Learning Algorithms for Grammars of Variable Arity Trees
| Autor: | Jian-Wu Xu, Radu Stefan Niculescu, Lucian Vlad Lita, Shipeng Yu, R. Bharat Rao, Jinbo Bi |
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| Rok vydání: | 2007 |
| Předmět: |
Elastic net regularization
business.industry Computer science Probabilistic logic Regression analysis Pattern recognition computer.software_genre Regularization (mathematics) Regression Support vector machine Expectation–maximization algorithm Prior probability Artificial intelligence Data mining business computer |
| Zdroj: | ICMLA |
| DOI: | 10.1109/icmla.2007.22 |
| Popis: | In this paper, we apply weighted ridge regression to tackle the highly unbalanced data issue in automatic large-scale ICD-9 coding of medical patient records. Since most of the ICD-9 codes are unevenly represented in the medical records, a weighted scheme is employed to balance positive and negative examples. The weights turn out to be associated with the instance priors from a probabilistic interpretation, and an efficient EM algorithm is developed to automatically update both the weights and the regularization parameter. Experiments on a large-scale real patient database suggest that the weighted ridge regression outperforms the conventional ridge regression and linear support vector machines (SVM). |
| Databáze: | OpenAIRE |
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