Journal articles: 'Standard error of measurement'

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Adamczak, Stanisław, Jacek Świderski, and Urszula Kmiecik-Sołtysiak. "Estimation of the uncertainty of the roundness measurement with a device with rotary spindle." Mechanik 90, no. 10 (October 9, 2017): 912–14. http://dx.doi.org/10.17814/mechanik.2017.10.145.

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The paper presents the estimation of uncertainty of roundness measurement using the Talyrond 73 by analyzing the sources of measurement errors such as measuring noise, signal drift, radial spindle error, repeatability, sensor gain error and uncertainty of measurement standards. The study included the following measurements: roller bearing, glass hemisphere and flick standard.

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Feldt, Leonard S., and Audrey L. Qualls. "Approximating Scale Score Standard Error of Measurement From the Raw Score Standard Error." Applied Measurement in Education 11, no. 2 (April 1998): 159–77. http://dx.doi.org/10.1207/s15324818ame1102_3.

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Apanasovich, Tatiyana V., Raymond J. Carroll, and Arnab Maity. "SIMEX and standard error estimation in semiparametric measurement error models." Electronic Journal of Statistics 3 (2009): 318–48. http://dx.doi.org/10.1214/08-ejs341.

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Woodruff, David. "Conditional Standard Error of Measurement in Prediction." Journal of Educational Measurement 27, no. 3 (September 1990): 191–208. http://dx.doi.org/10.1111/j.1745-3984.1990.tb00743.x.

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Ali, Salah H. R. "Performance Investigation of CMM Measurement Quality Using Flick Standard." Journal of Quality and Reliability Engineering 2014 (July 17, 2014): 1–11. http://dx.doi.org/10.1155/2014/960649.

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Quality of coordinate measuring machine (CMM) in dimension and form metrology is designed and performed at the NIS. The experimental investigation of CMM performance is developed by using reference Flick standard. The measurement errors of corresponding geometric evaluation algorithm (LSQ, ME, MC, and MI) and probe scanning speed (1, 2, 3, 4, and 5 mm/s) are obtained through repeated arrangement, comparison, and judgment. The experimental results show that the roundness error deviation can be evaluated effectively and exactly for CMM performance by using Flick standard. Some of influencing quantities for diameter and roundness form errors may dominate the results at all fitting algorithms under certain circumstances. It can be shown that the 2 mm/s probe speed gives smaller roundness error than 1, 3, 4, and 5 mm/s within 0.2 : 0.3 μm. It ensures that measurement at 2 mm/s is the best case to satisfy the high level of accuracy in the certain condition. Using Flick standard as a quality evaluation tool noted a high precision incremental in diameter and roundness form indication. This means a better transfer stability of CMM quality could be significantly improved. Moreover, some error formulae of data sets have been postulated to correlate the diameter and roundness measurements within the application range. Uncertainty resulting from CMM and environmental temperature has been evaluated and confirmed the quality degree of confidence in the proposed performance investigation.

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Icasio-Hernández, O., Y. I. Curiel-Razo, C. C. Almaraz-Cabral, S. R. Rojas-Ramirez, and J. J. González-Barbosa. "MEASUREMENT ERROR WITH DIFFERENT COMPUTER VISION TECHNIQUES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W7 (September 12, 2017): 227–35. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w7-227-2017.

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The goal of this work is to offer a comparative of measurement error for different computer vision techniques for 3D reconstruction and allow a metrological discrimination based on our evaluation results. The present work implements four 3D reconstruction techniques: passive stereoscopy, active stereoscopy, shape from contour and fringe profilometry to find the measurement error and its uncertainty using different gauges. We measured several dimensional and geometric known standards. We compared the results for the techniques, average errors, standard deviations, and uncertainties obtaining a guide to identify the tolerances that each technique can achieve and choose the best.

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Dasika, Saket S., Michael P. Sama, L. Felipe Pampolini, and Christopher B. Good. "Performance Validation of a Multi-Channel LiDAR Sensor: Assessing the Effects of Target Height and Sensor Velocity on Measurement Error." Transactions of the ASABE 62, no. 1 (2019): 231–44. http://dx.doi.org/10.13031/trans.12971.

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Abstract. The objective of this study was to determine the effects of sensor velocity and target height above ground level on height measurement error when using a multi-channel LiDAR sensor. A linear motion system was developed to precisely control the dynamics of the LiDAR sensor in an effort to remove uncertainty in the LiDAR position and velocity while under motion. The linear motion system allowed the LiDAR to translate forward and backward in one direction parallel to the ground. A user control interface was developed to operate the system under different velocity profiles and to log LiDAR data synchronous to the motion of the system. The performance of the linear motion system was validated with a tracking total station, and the results showed that the position and velocity control errors were negligible as compared to the LiDAR accuracy. The LiDAR was then validated using 25 test targets at varying heights above ground level (0.1, 0.3, 0.5, 0.6, and 0.8 m) with five different velocity profiles (0.1, 0.5, 1.0, 1.5, and 2.2 m s-1) and six replications to determine the effects of sensor velocity and target height on measurement error. The targets were painted white on one side and black on the other to determine the effect of relative intensity on LiDAR height measurement error. Generalized linear mixed models were fitted with the measurement error and the standard deviation of the measurement error as the responses. Sensor velocity, target height, and their interaction were considered as fixed effects to determine if there were significant differences in average error and standard deviation of error for different sensor velocities and target heights. The results indicated that the velocity of the LiDAR was a significant factor affecting the average error and standard deviation of error in height measurements. However, higher velocities tended to result in only slightly larger average errors. A three-fold increase in the standard deviation was observed when increasing the velocity from 0.1 to 2.2 m s-1. Height of the target was either a weakly significant or insignificant factor in average error and a weakly significant factor affecting the standard deviation of the LiDAR measurements, representing mixed results. The average error and standard deviation were less than 10 and 30 mm, respectively, for all replications. Relative intensities of the LiDAR measurements were 88.2% and 5.4% for white and black targets, respectively, and the different target colors exhibited a 4.7 mm shift in average estimated height error. These uncertainties may not be substantial for agricultural applications, where other sources of error, such as moving crop canopies or error in resolving the position of the sensor, are more likely to dominate overall measurement error. Keywords: LiDAR, Measurement error, Precision agriculture, Remote sensing, Validation.

