A Common Theoretical Framework for AC and Telluric Interference on Pipelines
Bibliographic record
Abstract
Abstract AC and telluric interference on pipelines are both due to electromagnetic induction by external sources. In the case of AC interference, the source is a nearby power line, tens of meters (typically 30 feet or more) above the ground, and with currents oscillating at a frequency of 50 or 60 Hertz (Hz). Telluric currents are caused by electric currents in the ionosphere, 100 kilometers (km) above the earth’s surface, varying on time scales from seconds to days. Although the heights and frequencies of the currents are different in these two situations, the underlying physical process of electromagnetic induction is the same in each case. To model these processes we can use the distributed source transmission line (DSTL) theory to look at the network response and the multi-layered cylinder (MLC) model to determine the frequency response of pipeline sections. We review the work that has been done using these methods to model both AC interference and telluric current interference. Many of the results for AC and telluric interference, although sometimes presented in different ways, are shown to be essentially the same. We also examine what characteristics of AC and telluric interference, such as the skin depth effects, lead to differences in the response of pipelines to AC and telluric currents.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.008 | 0.001 |
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".