Year: 2026
Type: article
Abstract: True-support error can decrease while an elemental composition assigns more mass incorrectly. We demonstrate this discrepancy in constrained regression of 5 keV energy-dispersive x-ray spectra, using 76 audited material–platform records representing 69 reference compositions. With identical compositions held out together, Ridge regression gives a pooled R 2 of 0.236, yet its ternary mean absolute error exceeds that of a uniform-on-support baseline. After one true element is removed, adding the highest-scored absent element lowers ternary true-support MAE by 3.04 percentage points while raising full-vector L 1 error by 33.14 points. An exact mass decomposition attributes the discrepancy to false-positive mass excluded from the support score. For fixed raw scores, Euclidean simplex projection makes full L 1 nondecreasing when the allowed support gains only absent elements. With an internally trained support detector, lowering the threshold from 0.5 to 0.3 recovers true elements in 37 records and improves both mean errors. Nine of the 76 records have lower true-support MAE and higher full L 1 .
Source: Physica Scripta
Author: Geonwoo Jeong
Institution: Gachon University
Language: English
Subfield: Surfaces, Coatings and Films
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7224130952