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arXiv 1111.4494stat.ME
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结构化稀疏聚合

Structured Sparse Aggregation

Daniel Percival

摘要:

我们介绍了一种方法,聚合许多最小二乘估计,使所得的估计有两个属性:稀疏性和结构。也就是说,在所得模型中仅使用少数候选协变量,并且所选协变量遵循假定为先验已知的候选协变量的某种结构。虽然稀疏性在许多环境中得到了很好的研究,包括聚合,但结构化稀疏方法仍在出现。我们展示了一个结构化稀疏聚合的一般框架,允许各种各样的结构,包括重叠的分组结构和一般的结构处罚定义为一组函数的协变量。我们证明了这样的估计满足结构稀疏预言不等式-它们的有限样本风险适应于目标的结构稀疏性。这些不等式表明,在适当的设置下,结构化稀疏估计执行至少以及,并可能远远优于,稀疏聚合估计。我们经验建立的有效性的方法,使用模拟和应用到艾滋病毒耐药性。

英文摘要:

We introduce a method for aggregating many least squares estimator so that the resulting estimate has two properties: sparsity and structure. That is, only a few candidate covariates are used in the resulting model, and the selected covariates follow some structure over the candidate covariates that is assumed to be known a priori. While sparsity is well studied in many settings, including aggregation, structured sparse methods are still emerging. We demonstrate a general framework for structured sparse aggregation that allows for a wide variety of structures, including overlapping grouped structures and general structural penalties defined as set functions on the set of covariates. We show that such estimators satisfy structured sparse oracle inequalities --- their finite sample risk adapts to the structured sparsity of the target. These inequalities reveal that under suitable settings, the structured sparse estimator performs at least as well as, and potentially much better than, a sparse aggregation estimator. We empirically establish the effectiveness of the method using simulation and an application to HIV drug resistance.

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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