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Record W1978429862 · doi:10.1088/0266-5611/23/3/025

Dynamic level set regularization for large distributed parameter estimation problems

2007· article· en· W1978429862 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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueInverse Problems · 2007
Typearticle
Languageen
FieldMathematics
TopicNumerical methods in inverse problems
Canadian institutionsUniversity of British Columbia
Fundersnot available
KeywordsMathematicsInverse problemConjugate gradient methodRegularization (linguistics)Applied mathematicsLinear systemIterative methodPiecewise linear functionMathematical optimizationScalingTikhonov regularizationAlgorithmComputer scienceMathematical analysis

Abstract

fetched live from OpenAlex

This paper considers inverse problems of shape recovery from noisy boundary data, where the forward problem involves the inversion of elliptic PDEs. The piecewise constant solution, a scaling and translation of a characteristic function, is described in terms of a smoother level set function. A fast and simple dynamic regularization method has been recently proposed that has a robust stopping criterion and typically terminates after very few iterations. Direct linear algebra methods have been used for the linear systems arising in both forward and inverse problems, which is suitable for problems of moderate size in 2D. For larger problems, especially in 3D, iterative methods are required. In this paper we extend our previous results to large-scale problems by proposing and investigating iterative linear system solvers in the present context. Perhaps contrary to one's initial intuition, the iterative methods are particularly useful for the inverse rather than the forward linear systems. Moreover, only very few preconditioned conjugate gradient iterations are applied towards the solution of the linear system for the inverse problem, allowing the regularizing effects of such iterations to take centre stage. The efficacy of the obtained method is demonstrated.

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)0.004
metaresearch head score (Gemma)0.004
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: Theoretical or conceptual
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.265
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0040.004
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.001
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 head0.117
GPT teacher head0.370
Teacher spread0.253 · 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