The growing interest in intelligent services and privacy protection for mobile devices has given rise to the widespread application of federated learning in Multi-access Edge Computing (MEC). Diverse user behaviors call for personalized services with heterogeneous Machine Learning (ML) models on different devices. Federated Multi-task Learning (FMTL) is proposed to train related but personalized ML models for different devices, whereas previous works suffer from excessive communication overhead during training and neglect the model heterogeneity among devices in MEC. Introducing knowledge distillation into FMTL can simultaneously enable efficient communication and model heterogeneity among clients, whereas existing methods rely on a public dataset, which is impractical in reality. To tackle this dilemma, Federated MultI-task Distillation for Multi-access Edge CompuTing (FedICT) is proposed. FedICT direct local-global knowledge aloof during bi-directional distillation processes between clients and the server, aiming to enable multi-task clients while alleviating client drift derived from divergent optimization directions of client-side local models. Specifically, FedICT includes Federated Prior Knowledge Distillation (FPKD) and Local Knowledge Adjustment (LKA). FPKD is proposed to reinforce the clients' fitting of local data by introducing prior knowledge of local data distributions. Moreover, LKA is proposed to correct the distillation loss of the server, making the transferred local knowledge better match the generalized representation. Experiments on three datasets show that FedICT significantly outperforms all compared benchmarks in various data heterogeneous and model architecture settings, achieving improved accuracy with less than 1.2% training communication overhead compared with FedAvg and no more than 75% training communication round compared with FedGKT.

Federated learning (FL) allows multiple clients cooperatively train models without disclosing local data. However, the existing works fail to address all these practical concerns in FL: limited communication resources, dynamic network conditions and heterogeneous client properties, which slow down the convergence of FL. To tackle the above challenges, we propose a heterogeneity-aware FL framework, called FedCG, with adaptive client selection and gradient compression. Specifically, the parameter server (PS) selects a representative client subset considering statistical heterogeneity and sends the global model to them. After local training, these selected clients upload compressed model updates matching their capabilities to the PS for aggregation, which significantly alleviates the communication load and mitigates the straggler effect. We theoretically analyze the impact of both client selection and gradient compression on convergence performance. Guided by the derived convergence rate, we develop an iteration-based algorithm to jointly optimize client selection and compression ratio decision using submodular maximization and linear programming. Extensive experiments on both real-world prototypes and simulations show that FedCG can provide up to 5.3$\times$ speedup compared to other methods.

Metric-based meta-learning is one of the de facto standards in few-shot learning. It composes of representation learning and metrics calculation designs. Previous works construct class representations in different ways, varying from mean output embedding to covariance and distributions. However, using embeddings in space lacks expressivity and cannot capture class information robustly, while statistical complex modeling poses difficulty to metric designs. In this work, we use tensor fields (``areas'') to model classes from the geometrical perspective for few-shot learning. We present a simple and effective method, dubbed hypersphere prototypes (HyperProto), where class information is represented by hyperspheres with dynamic sizes with two sets of learnable parameters: the hypersphere's center and the radius. Extending from points to areas, hyperspheres are much more expressive than embeddings. Moreover, it is more convenient to perform metric-based classification with hypersphere prototypes than statistical modeling, as we only need to calculate the distance from a data point to the surface of the hypersphere. Following this idea, we also develop two variants of prototypes under other measurements. Extensive experiments and analysis on few-shot learning tasks across NLP and CV and comparison with 20+ competitive baselines demonstrate the effectiveness of our approach.

Conceptual knowledge is fundamental to human cognition and knowledge bases. However, existing knowledge probing works only focus on evaluating factual knowledge of pre-trained language models (PLMs) and ignore conceptual knowledge. Since conceptual knowledge often appears as implicit commonsense behind texts, designing probes for conceptual knowledge is hard. Inspired by knowledge representation schemata, we comprehensively evaluate conceptual knowledge of PLMs by designing three tasks to probe whether PLMs organize entities by conceptual similarities, learn conceptual properties, and conceptualize entities in contexts, respectively. For the tasks, we collect and annotate 24k data instances covering 393 concepts, which is COPEN, a COnceptual knowledge Probing bENchmark. Extensive experiments on different sizes and types of PLMs show that existing PLMs systematically lack conceptual knowledge and suffer from various spurious correlations. We believe this is a critical bottleneck for realizing human-like cognition in PLMs. COPEN and our codes are publicly released at https://github.com/THU-KEG/COPEN.

Since the recent success of Vision Transformers (ViTs), explorations toward transformer-style architectures have triggered the resurgence of modern ConvNets. In this work, we explore the representation ability of DNNs through the lens of interaction complexities. We empirically show that interaction complexity is an overlooked but essential indicator for visual recognition. Accordingly, a new family of efficient ConvNets, named MogaNet, is presented to pursue informative context mining in pure ConvNet-based models, with preferable complexity-performance trade-offs. In MogaNet, interactions across multiple complexities are facilitated and contextualized by leveraging two specially designed aggregation blocks in both spatial and channel interaction spaces. Extensive studies are conducted on ImageNet classification, COCO object detection, and ADE20K semantic segmentation tasks. The results demonstrate that our MogaNet establishes new state-of-the-art over other popular methods in mainstream scenarios and all model scales. Typically, the lightweight MogaNet-T achieves 80.0\% top-1 accuracy with only 1.44G FLOPs using a refined training setup on ImageNet-1K, surpassing ParC-Net-S by 1.4\% accuracy but saving 59\% (2.04G) FLOPs.

