推荐系统(RS)是一个重要的在线应用程序,每天都会影响数十亿个用户。主流RS排名框架由两个部分组成:多任务学习模型(MTL),该模型可预测各种用户反馈,即点击,喜欢,分享和多任务融合模型(MTF),该模型(MTF)结合了多任务就用户满意度而言,输出分为最终排名得分。关于融合模型的研究并不多,尽管它对最终建议作为排名的最后一个关键过程有很大的影响。为了优化长期用户满意度,而不是贪婪地获得即时回报,我们将MTF任务作为Markov决策过程(MDP),并在推荐会话中提出,并建议基于批处理加固学习(RL)基于多任务融合框架(BATCHRL-MTF)包括批处理RL框架和在线探索。前者利用批处理RL从固定的批处理数据离线学习最佳推荐政策,以达到长期用户满意度,而后者则探索了潜在的高价值动作在线,以突破本地最佳难题。通过对用户行为的全面调查,我们通过从用户粘性和用户活动性的两个方面的微妙启发式方法对用户满意度进行了建模。最后,我们对十亿个样本级别的现实数据集进行了广泛的实验,以显示模型的有效性。我们建议保守的离线政策估计器(保守 - 访问器)来测试我们的模型离线。此外,我们在真实推荐环境中进行在线实验,以比较不同模型的性能。作为成功在MTF任务中应用的少数批次RL研究之一,我们的模型也已部署在一个大规模的工业短视频平台上,为数亿用户提供服务。
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图像检索系统可帮助用户实时浏览和搜索。随着云计算的兴起,检索任务通常外包到云服务器。但是,由于云服务器无法完全信任,因此云场景带来了隐私保护的艰巨挑战。为此,已经开发了基于图像加密的图像检索方案,首先是从密码图像中提取特征,然后根据这些功能构建检索模型。然而,大多数现有方法提取浅特征和设计微不足道的检索模型,从而导致密码图像的表现不足。在本文中,我们提出了一种名为“加密视觉变压器”(EVIT)的新型范式,该范式提高了密码图像的判别性表述能力。首先,为了捕获全面的统治信息,我们从密码图像中提取多级局部长度序列和全局Huffman代码频率特征,这些序列在JPEG压缩过程中由流密码加密。其次,我们将基于视觉变压器的检索模型设计为与多层次功能相结合,并提出了两种自适应数据增强方法,以提高检索模型的表示能力。我们的建议很容易通过自我监督的对比学习方式来适应无监督和监督的环境。广泛的实验表明,EVIT既可以实现出色的加密和检索性能,从而超过了当前方案,从而在大幅度的检索准确性方面优于当前方案,同时有效地保护图像隐私。代码可在\ url {https://github.com/onlinehuazai/evit}上公开获得。
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现有的伪装对象检测(COD)方法在很大程度上依赖于具有像素注释的大规模数据集。但是,由于边界模棱两可,注释伪装物体像素 - 智能(每图像需要约60分钟),这是非常耗时的和劳动密集型的。在本文中,我们使用涂鸦注释作为监督提出了第一个弱监督的伪装对象检测(COD)方法。为了实现这一目标,我们首先构建了一个带有4,040张图像和相应涂鸦注释的基于涂鸦的伪装对象数据集。值得注意的是,注释我们数据集中使用的涂鸦每图像仅需约10秒钟,这比每像素注释快360倍。但是,直接使用涂鸦注释进行监督的网络将无法本地化伪装对象的边界,并且往往会有不一致的预测,因为涂鸦注释仅描述了没有细节的对象的主要结构。为了解决这个问题,我们提出了一个由两个部分组成的新型一致性损失:可靠的跨视图损失,以在不同图像上获得可靠的一致性,以及在单个预测图内保持一致性的软内部视图损失。此外,我们观察到,人类使用语义信息来段区域接近伪装物体的边界。因此,我们设计了一个特征引导的损失,其中包括直接从图像中提取的视觉特征和模型捕获的语义显着特征。此外,我们提出了一个新颖的网络,该网络通过对结构信息和语义关系进行涂鸦学习来检测伪装的对象。实验结果表明,我们的模型在三个COD基准上的表现优于相关的最新方法,MAE的平均提高为11.0%,S量表为3.2%,E-Measure 2.5%,加权F-的4.4%。措施。
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Masked image modeling (MIM) performs strongly in pre-training large vision Transformers (ViTs). However, small models that are critical for real-world applications cannot or only marginally benefit from this pre-training approach. In this paper, we explore distillation techniques to transfer the success of large MIM-based pre-trained models to smaller ones. We systematically study different options in the distillation framework, including distilling targets, losses, input, network regularization, sequential distillation, etc, revealing that: 1) Distilling token relations is more effective than CLS token- and feature-based distillation; 2) An intermediate layer of the teacher network as target perform better than that using the last layer when the depth of the student mismatches that of the teacher; 3) Weak regularization is preferred; etc. With these findings, we achieve significant fine-tuning accuracy improvements over the scratch MIM pre-training on ImageNet-1K classification, using all the ViT-Tiny, ViT-Small, and ViT-base models, with +4.2%/+2.4%/+1.4% gains, respectively. Our TinyMIM model of base size achieves 52.2 mIoU in AE20K semantic segmentation, which is +4.1 higher than the MAE baseline. Our TinyMIM model of tiny size achieves 79.6% top-1 accuracy on ImageNet-1K image classification, which sets a new record for small vision models of the same size and computation budget. This strong performance suggests an alternative way for developing small vision Transformer models, that is, by exploring better training methods rather than introducing inductive biases into architectures as in most previous works. Code is available at https://github.com/OliverRensu/TinyMIM.
