Alexander M. Powell

h-index18
2papers
1,299citations

2 Papers

3.3LGAug 25, 2020
Stochastic Markov Gradient Descent and Training Low-Bit Neural Networks

Jonathan Ashbrock, Alexander M. Powell

The massive size of modern neural networks has motivated substantial recent interest in neural network quantization. We introduce Stochastic Markov Gradient Descent (SMGD), a discrete optimization method applicable to training quantized neural networks. The SMGD algorithm is designed for settings where memory is highly constrained during training. We provide theoretical guarantees of algorithm performance as well as encouraging numerical results.

1.2NAApr 22, 2015
Fusion frames and randomized subspace actions

Xuemei Chen, Alexander Powell

A randomized subspace action algorithm is investigated for fusion frame signal recovery problems. It is noted that Kaczmarz bounds provide upper bounds on the algorithm's error moments. The main question of which probability distributions on a random fusion frame lead to provably fast convergence is addressed. In particular, it is proven which distributions give minimal Kaczmarz bounds, and hence give best control on error moment upper bounds arising from Kaczmarz bounds. Uniqueness of the optimal distributions is also addressed.