Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning
It is desirable to combine the expressive power of deep learning with Gaussian Process (GP) in one expressive Bayesian learning model. Deep kernel learning showed success as a deep network used for feature extraction. Then, a GP was used as the function model. Recently, it was suggested that, albeit...
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oai:doaj.org-article:5d1c5ce622554acebb7962393986c3282021-11-25T17:29:12ZConditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning10.3390/e231113871099-4300https://doaj.org/article/5d1c5ce622554acebb7962393986c3282021-10-01T00:00:00Zhttps://www.mdpi.com/1099-4300/23/11/1387https://doaj.org/toc/1099-4300It is desirable to combine the expressive power of deep learning with Gaussian Process (GP) in one expressive Bayesian learning model. Deep kernel learning showed success as a deep network used for feature extraction. Then, a GP was used as the function model. Recently, it was suggested that, albeit training with marginal likelihood, the deterministic nature of a feature extractor might lead to overfitting, and replacement with a Bayesian network seemed to cure it. Here, we propose the conditional deep Gaussian process (DGP) in which the intermediate GPs in hierarchical composition are supported by the hyperdata and the exposed GP remains zero mean. Motivated by the inducing points in sparse GP, the hyperdata also play the role of function supports, but are hyperparameters rather than random variables. It follows our previous moment matching approach to approximate the marginal prior for conditional DGP with a GP carrying an effective kernel. Thus, as in empirical Bayes, the hyperdata are learned by optimizing the approximate marginal likelihood which implicitly depends on the hyperdata via the kernel. We show the equivalence with the deep kernel learning in the limit of dense hyperdata in latent space. However, the conditional DGP and the corresponding approximate inference enjoy the benefit of being more Bayesian than deep kernel learning. Preliminary extrapolation results demonstrate expressive power from the depth of hierarchy by exploiting the exact covariance and hyperdata learning, in comparison with GP kernel composition, DGP variational inference and deep kernel learning. We also address the non-Gaussian aspect of our model as well as way of upgrading to a full Bayes inference.Chi-Ken LuPatrick ShaftoMDPI AGarticledeep Gaussian processapproximate inferencedeep kernel learningBayesian learningmoment matchinginducing pointsScienceQAstrophysicsQB460-466PhysicsQC1-999ENEntropy, Vol 23, Iss 1387, p 1387 (2021) |
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deep Gaussian process approximate inference deep kernel learning Bayesian learning moment matching inducing points Science Q Astrophysics QB460-466 Physics QC1-999 |
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deep Gaussian process approximate inference deep kernel learning Bayesian learning moment matching inducing points Science Q Astrophysics QB460-466 Physics QC1-999 Chi-Ken Lu Patrick Shafto Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning |
description |
It is desirable to combine the expressive power of deep learning with Gaussian Process (GP) in one expressive Bayesian learning model. Deep kernel learning showed success as a deep network used for feature extraction. Then, a GP was used as the function model. Recently, it was suggested that, albeit training with marginal likelihood, the deterministic nature of a feature extractor might lead to overfitting, and replacement with a Bayesian network seemed to cure it. Here, we propose the conditional deep Gaussian process (DGP) in which the intermediate GPs in hierarchical composition are supported by the hyperdata and the exposed GP remains zero mean. Motivated by the inducing points in sparse GP, the hyperdata also play the role of function supports, but are hyperparameters rather than random variables. It follows our previous moment matching approach to approximate the marginal prior for conditional DGP with a GP carrying an effective kernel. Thus, as in empirical Bayes, the hyperdata are learned by optimizing the approximate marginal likelihood which implicitly depends on the hyperdata via the kernel. We show the equivalence with the deep kernel learning in the limit of dense hyperdata in latent space. However, the conditional DGP and the corresponding approximate inference enjoy the benefit of being more Bayesian than deep kernel learning. Preliminary extrapolation results demonstrate expressive power from the depth of hierarchy by exploiting the exact covariance and hyperdata learning, in comparison with GP kernel composition, DGP variational inference and deep kernel learning. We also address the non-Gaussian aspect of our model as well as way of upgrading to a full Bayes inference. |
format |
article |
author |
Chi-Ken Lu Patrick Shafto |
author_facet |
Chi-Ken Lu Patrick Shafto |
author_sort |
Chi-Ken Lu |
title |
Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning |
title_short |
Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning |
title_full |
Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning |
title_fullStr |
Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning |
title_full_unstemmed |
Conditional Deep Gaussian Processes: Empirical Bayes Hyperdata Learning |
title_sort |
conditional deep gaussian processes: empirical bayes hyperdata learning |
publisher |
MDPI AG |
publishDate |
2021 |
url |
https://doaj.org/article/5d1c5ce622554acebb7962393986c328 |
work_keys_str_mv |
AT chikenlu conditionaldeepgaussianprocessesempiricalbayeshyperdatalearning AT patrickshafto conditionaldeepgaussianprocessesempiricalbayeshyperdatalearning |
_version_ |
1718412285754474496 |