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Huo, Peng Fei, Chao Wang, and Ke Yu Qi. "Simulation and Analysis of Measurement Method for Projectile Axial Acceleration by MEMS Sensor." Advanced Materials Research 411 (November 2011): 461–65. http://dx.doi.org/10.4028/www.scientific.net/amr.411.461.

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Measurement of axial acceleration is necessary for projectile range prediction. Three measurement methods, dual-accelerometer configuration, dual-accelerometer filtering and direct filtering, are used to eliminate acceleration measurement errors caused by accelerometer configuration location, installation errors and space rotating of projectiles. Based on six-degree ballistic trajectory model, the three measurement methods of projectile axial acceleration are simulated, and the simulation results show that standard deviation of dual-accelerometer configuration measurement error is 35.7318, while standard deviation of dual-accelerometer filtering measurement error is 2.2958 and direct filtering measurement error is 0.3344.

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Barabás, B. "A Simple Testing Procedure for near Infrared Instruments." Journal of Near Infrared Spectroscopy 6, A (January 1998): A163—A170. http://dx.doi.org/10.1255/jnirs.188.

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The testing and adjusting procedure of near infrared (NIR) spectrophotometers is based on the measurement of some standards and, if necessary, on the adjustment of the constants in the calibration equation. For this work some use few standards, whereas others use 20 or more. This work was aimed to determine the range of error compensation and the minimum number of standards required. The experiments were applied to wheat protein measurement using two scanning spectrophotometers. The errors in the NIR measurements were characterised as bias, skew, error derived from skew ( Eskew) and standard error of difference corrected for bias and skew ( SEDc) parameters and supposed that errors derived from the change in the wavelength or reflectance of the instrument. The confidence intervals of bias and skew, derived from duplicate measurements of various numbers of wheat standards, were used to determine the minimum number of standards required. The range of error compensation was defined with those bias values, where SEDc was smaller, than an acceptable limit. The range of compensation corresponded to a bias value of ± 8 g kg−1 for wheat protein measurements. The detection of error of measurements required 4 wheat standards. The elimination of errors of bias and skew required 9 standards within the above limits. The developed procedure was tested in case of real instrument error. Diminishing a bias from 5.2 g kg−1 to 0.7 g kg−1 and the root mean square difference ( RMSD) to an acceptable level required the use of 9 standards, similar to the model experiment. The simplicity and rapidity (about 10 min) of the procedure enabled the routine test of NIR instruments. The range of error compensation and the number of standards referred to wheat protein. The simple modelling procedure proved also suitable for the determination of these values for other components and under other measuring conditions.

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Harvill, Leo M. "An NCME Instructional Module on. Standard Error of Measurement." Educational Measurement: Issues and Practice 10, no. 2 (June 1991): 33–41. http://dx.doi.org/10.1111/j.1745-3992.1991.tb00195.x.

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Bae, Yun Kyung, and Dong Hoon Hyun. "Dew Point Measurement Error due to Tube Length in a Calibration Instrumentation and the Evaluation of Measurement Uncertainty." Applied Mechanics and Materials 789-790 (September 2015): 519–25. http://dx.doi.org/10.4028/www.scientific.net/amm.789-790.519.

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The purpose of this paper is to analyze the effect of tube length in calibration instrumentation on dew point measurement of dew point sensors (DPS) and evaluation of measurement uncertainty. When measuring dew point temperature, various tube lengths between dew point generator and dew point sensor (DPS) cause a significant error due to moisture absorption of inner tube. The measurement is carried out to analyze the variation on measured dew point temperature for four cases of tube lengths with 300 mm, 1200 mm, 2500 mm and 5000 mm. The dew point temperature measurements were performed in the range from-60 °C to 10 °C by using calibrated standard chilled mirror hygrometer as reference standard. In order to investigate contribution to the standard uncertainty for the tube length variation as an uncertainty source, expanded uncertainties were evaluated for the cases including the effect of tube length variation as an uncertainty source and excluding it at each measurement point. The measurement was conducted according to standard calibration procedure of Korea Testing Laboratory which assures suitability and traceable results. It is also based on international standards.

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Samoylenko, O. M., O. V. Adamenko, and B. P. Kukareka. "Investigation of the Accuracy of Reference Instruments for Measuring Vertical Angles by Reference Method of Their Calibration." Metrology and instruments, no. 6 (January 11, 2020): 3–14. http://dx.doi.org/10.33955/2307-2180(6)2019.3-14.

