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Record W2146675507 · doi:10.1002/nla.1999

A cyclic algorithm for maximum likelihood estimation using Schur complement

2015· article· en· W2146675507 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

fundA Canadian funder is recorded on the work.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueNumerical Linear Algebra with Applications · 2015
Typearticle
Languageen
FieldEngineering
TopicTraffic Prediction and Management Techniques
Canadian institutionsnot available
FundersCentre interuniversitaire de recherche sur les reseaux d'entreprise, la logistique et le transport
KeywordsHessian matrixSchur complementCoordinate descentMathematicsComplement (music)AlgorithmMathematical optimizationMatrix (chemical analysis)Block (permutation group theory)Schur decompositionSystem of linear equationsHessian equationTransformation (genetics)Applied mathematicsLinear systemDescent (aeronautics)Eigenvalues and eigenvectorsPartial differential equation

Abstract

fetched live from OpenAlex

Summary Using the Schur complement of a matrix, we propose a computational framework for performing constrained maximum likelihood estimation in which the unknown parameters can be partitioned into two sets. Under appropriate regularity conditions, the corresponding estimating equations form a non‐linear system of equations with constraints. Solving this system is typically accomplished via methods which require computing or estimating a Hessian matrix. We present an alternative algorithm that solves the constrained non‐linear system in block coordinate descent fashion. An explicit form for the solution is given. The overall algorithm is shown in numerical studies to be faster than standard methods that either compute or approximate the Hessian as well as the classical Nelder–Mead algorithm. We apply our approach to a motivating problem of evaluating the effectiveness of Road Safety Policies. This includes several numerical studies on simulated data. Copyright © 2015 John Wiley & Sons, Ltd.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Other design · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.925
Threshold uncertainty score0.583

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.023
GPT teacher head0.272
Teacher spread0.248 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it