图对比度学习（GCL）一直是图形自学学习的新兴解决方案。 GCL的核心原理是在正视图中降低样品之间的距离，但在负视图中增加样品之间的距离。在实现有希望的性能的同时，当前的GCL方法仍然受到两个局限性：（1）增强的不可控制的有效性，该图扰动可能会产生针对语义和图形数据的特征流程的无效视图； （2）不可靠的二进制对比理由，对于非欧几里得图数据而言，难以确定构造观点的积极性和负面性。为了应对上述局限性，我们提出了一个新的对比度学习范式，即图形软对比度学习（GSCL），该范例通过排名的社区无需任何增强和二进制对比符合性，在较细性的范围内进行对比度学习。 GSCL建立在图接近的基本假设上，即连接的邻居比遥远的节点更相似。具体而言，我们在配对和列表的封闭式排名中，以保留附近的相对排名关系。此外，随着邻里规模的指数增长，考虑了更多的啤酒花，我们提出了提高学习效率的邻里抽样策略。广泛的实验结果表明，我们提出的GSCL可以始终如一地在各种公共数据集上实现与GCL相当复杂的各种公共数据集的最新性能。

室外（OOD）检测是面向任务的对话框系统中的关键组件，旨在确定查询是否不在预定义的支持的意图集之外。事实证明，先前基于软磁性的检测算法对OOD样品被过度自信。在本文中，我们分析了过度自信的OOD来自由于训练和测试分布之间的不匹配而导致的分布不确定性，这使得该模型无法自信地做出预测，因此可能导致异常软磁得分。我们提出了一个贝叶斯OOD检测框架，以使用Monte-Carlo辍学来校准分布不确定性。我们的方法是灵活的，并且可以轻松地插入现有的基于软磁性的基线和增益33.33 \％OOD F1改进，而与MSP相比仅增加了0.41 \％的推理时间。进一步的分析表明，贝叶斯学习对OOD检测的有效性。

随着面部伪造技术的快速发展，DeepFake视频在数字媒体上引起了广泛的关注。肇事者大量利用这些视频来传播虚假信息并发表误导性陈述。大多数现有的DeepFake检测方法主要集中于纹理特征，纹理特征可能会受到外部波动（例如照明和噪声）的影响。此外，基于面部地标的检测方法对外部变量更强大，但缺乏足够的细节。因此，如何在空间，时间和频域中有效地挖掘独特的特征，并将其与面部地标融合以进行伪造视频检测仍然是一个悬而未决的问题。为此，我们提出了一个基于多种模式的信息和面部地标的几何特征，提出了地标增强的多模式图神经网络（LEM-GNN）。具体而言，在框架级别上，我们设计了一种融合机制来挖掘空间和频域元素的联合表示，同时引入几何面部特征以增强模型的鲁棒性。在视频级别，我们首先将视频中的每个帧视为图中的节点，然后将时间信息编码到图表的边缘。然后，通过应用图形神经网络（GNN）的消息传递机制，将有效合并多模式特征，以获得视频伪造的全面表示。广泛的实验表明，我们的方法始终优于广泛使用的基准上的最先进（SOTA）。

任务概括是自然语言处理（NLP）的漫长挑战。最近的研究试图通过将NLP任务映射到人类可读的提示形式中来提高预训练语言模型的任务概括能力。但是，这些方法需要费力且不灵活的提示，并且在同一下游任务上的不同提示可能会获得不稳定的性能。我们提出了统一的架构提示，这是一种灵活且可扩展的提示方法，该方法会根据任务输入架构自动自动自定义每个任务的可学习提示。它在任务之间建模共享知识，同时保持不同任务架构的特征，从而增强任务概括能力。架构提示采用每个任务的明确数据结构，以制定提示，因此涉及几乎没有人类的努力。为了测试模式提示的任务概括能力，我们对各种一般NLP任务进行基于模式提示的多任务预训练。该框架在从8种任务类型（例如QA，NLI等）的16个看不见的下游任务上实现了强劲的零射击和很少的概括性能。此外，全面的分析证明了每个组件在架构提示中的有效性，其在任务组成性方面的灵活性以及在全DATA微调设置下提高性能的能力。

强化学习（RL）技术在许多具有挑战性的任务中引起了极大的关注，但是当应用于现实世界问题时，它们的性能急剧恶化。已经提出了各种方法，例如域随机化，以通过不同的环境设置下的培训代理来应对这种情况，因此在部署过程中可以将它们推广到不同的环境。但是，它们通常不包含与代理人正确相互作用的潜在环境因素信息，因此在面对周围环境变化时可能会过于保守。在本文中，我们首先将适应RL中的环境动态的任务形式化为使用上下文Markov决策过程（CMDP）的概括问题。然后，我们在上下文RL（AACC）中提出了不对称的参与者 - 作为处理此类概括任务的端到端参与者的方法。我们在一系列模拟环境中证明了AACC对现有基线的性能的基本改进。