A simple method to identify the spatial location complication due to the transient phonon relaxation on the Brillouin loss spectrum
Bibliographic record
Abstract
For the pump-probe stimulated Brillouin scattering with probe pulse of a few nanoseconds duration and with a finite DC level, the acoustic wave relaxation time varies with the pump power and DC level. For the pump power of 1- 6mW, the acoustic wave relaxation changes between 9 to 90 ns for polarization maintained fiber (PMF) at temperature of -45°C for 2 ns pulse width. When pulse to DC ratio of the probe varies from 10 to 20dB, the acoustic relaxation time changes between 24 to 45ns for single mode fiber (SMF) at 25°C. This induced a power increment spectral feature in detected AC pump signal in the Brillouin loss spectrum of two temperature or strain sections, where both spectral components appeared at the positions much longer than natural phonon relaxation time (~10ns) equivalent length. This can cause problem for the distributed sensor in determining the strain/temperature boundary, and central Brillouin peak fitting due to the multiple peak convolution, and it affects temperature and strain accuracy. We propose the 2 nd order partial derivative of Stokes signal with respect to frequency and position giving a maximum or minimum at the boundary between two different strained sections. This allows finding the true stress or temperature corresponded section.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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".