gbanyan
b6913d2f93
Structural: - Promote operational classifier definition from §III-L.0 to new §III-H.1, so the reader meets the five-way HC/MC/HSC/UN/LH rule before the §III-I/J/K diagnostic chain instead of ~130 lines after. §III-L renamed to "Anchor-Based Threshold Calibration"; §III-L.0 retains only calibration methodology, three units of analysis, any-pair semantics, and the FAR terminological note. §III-L.7 deleted (redundant with §III-J). - Reorganise §V-H Limitations into Primary / Secondary / Documented features / Engineering groupings (was a flat 14-item list). - Reframe §III-M from "ten-tool unsupervised-validation collection" to "each diagnostic addresses one specific unsupervised failure mode"; rename "What v4.0 does/does not claim" → "Limits / Scope of the present analysis"; retitle Table XXVII. Framing alignment (cross-section): - Strip all v3.x / v4.0 / v3.20 / v4-new / inherited lineage labels from rendered text (Abstract, Intro, §II, §III, §IV, §V, §VI, Appendix, Impact). - Replace "Paper A" rule references with "deployed" rule references. - Soften "validation" to "characterise" / "check" / "screening label" / "consistency check" / "support"; "verdict" → "screening label". - Remove codex-verified spike claims (non-Big-4 jittered dHash, Big-4 pooled cosine after firm-mean centring). Only formally scripted evidence (Scripts 39b–39e) retained; non-Big-4 evidence framed as corroborating raw-axis cosine, not as calibration evidence. - Strip script-provenance parentheticals from Introduction; defer Script 39c internal references and similar to Methodology / Appendix. Numerical / table fixes: - §III-C document-count arithmetic: 12 corrupted → 13 corrupted/unreadable, verified against sqlite DB and total-pdf/ folder counts (90,282 - 4,198 no-sig - 13 corrupted = 86,071 → 85,042 with detections → 182,328 sigs → 168,755 CPA-matched). Table I shows VLM-positive (86,084) and processed-for-extraction (86,071) as separate rows. - Wilson 95% CIs added for joint-rule ICCR rows in Table XXI / methodology table ([0.00011, 0.00018] and [0.00008, 0.00014]). - Unit error fixed: 0.3856 pp / 0.4431 pp → 0.3856 (38.6 pp) / 0.4431 (44.3 pp). Smaller revisions: - Pipeline framing: "detecting" → "screening" in Abstract / Intro / Conclusion for consistency with the unsupervised-screening positioning. - "hard ground-truth subset" → "conservative hard-positive subset" throughout. - §III-F SSIM / pixel-comparison rebuttal compressed from ~15 lines to 4; design-level argument deferred to supplementary materials. - "stakeholders can adopt / can derive thresholds" → "alternative operating points can be characterised by inverting" (less prescriptive). - "the same mechanism extending in milder form to Firms B/C/D" → "similar, milder production-related reuse patterns at Firms B/C/D" (mechanism claim softened). - Appendix A "non-hand-signed mode" / "two-mechanism mixture" lineage language aligned with v4 framing. Appendix B: - Rebuilt as a redirect-only stub. The HTML-commented obsolete table mapping (Table IX–XVIII labels with FAR / capture-rate / validation language) is removed; replaced with a short paragraph pointing to supplementary materials for full table-to-script provenance. Cross-references: - All §III-L references for the rule definition retargeted to §III-H.1; references for calibration still point to §III-L. - §III-H references for byte-level Firm A evidence / non-Big-4 reverse anchor retargeted to §III-H.2. Artefacts: - Combined manuscript regenerated: paper_a_v4_combined.md, 1314 lines (was 1346 pre-review). - Two review handoff documents added: paper/review_handoff_abstract_intro_20260515.md paper/review_handoff_body_20260515.md Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
8 lines
2.0 KiB
Markdown
8 lines
2.0 KiB
Markdown
# Abstract
|
||
|
||
<!-- IEEE Access target: <= 250 words, single paragraph -->
|
||
|
||
Regulations require Certified Public Accountants (CPAs) to attest each audit report with a signature, but digitization makes it feasible to reuse a stored signature image across reports — through administrative stamping or firm-level electronic signing — thereby undermining individualized attestation. We build an end-to-end pipeline for screening such *non-hand-signed* signatures at scale: a Vision-Language Model identifies signature pages, YOLOv11 localizes signatures, ResNet-50 supplies deep features, and a dual-descriptor layer combines cosine similarity with an independent-minimum perceptual hash (dHash) to separate *style consistency* from *image reproduction*. Applied to 90,282 Taiwan audit reports (2013–2023), the pipeline yields 182,328 signatures from 758 CPAs; primary analyses are scoped to the Big-4 sub-corpus (437 CPAs; 150,442 signatures). Distributional diagnostics show that the apparent multimodality of the descriptor distribution dissolves under joint firm-mean centring and integer-tie jitter ($p$ rises to $0.35$), so no within-population bimodal antimode anchors the operational thresholds. We instead adopt an anchor-based inter-CPA coincidence-rate (ICCR) calibration at three units: per-comparison ($0.0006$ at cos$>0.95$; $0.0013$ at dHash$\leq 5$; $0.00014$ jointly), pool-normalised per-signature ($0.11$ under the deployed any-pair high-confidence rule), and per-document ($0.34$ for the operational HC+MC alarm). Firm heterogeneity is decisive: Firm A's per-document HC+MC alarm rate is $0.62$ versus $0.09$–$0.16$ at Firms B/C/D after pool-size adjustment, and under the deployed any-pair rule $77$–$99\%$ of inter-CPA collisions concentrate within the source firm — consistent with firm-level template-like reuse. We position the system as a specificity-proxy-anchored screening framework with human-in-the-loop review, not as a validated forensic detector; no calibrated error rates are reportable without signature-level ground truth.
|
||
|
||
<!-- Word count: 247 -->
|