Uncertainty Analysis for Fiber Permeability Measurement

2005 ◽  
Vol 127 (4) ◽  
pp. 907-911 ◽  
Author(s):  
Chensong Dong
Keyword(s):  
Measurement Uncertainty ◽  
Uncertainty Propagation ◽  
Permeability Measurement ◽  
Parameter Uncertainties ◽  
Factors Affecting ◽  
Sources Of Uncertainty ◽  
Measurement Results ◽  
Simulation Results ◽  
Instrument Accuracy ◽  
Significant Factors

An uncertainty study for fiber permeability measurement is presented in this paper. The sources of uncertainty were identified. This paper focuses on the instrument and environmental uncertainties. The parameter uncertainties of both unsaturated and saturated measurements were estimated based on instrument accuracy limitations and environmental influences. Their influences on the permeability uncertainty were investigated by uncertainty propagation and Monte Carlo simulation. The significant factors affecting the permeability measurement uncertainty were identified. The results show that (1) unsaturated measurement has a higher accuracy than saturated measurement; (2) the significant factors affecting measurement results are pressure and viscosity. Based on the simulation results, the approaches to reduce measurement uncertainty were proposed.

Comparison between bottom-up and top-down approaches in the estimation of measurement uncertainty

2015 ◽  
Vol 53 (7) ◽  
Author(s):  
Jun Hyung Lee ◽  
Jee-Hye Choi ◽  
Jae Saeng Youn ◽  
Young Joo Cha ◽  
Woonheung Song ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Uncertainty Budget ◽  
Internal Quality ◽  
Systematic Bias ◽  
Top Down ◽  
Bottom Up ◽  
Sources Of Uncertainty ◽  
Clinical Laboratories ◽  
Measurement Results ◽  
Low Glucose

AbstractMeasurement uncertainty is a metrological concept to quantify the variability of measurement results. There are two approaches to estimate measurement uncertainty. In this study, we sought to provide practical and detailed examples of the two approaches and compare the bottom-up and top-down approaches to estimating measurement uncertainty.We estimated measurement uncertainty of the concentration of glucose according to CLSI EP29-A guideline. Two different approaches were used. First, we performed a bottom-up approach. We identified the sources of uncertainty and made an uncertainty budget and assessed the measurement functions. We determined the uncertainties of each element and combined them. Second, we performed a top-down approach using internal quality control (IQC) data for 6 months. Then, we estimated and corrected systematic bias using certified reference material of glucose (NIST SRM 965b).The expanded uncertainties at the low glucose concentration (5.57 mmol/L) by the bottom-up approach and top-down approaches were ±0.18 mmol/L and ±0.17 mmol/L, respectively (allWe presented practical and detailed examples for estimating measurement uncertainty by the two approaches. The uncertainties by the bottom-up approach were quite similar to those by the top-down approach. Thus, we demonstrated that the two approaches were approximately equivalent and interchangeable and concluded that clinical laboratories could determine measurement uncertainty by the simpler top-down approach.

scholarly journals Evaluation of measurement uncertainty of impact resistance of ceramic brick

2020 ◽  
Vol 185 ◽  
pp. 04040
Author(s):  
Chen Weizhe
Keyword(s):  
Measurement Uncertainty ◽  
Ceramic Tile ◽  
Impact Resistance ◽  
Final Conclusion ◽  
Test Results ◽  
Ceramic Brick ◽  
Sources Of Uncertainty ◽  
Related Data ◽  
Measurement Results

As the economy continues to grow rapidly, people's requirements for product quality are increasing year by year, including ceramic tile products, which, as a typical building material product, are widely used in various large and small buildings. The quality of ceramic tile products is mainly evaluated through inspection and testing. As an important part of the test results, measurement uncertainty is an important parameter that characterizes the reliability of the measurement results. This article analyzes the sources of uncertainty in the measurement of ceramic tile impact resistance, uses the measurement results and related data, and draws the final conclusion.

Evaluation of Measurement Uncertainty for Water Content Tests in Soil Samples

2013 ◽  
Vol 718-720 ◽  
pp. 984-988
Author(s):  
Zhi Qing Gao ◽  
Nai Qi Shen ◽  
Xu Li ◽  
Zong Yun Shu
Keyword(s):  
Measurement Uncertainty ◽  
Water Content ◽  
Measurement Accuracy ◽  
Soil Samples ◽  
Uncertainty Of Measurement ◽  
Expanded Uncertainty ◽  
Factors Affecting ◽  
Testing Conditions ◽  
Content Determination ◽  
Measurement Results

Measurement uncertainty in the water content test for soil samples is an index for evaluating the reliability of the experiment. It affects the accuracy of some parameters such as porosity and saturation, which are derived from water content. According to the requirements of the standard JJF 1059-1999 Uncertainty Evaluation and Denotation of the Measurement Results, the uncertainty for the measurement results of the water content in soil samples was evaluated. Concerning the characteristics of the water content determination in soil samples, a pail of soil sample was taken as specimen due to its relative homogeneity. The factors affecting the measurement accuracy were discussed. The result shows that the expanded uncertainty of measurement results of the water content in soil samples was 1.6% under the proposed testing conditions.

scholarly journals Metrological characterisation of current transformers calibration unit for accurate measurement

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 6
Author(s):  
Valentyn Isaiev ◽  
Oleh Velychko
Keyword(s):  
Measurement Uncertainty ◽  
Current Phase ◽  
Measuring Instruments ◽  
Current Transformers ◽  
Sources Of Uncertainty ◽  
Ratio Error ◽  
Phase Displacement ◽  
Measurement Results ◽  
The Difference ◽  
Detailed Presentation

<p class="Abstract"><span lang="EN-US">The manuscript presents a method for the metrological characterisation of the commercial AC comparators used to calibrate current transformers. The theoretical basis for simulating the difference between two almost identical currents has been outlined, as well as the mathematical models for both a ratio error and a phase displacement has been derived. The measurement setup, consisting of conventional measuring instruments, has been described with a detailed presentation of its parameters. The sources of uncertainty have been distinguished and analysed with determining the current phase shift which led to a significant increase of relative measurement uncertainty. The simulation of measurement results was yielded in two ways: physically using a method presented and virtually using a Monte Carlo method. The second method confirmed that evaluating the measurement uncertainty through derived sensitivity coefficients is correct enough. The simulation results in the range from 1 to 1200 parts per million for both ratio error and phase displacement motivated the use of a comparator characterised through the proposed method for accurate measurement, especially for very low errors.</span></p>

SIMULATION OF SOFT START OF SYNCHRONOUS ELECTRIC DRIVES

2019 ◽  
Author(s):  
Shakhboz Dadabaev
Keyword(s):  
Computer Simulation ◽  
Electric Drive ◽  
Water Supply Systems ◽  
Factors Affecting ◽  
Electric Drives ◽  
Soft Start ◽  
Simulation Results ◽  
Pumping Units ◽  
Negative Factors ◽  
Supply Systems

The main negative factors affecting the starting modes of synchronous electric drives of pumping units of irrigation water supply systems were identified, computer simulation of direct and soft start of synchronous electric drive was made, the simulation results are shown in graphs and a brief conclusion was made on the study.

