Bibliographic record
Abstract
Sound attenuation between work areas in open offices depends on barrier height and the sound-absorbing properties of the ceiling. Two methods for evaluating the sound-absorption ceilings are available: ASTM E1111, which gives a rating called the articulation class (AC), and ASTM C423, which gives sound-absorption average (SAA). Measurements of six ceiling systems made in accordance with ASTM E1111 and ASTM C423 provide a link between AC and SAA. Manufacturers often do not provide both ratings for their products, and it is useful to be able to use either rating system. SAA and measured AC for a 1.5-m-high screen are related by AC=102×SAA+91.4. SAA and calculated values of AC for a 1.8-m-high screen are related by AC=118 SAA+93. In the absence of E1111 test data, C423 SAA values can be used to select ceiling systems. The commonly recommended minimum SAA of 0.9 corresponds to an AC of 180 when the screen height is 1.5 m and to an AC of 200 when the screen height is 1.8 m. An approximate conversion from absorption coefficients to reflection coefficients agrees well with earlier work.
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.
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 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.008 | 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".