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Constructing energy-efficient mixed-precision neural networks through principal component analysis for edge intelligence

A preprint version of the article is available at arXiv.

Abstract

The ‘Internet of Things’ has brought increased demand for artificial intelligence-based edge computing in applications ranging from healthcare monitoring systems to autonomous vehicles. Quantization is a powerful tool to address the growing computational cost of such applications and yields significant compression over full-precision networks. However, quantization can result in substantial loss of performance for complex image classification tasks. To address this, we propose a principal component analysis (PCA)-driven methodology to identify the important layers of a binary network, and design mixed-precision networks. The proposed Hybrid-Net achieves a more than 10% improvement in classification accuracy over binary networks such as XNOR-Net for ResNet and VGG architectures on CIFAR-100 and ImageNet datasets, while still achieving up to 94% of the energy efficiency of XNOR-Nets. This work advances the feasibility of using highly compressed neural networks for energy-efficient neural computing in edge devices.

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Fig. 1: Illustration to show PCA analysis and subsequent Hybrid-Net design.
Fig. 2: Network configurations for comparison.
Fig. 3: Layer-wise principal component analysis trends for various networks.
Fig. 4: Illustration of the energy–accuracy optimality of Hybrid-Net.

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Data availability

All datasets used in this work are publicly available: CIFAR-10031 and ImageNet32.

Code availability

The publicly available tools Python and PyTorch were used to perform the experiments. Custom codes for the work are available at https://github.com/ichakra2/pca-hybrid.

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Acknowledgements

This work was supported in part by the Center for Brain-inspired Computing Enabling Autonomous Intelligence (C-BRIC), one of six centres in JUMP, a Semiconductor Research Corporation (SRC) programme sponsored by DARPA, in part by the National Science Foundation, in part by Intel, in part by the ONR-MURI programme and in part by the Vannevar Bush Faculty Fellowship.

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Contributions

I.C. and K.R. conceived the idea. I.C., D.R. and I.G. developed the simulation framework. I.C. carried out all experiments. I.C. and A.A. developed the energy and memory analysis framework. I.C., D.R., I.G. and K.R. analysed the results. I.C., D.R. and I.G. wrote the paper.

Corresponding author

Correspondence to Indranil Chakraborty.

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The authors declare no competing interests.

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Chakraborty, I., Roy, D., Garg, I. et al. Constructing energy-efficient mixed-precision neural networks through principal component analysis for edge intelligence. Nat Mach Intell 2, 43–55 (2020). https://doi.org/10.1038/s42256-019-0134-0

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