“…To overcome data sparseness, model-based recommendation methods have been proposed. The most popular method is based on matrix factorization recommendation [2], [4], [5], [9]- [12], [16], [17], [19]- [21], [23], [25]- [27], [30], [34], which decomposes the user-app, M =R m * n two-dimensional matrix into two M 1 =R m * k , M 2 =R k * n low-dimensional matrices. The two low-dimensional vectors are multiplied to obtain the similarity matrix of the original matrix, and the elements of the similarity matrix represent the user's preference for an app.…”