• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.563-564
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• 2021

협업 필터링은 데이터 분석을 통한 추천 시스템에서 대표적인 방법이다. 사용 방법은 다양한 아이템에 대해서 사용자들의 평가 데이터를 활용하여 공통적인 패턴을 찾아서 특정 사용자에 대한 선호 아이템을 추천하는 기법이다. 이에 본 논문에서는 여러 가지 알고리즘을 사용하여 지표 측정에 활용하였으며, 사용자 선호에 대한 예측에 적합한 알고리즘을 찾아서 제시하였다.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.67-74
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• 2011

Collaborative recommendation is one of the most widely used methods of automated product recommendation in e-Commerce. For analyzing the customer's preference, traditional explicit ratings are less desirable than implicit ratings because it may impose an additional burden to the customers of e-commerce companies which deals with a number of products. Cardinal scales generally used for representing the preference intensity also ineffective owing to its increasing estimation errors. In this paper, we propose a new way of constructing the ordinal scale-based customer profile for collaborative recommendation. A Web usage mining technique and lexicographic consensus are employed. An experiment shows that the proposed method performs better than existing CF methodologies.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.59-60
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• 2022

갈수록 개인화되어 가는 추천시스템은 다양한 모델에 의해 그 성능이 향상되고 있으며 최근 추세는 다른 분야와 마찬가지로 딥러닝 기반 모델을 적용하여 추천 품질을 향상하고 있다. 그러나 대다수의 추천시스템은 하나의 도메인에서 개별적으로 사용될 뿐, 유사도메인이나 상이한 도메인이나 모두 다른 도메인에서의 사용자 성향이나 아이템 유사성을 거의 또는 전혀 고려하지 않고 있다. 이는 추천결과의 sparsity와 cold-start 문제를 더 악화시키는 원인이 된다. 본 논문은 다양한 딥러닝 모델 적용 추천 모델 중 오토인코더 모델을 지역특화 협업에 적용한 모델을 간략하게 소개하고 해당 모델을 상이한 도메인 간의 적용하기 위한 첫 단계로 손실함수 부분에 대해 개념적으로 설명하고자 한다.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.05a
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• pp.246-254
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• 2007

최근 유비쿼터스 환경이 대두됨에 따라 정보의 밀도가 높아지고 있으며, 기업에서는 고객이 제품을 구매함과 동시에 고객의 정보를 저장하여 활용할 수 있게 되었다. 이와 같은 환경은 고객의 요구사항을 사전에 미리 파악하여 적절한 시점과 상황에 맞는 정보를 전달할 수 있도록 하는 추천시스템에 대한 필요성을 증대시켰으며, 다양한 영역에서 추천시스템과 관련된 연구들이 활발하게 이루어지고 있다. 지금까지의 추천시스템은 주로 제품 중심으로 논의되어 왔으나, 유비쿼터스 시장 환경에서는 매장에 대한 논의가 필요하게 되었다. 이는 고객이 다양한 매장을 방문할 수 있으며, 동일한 제품이라도 여러 매장에 동시에 존재할 수 있고, 매장 간의 동선이나 매장의 위치 및 분위기, 제품의 품질이나 가격 등에 대한 개인 선호도에 따라 같은 제품이라도 선호하는 매장은 다를 수 있기 때문이다. 따라서 본 연구에서는 고객의 선호도를 기반으로 유비쿼터스 시장 환경에 적합한 매장 추천시스템을 제안하고자 한다. 매장 추천시스템은 협업 필터링을 기반으로 하고 있으며, Apriori 알고리즘을 이용하여 관련성이 높은 매장들의 집합을 찾아 추천한다. 이 시스템은 기업보다는 고객 중심의 서비스를 제공해 줌으로써 고객의 쇼핑 효율성을 제고시킬 뿐 아니라 장기적인 관점에서 시장 활성화에 기여할 수 있을 것으로 기대한다.

• Journal of KIISE
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• v.44 no.6
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• pp.621-627
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• 2017

Collaborative filtering is a technique that effectively recommends unrated items for users. Collaborative filtering is based on the similarity of the items evaluated by users. The existing top-N recommendation methods are based on pair-wise and list-wise preference models. However, these methods do not effectively represent the relative preference of items that are evaluated by users, and can not reflect the importance of each item. In this paper, we propose a new method to represent user's latent preference by combining an existing preference model and the notion of inverse user frequency. The proposed method improves the accuracy of existing methods by up to two times.

