Research Case Studies

When More Expressive Graph Models Do Not Win

PyTorch Geometric · Cora · ESOL · GCN · GATv2 · TransformerConv · Scaffold Splits · Multi-Seed Evaluation

I revisited a set of graph-learning prototypes as a controlled benchmark spanning transductive node classification and molecular regression. Instead of presenting a single favorable checkpoint, I standardized GCN, graph-attention, and transformer-style models under validation-selected early stopping and repeated every experiment across three deterministic seeds.

On Cora, GCN and GAT reached the same 0.802 mean test accuracy, while GCN used approximately half the trainable parameters and showed lower seed variance. On ESOL, GCN produced the strongest mean out-of-scaffold result at 1.450 RMSE, but its run-to-run variance exposed a real generalization risk. The practical lesson is that model selection should follow graph structure, data regime, and uncertainty—not architectural complexity alone.

Cora node-embedding visualization and ESOL measured-versus-predicted solubility results
Real benchmark outputs from validation-selected checkpoints: learned Cora node embeddings and held-out ESOL scaffold-split predictions. Summary values report mean ± standard deviation across three deterministic seeds.

Reliable Human Recognition Is a Systems Problem

Facial Landmarks · Attribute Interpretation · Recognition-Aware Quality · Multispectral Sensing · Dense 3D Reconstruction · Pose Tracking

I organized a set of human-analysis prototypes into an artifact-backed research history spanning representation learning, sparse facial geometry, semantic interpretation, input-quality gating, domain alignment, dense 3D reconstruction. The central question is how recognition systems remain useful when observation quality, pose, sensor modality, and execution constraints change.

One archived face-quality experiment reports patch-wise attention producing the lowest divergence from verifier-derived score distributions: KL 466.01 versus 772.32 without attention, a 39.7% reduction. The repository also preserves seven dense meshes with 43,867 vertices and 86,906 faces each, plus a bounded, smoke-tested pose CLI. Historical results are labeled separately from current validation so the evidence remains useful without overstating reproducibility.

Artifact-backed human recognition research history spanning landmarks, attributes, face quality, multispectral sensing, dense 3D reconstruction, and pose tracking
Versioned evidence from repository artifacts across structure, semantics, reliability, sensing, geometry, and deployment. Quality values are archived historical results; the maintained pose path was smoke-tested on bundled video.

When Optimal Transport Helps—and When It Does Not

Weak Supervision · Optimal Transport · Domain Alignment · Negative Results · Multi-Seed Evaluation · Reliability Diagnostics

I reframed a collection of weakly supervised prototypes around one systems question: when should indirect supervision be solved with distribution alignment, and when is a simpler representation safer? A benchmark now separates rerunnable evidence from historical dataset-dependent work and evaluates document geometry and unpaired color transfer with explicit baselines, deterministic seeds, and numerical residuals.

On seven archived scripts, a weighted-centroid baseline outperformed compressed Sinkhorn OT: 100% versus 71.4% nearest-neighbor group agreement and 1.55× versus 1.07× group separation. For unpaired palette transfer, low-regularization OT reduced palette JSD from 0.401 to 0.274—a 31.8% reduction versus mean/std matching—but edge correlation fell from 0.996 to 0.854. The engineering outcome is an operating-point decision: add alignment capacity only when its fit benefit justifies the structure it changes.

A benchmark comparing a centroid baseline with Sinkhorn optimal transport and showing the fit-structure tradeoff in unpaired palette transfer
Current validation from bundled artifacts. Document groups are archive-defined and interpretive; palette metrics measure distribution fit rather than human preference. Dataset-dependent point-cloud, action, and captioning threads remain labeled historical.

Good Samples Are Not Enough for Reliable Generative Systems

GAN Objectives · Conditional Control · Image Translation · Diffusion · Failure Analysis · Temporal Stability

I reorganized a broad generative-model archive around a systems contract: fidelity, coverage, controllability, conditional adherence, and temporal stability can fail independently. A deterministic method now measures versioned outputs, exposes failure cases, and labels training-dependent claims historical when datasets or checkpoints are missing.

Conditional WGAN-GP outputs reached 97.5% ± 4.5% leave-one-checkpoint consistency. Across 24 Pix2Pix pairs, median condition-edge recall was 94.9%, but background color spill reached 31.4% in the worst archived case. Across 44 StyleGAN control sequences, illumination edits were smoother than pose: roughness 0.424 versus 0.929 and consecutive edge continuity 0.994 versus 0.930. The result is not an architecture leaderboard; it is an evaluation framework aligned to the generative-system contract.

Artifact-backed generative-systems evaluation across condition consistency, image-translation failures, and temporal control stability
Current versioned artifacts across condition consistency, conditional adherence, failure containment, and control stability. Diffusion fidelity and dataset-dependent training remain historical until reference data and checkpoints are restored.