scholarly journals UNIFORMITY OF RESULTS OF MULTIPLE MEASUREMENT SERIES DURING PREPARING A CONTROL SAMPLE FOR QUALIFICATION TESTS

Author(s):  
Нодари Абелашвили ◽  
Ника Абелашвили

The work examines the methodology for assessing the homogeneity of the control sample of interlaboratory qualification tests, which is the most important characteristic of determining its status. The criterion for assessing the homogeneity between the characterizing values of the samples is the root mean square deviation and standard deviation of the proficiency test of the control sample with the standard uncertainty of the assigned value, which is a requirement of the ISO 13528 standard. Ignoring this requirement may provoke a false assessment of the participated laboratories taking corrective action.

Author(s):  
N.I. Podobedov ◽  
V.V. Verenev ◽  
V.V. Korennoi

The aim of the work is to conduct a comparative analysis of the results of rolling hot-rolled strips in the finishing group of mill stands of 1680 strips with and without the use of an intermediate rewinding device (PUF). A comparative analysis of the results of measurements of the moment and longitudinal thickness during rolling in the finishing group of stands is given. Given the distribution of torque in the cages along the length of the strip. It is shown that the mean square deviation of the moment is noticeably less than the rolling time without PUF. The level of dynamic loads and the dynamic factor of the moment of elastic force during the rolling of bands with polyurethane foam and without polyurethane foam practically did not change. It is shown that when rolling without PUF on the finished strip there remains a trace of the temperature wedge in the form of a wedge of thickness. When rolling with PUF, the thickness of the strip along its length becomes more uniform. When rolling without PUF, a trace of a wedge of thickness in the form of a wedge remains on the finished strip. When rolling with PUF, the thickness of the strip along its length becomes more uniform. In general, a comparison of the average moment along the stripes, the standard deviation, the coefficient of variation of the moment and the deviation of the thickness shows the advantages of rolling with PUF.


2013 ◽  
Vol 47 (4) ◽  
pp. 2081
Author(s):  
D. Xirouchakis ◽  
A. Bouzinos

We have applied a simple GUM-based procedure to estimate the uncertainties of physical and mechanical properties in geological materials. First, we define the quantity to measure and decide whether we want to work with units or relative quantities. Subsequently, we calculate the repeatability standard deviation (sr) and the standard uncertainty. If we have proficiency test data or use certified reference materials, we use them to estimate the laboratory bias, the reproducibility standard deviation (sR) and the reproducibility standard uncertainty. We also make sure that we know or have estimated the standard uncertainty of the instruments that we use in the measurements. The latter is typically taken from the instrument calibration or precision statement. We estimate the standard uncertainty of the reference materials and the standard uncertainty of the laboratory bias. The final two steps include the calculation of (1) the laboratory standard uncertainty uncorrected for bias and corrected for bias, and (2) the laboratory expanded uncertainty at the 95% confidence limit.


In a recent paper Prof. Karl Pearson obtains the following results:— (i) If P = log 10 π when π denotes the parallax of a star, and σ P be the standard deviation, or square root of the mean square deviation of a series of values of P from the mean; then, for a uniform distribution of stars in space, 25 σ P 2 = 0·5240. (ii) If ͞m be the mean magnitude of all stars down to and including those of magnitude m 0 , then ͞m = m 0 — 0·7238, and σ m 2 = 0·5240.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Andrew T. McNutt ◽  
Paul Francoeur ◽  
Rishal Aggarwal ◽  
Tomohide Masuda ◽  
Rocco Meli ◽  
...  

AbstractMolecular docking computationally predicts the conformation of a small molecule when binding to a receptor. Scoring functions are a vital piece of any molecular docking pipeline as they determine the fitness of sampled poses. Here we describe and evaluate the 1.0 release of the Gnina docking software, which utilizes an ensemble of convolutional neural networks (CNNs) as a scoring function. We also explore an array of parameter values for Gnina 1.0 to optimize docking performance and computational cost. Docking performance, as evaluated by the percentage of targets where the top pose is better than 2Å root mean square deviation (Top1), is compared to AutoDock Vina scoring when utilizing explicitly defined binding pockets or whole protein docking. Gnina, utilizing a CNN scoring function to rescore the output poses, outperforms AutoDock Vina scoring on redocking and cross-docking tasks when the binding pocket is defined (Top1 increases from 58% to 73% and from 27% to 37%, respectively) and when the whole protein defines the binding pocket (Top1 increases from 31% to 38% and from 12% to 16%, respectively). The derived ensemble of CNNs generalizes to unseen proteins and ligands and produces scores that correlate well with the root mean square deviation to the known binding pose. We provide the 1.0 version of Gnina under an open source license for use as a molecular docking tool at https://github.com/gnina/gnina.


