A relaxation method for binary optimizations on constrained Stiefel manifold

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Xiao, Lianghai, Qian, Yitian, Pan, Shaohua
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929412213047296
author Xiao, Lianghai
Qian, Yitian
Pan, Shaohua
author_facet Xiao, Lianghai
Qian, Yitian
Pan, Shaohua
contents This paper focuses on a class of binary orthogonal optimization problems frequently arising in semantic hashing. Consider that this class of problems may have an empty feasible set, rendering them not well-defined. We introduce an equivalent model involving a restricted Stiefel manifold and a matrix box set, and then investigate its penalty problems induced by the $\ell_1$-distance from the box set and its Moreau envelope. The two penalty problems are always well-defined. Moreover, they serve as the global exact penalties provided that the original feasible set is non-empty. Notably, the penalty problem induced by the Moreau envelope is a smooth optimization over an embedded submanifold with a favorable structure. We develop a retraction-based line-search Riemannian gradient method to address the penalty problem. Finally, the proposed method is applied to supervised and unsupervised hashing tasks and is compared with several popular methods on the MNIST and CIFAR-10 datasets. The numerical comparisons reveal that our algorithm is significantly superior to other solvers in terms of feasibility violation, and it is comparable even superior to others in terms of evaluation metrics related to the Hamming distance.
format Preprint
id arxiv_https___arxiv_org_abs_2308_10506
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A relaxation method for binary optimizations on constrained Stiefel manifold
Xiao, Lianghai
Qian, Yitian
Pan, Shaohua
Optimization and Control
This paper focuses on a class of binary orthogonal optimization problems frequently arising in semantic hashing. Consider that this class of problems may have an empty feasible set, rendering them not well-defined. We introduce an equivalent model involving a restricted Stiefel manifold and a matrix box set, and then investigate its penalty problems induced by the $\ell_1$-distance from the box set and its Moreau envelope. The two penalty problems are always well-defined. Moreover, they serve as the global exact penalties provided that the original feasible set is non-empty. Notably, the penalty problem induced by the Moreau envelope is a smooth optimization over an embedded submanifold with a favorable structure. We develop a retraction-based line-search Riemannian gradient method to address the penalty problem. Finally, the proposed method is applied to supervised and unsupervised hashing tasks and is compared with several popular methods on the MNIST and CIFAR-10 datasets. The numerical comparisons reveal that our algorithm is significantly superior to other solvers in terms of feasibility violation, and it is comparable even superior to others in terms of evaluation metrics related to the Hamming distance.
title A relaxation method for binary optimizations on constrained Stiefel manifold
topic Optimization and Control
url https://arxiv.org/abs/2308.10506