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arXiv 1505.04097cs.AIcs.LGstat.ML
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MCODE:多变量条件离群值检测

MCODE: Multivariate Conditional Outlier Detection

University of Pittsburgh(匹兹堡大学)

Charmgil Hong, Milos Hauskrecht

摘要:

离群值检测的目的是识别偏离预期模式的异常数据实例。当异常值是上下文相关的并且当它们由多个结果变量值的不寻常组合定义时,异常值检测特别具有挑战性。在本文中,我们开发和研究了一种新的条件离群值检测方法的多元结果空间,其工作原理是(1)转换的条件检测到离群值检测问题在一个新的(无条件)空间和(2)定义离群值得分通过分析数据在新的空间。我们的方法依赖于多维分类问题的分类器链分解,该分类器链分解让我们将输出空间转换为概率向量,输出空间的每个维度都有一个概率。然后,应用于这些变换向量的离群值分数用于检测离群值。多个多维分类问题与不同的离群值注入率的实验表明,我们的方法是强大的,能够成功地识别离群值时,离群值是稀疏(表现在一个或很少的维度)或密集(影响多个维度)。

英文摘要:

Outlier detection aims to identify unusual data instances that deviate from expected patterns. The outlier detection is particularly challenging when outliers are context dependent and when they are defined by unusual combinations of multiple outcome variable values. In this paper, we develop and study a new conditional outlier detection approach for multivariate outcome spaces that works by (1) transforming the conditional detection to the outlier detection problem in a new (unconditional) space and (2) defining outlier scores by analyzing the data in the new space. Our approach relies on the classifier chain decomposition of the multi-dimensional classification problem that lets us transform the output space into a probability vector, one probability for each dimension of the output space. Outlier scores applied to these transformed vectors are then used to detect the outliers. Experiments on multiple multi-dimensional classification problems with the different outlier injection rates show that our methodology is robust and able to successfully identify outliers when outliers are either sparse (manifested in one or very few dimensions) or dense (affecting multiple dimensions).

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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