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arXiv 1407.5232math.STstat.TH
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关于DDM可信集的覆盖率和局部径向率

On coverage and local radial rates of DDM-credible sets

Eduard Belitser

摘要:

对于一般的统计模型,我们引入了关于模型参数的数据相关测度(DDM)的概念。DDM的典型例子是后验分布。与后验相似,DDM的质量由我们允许局部的收缩率表征,即,取决于参数。我们构造的置信集DDM可信集,并解决这样的集合的最优性问题,通过其“大小”(局部径向率)和其覆盖概率之间的权衡。在轻度不适定的白噪声逆信号模型中,我们构造了一个DDM作为关于某个先验的经验贝叶斯后验,并定义了它的(默认)可信集。然后,我们引入了“过度偏差限制”(EBR),比最近在文献中研究的“自相似性”和“抛光尾条件”更一般。在EBR下,我们建立了我们的可信集的置信最优性与一些局部(预言)径向率。在$\ell_2$中,我们还得到了非渐近一致的预言估计不等式和预言DDM-收缩率。所获得的局部结果比全局结果更强大:许多平滑尺度的自适应极大极小结果,特别是Szabo,van der Vaart和van Zanten(2015)所考虑的结果。

英文摘要:

For a general statistical model, we introduce the notion of data dependent measure (DDM) on the model parameter. Typical examples of DDM are the posterior distributions. Like for posteriors, the quality of a DDM is characterized by the contraction rate which we allow to be local, i.e., depending on the parameter. We construct confidence sets as DDM-credible sets and address the issue of optimality of such sets, via a trade-off between its "size" (the local radial rate) and its coverage probability. In the mildly ill-posed inverse signal-in-white-noise model, we construct a DDM as empirical Bayes posterior with respect to a certain prior, and define its (default) credible set. Then we introduce 'excessive bias restriction' (EBR), more general than 'self-similarity' and 'polished tail condition' recently studied in the literature. Under EBR, we establish the confidence optimality of our credible set with some local (oracle) radial rate. We also derive the oracle estimation inequality and the oracle DDM-contraction rate, non-asymptotically and uniformly in $\ell_2$. The obtained local results are more powerful than global: adaptive minimax results for a number of smoothness scales follow as consequence, in particular, the ones considered by Szabo, van der Vaart and van Zanten (2015).

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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