Comparison of first Saint Mary’s University Open-Path Fourier Transform Infrared (OP-FTIR) spectrometer measurement results with National Air Pollution Surveillance (NAPS) air quality measurements in Halifax
Bibliographic record
Abstract
The atmosphere is very complex and it involves many chemical and physical processes that affect the air people breathe.This is why it is important to characterize the air in the atmosphere in order to determine what people are exposed to every day.Carbon monoxide (CO), a toxic air pollutant emitted primarily as a result of incomplete combustion and oxidation of hydrocarbons, was measured in Halifax, Nova Scotia using an Open-Path Fourier Transform Infrared (OP-FTIR) spectrometer and compared to National Air Pollution Surveillance (NAPS) CO measurements as a verification step in the characterization of this new instrument.Measured NAPS data was compared to OP-FTIR spectrometer results for three different measurement campaigns: Robie Street (at Inglis for 2 hours), Rice Building (at SMU for ~1 week), and Lake Major (in Dartmouth for ~1 week).For each campaign, spectra were recorded and a concentration of CO was retrieved for each spectrum (one per minute) by the program MALT.The retrieved CO concentrations were plotted in a time series for each campaign and compared to NAPS CO concentration measurements obtained on Barrington Street at the same time.Data quality of the OP-FTIR spectrometer was assessed in detail, with the majority of spectral fit residuals and their RMS values below 0.01 (1%), indicating a reasonable fit between the measured spectra and the fitted spectra simulated by MALT.The technique's accuracy was previously conservatively estimated to be no worse than 10%; however, for all three campaigns, there was a clear systematic bias of up to 0.35 ppm (a factor of ~3) between the OP-FTIR spectrometer and NAPS measurements, along with unexplained enhancements in CO concentration at times and locations with minimal vehicle activity.Further studies are suggested in order to fully explain the reason for the systematic bias and unusual enhancements in CO concentration observed.September 15, 2016 I would like to start by thanking my supervisor, Dr. Aldona Wiacek, for all of her help, support, and inspiration throughout this long and challenging process.Thank you for allowing me the chance to apply my skills and explore a subject that is very complex, yet very interesting to me.I appreciate everything you have done and the time you have set aside in your busy schedule to help me through this.You have truly made this process an enjoyable and valuable experience.I would also like to thank Dr. Li Li
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".