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Reference method for simultaneous calibration of the three and more measurement standards for vertical angle measurement is developed. This method can to use for obtaining the systematic biases of the vertical angles measurements for each of the measuring standards relative of the horizontal plain was averaged from measurement results in time their calibration or comparison. For realization of the reference method was developed the autocollimationel electronic measurement standard for the automatization measurement of the vertical angles SeaLineZero_Standard™ (SLZ_S™). Summary standard deviation (k=1) of the vertical angle measurement relative the horizontal plane, from the results of their calibration by reference method, is not more 0,07ʺ…0,15ʺ. This result was obtained without the use the systematic biases, for each measurement standards, as measurements corrections (with opposite sign). The measuring standards, that were developed and researched, are necessary for obtaining the systematic biases of the vertical angle measurement for total stations and theodolites, that have the normed standard error 0,5ʺ and 1ʺ, when these instruments are calibrating.

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Eastwood, Annette, Will G. Hopkins, Pitre C. Bourdon, Robert T. Withers, and Christopher J. Gore. "Stability of hemoglobin mass over 100 days in active men." Journal of Applied Physiology 104, no. 4 (April 2008): 982–85. http://dx.doi.org/10.1152/japplphysiol.00719.2007.

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The purpose of this study was to investigate the suggestion in a recent meta-analysis that variability in hemoglobin mass increases when time between measurements increases from days to months. Hemoglobin mass of six active men was measured with the carbon monoxide method every 1–6 days for 100–114 days (42 ± 3 measurements, mean ± SD). Measurement error for each individual's series was estimated from the standard deviation of consecutive pairwise changes and compared with his total error (standard deviation of all values). Linear trends and periodicities in each series were quantified by regression and spectral analysis. Series with known random error and periodicity were also simulated and analyzed. There were clear differences in the pairwise error of measurement between subjects (range 1.4–2.7%). For five men, there was little difference between the total and pairwise errors; their mean ratio (1.06, 90% confidence limits 0.96–1.17) was less than ratios for simulated sinusoidal series with random error of 2%, amplitude of 2%, and periods of 20–100 days (ratios 1.13–1.21). Spectral analysis clearly revealed such periodicities in the simulated series but not in the series of these subjects. The sixth man, who had donated blood 12 days before commencing measurements, showed errors, trend, and periodicity consistent with gradual restoration of hemoglobin mass. Measurement error of hemoglobin mass does not increase over 100 days. Consequently, hemoglobin mass may be suitable for long-term monitoring of small changes that might occur with training or erythropoietin abuse, taking into consideration the small differences between athletes in errors and trends.

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Grimm, Kevin J., Kimberly Fine, and Gabriela Stegmann. "Accounting for standard errors of measurement when modeling change." International Journal of Behavioral Development 45, no. 1 (July 10, 2020): 11–18. http://dx.doi.org/10.1177/0165025420935617.

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Modeling within-person change over time and between-person differences in change over time is a primary goal in prevention science. When modeling change in an observed score over time with multilevel or structural equation modeling approaches, each observed score counts toward the estimation of model parameters equally. However, observed scores can differ in terms of their precision—both within and across participants. We propose an approach to weight observed scores by their level of precision, which is estimated as the inverse of their standard error of measurement in the context of item response modeling. Thus, scores with lower standard errors of measurement have greater weight, and scores with higher standard errors of measurement are down weighted. We discuss the weighting approaches and illustrate how to apply this approach with commonly available software. We then compare this approach to modeling change without weighting based on standard errors of measurement.

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Resch, Sylvia, Leif Ryd, Anders Stenström, Kjell Johnsson, and Kristbjörn Reynisson. "Measuring Hallux Valgus: A Comparison of Conventional Radiography and Clinical Parameters with Regard to Measurement Accuracy." Foot & Ankle International 16, no. 5 (May 1995): 267–70. http://dx.doi.org/10.1177/107110079501600504.

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To assess the repeatability and error of conventional x-ray measurements, intra- and interobserver evaluations of measurement accuracy were done on 20 preoperative and 40 postoperative (20 chevron and 20 proximal osteotomy) x-rays of hallux valgus patients. Standard x-rays showed an average interobserver error of measurement of 6.4° for the hallux valgus angle, 5.4° for the intermetatarsal angle, and 2.0 mm for the intermetatarsal distance. The intraobserver error did not differ greatly. The repeatability and error of two clinical measurements, ball circumference, and dorsal to plantar range of motion of the first metatarsophalangeal joint were evaluated for 20 healthy volunteers. The ball circumference had an average measurement error of 1.1 cm, whereas the dorsal and plantar range of motion of the great toe had an average measurement error of 12° in dorsiflexion and 16° in plantarflexion. In both clinical and radiographic parameters, linear measurements were more accurate than angular measurements. Although x-rays are of value in hallux valgus surgery, standard x-rays are less accurate than previously assumed. Small changes produced by osteotomies may be hidden by the postoperative measurement error. The results of hallux valgus surgery should primarily be evaluated clinically. When clinical and radiological evaluations are made, linear measurements may be preferable.

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Wang, Rong Xiang, and Xia Zhang. "Error Analysis and Improvement of Equal Precision Frequency Measurement." Applied Mechanics and Materials 687-691 (November 2014): 841–46. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.841.

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In accordance with the principle of equal precision frequency measurement and theory of errors, in this paper, the problems are discussed that the equal precision frequency measurement eliminates the standard frequency count error. In order to reduce the relative error and improve the measurement accuracy, a method is proposed for phase coincide detection between standard frequency multiplication and measurement frequency demultiplication to open or shut the gate, at the same time, a signal selector is also used to improve circuit performance. This method can effectively solve the problem that the frequency can not be detected without the synchronization signal and improve the performance of the frequency measurement system.