2021 ◽  
Author(s):  
Yi-Ting Chen ◽  

Due to the homogeneity of the product or sample, it will affect whether it meets the scope of application and purpose. For example, the reference materials(RM) produced by the reference material producer(RMP), and the proficiency test items selected by the proficiency testing provider(PTP), in order to ensure the reference materials or proficiency test items have consistent characteristics or comparability, they should be proved to have certain homogeneity. However, before performing homogeneity assessment, it is necessary to measure the characteristic parameters of the reference materials or proficiency test items to obtain a sufficient number of measured values for data analysis, but there may be outliers in the measured values that may affect data analysis and interpretation of the results. Therefore, this article will refer to ASTM E178-16a:2016[1], ISO 5725-2:1994[2], ISO 13528:2015[3], etc., to introduce several outlier detection and homogeneity assessment methods, supplemented by case studies. Finally, this article will remind the precautions for the use of the method, so that readers can choose the appropriate method for use in the actual analysis.


2019 ◽  
Vol 15 (1) ◽  
pp. 258-264 ◽  
Author(s):  
Hamid Reza Ghaieni ◽  
Saeed Tavangar ◽  
Mohammad Moein Ebrahimzadeh Qhomi

Purpose The purpose of this paper is to present simple correlation for calculating nitrated hydroxyl-terminated polybutadiene (NHTPB) enthalpy of formation. Design/methodology/approach It uses multiple linear regression methods. Findings The proposed correlation has determination coefficient 0.96. The correlation has root mean square deviation and the average absolute deviations values 53.4 and 46.1 respectively. Originality/value The predictive power of correlation is checked by cross-validation method (R2=0.96, Q L O O 2 = 0.96 ).


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Caixia Gao ◽  
Enyu Zhao ◽  
Chuanrong Li ◽  
Yonggang Qian ◽  
Lingling Ma ◽  
...  

The aim of this study is to evaluate the aerosol influence on LST retrieval with two algorithms (split-window (SW) method and a four-channel based method) using simulated data under typical conditions. The results show that the root mean square error (RMSE) decreases to approximately 2.3 K for SW method and 1.5 K for four channel based method when VZA = 60° and visibility = 3 km; an RMSE would be increased by approximately 1.0 K when visibility varies from 3 km to 23 km. Moreover, a detailed sensitivity analysis under a visibility of 3 km and 23 km is performed in terms of uncertainties of land surface emissivity (LSE), water vapor content (WVC), and instrument noise, respectively. It is noted that the four-channel based method is more sensitive to LSE than SW method, especially for dry atmosphere; LST error caused by a WVC uncertainty of 20% is within 1.5 K for SW method and within 0.8 K for four-channel based method; the instrument noise would introduce LST error with a maximum standard deviation of 0.5 K and 0.04 K for the four-channel based method and SW method, respectively.


2018 ◽  
Vol 29 (6) ◽  
pp. 585-592 ◽  
Author(s):  
Ana B Plaza-Puche ◽  
Liberdade C Salerno ◽  
Francesco Versaci ◽  
Daniel Romero ◽  
Jorge L Alio

Purpose:To evaluate the intrasubject repeatability of the ocular aberrometry obtained with a new ocular pyramidal aberrometer technology in a sample of normal eyes.Methods:A total of 53 healthy eyes of 53 subjects with ages ranging from 18 to 45 years were included in this study. In all cases, three consecutive acquisitions were obtained. Intrasubject repeatability of the measurements with a pyramidal aberrometer was calculated. Intrasubject repeatability for 4.0- and 6.0-mm pupils was evaluated within the subject standard deviation (Sw) and intraclass correlation coefficient.Results:Low values of the Swand intraclass correlation coefficient outcomes close to 1 were observed for the sphere and cylinder at 3.0-mm pupil size. Most low Swand intraclass correlation coefficient values close to 1 were observed for total, low-order aberrations and higher-order aberrations root mean square and for each Zernike coefficient analysis (intraclass correlation coefficient ⩾0.798) at 4.0-mm pupil size, with more limited outcomes for the aberrometric coefficient of Z(4, 4) with an intraclass correlation coefficient of 0.683. For a 6.0 mm pupil diameter, low Swand intraclass correlation coefficient values close to 1 were observed for all aberrometric parameters or Zernike coefficients analyzed (intraclass correlation coefficient ⩾0.850).Conclusion:The new pyramidal aberrometer Osiris provides repeatable and consistent measurements of ocular aberrometry measurements in normal eyes.


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