• Journal of KIISE:Software and Applications
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• v.31 no.2
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• pp.153-163
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• 2004

Many recommender systems are based on Content-based Filtering and Social Filtering Both methods have their own advantages and disadvantages, and they complement each other rather than compete. So incorporating of both methods can make the better system and combination technique controls the quality of the entire recommender system. In this paper, we presented each user has his own tendency to decide which is the better recommendation for himself among the various recommendation results, and suggested the Personalized combination technique. To represent user tendency, we defined and used loyalty, diversity and pioneerity and showed by experiments that our combination technique is useful. This combination technique improved the average coverage 23% and for the ceiling 40%.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2004.11a
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• pp.340-348
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• 2004

온라인상점의 상품추천시스템은 일대일마케팅의 대표적 실현수단으로써의 가치를 인정받고 있다. 대부분의 상품추천시스템은 시시각각 변화하는 소비자의 기호에 따라 상품을 어떻게 추천할 것인가에 대한 문제에 직면해 있다. 본 연구에서는 급변하는 온라인상점 환경에 탄력적으로 대응하기 위하여 데이터마이닝과 다중모형조합기법을 이용한 상품추천시스템 모형을 제안하고자 한다. 제안하는 상품추천시스템은 현재 운영중인 온라인상점 데이터로 프로토타입을 구축하고 실제 소비자에 대한 적용가능성을 검증하였으며, 그 결과 실제 유용할 것으로 확인되었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.714-717
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• 2008

협업여과 추천기법에는 사용자 기반 협업여과와 아이템 기반 협업여과가 있으며, 절차는 유사도 측정, 이웃 선정, 예측값 생성 단계로 이루어진다. 유사도 측정 단계에는 유클리드 거리(Euclidean Distance), 코사인 유사도(Cosine Similarity), 피어슨 상관계수(Pearson Correlation Coefficient) 방법 등이 있고, 이웃 선정 단계에는 상관 한계치(Correlation-Threshold), 근접 N 이웃(Best-N-Neighbors) 방법 등이 있다. 마지막으로 예측값 생성 단계에는 단순평균(Simple Average), 가중합(Weighted Sum), 조정 가중합(Adjusted Weighted Sum) 등이 있다. 이처럼 협업여과 추천기법에는 다양한 기법들이 사용되고 있다. 따라서 본 논문에서는 사용자 기반 협업여과와 아이템 기반 협업여과 추천기법에 사용되는 유사도 측정 기법과 예측값 생성 기법의 최적화된 조합을 알아보기 위해 성능 실험 및 비교 분석을 하였다. 실험은 GroupLens의 MovieLens 데이터 셋을 활용하였고 MAE(Mean Absolute Error)값을 이용하여 추천기법을 비교 하였다. 실험을 통해 유사도 측정 기법과 예측값 생성 기법의 최적화된 조합을 찾을 수 있었고, 사용자 기반 협업여과와 아이템 기반 협업여과의 성능비교를 통해 아이템 기반 협업여과의 성능이 보다 우수했음을 확인 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.68-71
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• 2008

웹 상에 정보가 폭발적으로 증가함에 따라 각 사용자에게 맞는 정보를 선별하여 제공하는 개인화 서비스는 매우 중요한 이슈가 되었다. 기존 추천시스템들은 컨텐츠 기반 필터링과 협업 필터링 기법을 기반으로 한다. 그러나 이러한 방법들은 충분히 수집된 사용자 정보를 필요로 하기 때문에, 적절한 추천이 이루어지기 까지 다소 시간이 소요되는 문제를 가지고 있다. 또한 사용자의 성향이 지나치게 편중되는 경우, 사용자의 취향변화를 반영하여 새로운 상품을 추천하는 것은 어렵다. 실제로 사용자들은 웹 사이트의 방문 목적에 따라 개인화된 상품추천을 원하기도 하고, 많은 사용자들에게 인기 있는 상품을 원하기도 한다. 본 논문에서는 사용자의 행동분석을 기반으로, 협업 필터링을 기반으로 하는 개인화된 추천과 다수의 사용자들에게 공통적으로 인기 있는 상품의 추천 비율을 동적으로 조합하여 최종 추천 상품들을 선별하는 새로운 적응형 추천 시스템을 제안한다. 본 논문에서는 MovieLens의 데이터 셋을 이용하여 기존 추천기법들과 추천결과에 대한 정확도를 비교 실험하였으며, 보다 높은 정확도를 보이는 실험결과를 통해 제안시스템의 유효성을 확인하였다.