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Li, Yang, Gao, Su, Wei, Lv, Liang, Li, and Fang. "Rapid Measurement and Identification Method for the Geometric Errors of CNC Machine Tools." Applied Sciences 9, no. 13 (July 2, 2019): 2701. http://dx.doi.org/10.3390/app9132701.

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Error compensation technology offers a significant means for improving the geometric accuracy of CNC machine tools (MTs) as well as extending their service life. Measurement and identification are important prerequisites for error compensation. In this study, a measurement system, mainly composed of a self-developed micro-angle sensor and an L-shape standard piece, is proposed. Meanwhile, a stepwise identification method, based on an integrated error model, is established. In one measurement, four degrees-of-freedom errors, including two-dimensional displacement and two-dimensional angle of a linear guideway, can be obtained. Furthermore, in accordance with the stepwise identification method, the L-shape standard piece is placed in three different planes, so that the measurement and identification of all 21 geometric errors can be implemented. An experiment is carried out on a coordinate measuring machine (CMM) to verify the system. The residual error of the angle error, translation error and squareness error are 1.5″, 2 μm and 3.37″, respectively, and these are compared to the values detected by a Renishaw laser interferometer.

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Chen, Xin, and Kiyoshi Takamasu. "Study on Scanning Squareness Measurement Method and Uncertainty Estimation." Key Engineering Materials 381-382 (June 2008): 569–72. http://dx.doi.org/10.4028/www.scientific.net/kem.381-382.569.

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This paper presents a scanning squareness measurement method for large ultra-precision components. A rectangular block as the squareness reference is used. The squareness error of the rectangular block is eliminated according to the geometric principle that the sum of four internal angles of a rectangle is 360°. And the straightness error of each line of the rectangular block is eliminated by means of scanning method with two 1D probes. The above two error separation technologies are combined effectively and the data processing method is developed. Additionally, the standard uncertainties including tilt and squareness errors of the rectangular block, temperature drift and random errors of the measured values of the probes are analyzed theoretically. It is confirmed that a combined standard uncertainty of less than 1 arcsec can be obtained for typical values of the parameters.

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Charter, Richard A. "Revisiting the Standard Errors of Measurement, Estimate, and Prediction and Their Application to Test Scores." Perceptual and Motor Skills 82, no. 3_suppl (June 1996): 1139–44. http://dx.doi.org/10.2466/pms.1996.82.3c.1139.

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In 1979 Dudek presented a simplification of Lord and Novick's 1968 work on standard errors and their application to test scores. However, the standard error of measurement has continued to be misinterpreted. The interpretations of the standard errors of measurement, estimate, and prediction are presented. The use of confidence intervals and their importance to test score interpretation are discussed.

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Ortner, Balder. "About Error Calculation in X-Ray Stress Measurement." Advanced Materials Research 996 (August 2014): 215–20. http://dx.doi.org/10.4028/www.scientific.net/amr.996.215.

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It is shown that the knowledge of standard deviations (Δσij) of the components of a stress tensor (σij) is not sufficient to calculate also standard deviations of quantities derived from the stress tensor, as principal stresses (σI, σII, σIII), von Mises stress, Tresca stress, and the components of the deviatoric stress tensor σ'ij. For such a calculation one needs all information about the measurement and the method for the calculation of σij. This information is: the accuracy of each measured lattice plane distance and the x-ray elastic factors Fij(φ,ψ,hkl) of each measured point. Equations are given for the calculation of the standard deviations of all the mentioned quantities. For special cases of measurement strategy the wanted calculations become easier. This is also given.

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Akkerhuis, T. S., and J. de Mast. "Quantifying the Random Component of Measurement Error of Nominal Measurements Without a Gold Standard." Quality and Reliability Engineering International 32, no. 6 (June 13, 2016): 1993–2003. http://dx.doi.org/10.1002/qre.2023.

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Ohlendorf, Arne, Alexander Leube, and Siegfried Wahl. "Advancing Digital Workflows for Refractive Error Measurements." Journal of Clinical Medicine 9, no. 7 (July 12, 2020): 2205. http://dx.doi.org/10.3390/jcm9072205.

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Advancements in clinical measurement of refractive errors should lead to faster and more reliable measurements of such errors. The study investigated different aspects of advancements and the agreement of the spherocylindrical prescriptions obtained with an objective method of measurement (“Aberrometry” (AR)) and two methods of subjective refinements (“Wavefront Refraction” (WR) and “Standard Refraction” (StdR)). One hundred adults aged 20–78 years participated in the course of the study. Bland–Altman analysis of the right eye measurement of the spherocylindrical refractive error (M) identified mean differences (±95% limits of agreement) between the different types of measurements of +0.36 D (±0.76 D) for WR vs. AR (t-test: p < 0.001), +0.35 D (± 0.84 D) for StdR vs. AR (t-test: p < 0.001), and 0.0 D (± 0.65 D) for StdR vs. WR (t-test: p < 0.001). Monocular visual acuity was 0.0 logMAR in 96% of the tested eyes, when refractive errors were corrected with measurements from AR, indicating that only small differences between the different types of prescriptions are present.

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Delamare, Eduardo Luiz, Gabriela Salatino Liedke, Mariana Boessio Vizzotto, Heraldo Luis Dias Da Silveira, Dalva Maria Pereira Padilha, José Luis Duarte Ribeiro, Priscila Fernanda Da Silveira, and Heloisa Emilia Dias Da Silveira. "Impact of landmark identification and standard measurement error on cephalometric analysis using a mathematical simulation model." Revista da Faculdade de Odontologia de Porto Alegre 53, no. 3 (February 23, 2012): 1–5. http://dx.doi.org/10.22456/2177-0018.38125.

