Three-Dimensional Nonaxisymmetric Pole Piece Shape Optimization for Biplanar Permanent-Magnet MRI Systems
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The pole pieces of a permanent-magnet system for magnetic resonance imaging (MRI) are optimized for maximum magnetic field homogeneity in the imaging volume. Axisymmetric and nonaxisymmetric optimized pole piece designs based on the same geometrical parameterization are presented. The optimization algorithm demonstrated is based on field calculations by the three-dimensional finite-element method and takes into account the nonlinearity of the magnetic materials involved. The necessity of the nonaxisymmetric design in obtaining suitable field homogeneity over a large imaging volume is demonstrated through comparison of various pole piece designs for a novel biplanar permanent-magnet assembly with reduced pole dimensions as required in the development of an integrated linear accelerator and MRI system for real-time image-guided adaptive radiotherapy. The sensitivity of the field inhomogeneities to geometrical variations in the nonaxisymmetric design surface is explored and statistical parameters quantifying this sensitivity are approximated.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it