NNTrainer: Light-Weight On-Device Training Framework

Modern consumer electronic devices have adopted deep learning-based intelligence services for their key features. Vendors have recently started to execute intelligence services on devices to preserve personal data in devices, reduce network and cloud costs. We find such a trend as the opportunity to personalize intelligence services by updating neural networks with user data without exposing the data out of devices: on-device training. For example, we may add a new class, my dog, Alpha, for robotic vacuums, adapt speech recognition for the users accent, let text-to-speech speak as if the user speaks. However, the resource limitations of target devices incur significant difficulties. We propose NNTrainer, a light-weight on-device training framework. We describe optimization techniques for neural networks implemented by NNTrainer, which are evaluated along with the conventional. The evaluations show that NNTrainer can reduce memory consumption down to 1/28 without deteriorating accuracy or training time and effectively personalizes applications on devices. NNTrainer is cross-platform and practical open source software, which is being deployed to millions of devices in the authors affiliation.