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Objective: To assess, using a mathematical simulation model, the participation of each coordinate involved in the formation of cephalometric angles and to determine the extent to which errors in the identification of cephalometric landmarks can, individually and collectively, influence the measurement of these angles. Material and Methods: The reference values and standard errors of 13 landmarks obtained from the analysis of 30 cephalograms were used. For each landmark, 1000 observations were simulated using the Monte Carlo method. On the basis of linear regression models, equations designed to estimate measurement errors due to landmark identification errors were obtained and analysed. Results: The coordinates most involved in the formation of the angles SNA, SNB, ANB, FMA, PPL, DFC, and AEF were Ny, Ny, Ax, Goy, Poy, Poy, and Ptmx, respectively, and the standard measurement errors for these angles were 1.2, 0.9, 0.8, 1.6, 1.5, 1.5, and 1.4, respectively. Conclusion: The standard measurement error of the angle depends on the geometric impact coefficient and the standard error of the coordinates involved in the formation of the angles, and the geometric impact coefficient varies according to the angle analysed.

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Hongying, Yang, Zhang Jingjing, Yang Zhihui, Zhou Jinli, Xie Wanzi, and Cui Shizhong. "Methods for improving the accuracy of CIE tristimulus values of object color by calculation Part II: Improvement on measurement wavelength ranges." Journal of Engineered Fibers and Fabrics 16 (January 2021): 155892502098596. http://dx.doi.org/10.1177/1558925020985964.

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The previous paper (part I) analyzed test errors of the spectrophotometer and their reasons, then systematically investigated the algorithms to reduce measuring bandpass error and intervals error. This paper (part II) focuses on the influence of measurement wavelength ranges and their truncation errors, and some algorithms to overcome the truncation errors. CIE recommends that tristimulus values are calculated over a range of 360–830 nm. However, most spectrophotometers do not meet it. The reduction of measurement range will result in a measurement range error or a truncation error. In this study, five ranges commonly employed in practice are selected for investigating the truncation errors, and three extrapolation methods are used to extend the data to compensate for the measurement range loss. Results are obtained by employing 1301 Munsell color chips under illuminant D65 and CIE 1964 standard observer. For the standard 1-nm intervals, the narrower the range, the larger the truncation error. For the usual-measured 10-nm intervals, bandpass error and intervals error should be handled at the same time, 380–780 nm Table LWL gives the highest accurate outcomes, which even improve the accuracy of the range 360–750 nm to an acceptable level. Whereas, ranges of 360–700 nm and 400–700 nm still need extrapolation to reduce their truncation errors even with Table LWL. Three extrapolation methods of nearest, linear and second-order all reduce the truncation error, but for different ranges, algorithms and illuminants, the optimal method of extrapolation varies.

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Nghiem, Linh H., Michael C. Byrd, and Cornelis J. Potgieter. "Estimation in linear errors-in-variables models with unknown error distribution." Biometrika 107, no. 4 (May 21, 2020): 841–56. http://dx.doi.org/10.1093/biomet/asaa025.

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Summary Parameter estimation in linear errors-in-variables models typically requires that the measurement error distribution be known or estimable from replicate data. A generalized method of moments approach can be used to estimate model parameters in the absence of knowledge of the error distributions, but it requires the existence of a large number of model moments. In this paper, parameter estimation based on the phase function, a normalized version of the characteristic function, is considered. This approach requires the model covariates to have asymmetric distributions, while the error distributions are symmetric. Parameters are estimated by minimizing a distance function between the empirical phase functions of the noisy covariates and the outcome variable. No knowledge of the measurement error distribution is needed to calculate this estimator. Both asymptotic and finite-sample properties of the estimator are studied. The connection between the phase function approach and method of moments is also discussed. The estimation of standard errors is considered and a modified bootstrap algorithm for fast computation is proposed. The newly proposed estimator is competitive with the generalized method of moments, despite making fewer model assumptions about the moment structure of the measurement error. Finally, the proposed method is applied to a real dataset containing measurements of air pollution levels.

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Blair, Graeme, Winston Chou, and Kosuke Imai. "List Experiments with Measurement Error." Political Analysis 27, no. 4 (May 20, 2019): 455–80. http://dx.doi.org/10.1017/pan.2018.56.

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Measurement error threatens the validity of survey research, especially when studying sensitive questions. Although list experiments can help discourage deliberate misreporting, they may also suffer from nonstrategic measurement error due to flawed implementation and respondents’ inattention. Such error runs against the assumptions of the standard maximum likelihood regression (MLreg) estimator for list experiments and can result in misleading inferences, especially when the underlying sensitive trait is rare. We address this problem by providing new tools for diagnosing and mitigating measurement error in list experiments. First, we demonstrate that the nonlinear least squares regression (NLSreg) estimator proposed in Imai (2011) is robust to nonstrategic measurement error. Second, we offer a general model misspecification test to gauge the divergence of the MLreg and NLSreg estimates. Third, we show how to model measurement error directly, proposing new estimators that preserve the statistical efficiency of MLreg while improving robustness. Last, we revisit empirical studies shown to exhibit nonstrategic measurement error, and demonstrate that our tools readily diagnose and mitigate the bias. We conclude this article with a number of practical recommendations for applied researchers. The proposed methods are implemented through an open-source software package.