Simulation of non-stationary thermal fields from a buried thermally insulated pipeline and its diagnostics

2007 ◽  
Vol 5 ◽  
pp. 127-132
Author(s):  
N.A. Vaganova
Keyword(s):  
Thermal Imaging ◽  
Software Package ◽  
Clay Soil ◽  
Underground Pipeline ◽  
Main Pipeline ◽  
Factors Affecting ◽  
Thermal Fields ◽  
Thermal Imaging Equipment ◽  
Principal Possibility ◽  
Significant Factors

To detect damage to the underground pipeline, a mathematical model, allowing to take into account the most significant Factors affecting the distribution of temperature on the day surface. To implement this model, a software package has been developed and results of numerical calculations. With the help of these calculations, in particular, It is established that modern thermal imaging equipment has a principal possibility to determine an unauthorized frame in the main pipeline at a depth of two meters in clay soil.

scholarly journals Modeling of German Low Voltage Cables with Ground Return Path

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Data ◽  
Analytical Calculation ◽  
Laboratory Measurement ◽  
Model Parameters ◽  
Calculation Methods ◽  
Modeling Approach ◽  
Measurement Results ◽  
Simulation Results ◽  
Return Path

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.

scholarly journals The Level of Conus Medullaris in 629 Healthy Japanese Individuals

2021 ◽  
Vol 10 (14) ◽  
pp. 3182
Author(s):  
Hiroaki Nakashima ◽  
Keigo Ito ◽  
Yoshito Katayama ◽  
Mikito Tsushima ◽  
Kei Ando ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Magnetic Resonance ◽  
Pelvic Tilt ◽  
Pelvic Incidence ◽  
Multivariate Regression Analysis ◽  
Conus Medullaris ◽  
Magnetic Resonance Images ◽  
Factors Affecting ◽  
Adult Volunteers ◽  
Significant Factors

The conus medullaris typically terminates at the L1 level; however, variations in its level and the factors associated with the conus medullaris level are unclear. We investigated the level of conus medullaris on magnetic resonance imaging in healthy volunteers. In total, 629 healthy adult volunteers (≥50 individuals of each sex and in each decade of age from 20 to 70) were enrolled. The level of the conus medullaris was assessed based on the T2-weighted sagittal magnetic resonance images, and factors affecting its level were investigated employing multivariate regression analysis including the participants’ background and radiographical parameters. L1 was the most common conus medullaris level. Participant height was significantly shorter in the caudally placed conus medullaris (p = 0.013). With respect to the radiographical parameters, pelvic incidence (p = 0.003), and pelvic tilt (p = 0.03) were significantly smaller in participants with a caudally placed conus medullaris. Multiple regression analysis showed that the pelvic incidence (p < 0.0001) and height (p < 0.0001) were significant factors affecting the conus medullaris level. These results indicated that the length of the spinal cord varies little among individuals and that skeletal differences affect the level of the conus medullaris.

Gas pipeline leakage detection in the presence of parameter uncertainty using robust extended Kalman filter

2021 ◽  
pp. 014233122198911
Author(s):  
Mohadese Jahanian ◽  
Amin Ramezani ◽  
Ali Moarefianpour ◽  
Mahdi Aliari Shouredeli
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Parameter Uncertainty ◽  
Oil And Gas ◽  
Estimation Error ◽  
Real Data ◽  
Gas Pipeline ◽  
Pipeline System ◽  
Parameter Uncertainties ◽  
Simulation Results

One of the most significant systems that can be expressed by partial differential equations (PDEs) is the transmission pipeline system. To avoid the accidents that originated from oil and gas pipeline leakage, the exact location and quantity of leakage are required to be recognized. The designed goal is a leakage diagnosis based on the system model and the use of real data provided by transmission line systems. Nonlinear equations of the system have been extracted employing continuity and momentum equations. In this paper, the extended Kalman filter (EKF) is used to detect and locate the leakage and to attenuate the negative effects of measurement and process noises. Besides, a robust extended Kalman filter (REKF) is applied to compensate for the effect of parameter uncertainty. The quantity and the location of the occurred leakage are estimated along the pipeline. Simulation results show that REKF has better estimations of the leak and its location as compared with that of EKF. This filter is robust against process noise, measurement noise, parameter uncertainties, and guarantees a higher limit for the covariance of state estimation error as well. It is remarkable that simulation results are evaluated by OLGA software.

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