Md. Asif Uddin

Elementa

The figure library

Every diagram on this site, at its own address. All are hand-written inline SVG using the site palette, so they stay legible in both themes and paste into a slide deck without becoming a screenshot of a screenshot.

FigPipelineHierarchiRetina

Plate I — HierarchiRetinapermalink
The HierarchiRetina three-stage pipelineA fundus image enters Stage I screening for referable diabetic retinopathy at grade 2 or above. It then branches to five parallel lesion segmentation models — microaneurysms, haemorrhages, hard exudates, cotton wool spots and vessels — whose masks rejoin the raw image as eight channels into Stage III, the lesion-guided grader. Stage III emits either an ordinal severity grade from one to four, or an ungradable verdict routed to human review.Fundus imageStage I · screening(referable DR, grade ≥ 2)MAHSMoEHEMultiScaleEXBrightSpotCWSwarm-upVesselsFOV maskStage III · LG-DRG(8 channels: RGB + 5 masks)Severity grade(CORN ordinal, 1–4)Ungradable(routed to human review)
Fig. 1 — The HierarchiRetina three-stage pipeline: screening, five parallel lesion segmenters, and lesion-guided grading over eight channels.

FigTokenBoundary

Book I, Proposition 1permalink
One string under three tokenisationsThe string "unhappiness" segmented three ways: as subwords un / happi / ness, as a single word token, and as ten individual characters. Each segmentation fixes which distinctions the model is able to represent at its input.unhappinesssubwordunhappinesswordunhappinesscharunhappiness
Fig. 2 — One string under three tokenisations. The segmentation chosen at the input fixes which distinctions the model is able to represent at all.

FigAttentionWeights

Book I, Proposition 4permalink
Attention as a weighted average over valuesA single query is compared against four keys. The resulting softmax weights — 0.06, 0.61, 0.09 and 0.24 — are shown as horizontal bars, and the output is the sum of the value vectors scaled by those weights. The weights come from content, not from position.query qsoftmax(q · kᵢ / √d)k₁0.06k₂0.61k₃0.09k₄0.24Σ wᵢ vᵢweights are content-addressed — nothing here depends on i
Fig. 3 — Attention as a weighted average over values, with weights computed by comparing a query against every key. Nothing in the computation depends on position.

FigPermutation

Book I, Proposition 7permalink
Permutation equivariance, and the repairIn the upper panel, self-attention alone maps a shuffled input to an identically shuffled output: reordering the tokens carries no information. In the lower panel the same tokens carry positional encodings, so a reordering produces a genuinely different output.attention aloneattention + positionthecatsatsatthecatthecatsatsatthecat+p1+p2+p3+p1+p2+p3the′cat′sat′sat′the′cat′the′cat′sat′cat′sat′the′same output, merely reordered — the model cannot tell the two inputs apartdifferent output — order is now information
Fig. 4 — Permutation equivariance and its repair. Without positional encoding a reordered input yields a merely reordered output; with it, order becomes information.