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Miller, Jonathan, Simon Fletcher, Andrew Longstaff, and Simon Parkinson. "Simultaneous Constant Velocity Measurement of the Motion Errors of Linear Axes." International Journal of Automation Technology 14, no. 3 (May 5, 2020): 417–28. http://dx.doi.org/10.20965/ijat.2020.p0417.

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The current standard for machine tool calibration supports the use of quasi-static measurement techniques. When measuring the six degrees of freedom motion errors, the measurements are typically taken consecutively. This introduces uncertainty when comparing the results due to machine deformation during individual measurements. Furthermore, quasi-static measurement techniques are known to be time consuming, a problem that is exacerbated as each degree of freedom must be measured separately. Additionally, the spatial resolution between the selected target positions can have an impact on calibration quality. In the following paper, the benefits of measuring the six motion errors simultaneously while the axis under test is traversing at a nominally constant velocity are presented. Firstly, the motivation for simultaneous continuous capture is presented. Secondly, continuous motion measurements are compared with quasi-static measurements for the six degrees of freedom motion errors showing sub-micrometer and sub-arcsecond correlation. The full effect of a ball screw pitch error is shown which can be missed using traditional quasi-static measurement techniques. Finally, wavelet analysis is performed for further spatial diagnostics along with correlation coefficients calculated to quantify the linear dependency between the six error motions.

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Prijowuntato, Sebastianus Widanarto, Djemari Mardapi, and Budiyono Budiyono. "PERBANDINGAN ESTIMASI KESALAHAN PENGUKURAN STANDARD SETTING DALAM PENILAIAN KOMPETENSI AKUNTANSI SMK." Jurnal Penelitian dan Evaluasi Pendidikan 19, no. 2 (October 1, 2015): 176–88. http://dx.doi.org/10.21831/pep.v19i2.5578.

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Penelitian ini bertujuan untuk mengestimasi kesalahan pengukuran pada metode Angoff, Ebel, dan Bookmark dalam penilaian kompetensi Akuntnasi jenjang SMK di DIY yang digunakan standard setter dalam menentukan cut score. Penelitian ini merupakan penelitian kuantitatif. Sumber data dalam penelitian ini adalah respon peserta Ujian Nasional Praktik Akuntansi Paket 2 tahun ajaran 2011/2012 dengan 338 siswa. Guru-guru yang terlibat dalam Focus Group Discussion (FGD) berjumlah sembilan orang yang terdiri dari tujuh wanita dan dua pria. Teknik analisis dalam penelitian ini dibagi dalam tiga tahap yaitu: (1) persiapan, (2) FGD, (3) estimasi kesalahan pengukuran dengan menggunakan Bootstrap. Hasil penelitian menunjukkan bahwa cut score untuk metode Angoff sebesar 67,809, Ebel sebesar 59,034, dan Bookmark sebesar 57,022. Metode Angoff memiliki estimasi kesalahan pengukuran yang paling kecil (2,102) dibandingkan dengan metode Ebel (4,004) dan metode Bookmark (4,042). Oleh karena itu, metode Angoff merupakan metode yang tepat untuk mengestimasi kesalahan pengukuran pada standard setting. Kata kunci: Estimasi kesalahan pengukuran, Bootstrap, Cut Score ESTIMATION OF STANDARD SETTING ERROR MEASUREMENT IN ACCOUNTING COMPETENCY ASSESSMENT IN VOCATIONAL SCHOOLS Abstract This research aims to estimate the measurement error in the Angof, Ebel, and Bookmark methods in Accounting Competency Assessment in Vocational Schools in DIY used by standard setters in deciding a cut score. This research is quantitative research. Data source in this study was the cut score of seven vocational schools in Yogyakarta that were randomly established. The reseach data were students’ answers to the National Examination in Accounting Subject of Package 2 in the academic year of 2011/2012 with 338 students. The teachers who engaged in the Focus Group Discussion (FGD) were nine teachers, consisting of seven women and two men. The technical analysis was divided into three stages. 1) preparation, 2) FGD, 3) estimated error measurement by using the Bootstrap method. The results show that the cut score for the Angoff method is 67.809, Ebel method is 59.034, and Bookmark method is 57.022. The Angoff method has the least estimation of the measurement errors (2.102) as compared with the Ebel method (4.004) and the Bookmark method (4.042). Therefore, the Angoff method is the right method for estimating error measurement on standard setting. Keywords: Estimation of error measurement, Bootstrap, Cut Score

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Lynch, Thomas B. "Effects of measurement error on Monte Carlo integration estimators of tree volume: critical height sampling and vertical Monte Carlo methods." Canadian Journal of Forest Research 45, no. 4 (April 2015): 463–70. http://dx.doi.org/10.1139/cjfr-2014-0375.

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The effects of measurement error on Monte Carlo (MC) integration estimators of individual-tree volume that sample upper-stem heights at randomly selected cross-sectional areas (termed vertical methods) were studied. These methods included critical height sampling (on an individual-tree basis), vertical importance sampling (VIS), and vertical control variate sampling (VCS). These estimators were unbiased in the presence of two error models: additive measurement error with mean zero and multiplicative measurement error with mean one. Exact mathematical expressions were derived for the variances of VIS and VCS that include additive components for sampling error and measurement error, which together comprise total variance. Previous studies of sampling error for MC integration estimators of tree volume were combined with estimates of upper-stem measurement error obtained from the mensurational literature to compute typical estimates of total standard errors for VIS and VCS. Through examples, it is shown that measurement error can substantially increase the total root mean square error of the volume estimate, especially for small trees.

