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arXiv 2109.00201cs.LGcs.AIcs.CV
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特征选择和数据重采样对不平衡分类联合影响的实证研究

An Empirical Study on the Joint Impact of Feature Selection and Data Re-sampling on Imbalance Classification

Henan University(河南大学);University Campus Bio-Medico of Rome(罗马生物医学大学);University of Granada(格拉纳达大学)

Chongsheng Zhang, Paolo Soda, Jingjun Bi, Gaojuan Fan, George Almpanidis, Salvador Garcia

摘要:

在预测任务中,真实世界的数据集通常呈现不同程度的不平衡(即,长尾或偏态)分布。虽然大多数(头)类有足够的样本,少数(尾)类可以由相当有限数量的样本代表。数据预处理已被证明是非常有效的处理这些问题。一方面,数据重新采样是解决类别不平衡的常用方法。另一方面,减少特征空间的降维是用于减少数据集中的噪声和不一致性的传统技术。然而,特征选择和高性能的不平衡分类数据重采样之间的可能的协同作用很少被调查。针对这一问题,本文对特征选择和重采样对两类不平衡分类的联合影响进行了全面的实证研究。具体来说,我们研究了两个相反的管道的性能不平衡分类之前或之后的数据重新采样应用特征选择。我们进行了大量的实验,共有9225个测试,在52个公开可用的数据集,使用9个特征选择方法,6个重采样类不平衡学习的方法,和3个著名的分类算法。实验结果表明,这两个管道之间没有恒定的赢家,因此,它们都应该被考虑,以获得最佳性能的模型不平衡分类。我们发现,不平衡分类模型的性能不仅取决于所采用的分类器和大多数和少数样本的数量之间的比例,但也取决于样本数量和特征之间的比例。总的来说,本研究为非均衡学习的研究者和实践者提供了新的参考价值。

英文摘要:

In predictive tasks, real-world datasets often present different degrees of imbalanced (i.e., long-tailed or skewed) distributions. While the majority (the head) classes have sufficient samples, the minority (the tail) classes can be under-represented by a rather limited number of samples. Data pre-processing has been shown to be very effective in dealing with such problems. On one hand, data re-sampling is a common approach to tackling class imbalance. On the other hand, dimension reduction, which reduces the feature space, is a conventional technique for reducing noise and inconsistencies in a dataset. However, the possible synergy between feature selection and data re-sampling for high-performance imbalance classification has rarely been investigated before. To address this issue, we carry out a comprehensive empirical study on the joint influence of feature selection and re-sampling on two-class imbalance classification. Specifically, we study the performance of two opposite pipelines for imbalance classification by applying feature selection before or after data re-sampling. We conduct a large number of experiments, with a total of 9225 tests, on 52 publicly available datasets, using 9 feature selection methods, 6 re-sampling approaches for class imbalance learning, and 3 well-known classification algorithms. Experimental results show that there is no constant winner between the two pipelines; thus both of them should be considered to derive the best performing model for imbalance classification. We find that the performance of an imbalance classification model not only depends on the classifier adopted and the ratio between the number of majority and minority samples, but also depends on the ratio between the number of samples and features. Overall, this study should provide new reference value for researchers and practitioners in imbalance learning.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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