3 papers
math.OC2021
The Proximity Operator of the Log-Sum Penalty
Ashley Prater-Bennette, Lixin Shen, Erin E. Tripp
The log-sum penalty is often adopted as a replacement for the pseudo-norm in compressive sensing and low-rank optimization. The hard-thresholding operator, i.e., the proxi…
math.OC2019
Algorithmic Versatility of SPF-regularization Methods
Lixin Shen, Bruce W. Suter, Erin E. Tripp
Sparsity promoting functions (SPFs) are commonly used in optimization problems to find solutions which are assumed or desired to be sparse in some basis. For example, the l1-regula…
math.OC2018
Structured Sparsity Promoting Functions
Lixin Shen, Bruce W. Suter, Erin E. Tripp
Motivated by the minimax concave penalty based variable selection in high-dimensional linear regression, we introduce a simple scheme to construct structured semiconvex sparsity pr…