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In this paper, we propose a robust 3D detector, named Cross Modal Transformer (CMT), for end-to-end 3D multi-modal detection. Without explicit view transformation, CMT takes the image and point clouds tokens as inputs and directly outputs accurate 3D bounding boxes. The spatial alignment of multi-modal tokens is performed implicitly, by encoding the 3D points into multi-modal features. The core design of CMT is quite simple while its performance is impressive. CMT obtains 73.0% NDS on nuScenes benchmark. Moreover, CMT has a strong robustness even if the LiDAR is missing. Code will be released at https://github.com/junjie18/CMT.
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Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.
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Blind image quality assessment (BIQA) remains challenging due to the diversity of distortion and image content variation, which complicate the distortion patterns crossing different scales and aggravate the difficulty of the regression problem for BIQA. However, existing BIQA methods often fail to consider multi-scale distortion patterns and image content, and little research has been done on learning strategies to make the regression model produce better performance. In this paper, we propose a simple yet effective Progressive Multi-Task Image Quality Assessment (PMT-IQA) model, which contains a multi-scale feature extraction module (MS) and a progressive multi-task learning module (PMT), to help the model learn complex distortion patterns and better optimize the regression issue to align with the law of human learning process from easy to hard. To verify the effectiveness of the proposed PMT-IQA model, we conduct experiments on four widely used public datasets, and the experimental results indicate that the performance of PMT-IQA is superior to the comparison approaches, and both MS and PMT modules improve the model's performance.
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Automatic music generation with artificial intelligence typically requires a large amount of data which is hard to obtain for many less common genres and musical instruments. To tackle this issue, we present ongoing work and preliminary findings on the possibility for deep models to transfer knowledge from language to music, by finetuning large language models pre-trained on a massive text corpus on only hundreds of MIDI files of drum performances. We show that by doing so, one of the largest, state-of-the-art models (GPT3) is capable of generating reasonable drum grooves, while models that are not pre-trained (Transformer) shows no such ability beyond naive repetition. Evaluating generated music is a challenging task, more so is evaluating drum grooves with little precedence in literature. Hence, we propose a tailored structural evaluation method and analyze drum grooves produced by GPT3 compared to those played by human professionals, exposing the strengths and weaknesses of such generation by language-to-music transfer. Our findings suggest that language-to-music transfer learning with large language models is viable and promising.
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Few Shot Instance Segmentation (FSIS) requires models to detect and segment novel classes with limited several support examples. In this work, we explore a simple yet unified solution for FSIS as well as its incremental variants, and introduce a new framework named Reference Twice (RefT) to fully explore the relationship between support/query features based on a Transformer-like framework. Our key insights are two folds: Firstly, with the aid of support masks, we can generate dynamic class centers more appropriately to re-weight query features. Secondly, we find that support object queries have already encoded key factors after base training. In this way, the query features can be enhanced twice from two aspects, i.e., feature-level and instance-level. In particular, we firstly design a mask-based dynamic weighting module to enhance support features and then propose to link object queries for better calibration via cross-attention. After the above steps, the novel classes can be improved significantly over our strong baseline. Additionally, our new framework can be easily extended to incremental FSIS with minor modification. When benchmarking results on the COCO dataset for FSIS, gFSIS, and iFSIS settings, our method achieves a competitive performance compared to existing approaches across different shots, e.g., we boost nAP by noticeable +8.2/+9.4 over the current state-of-the-art FSIS method for 10/30-shot. We further demonstrate the superiority of our approach on Few Shot Object Detection. Code and model will be available.
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Graph Neural Networks (GNNs) have shown satisfying performance on various graph learning tasks. To achieve better fitting capability, most GNNs are with a large number of parameters, which makes these GNNs computationally expensive. Therefore, it is difficult to deploy them onto edge devices with scarce computational resources, e.g., mobile phones and wearable smart devices. Knowledge Distillation (KD) is a common solution to compress GNNs, where a light-weighted model (i.e., the student model) is encouraged to mimic the behavior of a computationally expensive GNN (i.e., the teacher GNN model). Nevertheless, most existing GNN-based KD methods lack fairness consideration. As a consequence, the student model usually inherits and even exaggerates the bias from the teacher GNN. To handle such a problem, we take initial steps towards fair knowledge distillation for GNNs. Specifically, we first formulate a novel problem of fair knowledge distillation for GNN-based teacher-student frameworks. Then we propose a principled framework named RELIANT to mitigate the bias exhibited by the student model. Notably, the design of RELIANT is decoupled from any specific teacher and student model structures, and thus can be easily adapted to various GNN-based KD frameworks. We perform extensive experiments on multiple real-world datasets, which corroborates that RELIANT achieves less biased GNN knowledge distillation while maintaining high prediction utility.
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