基于RAdaboost-SVDD的异常值检测OA
RAdaboost-SVDD Algorithm for Anomaly Detection
支持向量数据描述(SVDD)是单类分类(OCC)中广泛应用的异常值检测方法,但在应对复杂数据分布或高噪声场景时,其性能可能受到限制.为此,本文提出一种结合Adaboost和SVDD的改进方法RAdaboost-SVDD,通过将SVDD作为弱分类器,在Adaboost框架下构建多个SVDD模型,形成一个集成的强分类器.首先利用SVDD构建初始超球体,然后在每轮迭代中动态调整样本权重,增强模型对误分类样本的关注,以逐步提升整体检测性能,最后通过投票机制集成强分类器.尽管SVDD本身是一种强分类器,对异常样本具有较高的敏感性,但当与传统Adaboost结合时,由于Adaboost使用指数损失函数,异常样本的误分类损失会被显著放大,导致模型对异常样本过度敏感,进而增加整体训练误差.针对这一问题,本文对Adaboost损失函数进行改进,以减少对异常样本的过度关注,从而提高模型的鲁棒性.实验结果表明,该方法在处理高噪声和复杂分布数据时,显著提升了异常值检测的精度和鲁棒性,充分验证了其在单类分类任务中的优势和实用性.
Support Vector Data Description(SVDD)is widely used in anomaly detection for one-class classification(OCC).However,its performance may be limited when dealing with complex data distributions or high-noise scenarios.To address this issue,this paper proposes an improved method RAdaboost-SVDD that combines Adaboost and SVDD.By using SVDD as a weak classifier,multiple SVDD models are constructed under the Adaboost framework to form an integrated strong classifier.The ini-tial hypersphere is built using SVDD,and during each iteration,sample weights are dynamically adjusted to enhance the model's focus on misclassified samples,thereby progressively improving overall detection performance.Finally,the strong classifier is in-tegrated using a voting mechanism.Although SVDD itself is a strong classifier with high sensitivity to anomalies,its combination with traditional Adaboost can lead to significant amplification of misclassification losses for anomalies due to Adaboost's use of an exponential loss function.This over-sensitivity to anomalies increases the overall training error.To address this issue,this pa-per modifies the Adaboost loss function to reduce overemphasis on anomalies,thereby improving the model's robustness.Experi-mental results demonstrate that the proposed method significantly improves anomaly detection accuracy and robustness when han-dling noisy and complex data distributions and fully verifies that it has advantages and practicality in the single-class classifica-tion task.
张加伟;刘尉;安彦蓉
河海大学数学学院,江苏 南京 210098河海大学数学学院,江苏 南京 210098南京邮电大学管理学院,江苏 南京 210003
信息技术与安全科学
支持向量数据描述Adaboost算法损失函数异常值检测
Support Vector Data Description(SVDD)Adaboost algorithmloss functionanomaly detection
《计算机与现代化》 2026 (5)
17-24,8
江苏省高校哲学社会科学项目(2023SJYB0125)江苏省"双创博士"项目(JSSCBS210499)南京邮电大学引进人才科研启动基金(人文社科类)资助项目(NYY221014)
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