最近，联邦学习（FL）获得了深入的研究，因为它具有为分散客户提供协作训练机器学习模型的数据隐私的能力。通常，部署了参数服务器（PS）来汇总不同客户端贡献的模型参数。分散的联合学习（DFL）已从FL升级，该学习允许客户直接与邻居聚集模型参数。 DFL对于车辆网络特别可行，因为车辆以车辆到车辆（V2V）方式相互通信。但是，由于车辆路线和通信距离的限制，单个车辆很难与他人充分交流模型。促成单个车辆模型的数据源可能没有足够多样化，从而导致模型准确性差。为了解决这个问题，我们提出了DFL-DDS（带有多元化数据源）算法的DFL-DDS，以使DFL中的数据源多样化。具体而言，每辆车都保持状态向量以记录每个数据源对其模型的贡献权重。采用Kullback-Leibler（KL）差异来衡量国家向量的多样性。为了提高DFL的收敛性，车辆通过最大程度地减少其状态向量的KL差异来调整每个数据源的聚合权重，并且可以在理论上证明其在多元化数据源中的有效性。最后，通过广泛的实验（使用MNIST和CIFAR-10数据集）评估DFL-DDS的优势，这些实验表明DFL-DD可以加速DFL的收敛性，并显着提高模型的准确性，并显着提高与最先进的盆地相比。

最近，基于区块链的联合学习（BFL）引起了密集的研究关注，因为培训过程是可审核的，并且该体系结构无助于避免了Vanilla Federated学习（VFL）中参数服务器的单点故障。然而，BFL大大升级了通信流量量，因为BFL客户端获得的所有本地模型更新（即，模型参数的更改）都将转移给所有矿工进行验证以及所有客户端以进行聚合。相比之下，参数服务器和VFL中的客户端仅保留汇总模型更新。因此，BFL的巨大沟通流量将不可避免地损害培训效率，并阻碍BFL现实的部署。为了提高BFL的实用性，我们是第一个通过压缩BFL中的通信（称为BCFL）来提出基于快速区块链的联合学习框架的人之一。同时，我们得出了BCFL的收敛速率，而非凸损失损失。为了最大化最终模型的准确性，我们进一步提出问题，以最大程度地减少收敛率的训练损失，而相对于压缩率和块生成速率的训练时间有限，这是BI-CONVEX优化问题，可以是有效解决。最后，为了证明BCFL的效率，我们对标准CIFAR-10和女权主义数据集进行了广泛的实验。我们的实验结果不仅验证了我们的分析的正确性，而且还表明BCFL可以显着将通信流量降低95-98％，或者与BFL相比，训练时间缩短了90-95％。

联合学习（FL）引发了高通信开销，这可以通过压缩模型更新而大大缓解。然而，网络环境中压缩和模型精度之间的权衡仍不清楚，为简单起见，大多数实现仅采用固定压缩率。在本文中，我们首次系统地检查了该权衡，识别压缩误差对最终模型精度的影响，相对于学习率。具体而言，我们将每个全局迭代的压缩误差因其强大凸面和非凸损耗下的收敛速度分析。然后，我们通过策略性地调整每次迭代中的压缩速率来提高最终模型精度来最大化最终模型精度的适应框架。我们讨论了具有代表压缩算法的实用网络中框架的关键实施问题。对流行的MNIST和CIFAR-10数据集的实验证实，我们的解决方案有效地降低了网络流量，但在FL中保持了高模型精度。

对比度学习已逐渐应用于学习高质量的无监督句子嵌入。据我们所知，在以前的无监督方法中，最新的最新方法是无监督的SIMCSE（Unsup-Simcse）。 Unsup-Simcse在训练阶段使用Infonce1Loss功能，通过将语义上相似的句子拉在一起并分开不相似。从理论上讲，我们希望在Unsup-Simcse中使用较大的批次，以在样本中进行更充分的比较并避免过度拟合。但是，增加批量的大小并不总是会导致改进，而是在批处理大小超过阈值时会导致性能降解。通过统计观察，我们发现这可能是由于在批量生产大小后引入了低信心负对。为了减轻这个问题，我们在Infonce损失函数上引入了一种简单的平滑策略，称为Gaussian平滑infonce（GS-Infonce）。特别是，我们将随机的高斯噪声向量添加为负样品，它们的负面样品空间的平滑性。简单，提出的平滑策略为Unsup-Simcse带来了重大改进。我们评估GS-INFONCEON标准语义文本相似性（STS）任务。 GS-Infonce的平均长矛人相关性优于最先进的Unsup-Simcse，在Bert-Base，Bert-Large，Roberta-Base的基础上，长矛人的相关性为1.38％，0.72％，1.17％和0.28％和罗伯塔·洛尔格（Roberta-Large）。

Unlike traditional distributed machine learning, federated learning stores data locally for training and then aggregates the models on the server, which solves the data security problem that may arise in traditional distributed machine learning. However, during the training process, the transmission of model parameters can impose a significant load on the network bandwidth. It has been pointed out that the vast majority of model parameters are redundant during model parameter transmission. In this paper, we explore the data distribution law of selected partial model parameters on this basis, and propose a deep hierarchical quantization compression algorithm, which further compresses the model and reduces the network load brought by data transmission through the hierarchical quantization of model parameters. And we adopt a dynamic sampling strategy for the selection of clients to accelerate the convergence of the model. Experimental results on different public datasets demonstrate the effectiveness of our algorithm.

