• •    

非独立同分布数据下的自正则化联邦学习优化方法

蓝梦婕1,蔡剑平1,孙岚2   

  1. 1. 福州大学计算机与大数据学院
    2. 福州大学数学与计算机科学学院
  • 收稿日期:2022-08-01 修回日期:2022-08-15 发布日期:2022-09-23
  • 通讯作者: 蓝梦婕

Self-regularization method for Non-IID data in federated learning

  • Received:2022-08-01 Revised:2022-08-15 Online:2022-09-23

摘要: 联邦学习(FL)是一种新的分布式机器学习范式,它在保护设备数据隐私的同时打破数据壁垒,使各方能在不共享本地数据的前提下协作训练机器学习模型,但如何处理不同客户端的非独立同分布(Non-IID)数据仍是联邦学习的一个巨大挑战,目前提出的一些解决方案没有利用好本地模型和全局模型的隐含关系 ,无法简单而高效地解决问题 。针对联邦学习中不同客户端数据的非独立同分布问题,提出新的联邦学习优化算法FedSR和Dyn-FedSR。FedSR在每一轮训练过程中引入自正则化惩罚项动态修改本地损失函数,通过构建本地模型和全局模型的关系,使本地模型靠近聚合丰富知识的全局模型,缓解Non-IID数据带来的客户端偏移问题;Dyn-FedSR则在FedSR基础上通过计算本地模型和全局模型的相似度动态确定正则项系数。对不同任务进行大量的实验分析表明,FedSR和Dyn-FedSR在各种场景下的表现都明显优于FedAvg,FedProx和SCAFFOLD之类的联邦学习算法,能够实现高效通信和更高的准确率, 对不平衡数据和不确定的本地更新具有鲁棒性。

关键词: 联邦学习, 非独立同分布数据, 客户端偏移, 正则化, 分布式机器学习, 隐私保护

Abstract: Federated Learning (FL) is a new distributed machine learning paradigm that breaks down data barriers while protecting data privacy, enabling clients to collaboratively train a machine learning model without sharing local data. However, how to deal with Non-independent identical distribution (Non-IID) data from different clients remains a huge challenge in federated learning. Although several studies have proposed some solutions to this problem, few of them utilized the implicit relationship between the global and local models to solve the problem simply and efficiently. To address the Non-IID issue in federated learning, novel optimization algorithms including FedSR and Dyn-FedSR were proposed in this paper:. Self-regularization penalty terms were introduced in each training round to dynamically regularize the local loss function in FedSR, which alleviated the Non-IID problem by constructing a relationship between the global and local models. The local model was close to the global model that aggregated richer knowledge in this way. The self-regularization penalty term was dynamically determined by calculating the similarity between the global and local models in Dyn-FedSR. Extensive experimental analyses on different tasks demonstrate that FedSR and Dyn-FedSR significantly outperform the state-of-the-art federated learning algorithms such as FedAvg, FedProx and SCAFFOLD in various scenarios, enabling efficient communication and higher accuracy, robustness to unbalanced data and uncertain local updates.

Key words: Federated Learning (FL), Non-IID data, client drift, regularization, distributed machine learning, privacy preserving

中图分类号: