scholarly journals Method for determining uncertainty and error in the process of ophthalmic lens calibration

TecnoLógicas ◽  
2021 ◽  
Vol 24 (52) ◽  
pp. e1910
Author(s):  
Alejandro Salgar-Marín ◽  
Javier Alberto Vargas ◽  
Andrés Felipe Ramírez-Barrera
Keyword(s):  
Mathematical Model ◽  
Direct Contact ◽  
Experimental Result ◽  
Uncertainty Measure ◽  
Expanded Uncertainty ◽  
Eye Care ◽  
Reliable Measurement ◽  
Uncertainty In Measurement ◽  
Dioptric Power ◽  
Expression Of Uncertainty

In the present investigation, a scientific procedure was developed, and a mathematical model was proposed, with the objective of determining, under standard conditions, the uncertainty, and the measurement of dioptric power in ophthalmic lenses. The methodology of the scientific procedure is based on the fundamentals of geometric optics, this process guarantees and establishes a standardized uncertainty measure in repeatable and reproducible processes. The methodology is complemented with a proposed mathematical model based on the guide for the expression of uncertainty in measurement - GUM. This model can be applied to lenses used for calibrating eye care equipment (such as lensometers, which are used to diagnose myopia and farsightedness) by evaluating the lenses without having direct contact with patients. When the proposed mathematical model was applied, its experimental result was a maximum expanded uncertainty of ± 0.0079 diopters in a 0.5-diopter lens. This is optimal compared to the result of other authors this article, who reported a maximum expanded uncertainty of ± 0.0086 diopters. In conclusion, the application of this scientific procedure provides manufacturers and users of this type of lenses with a reliable measurement thanks to a calibration process based on geometrical optics and centered on patient safety.

Assessment of the Uncertainty in the Measurement of Depth of Decarburization of Steel Rail

2012 ◽  
Vol 524-527 ◽  
pp. 1989-1992
Author(s):  
Yi Qiang Sun ◽  
Li Xin Wu ◽  
Zhi Fen Wang ◽  
Ping Zhang
Keyword(s):  
Cross Section ◽  
Standard Uncertainty ◽  
Expanded Uncertainty ◽  
Steel Rail ◽  
Uncertainty In Measurement ◽  
The Cross ◽  
Expression Of Uncertainty

In order to analysis the factors effect the uncertainty in the measurement of depth of decarburization and characterized the dispersity of the measuring results, according to the theory of the uncertainty in measurement and JJF1059-1999 Evaluation and Expression of Uncertainty in Measurement, the uncertainty in the measurement of depth of decarburization of steel rail was assessed, which was caused by the uneven of decarburization and the repetitiveness of the measure, the obliquity of the cross section, the accurate degree of the measure instrument, the approximate of the value. The combined standard uncertainty and the expanded uncertainty was calculated, and the report of the uncertainty was given.

Measurement Uncertainty Research on Current Operation Humidity Sensor

2014 ◽  
Vol 575 ◽  
pp. 533-536
Author(s):  
Li Na Wu ◽  
Hui Guo Lu
Keyword(s):  
Measurement Uncertainty ◽  
Humidity Sensor ◽  
Dew Point ◽  
Weather Station ◽  
Expanded Uncertainty ◽  
Uncertainty In Measurement ◽  
Calibration Chamber ◽  
Current Operation ◽  
Expression Of Uncertainty ◽  
Over Time

According to Evaluation and Expression of Uncertainty in Measurement (JJF1059.1-2012), measurement error of each element sensor in automatic weather station will be in drift over time, temperature and other environmental factors. In order to ensure the accuracy, reliability of observational data of each element,in this paper,humidity calibration chamber provided environment, and precision dew-point transmitter as the standard device. The article has introduced the general methods and detailed procedures of how to use HMP45D temperature and humidity sensor for humidity measurement uncertainty evaluation.Finally,it gave an evaluation example.By analyzing and calculating the each component of measurement uncertainty,we got the expanded uncertainty of humidity is 1.50%RH and 1.46%RH, with temperature of 22degrees and 40degrees, 30%-75% relative humidity.

Verification of the Calculation Assumptions Applied to Solutions of the Acoustic Measurements Uncertainty

2015 ◽  
Vol 39 (2) ◽  
pp. 199-202
Author(s):  
Wojciech Batko ◽  
Renata Bal
Keyword(s):  
Normal Distribution ◽  
Confidence Intervals ◽  
Uncertainty Of Measurement ◽  
Acoustic Measurements ◽  
Uncertainty In Measurement ◽  
Sound Levels ◽  
Measurement Results ◽  
Analysis Of Results ◽  
Essential Problem ◽  
Expression Of Uncertainty

Abstract The assessment of the uncertainty of measurement results, an essential problem in environmental acoustic investigations, is undertaken in the paper. An attention is drawn to the - usually omitted - problem of the verification of assumptions related to using the classic methods of the confidence intervals estimation, for the controlled measuring quantity. Especially the paper directs attention to the need of the verification of the assumption of the normal distribution of the measuring quantity set, being the base for the existing and binding procedures of the acoustic measurements assessment uncertainty. The essence of the undertaken problem concerns the binding legal and standard acts related to acoustic measurements and recommended in: 'Guide to the expression of uncertainty in measurement' (GUM) (OIML 1993), developed under the aegis of the International Bureau of Measures (BIPM). The model legitimacy of the hypothesis of the normal distribution of the measuring quantity set in acoustic measurements is discussed and supplemented by testing its likelihood on the environment acoustic results. The Jarque-Bery test based on skewness and flattening (curtosis) distribution measures was used for the analysis of results verifying the assumption. This test allows for the simultaneous analysis of the deviation from the normal distribution caused both by its skewness and flattening. The performed experiments concerned analyses of the distribution of sound levels: LD, LE, LN, LDWN, being the basic noise indicators in assessments of the environment acoustic hazards.

Interpretation and use of standard atomic weights (IUPAC Technical Report)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Adriaan M. H. van der Veen ◽  
Juris Meija ◽  
Antonio Possolo ◽  
David Brynn Hibbert
Keyword(s):  
Monte Carlo ◽  
Atomic Weight ◽  
Standard Uncertainty ◽  
Uncertainty In Measurement ◽  
Propagation Of Uncertainty ◽  
A Value ◽  
The Monte Carlo Method ◽  
Technical Report ◽  
Molecular Masses ◽  
Expression Of Uncertainty

Abstract Many calculations for science or trade require the evaluation and propagation of measurement uncertainty. Although relative atomic masses (standard atomic weights) of elements in normal terrestrial materials and chemicals are widely used in science, the uncertainties associated with these values are not well understood. In this technical report, guidelines for the use of standard atomic weights are given. This use involves the derivation of a value and a standard uncertainty from a standard atomic weight, which is explained in accordance with the requirements of the Guide to the Expression of Uncertainty in Measurement. Both the use of standard atomic weights with the law of propagation of uncertainty and the Monte Carlo method are described. Furthermore, methods are provided for calculating uncertainties of relative molecular masses of substances and their mixtures. Methods are also outlined to compute material-specific atomic weights whose associated uncertainty may be smaller than the uncertainty associated with the standard atomic weights.

ISO/TS 20914:2019 – a critical commentary

2020 ◽  
Vol 58 (8) ◽  
pp. 1182-1190 ◽  
Author(s):  
Ian Farrance ◽  
Robert Frenkel ◽  
Tony Badrick
Keyword(s):  
Measurement Uncertainty ◽  
Measurement Data ◽  
International Normalized Ratio ◽  
Medical Laboratory ◽  
Uncertainty In Measurement ◽  
Medical Laboratories ◽  
Functional Relationships ◽  
Critical Commentary ◽  
Combined Uncertainty ◽  
Expression Of Uncertainty

AbstractThe long-anticipated ISO/TS 20914, Medical laboratories – Practical guidance for the estimation of measurement uncertainty, became publicly available in July 2019. This ISO document is intended as a guide for the practical application of estimating uncertainty in measurement (measurement uncertainty) in a medical laboratory. In some respects, the guide does indeed meet many of its stated objectives with numerous very detailed examples. Even though it is claimed that this ISO guide is based on the Evaluation of measurement data – Guide to the expression of uncertainty in measurement (GUM), JCGM 100:2008, it is with some concern that we believe several important statements and statistical procedures are incorrect, with others potentially misleading. The aim of this report is to highlight the major concerns which we have identified. In particular, we believe the following items require further comment: (1) The use of coefficient of variation and its potential for misuse requires clarification, (2) pooled variance and measurement uncertainty across changes in measuring conditions has been oversimplified and is potentially misleading, (3) uncertainty in the results of estimated glomerular filtration rate (eGFR) do not include all known uncertainties, (4) the international normalized ratio (INR) calculation is incorrect, (5) the treatment of bias uncertainty is considered problematic, (6) the rules for evaluating combined uncertainty in functional relationships are incomplete, and (7) specific concerns with some individual statements.

Experiment and Numerical Simulation of Bubble Behaviors in Argon Gas Injection Into Lead-Bismuth Pool

2006 ◽  
Author(s):  
Yumi Yamada ◽  
Toyou Akashi ◽  
Minoru Takahashi
Keyword(s):  
Direct Contact ◽  
Two Phase Flow ◽  
Experimental Result ◽  
Feed Water ◽  
Force Model ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Argon Gas ◽  
Bubble Rising

In a lead-bismuth alloy (45%Pb-55%Bi) cooled direct contact boiling water fast reactor (PBWFR), steam can be produced by direct contact of feed water with primary Pb-Bi coolant in the upper core plenum, and Pb-Bi coolant can be circulated by buoyancy forces of steam bubbles. As a basic study to investigate the two-phase flow characteristics in the chimneys of PBWFR, a two-dimensional two-phase flow was simulated by injecting argon gas into Pb-Bi pool in a rectangular vessel (400mm in length, 1500mm in height, 50mm in width), and bubble behaviors were investigated experimentally. Bubble sizes, bubble rising velocities and void fractions were measured using void probes. Argon gas was injected through five nozzles of 4mm in diameter into Pb-Bi at two locations. The experimental conditions are the pressure of atmospheric pressure, Pb-Bi temperatures of 443K, and the flow rate of injection Ar gas is 10, 20, and 30 NL/min. The measured bubble rising velocities were distributed in the range from 1 to 3 m/s. The average velocity was about 0.6 m/s. The measured bubble chord lengths were distributed from 1mm up to 30mm. The average chord length was about 7mm. An analysis was performed by two-dimensional and two-fluid model. The experimental results were compared with the analytical results to evaluate the validity of the analytical model. Although large diameter bubbles were observed in the experiment, the drag force model for spherical bubbles performed better for simulation of the experimental result because of high surface tension force of Pb-Bi.

scholarly journals XML-based IUPAC standard for experimental, predicted, and critically evaluated thermodynamic property data storage and capture (ThermoML) (IUPAC Recommendations 2006)

2006 ◽  
Vol 78 (3) ◽  
pp. 541-612 ◽  
Author(s):  
Michael Frenkel ◽  
Robert D. Chiroco ◽  
Vladimir Diky ◽  
Qian Dong ◽  
Kenneth N. Marsh ◽  
...  
Keyword(s):  
Data Storage ◽  
Chemical Reactions ◽  
Data Communication ◽  
Thermochemical Property ◽  
Uncertainty In Measurement ◽  
Communication Processes ◽  
Property Data ◽  
Extensible Markup ◽  
Pure Compounds ◽  
Expression Of Uncertainty

ThermoML is an Extensible Markup Language (XML)-based new IUPAC standard for storage and exchange of experimental, predicted, and critically evaluated thermophysical and thermochemical property data. The basic principles, scope, and description of all structural elements of ThermoML are discussed. ThermoML covers essentially all thermodynamic and transport property data (more than 120 properties) for pure compounds, multicomponent mixtures, and chemical reactions (including change-of-state and equilibrium reactions). Representations of all quantities related to the expression of uncertainty in ThermoML conform to the Guide to the Expression of Uncertainty in Measurement (GUM). The ThermoMLEquation schema for representation of fitted equations with ThermoML is also described and provided as supporting information together with specific formulations for several equations commonly used in the representation of thermodynamic and thermophysical properties. The role of ThermoML in global data communication processes is discussed. The text of a variety of data files (use cases) illustrating the ThermoML format for pure compounds, mixtures, and chemical reactions, as well as the complete ThermoML schema text, are provided as supporting information.

Numerical Simulation Study of Metal Transfer in MIG Welding with Magnetic Control

2014 ◽  
Vol 532 ◽  
pp. 545-548 ◽  
Author(s):  
Chao Yang ◽  
Shu Yuan Jiang ◽  
Hai Bo Bi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Mathematical Model ◽  
Simulation Study ◽  
Electromagnetic Theory ◽  
Metal Transfer ◽  
Experimental Result ◽  
Magnetic Control ◽  
Mig Welding ◽  
Model Based

This paper simulate the mode of metal transfer in MIG magnetic control welding by using CFD software FLUENT, establishing mathematical model based on fluid dynamics and electromagnetic theory, and simulate the form, grow and drop process of metal transfer with and without magnetic. Meanwhile, do experiments to confirm the simulate result, and it is well consistent with the experimental result.

Establishment of Mathematical Model in Evaluation of Uncertainty in Indication Error Measurement Results

2014 ◽  
Vol 651-653 ◽  
pp. 428-431
Author(s):  
Xia Zhao
Keyword(s):  
Mathematical Model ◽  
Electrical Measuring ◽  
Electrical Measuring Instrument ◽  
Error Measurement ◽  
Measuring Instrument ◽  
Uncertainty In Measurement ◽  
Measurement Result ◽  
Three Phase ◽  
Measurement Results ◽  
Calibration Device

Taking Model DK-52 (Grade 0.05) multi-function three-phase electrical measuring instrument calibration device as an example, the paper describes how to evaluate the uncertainty in measurement result of indication errors in mathematical model.

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