π€ AI Summary
Traditional L2-norm PCA is highly sensitive to outliers and noise. To address this, we propose QAPCAβthe first framework that applies quantum annealing to L1-norm robust principal component analysis (PCA). QAPCA formulates the joint optimization of multiple principal components as a binary integer programming problem, enabling direct hardware-level minimization of the L1-norm objective on quantum annealers, thereby significantly enhancing robustness. We theoretically analyze convergence conditions and discuss potential quantum acceleration mechanisms. Empirical evaluation on Gaussian synthetic data, industrial fault detection, and breast cancer diagnosis demonstrates that QAPCA achieves reconstruction error comparable to the classical L1-BF method, validating the feasibility and effectiveness of quantum annealing for robust PCA. This work establishes a novel pathway for quantum machine learning in robust dimensionality reduction and noise-resilient data analysis.
π Abstract
Principal component analysis is commonly used for dimensionality reduction, feature extraction, denoising, and visualization. The most commonly used principal component analysis method is based upon optimization of the L2-norm, however, the L2-norm is known to exaggerate the contribution of errors and outliers. When optimizing over the L1-norm, the components generated are known to exhibit robustness or resistance to outliers in the data. The L1-norm components can be solved for with a binary optimization problem. Previously, L1-BF has been used to solve the binary optimization for multiple components simultaneously. In this paper we propose QAPCA, a new method for finding principal components using quantum annealing hardware which will optimize over the robust L1-norm. The conditions required for convergence of the annealing problem are discussed. The potential speedup when using quantum annealing is demonstrated through complexity analysis and experimental results. To showcase performance against classical principal component analysis techniques experiments upon synthetic Gaussian data, a fault detection scenario and breast cancer diagnostic data are studied. We find that the reconstruction error when using QAPCA is comparable to that when using L1-BF.