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Lee, King Sun. "The Development and Design of a Laser Detection System for Tire Thickness Measurement." Applied Mechanics and Materials 418 (September 2013): 128–31. http://dx.doi.org/10.4028/www.scientific.net/amm.418.128.

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This system is a self-developed real-time thickness inspection system including high-precision laser sensors and a mobile platform for on-line detection of tire rubber skin. The measurement data is used to calculate the standard deviation and process capability indices, and to evaluate measurement capacity. The system is a real-time measurement system in which the obtained measuring data compare with the standard value and show any errors. A technician can adjust the process parameters precisely on-line to improve product quality. The standard deviation of repeatability of the system for height is within +/- 0.0081 mm. The repeatability error of the horizontal sliding rail is within 0.0145mm, while the measurement error between this system and a coordinated measuring machine is within 0.028mm.

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Smith, J. D. "A Modular System for Transmission Error Measurement." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 202, no. 6 (November 1988): 439–42. http://dx.doi.org/10.1243/pime_proc_1988_202_146_02.

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A modular system of electronics for measuring transmission error with standard rotary optical encoders is described. The system can work flexibly with an overall speed range of the order of a 1000 to 1 by changing the order of the modules and will respond correctly to speed variations in both input and output of a synchronous drive such as a gear, chain or toothed belt drive.

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Urekar, Marjan, Marina Bulat, Bojan Vujicic, and Dragan Pejic. "Composite resistor standard for calibration of measuring transducers in laboratory conditions." Serbian Journal of Electrical Engineering 13, no. 1 (2016): 71–82. http://dx.doi.org/10.2298/sjee1601071u.

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Calibration of measuring transducers for precision measurement is done by measuring voltage drop at the resistor standard, produced by output dc current proportional to the input measured value. Resistance fluctuations due to the temperature coefficient of the resistor standard are minor, thanks to the stable temperature conditions in laboratory environment. This fact brings the need to calculate the effect of resistor self-heating on its resistance. This thermal effect, produced by the flow of current through the resistor, is often disregarded. For the precise measurements this can be a significant source of error and must be quantified. This paper describes mathematical model of measurement error, resistor self-heating coefficient is defined, as it?s not usually given in product datasheets. The effect on measurement results is given in detail. Composite resistor standard prototype is described, made from off-the-shelf mass produced components, calculated and hand selected to cancel the self-heating coefficient effects. The prototype is compared to the existing commercially available high performance resistor standard.

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Muoka, Alexander K., George O. Agogo, Oscar O. Ngesa, and Henry G. Mwambi. "A Method to adjust for measurement error in multiple exposure variables measured with correlated errors in the absence of an internal validation study." F1000Research 9 (December 18, 2020): 1486. http://dx.doi.org/10.12688/f1000research.27892.1.

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Difficulty in obtaining the correct measurement for an individual’s longterm exposure is a major challenge in epidemiological studies that investigate the association between exposures and health outcomes. Measurement error in an exposure biases the association between the exposure and a disease outcome. Usually, an internal validation study is required to adjust for exposure measurement error; it is challenging if such a study is not available. We propose a general method for adjusting for measurement error where multiple exposures are measured with correlated errors (a multivariate method) and illustrate the method using real data. We compare the results from the multivariate method with those obtained using a method that ignores measurement error (the naive method) and a method that ignores correlations between the errors and true exposures (the univariate method). It is found that ignoring measurement error leads to bias and underestimates the standard error. A sensitivity analysis shows that the magnitude of adjustment in the multivariate method is sensitive to the magnitude of measurement error, sign, and the correlation between the errors. We conclude that the multivariate method can be used to adjust for bias in the outcome-exposure association in a case where multiple exposures are measured with correlated errors in the absence of an internal validation study. The method is also useful in conducting a sensitivity analysis on the magnitude of measurement error and the sign of the error correlation.

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Ilchmann, T., U. Kesteris, and H. Wingstrand. "Effect of Pelvic Tilt on Radiographic Migration and Wear Measurements after Total Hip Arthroplasty." HIP International 8, no. 1 (January 1998): 16–23. http://dx.doi.org/10.1177/112070009800800102.

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Tilt effects on radiographic measurements after total hip arthroplasty should be studied. A new computerized method for measurement, called EBRA, making three-dimensional calculations and intended to identify tilted radiographs was evaluated for its clinical usefulness. In an experimental set-up repeated radiographs were taken with a human pelvis tilted gradually around its horizontal and vertical axes. Migration and wear were measured with the EBRA method and the results were compared with those made using standard methods. Tilted radiographs were identified and excluded from analysis by the EBRA method, significantly reducing the maximum error of measurement. A systematic error of measurement was found in the presence of consecutively changing tilt in a single direction. Wear measurements were only slightly affected by pelvic tilt. A pelvic tilt can cause considerable errors in the measurement of cup migration-i.e. up to 8.2 mm. The EBRA method improves the accuracy of measurements by taking the effects of tilt into account.

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Vorontsov, Yurii I. "Standard quantum limits of measurement error and methods of overcoming them." Uspekhi Fizicheskih Nauk 164, no. 1 (1994): 89. http://dx.doi.org/10.3367/ufnr.0164.199401d.0089.

