A general wave decomposition formula for the measurement of normal incidence sound transmission loss in impedance tube
Bibliographic record
Abstract
Two types of general methods can be found in the literature for the determination of the normal incidence sound transmission loss (nSTL) of acoustical elements. The first one is based on the transfer matrix (TM) approach, and the second one is based on the wavefield decomposition (WD) theory. From all the techniques proposed in the literature, the general TM methods (two-load or two-source location) are the only methods yielding the exact nSTL of an acoustical element without any assumptions on its symmetry and on the termination (i.e., the load). Except for the case of an anechoic termination, there is no method based on the WD theory which yields exact nSTL. This paper presents a general WD method to measure the exact nSTL of an acoustical element without any assumptions on its symmetry and on the termination. Similar to general TM methods for non-symmetrical elements, four microphones and two loads will be required. As a first validation of the method, symmetrical and non-symmetrical porous materials are investigated. Results are discussed and compared with some existing methods and with the classical two-load method. A perfect agreement is found with the classical two-load method.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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 source (direct Gemma or distilled Codex), 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".