计算机应用

• 人工智能与仿真 •    下一篇

融入用户和项目特征的概率矩阵分解推荐算法

薛建宇,刘献忠   

  1. 华东师范大学
  • 收稿日期:2020-11-03 修回日期:2021-01-11 发布日期:2021-01-11 出版日期:2021-01-27
  • 通讯作者: 薛建宇

Probabilistic matrix factorization recommendation algorithm fused with user and item characteristics

  • Received:2020-11-03 Revised:2021-01-11 Online:2021-01-11 Published:2021-01-27

摘要: 与传统的协同过滤推荐算法相比,概率矩阵分解(PMF)模型在大型、稀疏的数据集上表现良好,但其仅利用了用户对项目的评分信息,没有充分考虑用户和项目的特征,因此在推荐准确度等方面仍具有很大的提升空间。基于概率矩阵分解模型,融合用户属性特征、用户偏好特征和项目标签特征,提出一种新的推荐算法UFIF-PMF(PMF Model Combining User Feature and Item Feature)。首先,根据用户属性信息计算用户属性相似度,利用项目标签信息和用户评分信息计算用户偏好相似度,并通过加权构建用户相似度矩阵,然后,构建基于项目标签信息的项目相似度矩阵,接着,将用户相似度矩阵和项目相似度矩阵融入到概率矩阵分解模型中,最后,在电影公开数据集Movielens上进行模型训练和对比实验。实验结果表明,与PMF、基于用户偏好的概率矩阵分解推荐算法(USPMF)和融合物品相似度的概率矩阵分解推荐算法(ISPMF)相比,UFIF-PMF算法的均方根误差(RMSE)分别下降6.27%、3.65%和3.49%,平均绝对误差(MAE)分别下降8.46%、4.8%和4.67%,同时有效缓解了推荐系统的冷启动和数据稀疏问题,有较强的可扩展性。

Abstract: Compared with the traditional collaborative recommendation algorithm, the Probabilistic Matrix Factorization (PMF) model performed well on large and sparse datasets. However, only the user’s rating information on the term was used in the model, the user and item char-acteristics were not fully considered. Therefore, there is still a lot of room for improvement in terms of recommendation accuracy. PMF Model Combining User Feature and Item Feature (UFIF-PMF) was proposed by combing user attribute features, user preference features and item tag features into PMF model. Firstly, the user attribute similarity according to the attribute information was calculated, and then the user preference similarity was calculated by use of the item label information and the user rating information, thus the user similarity matrix was constructed by weighting. Secondly, the item similarity matrix based on the item label information was constructed. Thirdly, the user similarity matrix and the item similarity matrix were incorporated into PMF model. Finally, the model training and comparison experiments on Movielens dataset were performed. The experimental results show that, compared with PMF, Matrix factorization recom-mendation algorithm based on user’s preference (USPMF) and PMF recommendation algorithm combing item similarity (ISPMF), the Root Mean Square Error (RMSE) of UFIF-PMF decreased by 6.27%, 3.65% and 3.49%, and Mean Absolute Error (MAE) decreased by 8.46%, 4.8% and 4.67% respectively. Furthermore, it effectively alleviates the problems of cold start and data sparsity, and has strong scalability.

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