{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T17:16:43Z","timestamp":1778779003566,"version":"3.51.4"},"reference-count":31,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T00:00:00Z","timestamp":1777507200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Computation"],"abstract":"<jats:p>This work considers admissibility-enforcing reconstruction of reaction-channel subgroup levels on prescribed total-subgroup support and probabilities, a setting in which conventional exact reconstruction may produce negative reaction-channel levels. The proposed reconstruction relaxes conventional full matching by retaining selected low-order channel quantities associated with limiting dilution responses exactly, while fitting the remaining matching conditions in a constrained least-squares sense under nonnegativity. The exact-retention constraints are embedded through a null-space parametrization, which reduces the reconstruction to a convex optimization problem over the remaining degrees of freedom. Two variants are examined: a single-retention formulation, which is automatically feasible for nonnegative retained data, and a two-retention formulation, which is more restrictive and depends on compatibility with the fixed total-subgroup rule. Numerical tests for 238U capture data show that the proposed reconstruction removes the negative reaction-channel levels observed in the violating groups. Restoring admissibility entails deterioration in response accuracy relative to the unconstrained full-matching baseline, reflecting the trade-off between exact matching and nonnegativity on the fixed rule. Of the two variants considered, the single-retention formulation shows more stable overall behavior in the present comparison. In particular, for all violating cases at orders N\u226510, it restores nonnegativity, with the reported 95th-percentile relative errors in the folded effective cross section not exceeding 8.90\u00d710\u22127.<\/jats:p>","DOI":"10.3390\/computation14050103","type":"journal-article","created":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T06:50:01Z","timestamp":1777618201000},"page":"103","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Admissible Reconstruction of Reaction-Channel Levels on Fixed Subgroup Support and Probabilities in Algebraic Probability Table Construction"],"prefix":"10.3390","volume":"14","author":[{"given":"Beichen","family":"Zheng","sequence":"first","affiliation":[{"name":"China Nuclear Data Center, China Institute of Atomic Energy, Beijing 102413, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lili","family":"Wen","sequence":"additional","affiliation":[{"name":"China Nuclear Data Center, China Institute of Atomic Energy, Beijing 102413, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"450","DOI":"10.13182\/NSE72-3","article-title":"The Probability Table Method for Treating Unresolved Neutron Resonances in Monte Carlo Calculations","volume":"49","author":"Levitt","year":"1972","journal-title":"Nucl. 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