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Sequential recommender systems aims to predict the users' next interaction through user behavior modeling with various operators like RNNs and attentions. However, existing models generally fail to achieve the three golden principles for sequential recommendation simultaneously, i.e., training efficiency, low-cost inference, and strong performance. To this end, we propose RecBLR, an Efficient Sequential Recommendation Model based on Behavior-Dependent Linear Recurrent Units to accomplish the impossible triangle of the three principles. By incorporating gating mechanisms and behavior-dependent designs into linear recurrent units, our model significantly enhances user behavior modeling and recommendation performance. Furthermore, we unlock the parallelizable training as well as inference efficiency for our model by designing a hardware-aware scanning acceleration algorithm with a customized CUDA kernel. Extensive experiments on real-world datasets with varying lengths of user behavior sequences demonstrate RecBLR's remarkable effectiveness in simultaneously achieving all three golden principles - strong recommendation performance, training efficiency, and low-cost inference, while exhibiting excellent scalability to datasets with long user interaction histories.

Although prior state-of-the-art (SOTA) deblurring networks achieve high metric scores on synthetic datasets, there are two challenges which prevent them from perceptual image deblurring. First, a deblurring model overtrained on synthetic datasets may collapse in a broad range of unseen real-world scenarios. Second, the conventional metrics PSNR and SSIM may not correctly reflect the perceptual quality observed by human eyes. To this end, we propose DeblurDiNAT, a generalizable and efficient encoder-decoder Transformer which restores clean images visually close to the ground truth. We adopt an alternating dilation factor structure to capture local and global blur patterns. We propose a local cross-channel learner to assist self-attention layers to learn short-range cross-channel relationships. In addition, we present a linear feed-forward network and a non-linear dual-stage feature fusion module for faster feature propagation across the network. Compared to nearest competitors, our model demonstrates the strongest generalization ability and achieves the best perceptual quality on mainstream image deblurring datasets with 3%-68% fewer parameters.

Sequential recommendation aims to estimate the dynamic user preferences and sequential dependencies among historical user behaviors. Although Transformer-based models have proven to be effective for sequential recommendation, they suffer from the inference inefficiency problem stemming from the quadratic computational complexity of attention operators, especially for long behavior sequences. Inspired by the recent success of state space models (SSMs), we propose Mamba4Rec, which is the first work to explore the potential of selective SSMs for efficient sequential recommendation. Built upon the basic Mamba block which is a selective SSM with an efficient hardware-aware parallel algorithm, we design a series of sequential modeling techniques to further promote model performance while maintaining inference efficiency. Through experiments on public datasets, we demonstrate how Mamba4Rec effectively tackles the effectiveness-efficiency dilemma, outperforming both RNN- and attention-based baselines in terms of both effectiveness and efficiency. The code is available at https://github.com/chengkai-liu/Mamba4Rec.