← Prem Kumar Perumal / AI portfolioSYNTHETIC DATA · RESEARCH DEMO

AEROSOL SCIENCE × MACHINE LEARNING × BIOSECURITY

AeroEvidence

From airborne signals to evidence for review.

An AI screening demonstrator that brings particle measurements, fluorescence and environmental context into one interpretable workflow.

All readings and reference labels are simulated. A biological-like signal is a screening cue, not confirmation of a pathogen, viability, intent or threat.
Simulation paused 00:00
PARTICLE CONCENTRATION—particles/L · simulated
FLUORESCENT FRACTION—optical proxy · simulated
RELATIVE HUMIDITY—environmental context
MODEL SCORE—synthetic biological-like class

SIMULATED SENSOR STREAM

Watch the signal evolve

Frame 0
Total particle concentrationFluorescent particle concentration

Each frame represents one illustrative minute. Time and concentrations are demonstration values, not instrument observations.

SIZE-RESOLVED VIEW

Particle distribution

Illustrative optical size bins. These are not SMPS measurements or a calibrated biological size signature.

INTERPRETABLE SCORE

Why this prediction?

Signed contributions to model log-odds, relative to training-standardised features. Association in a synthetic model does not establish cause.

VALIDATION EVIDENCE

Performance on validation data

Confusion matrix

Reference: synthetic biological-like event vs other synthetic frames.

Reference / predictionReview flagNo flag
Biological-like
Other

The biosecurity interpretation

In this demo, an alert starts a review of sensor quality and environmental context. Confirmation would require appropriate independent evidence through established laboratory and organisational procedures.

A missed synthetic event and an unnecessary review are both counted. No score on this page estimates the probability of a biological attack.

Fluorescence alone is not biological identification. The interferent scenario is included to make this limitation visible.

FRAME REVIEW LOG

Inspect every observation

Latest 12 frames
MinuteScenarioParticles/LFluorescent %ScoreFlagSynthetic truth

METHOD, EXPERTISE & LIMITATIONS

Built around aerosol measurement judgement.

Aerosol science

Particle number, size distributions and environmental conditions help interpret an airborne signal. The demo connects to Prem’s work in aerosol dispersion and exposure assessment; it does not reproduce his experimental datasets.

Machine learning

A seeded synthetic generator creates overlapping background, biological-like, dust and fluorescent-interferent examples. A stratified 60/20/20 split supports training, validation and a test set sealed until the threshold is locked.

Biological assurance

Optical proxies can support screening. Species identity, viability and health significance require separate evidence. Non-biological fluorescence and unrepresented conditions can confound predictions.

Technical implementation and reproducibility

Seed 73, 1,800 examples. Logistic regression: 800 iterations, full-batch gradient descent, learning rate 0.12, L2 = 0.01, intercept unpenalised. Feature means and standard deviations are fitted on training data only. Inputs: fluorescence fraction, coarse fraction and natural log of particle concentration relative to an illustrative baseline of 500 particles/L. Point estimates and Wilson 95% intervals describe synthetic performance only.

Concentrations and particle-size histograms are generated for illustration. Labels come from the selected synthetic scenario, not measurements. High humidity is an out-of-training-distribution stress scenario; its model scores are especially unreliable. The simulated sequence is not a field validation dataset.

After revealing test results, retuning by resetting is exploratory. The browser-side seal is a workflow aid, not a security boundary. No live sensors, cloud AI API, external data, local storage or operational deployment are configured. Exported reports include model parameters, data provenance, frame readings and evaluation metrics. Portfolio demonstration built with AI-assisted development.

Scientific context

The research below motivates the need to consider fluorescence interference. It does not validate this simulator or its chosen synthetic distributions.