• 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 Digital Convergence
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• v.11 no.1
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• pp.249-254
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• 2013

The number of channels are increased into several hundreds of channels when coming out the digital broadcasting era. In this environment, viewers searching for programs will be very difficult to do. In addition, recent popularization of smart devices are receiving the services that they previously had not been given to. A TV program recommended a system that has been studied as a way to solve these problems. However, most studies have been studied in most web-based research results when applied to broadcast TV for TV program recommendations. In particular, the combination of the current members who watch TV are not considered. In this paper, the environment and TV viewers are considering a combination of the members of the TV program's recommended system proposal. In order to make a group deal successful, we employ the face recognition.

• Journal of the Korean Society for information Management
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• v.40 no.1
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• pp.121-148
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• 2023

The purpose of this study is to propose a scholarly paper recommendation system based on metadata attribute similarity with excellent performance. This study suggests a scholarly paper recommendation method that combines techniques from two sub-fields of Library and Information Science, namely metadata use in Information Organization and co-citation analysis, author bibliographic coupling, co-occurrence frequency, and cosine similarity in Bibliometrics. To conduct experiments, a total of 9,643 paper metadata related to "inequality" and "divide" were collected and refined to derive relative coordinate values between author, keyword, and title attributes using cosine similarity. The study then conducted experiments to select weight conditions and dimension numbers that resulted in a good performance. The results were presented and evaluated by users, and based on this, the study conducted discussions centered on the research questions through reference node and recommendation combination characteristic analysis, conjoint analysis, and results from comparative analysis. Overall, the study showed that the performance was excellent when author-related attributes were used alone or in combination with title-related attributes. If the technique proposed in this study is utilized and a wide range of samples are secured, it could help improve the performance of recommendation techniques not only in the field of literature recommendation in information services but also in various other fields in society.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.66-73
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• 2007

Internet is a part of our common life and tremendous information is cumulated. In these trends, the personalization becomes a very important technology which could find exact information to present users. Previous personalized services use content based filtering which is able to recommend by analyzing the content and collaborative filtering which is able to recommend contents according to preference of users group. But, collaborative filtering needs the evaluation of some amount of data. Also, It cannot reflect all data of users because it recommends items based on data of some users who have similar inclination. Therefore, we need a new recommendation method which can recommend prefer items without preference data of users. In this paper, we proposed the apparel coordination system using personalized preference on the semantic web. This paper provides the results which this system can reduce the searching time and advance the customer satisfaction measurement according to user's feedback to system.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.178-182
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• 2006

인터넷과 웹이 일상생활의 일부가 되면서 온라인상에는 방대한 양의 정보가 쌓이게 되었다. 이러한 흐름 속에서 정보의 양은 급속도로 늘어나는 현상을 보이며, ‘개인화’ 를 통해 수많은 데이터들 사이에서 원하는 정보를 자동으로 찾아내는 기술의 중요성이 부각되고 있다. 이를 ‘추천시스템’ 이라 부르며, 내용기반 필터링과 협력적 필터링 등의 연구가 활발히 이루어지고 있다. 그러나 사용자에게 가장 중요한 영향을 미치는 또래의 선호도, 지역, 시대 등의 복합적인 환경을 반영하는데 아직까지 어려움을 지니고 있다. 따라서 본 논문에서는 기존의 필터링들을 조합하고 좀더 편리하게 정보를 공유하고 학습할 수 있는 시맨틱 웹에서 연관 이웃 마이닝 기법을 통해 개인화된 추천 시스템을 설계한다. 생활에서 흔히 접할 수 있는 의상을 다양한 사용자에게 특화되어 코디해주는 시스템을 웹에서 제공한 결과 불필요한 검색시간이 줄어들고 사용자의 피드백을 통해 점차 만족도가 향상됨을 알 수 있었다.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.183-190
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• 2009

The core technique of ubiquitous computing is the context aware computing and the context aware technique is more like software so the important research work is to develop the core engines first and the adapted device for the engines. When ubiquitous computing era comes, the current existing internet shopping mall, the form of searching the direct goods and ordering the goods by the customers evolves and develops the form of system that recommends the goods by the search engine which combined with the input data and technique of case based reasoning and intelligent agent that is based on the context aware technique. In this paper, search engine which is based on the case based reasoning and intelligent agent is designed and the prototype is implemented to be adapted to the internet fashion expert shopping mall.