Checklist ROAI 2026 County Stage, Grades 11–12 · Task 2
Nuclear Data Analysis from a Webcam
Count radiation-hit pixels in an X-ray webcam frame and classify webcam frames by radiation source (radium, thorium or X-rays).
The task
A student uses a webcam as a makeshift radiation detector: ionising radiation leaves bright pixels in the frames. X-rays produce isolated dots, whereas his thorium lens and radium watch also produce tracks caused by beta particles.
Subtask 1 asks for the number of non-zero (radiated) pixels in xrays.png. Subtask 2 asks for the source of each test image: radium, thorium or xrays.
Abridged by SOTA from the official materials. The official statement has the exact rules, and it wins wherever this summary differs.
At a glance
- You get
- 300 labelled images (train) and 300 unlabelled images (test), with their CSV indexes and
xrays.png, all supplied in the starter kit. - You submit
- CSV with subtaskID, datapointID and answer (pixel count for subtask 1; class name per test image for subtask 2).
- Scoring
- Subtask 1 (30 points): exact count. Subtask 2 (70 points): F1; full marks for F1 strictly above 0.97, partial credit scaled towards that threshold.
- Rules
- On-site at partner county centres, in the prepared local Jupyter environment
- Only the packages listed in the round rules may be used
- Mobile phones and other electronic or information sources are forbidden in the room
- Format
- ROAI 2026 county stage, grades 11–12, 8 March 2026.