Participants in political discourse employ rhetorical strategies -- such as hedging, attributions, or denials -- to display varying degrees of belief commitments to claims proposed by themselves or others. Traditionally, political scientists have studied these epistemic phenomena through labor-intensive manual content analysis. We propose to help automate such work through epistemic stance prediction, drawn from research in computational semantics, to distinguish at the clausal level what is asserted, denied, or only ambivalently suggested by the author or other mentioned entities (belief holders). We first develop a simple RoBERTa-based model for multi-source stance predictions that outperforms more complex state-of-the-art modeling. Then we demonstrate its novel application to political science by conducting a large-scale analysis of the Mass Market Manifestos corpus of U.S. political opinion books, where we characterize trends in cited belief holders -- respected allies and opposed bogeymen -- across U.S. political ideologies.

While inferring common actor states (such as position or velocity) is an important and well-explored task of the perception system aboard a self-driving vehicle (SDV), it may not always provide sufficient information to the SDV. This is especially true in the case of active emergency vehicles (EVs), where light-based signals also need to be captured to provide a full context. We consider this problem and propose a sequential methodology for the detection of active EVs, using an off-the-shelf CNN model operating at a frame level and a downstream smoother that accounts for the temporal aspect of flashing EV lights. We also explore model improvements through data augmentation and training with additional hard samples.

A key feature of federated learning (FL) is to preserve the data privacy of end users. However, there still exist potential privacy leakage in exchanging gradients under FL. As a result, recent research often explores the differential privacy (DP) approaches to add noises to the computing results to address privacy concerns with low overheads, which however degrade the model performance. In this paper, we strike the balance of data privacy and efficiency by utilizing the pervasive social connections between users. Specifically, we propose SCFL, a novel Social-aware Clustered Federated Learning scheme, where mutually trusted individuals can freely form a social cluster and aggregate their raw model updates (e.g., gradients) inside each cluster before uploading to the cloud for global aggregation. By mixing model updates in a social group, adversaries can only eavesdrop the social-layer combined results, but not the privacy of individuals. We unfold the design of SCFL in three steps. \emph{i) Stable social cluster formation. Considering users' heterogeneous training samples and data distributions, we formulate the optimal social cluster formation problem as a federation game and devise a fair revenue allocation mechanism to resist free-riders. ii) Differentiated trust-privacy mapping}. For the clusters with low mutual trust, we design a customizable privacy preservation mechanism to adaptively sanitize participants' model updates depending on social trust degrees. iii) Distributed convergence}. A distributed two-sided matching algorithm is devised to attain an optimized disjoint partition with Nash-stable convergence. Experiments on Facebook network and MNIST/CIFAR-10 datasets validate that our SCFL can effectively enhance learning utility, improve user payoff, and enforce customizable privacy protection.

Transformer-based models have been widely demonstrated to be successful in computer vision tasks by modelling long-range dependencies and capturing global representations. However, they are often dominated by features of large patterns leading to the loss of local details (e.g., boundaries and small objects), which are critical in medical image segmentation. To alleviate this problem, we propose a Dual-Aggregation Transformer Network called DuAT, which is characterized by two innovative designs, namely, the Global-to-Local Spatial Aggregation (GLSA) and Selective Boundary Aggregation (SBA) modules. The GLSA has the ability to aggregate and represent both global and local spatial features, which are beneficial for locating large and small objects, respectively. The SBA module is used to aggregate the boundary characteristic from low-level features and semantic information from high-level features for better preserving boundary details and locating the re-calibration objects. Extensive experiments in six benchmark datasets demonstrate that our proposed model outperforms state-of-the-art methods in the segmentation of skin lesion images, and polyps in colonoscopy images. In addition, our approach is more robust than existing methods in various challenging situations such as small object segmentation and ambiguous object boundaries.

Users' involvement in creating and propagating news is a vital aspect of fake news detection in online social networks. Intuitively, credible users are more likely to share trustworthy news, while untrusted users have a higher probability of spreading untrustworthy news. In this paper, we construct a dual-layer graph (i.e., the news layer and the user layer) to extract multiple relations of news and users in social networks to derive rich information for detecting fake news. Based on the dual-layer graph, we propose a fake news detection model named Us-DeFake. It learns the propagation features of news in the news layer and the interaction features of users in the user layer. Through the inter-layer in the graph, Us-DeFake fuses the user signals that contain credibility information into the news features, to provide distinctive user-aware embeddings of news for fake news detection. The training process conducts on multiple dual-layer subgraphs obtained by a graph sampler to scale Us-DeFake in large scale social networks. Extensive experiments on real-world datasets illustrate the superiority of Us-DeFake which outperforms all baselines, and the users' credibility signals learned by interaction relation can notably improve the performance of our model.