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Record W3174966384 · doi:10.1109/tpami.2021.3091682

Signed Graph Metric Learning via Gershgorin Disc Perfect Alignment

2021· article· en· W3174966384 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.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueIEEE Transactions on Pattern Analysis and Machine Intelligence · 2021
Typearticle
Languageen
FieldComputer Science
TopicFace and Expression Recognition
Canadian institutionsYork University
FundersChina Postdoctoral Science FoundationNatural Sciences and Engineering Research Council of CanadaNational Natural Science Foundation of China
KeywordsMathematicsCombinatoricsDiagonalEigenvalues and eigenvectorsMetric (unit)Diagonal matrixSymmetric matrixDiscrete mathematicsAlgorithmGeometry

Abstract

fetched live from OpenAlex

Given a convex and differentiable objective <inline-formula><tex-math notation="LaTeX">$Q({\mathbf M})$</tex-math></inline-formula> for a real symmetric matrix <inline-formula><tex-math notation="LaTeX">${\mathbf M}$</tex-math></inline-formula> in the positive definite (PD) cone—used to compute Mahalanobis distances—we propose a fast general metric learning framework that is entirely projection-free. We first assume that <inline-formula><tex-math notation="LaTeX">${\mathbf M}$</tex-math></inline-formula> resides in a space <inline-formula><tex-math notation="LaTeX">${\mathcal S}$</tex-math></inline-formula> of generalized graph Laplacian matrices corresponding to balanced signed graphs. <inline-formula><tex-math notation="LaTeX">${\mathbf M}\in {\mathcal S}$</tex-math></inline-formula> that is also PD is called a graph metric matrix. Unlike low-rank metric matrices common in the literature, <inline-formula><tex-math notation="LaTeX">${\mathcal S}$</tex-math></inline-formula> includes the important diagonal-only matrices as a special case. The key theorem to circumvent full eigen-decomposition and enable fast metric matrix optimization is Gershgorin disc perfect alignment (GDPA): given <inline-formula><tex-math notation="LaTeX">${\mathbf M}\in {\mathcal S}$</tex-math></inline-formula> and diagonal matrix <inline-formula><tex-math notation="LaTeX">${\mathbf S}$</tex-math></inline-formula> , where <inline-formula><tex-math notation="LaTeX">$S_{ii} = 1/v_i$</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">${\mathbf v}$</tex-math></inline-formula> is the first eigenvector of <inline-formula><tex-math notation="LaTeX">${\mathbf M}$</tex-math></inline-formula> , we prove that Gershgorin disc left-ends of similarity transform <inline-formula><tex-math notation="LaTeX">${\mathbf B}= {\mathbf S}{\mathbf M}{\mathbf S}^{-1}$</tex-math></inline-formula> are perfectly aligned at the smallest eigenvalue <inline-formula><tex-math notation="LaTeX">$\lambda _{\min }$</tex-math></inline-formula> . Using this theorem, we replace the PD cone constraint in the metric learning problem with tightest possible linear constraints per iteration, so that the alternating optimization of the diagonal / off-diagonal terms in <inline-formula><tex-math notation="LaTeX">${\mathbf M}$</tex-math></inline-formula> can be solved efficiently as linear programs via the Frank-Wolfe method. We update <inline-formula><tex-math notation="LaTeX">${\mathbf v}$</tex-math></inline-formula> using Locally Optimal Block Preconditioned Conjugate Gradient (LOBPCG) with warm start as entries in <inline-formula><tex-math notation="LaTeX">${\mathbf M}$</tex-math></inline-formula> are optimized successively. Experiments show that our graph metric optimization is significantly faster than cone-projection schemes, and produces competitive binary classification performance.

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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: Empirical · Consensus signal: none
Teacher disagreement score0.991
Threshold uncertainty score0.746

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.002
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 head0.016
GPT teacher head0.255
Teacher spread0.239 · 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