LGNov 23, 2020
Neural collapse with unconstrained featuresDustin G. Mixon, Hans Parshall, Jianzong Pi
Neural collapse is an emergent phenomenon in deep learning that was recently discovered by Papyan, Han and Donoho. We propose a simple "unconstrained features model" in which neural collapse also emerges empirically. By studying this model, we provide some explanation for the emergence of neural collapse in terms of the landscape of empirical risk.
LGAug 10, 2020
Lie PCA: Density estimation for symmetric manifoldsJameson Cahill, Dustin G. Mixon, Hans Parshall
We introduce an extension to local principal component analysis for learning symmetric manifolds. In particular, we use a spectral method to approximate the Lie algebra corresponding to the symmetry group of the underlying manifold. We derive the sample complexity of our method for a variety of manifolds before applying it to various data sets for improved density estimation.