Liu, Xiaolong
Graph-based Alignment and Uniformity for Recommendation
Yang, Liangwei, Liu, Zhiwei, Wang, Chen, Yang, Mingdai, Liu, Xiaolong, Ma, Jing, Yu, Philip S.
Collaborative filtering-based recommender systems (RecSys) rely on learning representations for users and items to predict preferences accurately. Representation learning on the hypersphere is a promising approach due to its desirable properties, such as alignment and uniformity. However, the sparsity issue arises when it encounters RecSys. To address this issue, we propose a novel approach, graph-based alignment and uniformity (GraphAU), that explicitly considers high-order connectivities in the user-item bipartite graph. GraphAU aligns the user/item embedding to the dense vector representations of high-order neighbors using a neighborhood aggregator, eliminating the need to compute the burdensome alignment to high-order neighborhoods individually. To address the discrepancy in alignment losses, GraphAU includes a layer-wise alignment pooling module to integrate alignment losses layer-wise. Experiments on four datasets show that GraphAU significantly alleviates the sparsity issue and achieves state-of-the-art performance. We open-source GraphAU at https://github.com/YangLiangwei/GraphAU.
Dimension Independent Mixup for Hard Negative Sample in Collaborative Filtering
Wu, Xi, Yang, Liangwei, Gong, Jibing, Zhou, Chao, Lin, Tianyu, Liu, Xiaolong, Yu, Philip S.
To address this In the contemporary era of voluminous data [17], individuals are limitation, we propose Dimension Independent Mixup for Hard inundated with an incessant influx of content generated by the internet. Negative Sampling (DINS), which is the first Area-wise sampling To address the issue of information overload, Recommender method for training CF-based models. DINS comprises three modules: Systems (RecSys) are employed to assist users in locating the most Hard Boundary Definition, Dimension Independent Mixup, relevant information and are increasingly pivotal in online services and Multi-hop Pooling. Experiments with real-world datasets on such as news feed [30], music suggestion [5], and online shopping both matrix factorization and graph-based models demonstrate [9]. Collaborative filtering (CF) [13], a highly effective method that DINS outperforms other negative sampling methods, establishing that predicts a user's preference based on their past interactions, is its effectiveness and superiority. Our work contributes a new widely employed. The latest CF-based models [10, 28] incorporate perspective, introduces Area-wise sampling, and presents DINS historical interactions into condensed user/item vectors and predict as a novel approach that achieves state-of-the-art performance for a user's preference for each item based on the dot product of negative sampling.
NORM: Knowledge Distillation via N-to-One Representation Matching
Liu, Xiaolong, Li, Lujun, Li, Chao, Yao, Anbang
Existing feature distillation methods commonly adopt the One-to-one Representation Matching between any pre-selected teacher-student layer pair. In this paper, we present N-to-One Representation (NORM), a new two-stage knowledge distillation method, which relies on a simple Feature Transform (FT) module consisting of two linear layers. In view of preserving the intact information learnt by the teacher network, during training, our FT module is merely inserted after the last convolutional layer of the student network. The first linear layer projects the student representation to a feature space having N times feature channels than the teacher representation from the last convolutional layer, and the second linear layer contracts the expanded output back to the original feature space. By sequentially splitting the expanded student representation into N non-overlapping feature segments having the same number of feature channels as the teacher's, they can be readily forced to approximate the intact teacher representation simultaneously, formulating a novel many-to-one representation matching mechanism conditioned on a single teacher-student layer pair. After training, such an FT module will be naturally merged into the subsequent fully connected layer thanks to its linear property, introducing no extra parameters or architectural modifications to the student network at inference. Extensive experiments on different visual recognition benchmarks demonstrate the leading performance of our method. For instance, the ResNet18|MobileNet|ResNet50-1/4 model trained by NORM reaches 72.14%|74.26%|68.03% top-1 accuracy on the ImageNet dataset when using a pre-trained ResNet34|ResNet50|ResNet50 model as the teacher, achieving an absolute improvement of 2.01%|4.63%|3.03% against the individually trained counterpart. Code is available at https://github.com/OSVAI/NORM
Ranking-based Group Identification via Factorized Attention on Social Tripartite Graph
Yang, Mingdai, Liu, Zhiwei, Yang, Liangwei, Liu, Xiaolong, Wang, Chen, Peng, Hao, Yu, Philip S.
Due to the proliferation of social media, a growing number of users search for and join group activities in their daily life. This develops a need for the study on the ranking-based group identification (RGI) task, i.e., recommending groups to users. The major challenge in this task is how to effectively and efficiently leverage both the item interaction and group participation of users' online behaviors. Though recent developments of Graph Neural Networks (GNNs) succeed in simultaneously aggregating both social and user-item interaction, they however fail to comprehensively resolve this RGI task. In this paper, we propose a novel GNN-based framework named Contextualized Factorized Attention for Group identification (CFAG). We devise tripartite graph convolution layers to aggregate information from different types of neighborhoods among users, groups, and items. To cope with the data sparsity issue, we devise a novel propagation augmentation (PA) layer, which is based on our proposed factorized attention mechanism. PA layers efficiently learn the relatedness of non-neighbor nodes to improve the information propagation to users. Experimental results on three benchmark datasets verify the superiority of CFAG. Additional detailed investigations are conducted to demonstrate the effectiveness of the proposed framework.