Learning Kernel Stein Discrepancy for Training Energy-Based Models
The primary challenge in unsupervised learning is training unnormalized density models and then generating similar samples. Few traditional unnormalized models know what the quality of the trained model is, as most models are evaluated by downstream tasks and often involve complex sampling processes...
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MDPI AG
2023-11-01
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author | Lu Niu Shaobo Li Zhenping Li |
author_facet | Lu Niu Shaobo Li Zhenping Li |
author_sort | Lu Niu |
collection | DOAJ |
description | The primary challenge in unsupervised learning is training unnormalized density models and then generating similar samples. Few traditional unnormalized models know what the quality of the trained model is, as most models are evaluated by downstream tasks and often involve complex sampling processes. Kernel Stein Discrepancy (KSD), a goodness-of-fit test method, can measure the discrepancy between the generated samples and the theoretical distribution; therefore, it can be employed to measure the quality of trained models. We first demonstrate that, under certain constraints, KSD is equal to Maximum Mean Discrepancy (MMD), a two-sample test method. PT KSD GAN (Kernel Stein Discrepancy Generative Adversarial Network with a Pulling-Away Term) is produced to compel generated samples to approximate the theoretical distribution. The generator, functioning as an implicit generative model, employs KSD as loss to avoid tedious sampling processes. In contrast, the discriminator is trained to identify the data manifold, also known as an explicit energy-based model. To demonstrate the effectiveness of our approach, we undertook experiments on two-dimensional toy datasets. Our results highlight that our generator adeptly captures the accurate density distribution, while the discriminator proficiently recognizes the unnormalized approximate distribution shape. When applied to linear Independent Component Analysis datasets, the log likelihoods of PT KSD GAN improve by about 5‰ over existing methods when the data dimension is less than 30. Furthermore, our tests on image datasets reveal that the PT KSD GAN excels in navigating high-dimensional challenges, yielding authentically genuine samples. |
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institution | Directory Open Access Journal |
issn | 2076-3417 |
language | English |
last_indexed | 2024-03-09T17:03:24Z |
publishDate | 2023-11-01 |
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spelling | doaj.art-4b86155de8f84c558b9626833dd536352023-11-24T14:27:03ZengMDPI AGApplied Sciences2076-34172023-11-0113221229310.3390/app132212293Learning Kernel Stein Discrepancy for Training Energy-Based ModelsLu Niu0Shaobo Li1Zhenping Li2Chengdu Institute of Computer Applications, Chinese Academy of Sciences, Chengdu 610041, ChinaChengdu Institute of Computer Applications, Chinese Academy of Sciences, Chengdu 610041, ChinaChengdu Institute of Computer Applications, Chinese Academy of Sciences, Chengdu 610041, ChinaThe primary challenge in unsupervised learning is training unnormalized density models and then generating similar samples. Few traditional unnormalized models know what the quality of the trained model is, as most models are evaluated by downstream tasks and often involve complex sampling processes. Kernel Stein Discrepancy (KSD), a goodness-of-fit test method, can measure the discrepancy between the generated samples and the theoretical distribution; therefore, it can be employed to measure the quality of trained models. We first demonstrate that, under certain constraints, KSD is equal to Maximum Mean Discrepancy (MMD), a two-sample test method. PT KSD GAN (Kernel Stein Discrepancy Generative Adversarial Network with a Pulling-Away Term) is produced to compel generated samples to approximate the theoretical distribution. The generator, functioning as an implicit generative model, employs KSD as loss to avoid tedious sampling processes. In contrast, the discriminator is trained to identify the data manifold, also known as an explicit energy-based model. To demonstrate the effectiveness of our approach, we undertook experiments on two-dimensional toy datasets. Our results highlight that our generator adeptly captures the accurate density distribution, while the discriminator proficiently recognizes the unnormalized approximate distribution shape. When applied to linear Independent Component Analysis datasets, the log likelihoods of PT KSD GAN improve by about 5‰ over existing methods when the data dimension is less than 30. Furthermore, our tests on image datasets reveal that the PT KSD GAN excels in navigating high-dimensional challenges, yielding authentically genuine samples.https://www.mdpi.com/2076-3417/13/22/12293hypothesis testingenergy-based modelKernel Stein DiscrepancyMaximum Mean Discrepancy |
spellingShingle | Lu Niu Shaobo Li Zhenping Li Learning Kernel Stein Discrepancy for Training Energy-Based Models Applied Sciences hypothesis testing energy-based model Kernel Stein Discrepancy Maximum Mean Discrepancy |
title | Learning Kernel Stein Discrepancy for Training Energy-Based Models |
title_full | Learning Kernel Stein Discrepancy for Training Energy-Based Models |
title_fullStr | Learning Kernel Stein Discrepancy for Training Energy-Based Models |
title_full_unstemmed | Learning Kernel Stein Discrepancy for Training Energy-Based Models |
title_short | Learning Kernel Stein Discrepancy for Training Energy-Based Models |
title_sort | learning kernel stein discrepancy for training energy based models |
topic | hypothesis testing energy-based model Kernel Stein Discrepancy Maximum Mean Discrepancy |
url | https://www.mdpi.com/2076-3417/13/22/12293 |
work_keys_str_mv | AT luniu learningkernelsteindiscrepancyfortrainingenergybasedmodels AT shaoboli learningkernelsteindiscrepancyfortrainingenergybasedmodels AT zhenpingli learningkernelsteindiscrepancyfortrainingenergybasedmodels |