia, and other countries, where UAR is enacted and implemented. Further, this study tries to draw up a specific scheme for ensuring universal right to view through conducting a survey on public television viewers. We will include specific guidelines for selecting events of public attention, criteria for selecting broadcasting companies regarding priority, and relevant operating rules regarding relayed broadcasting.

• Journal of The Korean Association For Science Education
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• v.18 no.3
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• pp.371-382
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• 1998

The years from 1895 to 1915 marked an important period in Korean because it was the start of modern education during which a new school system was developed. In particular, the Government made laws and rules concerning the use of textbooks in schools. In this research information about books in use in schools was obtained from the {School Textbook List} which was drawn up during this period. Science textbooks printed in Korea from 1895 to 1915 were control1ed in their use by the Ministry of Education and the Government General of Chosen. They used the Private School Ordinance, Regulations for Official Examination of Textbooks in 1908, and Law of Publication in 1909 as the main means of controlling textbooks. The official examination of textbooks under the Japanese rule of Korea resulted in an increasing number of science textbooks being banned. While science textbooks had enjoyed more freedom from control by the Government General of Chosen than other textbooks, the situation changed significantly as Japan to intensify the control of all kinds of textbooks in Korea.