Collaborative Tag-Based Recommendation Methods Using the Principle of Latent Factor Models

잠재 요인 모델의 원리를 이용한 협업 태그 기반 추천 방법

  • 김형도 (한양사이버대학교 경영학부)
  • Published : 2009.11.30

Abstract

Collaborative tagging systems allow users to attach tags to diverse sharable contents in social networks. These tags provide usefulness in reusing the contents for all community members as well as their creators. Three-dimensional data composed of users, items, and tags are used in the collaborative tag-based recommendation. They are generally more voluminous and sparse than two-dimensional data composed of users and items. Therefore, there are many difficulties in applying existing collaborative filtering methods directly to them. Latent factor models, which are also successful in the area of collaborative filtering recently, discover latent features(factors) for explaining observed values and solve problems based on the features. However, establishing the models require much time and efforts. In order to apply the latent factor models to three-dimensional collaborative filtering data, we have to overcome the difficulty of establishing them. This paper proposes various methods for determining preferences of users to items via establishing an intuitive model by assuming tags used for items as latent factors to users and items respectively. They are compared using real data for concluding desirable directions.

협업에 의한 태그 작성 시스템은 소셜 네트워크에서 다양한 공유 콘텐츠에 사용자가 태그를 부착할 수 있도록 허용하는데, 이러한 태그들은 본인뿐만 아니라 모든 커뮤니티 사용자들이 콘텐츠를 이용하는데 유용함을 준다. 협업 태그 기반의 추천에서는 사용자와 항목, 그리고 태그로 이루어진 3차원 데이터를 이용하는데, 이 데이터는 일반적으로 사용자와 항목으로 이루어진 2차원 데이터에 비하여 더 방대한 반면, 희소성(Sparsity)이 더 높다. 따라서 기존의 협업 필터링 기법을 바로 적용하는데 어려움이 많다. 잠재 요인 모델(Latent Factor Model)은 관찰된 값을 설명하는 잠재된 특징(요인)들을 밝히고, 이를 이용해서 문제를 해결하기 위한 모델로서 최근 협업 필터링에서도 성공적으로 적용되고 있으나, 모델을 학습하거나 개선하는 단계에서는 많은 시간과 노력이 필요하다는 단점이 있다. 이러한 잠재 요인 모델을 3차원 협업 태그 데이터에 적용하기 위해서는, 계산이 복잡한 협업 필터링 모델 수립의 어려움을 극복해야 한다. 이 논문에서는 사용자가 항목에 대해 사용한 태그들을 사용자 및 항목에 대한 잠재요인으로 간주하여 직관적인 모델을 수립하고, 사용자의 아이템에 대한 선호도를 결정하는 여러 가지 방법들을 제안하고, 실제 협업 태그 데이터를 이용하여 이들을 비교 평가한다.

Keywords

References

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