Keyphrases
- matrix factorization
- lower bound
- upper bound
- collaborative filtering
- recommender systems
- low rank
- missing data
- factor analysis
- objective function
- negative matrix factorization
- optimal solution
- nonnegative matrix factorization
- factorization methods
- worst case
- stochastic gradient descent
- data matrix
- data sparsity
- high order
- variational bayesian
- personalized ranking
- co occurrence
- implicit feedback
- factor matrices
- probabilistic matrix factorization