专栏名称: 机器学习研究会
机器学习研究会是北京大学大数据与机器学习创新中心旗下的学生组织,旨在构建一个机器学习从事者交流的平台。除了及时分享领域资讯外,协会还会举办各种业界巨头/学术神牛讲座、学术大牛沙龙分享会、real data 创新竞赛等活动。
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【推荐】卷积神经网络类间不平衡问题系统研究

机器学习研究会  · 公众号  · AI  · 2017-10-18 22:41

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摘要

转自:爱可可-爱生活

论文《A systematic study of the class imbalance problem in convolutional neural networks》摘要:

In this study, we systematically investigate the impact of class imbalance on classification performance of convolutional neural networks (CNNs) and compare frequently used methods to address the issue. Class imbalance is a common problem that has been comprehensively studied in classical machine learning, yet very limited systematic research is available in the context of deep learning. In our study, we use three benchmark datasets of increasing complexity, MNIST, CIFAR-10 and ImageNet, to investigate the effects of imbalance on classification and perform an extensive comparison of several methods to address the issue: oversampling, undersampling, two-phase training, and thresholding that compensates for prior class probabilities. Our main evaluation metric is area under the receiver operating characteristic curve (ROC AUC) adjusted to multi-class tasks since overall accuracy metric is associated with notable difficulties in the context of imbalanced data. Based on results from our experiments we conclude that (i) the effect of class imbalance on classification performance is detrimental; (ii) the method of addressing class imbalance that emerged as dominant in almost all analyzed scenarios was oversampling; (iii) oversampling should be applied to the level that totally eliminates the imbalance, whereas undersampling can perform better when the imbalance is only removed to some extent; (iv) as opposed to some classical machine learning models, oversampling does not necessarily cause overfitting of CNNs; (v) thresholding should be applied to compensate for prior class probabilities when overall number of properly classified cases is of interest.


链接:

https://arxiv.org/abs/1710.05381


原文链接:

https://m.weibo.cn/1402400261/4164068987815246

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