Passive amplification and directivity from air-coupled surface waves generated above a structured ground
Bibliographic record
Abstract
An outdoor experiment is reported in which air-coupled surface waves are generated in the frequency range between 63 and 130 Hz above a strip of structured ground of finite width. Since the sound pressure above the structured ground can be greater than if the ground was rigid, passive amplification can be obtained. The experimental results are compared to theoretical calculations that use a boundary element method. Both predict gains of up to 6 dB, relative to the pressure on a rigid plane when the strip width is of the order of one wavelength. Due to their finite width, the surface wave strips have a directional response. For a source at a large distance from the strip, the sound pressure level is up to 6 dB greater for sound arriving along the axis of the strip than transverse. For sources near the strip, as might arise in a near-field beamforming application, this difference can be as much as 25 dB.
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How this classification was reachedexpand
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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".