我们可以在单个网络中训练混合歧视生成模型吗？最近在肯定中回答了这个问题，引入了基于联合能量的模型（JEM）的领域，该模型（JEM）同时达到了高分类的精度和图像生成质量。尽管有最近的进步，但仍存在两个性能差距：标准软磁性分类器的准确性差距，以及最先进的生成模型的发电质量差距。在本文中，我们引入了各种培训技术，以弥合JEM的准确性差距和一代质量差距。 1）我们结合了最近提出的清晰度最小化（SAM）框架来训练JEM，从而促进了能量景观的平滑度和JEM的普遍性。 2）我们将数据扩展排除在JEM的最大似然估计管道中，并减轻数据增强对图像生成质量的负面影响。在多个数据集上进行的广泛实验表明，我们的Sada-Jem在图像分类，图像产生，校准，分布外检测和对抗性鲁棒性方面实现了最先进的表现，并优于JEM JEM。

扩散降级概率模型（DDPM）和视觉变压器（VIT）分别在生成任务和判别任务中表现出重大进展，到目前为止，这些模型已在其自身领域中很大程度上开发出来。在本文中，我们通过将VIT结构集成到DDPM之间，建立DDPM和VIT之间的直接联系，并引入一种称为“生成Vit（Genvit）”的新生成模型。VIT的建模灵活性使我们能够将Genvit进一步扩展到混合判别生成建模，并引入混合VIT（HYBVIT）。我们的工作是最早探索单个VIT以共同探索图像生成和分类的人之一。我们进行了一系列实验，以分析提出的模型的性能，并证明它们在生成和判别任务中都超过了先前的最新技术。我们的代码和预培训模型可以在https://github.com/sndnyang/diffusion_vit中找到。

由于知识图（kgs）的不完整，旨在预测kgs中未观察到的关系的零照片链接预测（ZSLP）引起了研究人员的最新兴趣。一个常见的解决方案是将关系的文本特征（例如表面名称或文本描述）用作辅助信息，以弥合所见关系和看不见的关系之间的差距。当前方法学习文本中每个单词令牌的嵌入。这些方法缺乏稳健性，因为它们遭受了量不足（OOV）的问题。同时，建立在字符n-grams上的模型具有为OOV单词生成表达式表示的能力。因此，在本文中，我们提出了一个为零链接预测（HNZSLP）的层次N-gram框架，该框架考虑了ZSLP的关系n-gram之间的依赖项。我们的方法通过首先在表面名称上构造层次n-gram图来进行起作用，以模拟导致表面名称的N-gram的组织结构。然后，将基于变压器的革兰amtransformer呈现，以建模层次n-gram图，以构建ZSLP的关系嵌入。实验结果表明，提出的HNZSLP在两个ZSLP数据集上实现了最先进的性能。

文本到图像综合的目标是生成与给定文本描述匹配的视觉现实图像。在实践中，人类注释的标题在同一图像中具有很大的内容方差和单词的选择。相同图像的标题之间的语言差异导致偏离地面真理的合成图像。为了解决这个问题，我们提出了一种对比的学习方法来提高质量，增强合成图像的语义一致性。在预先预测阶段，我们利用对比的学习方法来学习对应于相同图像的标题的一致文本表示。此外，在GaN训练的以下阶段，我们采用对比学习方法来增强来自与相同图像相关的标题的所生成的图像之间的一致性。我们分别评估了我们在数据集幼崽和Coco上的两个流行文本到图像综合模型，ATTNGAN和DM-GAN的方法。实验结果表明，我们的方法可以有效地提高三个度量的合成图像的质量：是，FID和R精度。特别是，在挑战的Coco DataSet上，我们的方法将FID显着地通过29.60％的Attngan来增强29.60％，并在DM-GaN中达到21.96％。

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.

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.

