基于实例硬度加权采样的增强Bagging集成分类方法OA
An enhanced Bagging ensemble classification method based on instance-hardness weighted sampling
作为一种典型机器学习方法,集成学习旨在组合多个基分类器的输出结果,进行决策.其中,Bagging集成学习方法常被用于分类、回归、噪声环境建模及不均衡数据学习等.在噪声数据集上,传统的Bagging集成方法面临分类性能不稳定、对难分类样本关注不足的挑战.本文提出了一种融合实例硬度(Instance Hardness,IH)与增强自助采样机制(Enhanced Bootstrapping)的新型集成学习方法——eNewBagging,方法在eBagging框架基础上引入了基于实例硬度的加权采样策略,并通过为样本分配自适应权重来抑制噪声样本的影响、强化难分类样本学习,以便在保持分类器多样性的同时提高整体精度与鲁棒性.验证实验在 7个UCI与 KEEL公开数据集上进行.原始数据在 k-近邻(k-Nearest Neighbors)与决策树(Deci-sion Tree)基分类器下进行分类,并在从2%到30%的不同噪声水平下与只用k-近邻的多种基分类器进行性能比较.结果显示,eNewBagging算法在ACC、AUC与F1等3项指标上均取得最优或次优表现,相较BaggingIH算法与GrpMixBag算法在高噪声数据集上的下降幅度更小,表现出更强的噪声鲁棒性,从而所提方法能够在保持偏差与方差平衡的同时实现分类器边界样本的强化学习,显著提升模型在复杂数据环境中的泛化性能.本文的结果为解决噪声干扰与样本复杂性条件下的集成学习性能退化问题提供了一种高效框架.
Ensemble learning is a class of machine learning methods that make decisions by constructing and combining the outputs of multiple base classifiers.Among these,the representative Bagging ensemble method is frequently utilized for classification,regression,modeling in noisy environments,and learning from imbalanced data.Addressing the issues of unstable classification performance and insufficient focus on hard-to-classify samples inherent in traditional Bagging methods when applied to noisy datasets,a new en-semble learning method named eNewBagging is proposed,which integrates Instance Hardness(IH)with an enhanced bootstrapping mechanism.Based on the eBagging framework,an IH-based weighted sampling strat-egy is introduced.By allocating adaptive weights to samples,this method suppresses the influence of noisy samples and intensifies the learning of hard-to-classify samples,thereby improving overall accuracy and ro-bustness while maintaining classifier diversity.Experiments are conducted on seven public datasets from UCI and KEEL.Evaluations on the original data are performed using two base classifiers:k-Nearest Neighbors(kNN)and Decision Trees(DT).Furthermore,performance comparisons are conducted exclusively using the kNN base classifier under varying noise level ratios ranging from 2%to 30%.The results indicate that eN-ewBagging can achieve optimal or sub-optimal performance across the ACC,AUC,and F1 metrics.In com-parison with BaggingIH and GrpMixBag,eNewBagging exhibits a smaller margin of decline on highly noisy datasets,demonstrating stronger noise robustness.While preserving the bias-variance balance,this method achieves enhanced learning of borderline samples,significantly elevating the model's generalization perfor-mance in complex data environments.It is expected that the eNewBagging method can provide an efficient framework to overcome the performance degradation of ensemble learning caused by noise interference and sample complexity.
杨起年;姚诗梦;张砾匀;罗应婷
四川大学数学学院,成都 610065四川大学数学学院,成都 610065四川大学数学学院,成都 610065四川大学数学学院,成都 610065
信息技术与安全科学
集成学习BaggingeBagging实例硬度分类
ensemble learningBaggingeBagginginstance hardnessclassification
《四川大学学报(自然科学版)》 2026 (4)
823-834,12
四川省自然科学基金(2026NSFSCZY0056)
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