Clustered federated learning (CFL) is proposed to mitigate the performance deterioration stemming from data heterogeneity in federated learning (FL) by grouping similar clients for cluster-wise model training. However, current CFL methods struggle due to inadequate integration of global and intra-cluster knowledge and the absence of an efficient online model similarity metric, while treating the cluster count as a fixed hyperparameter limits flexibility and robustness. In this paper, we propose an adaptive CFL framework, named FedAC, which (1) efficiently integrates global knowledge into intra-cluster learning by decoupling neural networks and utilizing distinct aggregation methods for each submodule, significantly enhancing performance; (2) includes a costeffective online model similarity metric based on dimensionality reduction; (3) incorporates a cluster number fine-tuning module for improved adaptability and scalability in complex, heterogeneous environments. Extensive experiments show that FedAC achieves superior empirical performance, increasing the test accuracy by around 1.82% and 12.67% on CIFAR-10 and CIFAR-100 datasets, respectively, under different non-IID settings compared to SOTA methods.

在本文中，我们提出了一种自适应的聚类联邦学习框架，名为FedAC，它通过解耦神经网络并为每个子模块使用不同的聚合方法，有效地将全局知识融合到簇内学习中，同时采用一种经济高效的在线模型相似度度量基于降维技术，以及一个用于改进复杂异构环境中自适应性和可扩展性的簇数微调模块。广泛的实验结果表明，相较于现有方法，FedAC在不同的非独立同分布设置下，CIFAR-10和CIFAR-100数据集的测试准确率分别提高了约1.82%和12.67%。

FedAC：一种适应性聚类的异构数据联邦学习框架