Reducing the computational complexity of narrowband 2D fan filters using shaped 2D window functions
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Bibliographic record
Abstract
Two-dimensional (2D) discrete-domain FIR narrow fan filters may be used for the selective filtering of sampled broadband 2D plane waves on the basis of their directions of arrival (DOA). We show that the 2D region of support (ROS) of the unit impulse response h(n/sub 1/,n/sub 2/) of such filters may be reduced in size by using a shaped 2D window function, where the shape is determined by the angle and angular width of the fan. Relative to the widely used square-shaped window function, significant reductions in computational complexity are demonstrated using various shaped window functions. An approximately parabolically-bounded (PB) shaped 2D window function is shown to be especially effective. The method may be extended to 3D cone filters, for which the reduction in computational complexity is expected to be larger than for the 2D case.
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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) | 0.000 | 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