The development of social media user stance detection and bot detection methods rely heavily on large-scale and high-quality benchmarks. However, in addition to low annotation quality, existing benchmarks generally have incomplete user relationships, suppressing graph-based account detection research. To address these issues, we propose a Multi-Relational Graph-Based Twitter Account Detection Benchmark (MGTAB), the first standardized graph-based benchmark for account detection. To our knowledge, MGTAB was built based on the largest original data in the field, with over 1.55 million users and 130 million tweets. MGTAB contains 10,199 expert-annotated users and 7 types of relationships, ensuring high-quality annotation and diversified relations. In MGTAB, we extracted the 20 user property features with the greatest information gain and user tweet features as the user features. In addition, we performed a thorough evaluation of MGTAB and other public datasets. Our experiments found that graph-based approaches are generally more effective than feature-based approaches and perform better when introducing multiple relations. By analyzing experiment results, we identify effective approaches for account detection and provide potential future research directions in this field. Our benchmark and standardized evaluation procedures are freely available at: https://github.com/GraphDetec/MGTAB.

Given the increasingly intricate forms of partial differential equations (PDEs) in physics and related fields, computationally solving PDEs without analytic solutions inevitably suffers from the trade-off between accuracy and efficiency. Recent advances in neural operators, a kind of mesh-independent neural-network-based PDE solvers, have suggested the dawn of overcoming this challenge. In this emerging direction, Koopman neural operator (KNO) is a representative demonstration and outperforms other state-of-the-art alternatives in terms of accuracy and efficiency. Here we present KoopmanLab, a self-contained and user-friendly PyTorch module of the Koopman neural operator family for solving partial differential equations. Beyond the original version of KNO, we develop multiple new variants of KNO based on different neural network architectures to improve the general applicability of our module. These variants are validated by mesh-independent and long-term prediction experiments implemented on representative PDEs (e.g., the Navier-Stokes equation and the Bateman-Burgers equation) and ERA5 (i.e., one of the largest high-resolution data sets of global-scale climate fields). These demonstrations suggest the potential of KoopmanLab to be considered in diverse applications of partial differential equations.

A recent study has shown a phenomenon called neural collapse in that the within-class means of features and the classifier weight vectors converge to the vertices of a simplex equiangular tight frame at the terminal phase of training for classification. In this paper, we explore the corresponding structures of the last-layer feature centers and classifiers in semantic segmentation. Based on our empirical and theoretical analysis, we point out that semantic segmentation naturally brings contextual correlation and imbalanced distribution among classes, which breaks the equiangular and maximally separated structure of neural collapse for both feature centers and classifiers. However, such a symmetric structure is beneficial to discrimination for the minor classes. To preserve these advantages, we introduce a regularizer on feature centers to encourage the network to learn features closer to the appealing structure in imbalanced semantic segmentation. Experimental results show that our method can bring significant improvements on both 2D and 3D semantic segmentation benchmarks. Moreover, our method ranks 1st and sets a new record (+6.8% mIoU) on the ScanNet200 test leaderboard. Code will be available at https://github.com/dvlab-research/Imbalanced-Learning.

Benefiting from the intrinsic supervision information exploitation capability, contrastive learning has achieved promising performance in the field of deep graph clustering recently. However, we observe that two drawbacks of the positive and negative sample construction mechanisms limit the performance of existing algorithms from further improvement. 1) The quality of positive samples heavily depends on the carefully designed data augmentations, while inappropriate data augmentations would easily lead to the semantic drift and indiscriminative positive samples. 2) The constructed negative samples are not reliable for ignoring important clustering information. To solve these problems, we propose a Cluster-guided Contrastive deep Graph Clustering network (CCGC) by mining the intrinsic supervision information in the high-confidence clustering results. Specifically, instead of conducting complex node or edge perturbation, we construct two views of the graph by designing special Siamese encoders whose weights are not shared between the sibling sub-networks. Then, guided by the high-confidence clustering information, we carefully select and construct the positive samples from the same high-confidence cluster in two views. Moreover, to construct semantic meaningful negative sample pairs, we regard the centers of different high-confidence clusters as negative samples, thus improving the discriminative capability and reliability of the constructed sample pairs. Lastly, we design an objective function to pull close the samples from the same cluster while pushing away those from other clusters by maximizing and minimizing the cross-view cosine similarity between positive and negative samples. Extensive experimental results on six datasets demonstrate the effectiveness of CCGC compared with the existing state-of-the-art algorithms.