Keyphrases
- recommender systems
- nonnegative matrix factorization
- matrix factorization
- collaborative filtering
- probabilistic latent semantic indexing
- negative matrix factorization
- active set
- data representation
- nonnegative matrix
- least squares
- sparsity constraints
- principal component analysis
- objective function
- cluster analysis
- data clustering
- spectral clustering
- original data
- machine learning
- document clustering
- missing data
- xml documents
- image processing