• Title/Summary/Keyword: hierarchical penalization

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Hierarchically penalized support vector machine for the classication of imbalanced data with grouped variables (그룹변수를 포함하는 불균형 자료의 분류분석을 위한 서포트 벡터 머신)

  • Kim, Eunkyung;Jhun, Myoungshic;Bang, Sungwan
    • The Korean Journal of Applied Statistics
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    • v.29 no.5
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    • pp.961-975
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    • 2016
  • The hierarchically penalized support vector machine (H-SVM) has been developed to perform simultaneous classification and input variable selection when input variables are naturally grouped or generated by factors. However, the H-SVM may suffer from estimation inefficiency because it applies the same amount of shrinkage to each variable without assessing its relative importance. In addition, when analyzing imbalanced data with uneven class sizes, the classification accuracy of the H-SVM may drop significantly in predicting minority class because its classifiers are undesirably biased toward the majority class. To remedy such problems, we propose the weighted adaptive H-SVM (WAH-SVM) method, which uses a adaptive tuning parameters to improve the performance of variable selection and the weights to differentiate the misclassification of data points between classes. Numerical results are presented to demonstrate the competitive performance of the proposed WAH-SVM over existing SVM methods.