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arXiv 2106.14392stat.COstat.ME

基于混合 Copula 的灵活变分贝叶斯方法

Flexible Variational Bayes based on a Copula of a Mixture

David Gunawan, Robert Kohn, David Nott

AI总结:

本文提出一种基于混合 Copula 的灵活变分贝叶斯近似方法,结合提升、自然梯度和方差缩减技术,能够有效逼近多峰、偏态和重尾后验分布,并成功应用于贝叶斯深度前馈神经网络回归模型。

摘要:

变分贝叶斯方法通过一族可处理的分布来近似后验密度,其参数通过优化进行估计。当精确推断不可行或代价非常高昂时,变分近似十分有用。本文提出了一种基于混合 Copula 的灵活变分近似方法,该方法通过结合提升(boosting)、自然梯度和方差缩减技术来实现。文章利用模拟数据集和真实数据集逼近多峰、偏态和重尾后验分布,并将该方法应用于贝叶斯深度前馈神经网络回归模型,从而验证了该方法的有效性。

英文摘要:

Variational Bayes methods approximate the posterior density by a family of tractable distributions whose parameters are estimated by optimisation. Variational approximation is useful when exact inference is intractable or very costly. Our article develops a flexible variational approximation based on a copula of a mixture, which is implemented by combining boosting, natural gradient, and a variance reduction method. The efficacy of the approach is illustrated by using simulated and real datasets to approximate multimodal, skewed and heavy-tailed posterior distributions, including an application to Bayesian deep feedforward neural network regression models.

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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