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A Comparison of Adaptive Processing Techniques with Nth Root Beam Forming Methods

2007· article· en· W2101493337 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueGeophysical Journal of the Royal Astronomical Society · 2007
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicSeismic Imaging and Inversion Techniques
Canadian institutionsWestern University
FundersUK Atomic Energy Authority
KeywordsSlownessAzimuthAlgorithmComputer scienceWaveletSignal processingNoise (video)SIGNAL (programming language)GeologyMathematicsGeometryDigital signal processingSeismologyComputer vision

Abstract

fetched live from OpenAlex

Small differences in slowness and azimuth for overlapping phases especially where the branches of the travel-time curve are triplicated must be resolved for a meaningful inversion of array data. A computer program package has been written in FORTRAN IV which enables a user to determine, automatically, the apparent azimuth and slowness of any portion of the seismic wavetrain recorded at various arrays if he has the raw data on digital tape and has access to any modern computer. These programs make use of two methods, (i) adaptive processing, and (ii) Nth root beam forming which have been compared to determine the apparent azimuth and slowness of the seismic wavelets. The former method is performed by cross correlating the signal on each channel with a velocity and azimuth filtered trace in an iterative manner until the convergence takes place. In the latter method the operation is done by delaying the various channels to align a group of arrivals with a particular velocity and azimuth; taking the Nth root of the signal; summing and then raising the result to the Nth power. The value of apparent velocity and azimuth which produces a maximum filtered signal is determined. Experiments with clean and noisy synthetic data have shown that the adaptive processing method is more successful for resolving small differences in apparent velocity and azimuth of overlapping wavelets. It also has an advantage that a set of residuals may easily be obtained from the analysis. The Nth root method is extremely powerful in enhancing the signal to noise ratio at the expense of signal distortion. The computation time for both methods is about the same.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Other design · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.763
Threshold uncertainty score0.308

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.015
GPT teacher head0.281
Teacher spread0.265 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it