• The Journal of Society for e-Business Studies
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• v.14 no.1
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• pp.1-11
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• 2009

Many neighbors are needed for making the recommendation quality better and stable in collaborative filtering. Furthermore, the quality is not so good mainly due to a reason that high similarity between two users does not guarantee the same preference to items considered for recommendation. Dissimilar users who have consistency in item selection can be useful for predicting preferences. This paper proposes a new collaborative filtering method, defining trust based on consistency for improving this phenomenon. Empirical studies show that such a method reduces the number of neighbors required to make the recommendation quality stable and the recommendation quality itself is also significantly improved.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.1-10
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• 2013

Personalization aims to provide customized contents to each user by using the user's personal preferences. In this sense, the core parts of personalization are regarded as recommendation technologies, which can recommend the proper contents or products to each user according to his/her preference. Prior studies have proposed novel recommendation technologies because they recognized the importance of recommender systems. Among several recommendation technologies, collaborative filtering (CF) has been actively studied and applied in real-world applications. The CF, however, often suffers sparsity or scalability problems. Prior research also recognized the importance of these two problems and therefore proposed many solutions. Many prior studies, however, suffered from problems, such as requiring additional time and cost for solving the limitations by utilizing additional information from other sources besides the existing user-item matrix. This study proposes a novel implicit rating approach for collaborative filtering in order to mitigate the sparsity problem as well as to enhance the performance of recommender systems. In this study, we propose the methods of reducing the sparsity problem through supplementing the user-item matrix based on the implicit rating approach, which measures the trust level among users via the existing user-item matrix. This study provides the preliminary experimental results for testing the usefulness of the proposed model.

• Journal of Information Management
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• v.41 no.4
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• pp.227-249
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• 2010

Scholarly information has increased tremendously according to the development of IT, especially the Internet. However, simultaneously, people have to spend more time and exert more effort because of information overload. There have been many research efforts in the field of expert systems, data mining, and information retrieval, concerning a system that recommends user-expected information items through presumption. Recently, the hybrid system combining a content-based recommendation system and collaborative filtering or combining recommendation systems in other domains has been developed. In this paper we resolved the problem of the current recommendation system and suggested a new system combining collaborative filtering and Naive Bayes Classification. In this way, we resolved the over-specialization problem through collaborative filtering and lack of assessment information or recommendation of new contents through Naive Bayes Classification. For verification, we applied the new model in NDSL's paper service of KISTI, especially papers from journals about Sitology and Electronics, and witnessed high satisfaction from 4 experimental participants.

• Information Systems Review
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• v.8 no.2
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• pp.139-154
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• 2006

Recommender systems help users find their interesting items more easily or provide users with meaningful items based on their preferences. Collaborative filtering(CF) recommender systems, the most successful recommender system, use opinions of users to recommend for an active user who needs recommendation. That is, ratings which users have voted on items to indicate preference on them are the source for making recommendation. Although CF systems are designed only to use users' preferences as the source of recommendation, use of some available information is believed to increase both the performance and the accuracy of CF systems. In this paper, we propose a CF recommender system which utilizes both degree of match and demographic information(e.g., occupation, gender, age) to increase the performance and the accuracy. Since more and more information is accumulated in CF systems, it is important to reduce the data volume while maintaining the same or the higher level of accuracy. We used both degree of match and demographic information as criteria for reducing the data volume, thereby naturally enhancing the performance. It is shown that using degree of match improves the prediction accuracy too in CF systems and also that using some demographic information also results in better accuracy.

• Journal of Digital Contents Society
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• v.18 no.4
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• pp.707-712
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• 2017

As the amount of data increases exponentially, the recommender system is attracting interest in various industries such as movies, books, and music, and is being studied. The recommendation system aims to propose an appropriate item to the user based on the user's past preference and click stream. Typical examples include Netflix's movie recommendation system and Amazon's book recommendation system. Previous studies can be categorized into three types: collaborative filtering, content-based recommendation, and hybrid recommendation. However, existing recommendation systems have disadvantages such as sparsity, cold start, and scalability problems. To improve these shortcomings and to develop a more accurate recommendation system, we have designed a recommendation system as a factorization machine using actual online product purchase data.