arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2201.03019cs.LGcs.AI

基于生成式伪回放的鲁棒且资源高效的无数据知识蒸馏

Robust and Resource-Efficient Data-Free Knowledge Distillation by Generative Pseudo Replay

Institute for Infocomm Research, A*STAR(新加坡科技研究局信息通信研究所);School of Computing, National University of Singapore(新加坡国立大学计算机学院)

Kuluhan Binici, Shivam Aggarwal, Nam Trung Pham, Karianto Leman, Tulika Mitra

AI总结:

针对无数据知识蒸馏中因合成数据分布偏移导致的知识退化问题,提出基于变分自编码器的生成式伪回放方法,无需存储样本即可防止知识退化,在提升模型准确率期望的同时消除了内存开销。

摘要:

无数据知识蒸馏(KD)允许在缺乏原始训练数据的情况下,将知识从已训练的神经网络(教师模型)迁移到更紧凑的网络(学生模型)中。现有工作使用验证集来监测学生在真实数据上的准确率,并报告整个过程中的最高性能。然而,在蒸馏时验证数据也可能不可用,使得记录达到峰值准确率的学生快照变得不可行。因此,一种实用的无数据KD方法应当是鲁棒的,并且理想情况下在蒸馏过程中提供单调递增的学生准确率。这极具挑战性,因为学生模型会由于合成数据的分布偏移而经历知识退化。克服该问题的一种直接方法是周期性地存储并重放生成的样本,但这会增加内存占用并引发隐私担忧。我们提出使用生成网络来对先前观察到的合成样本分布进行建模。具体而言,我们设计了一个变分自编码器(VAE),其训练目标经过定制以最优地学习合成数据表示。学生模型通过生成式伪回放技术进行重放,样本由VAE产生。因此,无需存储任何样本即可防止知识退化。在图像分类基准上的实验表明,我们的方法优化了蒸馏模型准确率的期望值,同时消除了样本存储方法带来的巨大内存开销。

英文摘要:

Data-Free Knowledge Distillation (KD) allows knowledge transfer from a trained neural network (teacher) to a more compact one (student) in the absence of original training data. Existing works use a validation set to monitor the accuracy of the student over real data and report the highest performance throughout the entire process. However, validation data may not be available at distillation time either, making it infeasible to record the student snapshot that achieved the peak accuracy. Therefore, a practical data-free KD method should be robust and ideally provide monotonically increasing student accuracy during distillation. This is challenging because the student experiences knowledge degradation due to the distribution shift of the synthetic data. A straightforward approach to overcome this issue is to store and rehearse the generated samples periodically, which increases the memory footprint and creates privacy concerns. We propose to model the distribution of the previously observed synthetic samples with a generative network. In particular, we design a Variational Autoencoder (VAE) with a training objective that is customized to learn the synthetic data representations optimally. The student is rehearsed by the generative pseudo replay technique, with samples produced by the VAE. Hence knowledge degradation can be prevented without storing any samples. Experiments on image classification benchmarks show that our method optimizes the expected value of the distilled model accuracy while eliminating the large memory overhead incurred by the sample-storing methods.

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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