Matrix factorization (MF), a popular unsupervised learning technique for data representation, has been widely applied in data mining and machine learning. According to different application scenarios, one can impose different constraints on the factorization to find the desired basis, which captures high-level semantics for the given data, and learns the compact representation corresponding to the basis. We note that almost all previous work on MF in data mining has ignored to find such a basis, which can carry high-order semantics in the data. In this work, we propose a novel MF framework called Joint Hypergraph Embedding and Sparse Coding, in which the obtained basis captures high-order semantic information in data. Experimental results on data clustering demonstrate that the proposed method consistently outperforms the other state-of-the-art matrix factorization methods.

Abstract User-generated content is daily produced in social media, as such user interest summarization is critical to distill salient information from massive information for recommendation tasks. While the interested messages (e.g., tags or posts) from a single user are usually sparse becoming a bottleneck for existing methods, we propose a neural inference method (NIGraphNet) by mining user social interest for item recommendation. It can unearth user latent topics combined with user relation learning. Specifically, we exploit a neural variational inference approach to learn the distributions between user interests and hidden topics. (We denote it as interest-topic distributions in the following.) Then, we adopt a unified graph-based training loss that jointly learns the hidden topics and user relations for item recommendation. Experiments on two datasets collected from well-known social media platforms demonstrate the superior performance of our model in the tasks of user interest summarization and item recommendation. Further discussions also show that exploiting the latent topic representations and user relations is conducive to the user’s automatic language understanding.

Matrix factorization (MF), a popular unsupervised learning technique for data representation, has been widely applied in data mining and machine learning. According to different application scenarios, one can impose different constraints on the factorization to find the desired basis, which captures high-level semantics for the given data, and learns the compact representation corresponding to the basis. We note that almost all previous work on MF in data mining has ignored to find such a basis, which can carry high-order semantics in the data. In this article, we propose a novel MF framework called Joint Hypergraph Embedding and Sparse Coding (JHESC), in which the obtained basis captures high-order semantic information in data. Specifically, we first propose a new hypergraph learning model to obtain a more discriminative basis by hypergraph-based Laplacian Eigenmap, then sparse coding is conducted on the learned basis such that the new representation has stronger identification capability. In addition, we extend the proposed method to the reproducing kernel Hilbert space for dealing with nonlinear data more effectively. Extensive experimental results on data clustering demonstrate that the proposed method consistently outperforms the other state-of-the-art matrix factorization methods.

Multimodal clustering has become a fundamental and important problem in the data mining community since the development of multimedia technology over the last two decades has led to a tremendous increase in unlabeled multimodal data. Although a panoply of multimodal subspace clustering methods shows promising performance via fusing information from different views of multimodal data, most of them consist of two sequential steps, i.e., learning a consensus affinity matrix from the original data and then feeding the resulting affinity matrix into the framework of spectral clustering. However, this leads to the suboptimal clustering performance due to the following limitations: 1) the two steps of learning the affinity matrix and clustering are carried out independently; 2) the affinity matrix may be unreliable; 3) the post-processing requirement, such as K-means. To address these issues, we propose a novel multimodal subspace clustering method via adaptively learning a similarity graph on a latent low-rank representation space. In particular, the number of connected components of the learned graph is precisely equal to the number of clusters, i.e., the optimal solution of the associated problem directly reveals the clustering structure of data. Extensive evaluations on several benchmark multimodal datasets demonstrate that the proposed approach outperforms state-of-the-art methods.

In the era of big data, multi-view clustering has drawn considerable attention in machine learning and data mining communities due to the existence of a large number of unlabeled multi-view data in reality. Traditional spectral graph theoretic methods have recently been extended to multi-view clustering and shown outstanding performance. However, most of them still consist of two separate stages: learning a fixed common real matrix (i.e., continuous labels) of all the views from original data, and then applying K-means to the resulting common label matrix to obtain the final clustering results. To address these, we design a unified multi-view spectral clustering scheme to learn the discrete cluster indicator matrix in one stage. Specifically, the proposed framework directly obtain clustering results without performing K-means clustering. Experimental results on several famous benchmark datasets verify the effectiveness and superiority of the proposed method compared to the state-of-the-arts.