Совершенствование научно-методических подходов в области метрологического обеспечения технологий контроля герметичности на опасных производственных объектах

In this article the analysis of metrological assurance of control technologies integrity subject to the rules of safety at hazardous production facilities. Deals with the scientific and methodological aspects of the evaluation of threshold sensitivity of control systems integrity using controlled leaks, containing in its composition of standard samples for reproduction of units of volumetric and mass flow of gas, which expands the scope of their applicability.В настоящей статье проводится анализ метрологического обеспечения технологий контроля герметичности с учетом правил безопасности на опасных производственных объектах. Рассматриваются научные и методические аспекты оценки пороговой чувствительности систем контроля герметичности с использованием контрольных течей, содержащих в своем составе стандартные образцы воспроизведения единиц объемного и массового расходов газа, что расширяет сферу их применимости

The improvement of methodological approaches in the field of metrological provision of technology leakage control at hazardous production facilities

In this article the analysis of metrological assurance of control technologies integrity subject to the rules of safety at hazardous production facilities. Deals with the scientific and methodological aspects of the evaluation of threshold sensitivity of control systems integrity using controlled leaks, containing in its composition of standard samples for reproduction of units of volumetric and mass flow of gas, which expands the scope of their applicability

The “Laboratory” Effect: Comparing Radiologists' Performance and Variability during Prospective Clinical and Laboratory Mammography Interpretations1

When deciding whether to recall a woman for additional diagnostic examinations, experienced radiologists performed significantly better on average and, as important, more consistently in the clinic than in the laboratory when interpreting the same examinations

Binary and multi-category ratings in a laboratory observer performance study: A comparison

The authors investigated radiologists, performances during retrospective interpretation of screening mammograms when using a binary decision whether to recall a woman for additional procedures or not and compared it with their receiver operating characteristic (ROC) type performance curves using a semi-continuous rating scale. Under an Institutional Review Board approved protocol nine experienced radiologists independently rated an enriched set of 155 examinations that they had not personally read in the clinic, mixed with other enriched sets of examinations that they had individually read in the clinic, using both a screening BI-RADS rating scale (recall∕not recall) and a semi-continuous ROC type rating scale (0 to 100). The vertical distance, namely the difference in sensitivity levels at the same specificity levels, between the empirical ROC curve and the binary operating point were computed for each reader. The vertical distance averaged over all readers was used to assess the proximity of the performance levels under the binary and ROC-type rating scale. There does not appear to be any systematic tendency of the readers towards a better performance when using either of the two rating approaches, namely four readers performed better using the semi-continuous rating scale, four readers performed better with the binary scale, and one reader had the point exactly on the empirical ROC curve. Only one of the nine readers had a binary “operating point” that was statistically distant from the same reader’s empirical ROC curve. Reader-specific differences ranged from −0.046 to 0.128 with an average width of the corresponding 95% confidence intervals of 0.2 and p-values ranging for individual readers from 0.050 to 0.966. On average, radiologists performed similarly when using the two rating scales in that the average distance between the run in individual reader’s binary operating point and their ROC curve was close to zero. The 95% confidence interval for the fixed-reader average (0.016) was (−0.0206, 0.0631) (two-sided p-value 0.35). In conclusion the authors found that in retrospective observer performance studies the use of a binary response or a semi-continuous rating scale led to consistent results in terms of performance as measured by sensitivity-specificity operating points