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Sun, X., and X. Li. "PMU97 METHODOLOGICAL ADVANTAGES OF STANDARD ERROR OF MEASUREMENT FOR RESPONDER DEFINITION." Value in Health 23 (May 2020): S251. http://dx.doi.org/10.1016/j.jval.2020.04.863.

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Vorontsov, Yurii I. "Standard quantum limits of measurement error and methods of overcoming them." Physics-Uspekhi 37, no. 1 (January 31, 1994): 81–96. http://dx.doi.org/10.1070/pu1994v037n01abeh000004.

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Spiegelman, Clifford H. "Two Pitfalls of Using Standard Regression Diagnostics When BothXandYHave Measurement Error." American Statistician 40, no. 3 (August 1986): 245–48. http://dx.doi.org/10.1080/00031305.1986.10475402.

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Li, Cheng, Jeramy C. Ashlock, and Xuhao Wang. "Quantifying Repeatability Reproducibility Sources of Error and Capacity of a Measurement: Demonstrated Using Laboratory Soil Plasticity Tests." Advances in Civil Engineering 2019 (July 2, 2019): 1–11. http://dx.doi.org/10.1155/2019/4539549.

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The repeatability, reproducibility, and sources of error inherent in a given measurement are important considerations for potential users. To quantify errors arising from a single operator or multiple laboratories, most testing standards uses a one-way analysis of variance- (ANOVA-) based method, which utilizes a simple standard deviation across all measurements. However, this method does not allow users to quantify the sources of error and capacity (i.e., the precision to tolerance ratio). In this study, an innovative two-way ANOVA-based analysis method is selected to quantify the relative contributions of different sources of error and determine whether a measurement can be used to check conformance of a measured characteristic to engineering specifications. In this study, the standardized Atterberg limits tests, fall-cone device Atterberg limits tests, and bar linear shrinkage tests widely used for determining the soil plasticity were selected for evaluation and demonstration. Comparisons between results of the various testing methods are presented, and the error sources contributing to the overall variations between tests are discussed. Based on the findings of this study, the authors suggest use of two-way ANOVA-based R&R analysis to quantify the sources of measurement error and capacity and also recommend using the fall cone device and ASTM standardized thread rolling device for determining liquid and plastic limits of soils, respectively.

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Surdu, M. "Some Features of the Calibration Equipment for Measuring the Parameters of Impedance." Metrology and instruments, no. 6 (December 28, 2018): 21–27. http://dx.doi.org/10.33955/2307-2180(6)2018.21-27.

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Peculiarities of the accurate impedance meters calibration are considered. Author show that most important and complicate part of calibration procedure consists in determination of two uncertainty components: additive error and error, caused by nonlinearity of the meter transfer function. Problems of the determination of the additive error are caused by the fact, that there no exist accurate standard of the zero impedance. Author considers the creation of proper zero impedance standard, whose impedance can be arbitrarily close to zero and its impedance remnant can be estimated on the base of its geometrical dimensions. Implementation of such standard is very simple, cheap, and easily carried out. This standard works well on DC. Standard of zero impedance for AC measurement consists of two coaxial T-branches, which are connected through insertion piece. Such standard eliminates influence of the possible mutual inductive connection between current and voltage loops of the proper cables, which connect the “zero impedance standard” and measuring devise. To determine nonlinearity of the transfer function author analyze using of the non accurate resistive or alternative impedance dividers. To use such dividers in whole range of measurements special structures of these dividers where developed. In these structures measurement of the divider standards are provided together with impedance of their terminals. It eliminates influence of the impedance of these terminals on the accuracy of meter calibration or unit transfer. Special complex of two-standards dividers were developed to simplify the accurate calibration of the impedance meters.

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Pereira, Alamanda Kfoury, Zilma Silveira Nogueira Reis, Maria Cândida Ferrarez Bouzada, Eduardo Araújo de Oliveira, Gabriel Osanan, and Antônio Carlos Vieira Cabral. "Antenatal Ultrasonographic Anteroposterior Renal Pelvis Diameter Measurement: Is It a Reliable Way of Defining Fetal Hydronephrosis?" Obstetrics and Gynecology International 2011 (2011): 1–5. http://dx.doi.org/10.1155/2011/861865.

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Purpose. It was to quantify the intraobserver and interobserver variability of the sonographic measurements of renal pelvis and classify hydronephrosis severity.Methods. Two ultrasonographers evaluated 17 fetuses from 23 to 39 weeks of gestation. Renal pelvis APD were taken in 50 renal units. For intraobserver error, one of them performed three sequential measurements. The mean and standard deviation from the absolute and percentage differences between measurements were calculated. Bland-Altman plots were used to visually assess the relationship between the precision of repeated measurements. Hydronephrosis was classified as mild (5.0 to 9.9 mm), moderate (10.0 to 14.9 mm), or severe (≥15.0 mm). Interrater agreement were obtained using the Kappa index.Results. Absolute intraobserver variation in APD measurements was %. Interobserver variation of ultrasonographers was %. Neither intraobserver or interobserver error increased with increasing APD size. The overall percentage of agreement with the antenatal hydronephrosis diagnosis was 64%. Cohen's Kappa to hydronephrosis severity was 0.51 (95% CI, 0.33 to 0.69).Conclusion. Inter and intraobserver APD measurement errors were low in these group, but the agreement to hydronephrosis diagnosis and classification was fair. We suggest that standard and serial APD measurement can better define and evaluate fetal hydronephrosis.

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Губін, Сергій Вікторович, Сергій Олександрович Тишко, Олег Євгенович Забула, and Юрій Миколайович Черниченко. "ОСЦИЛОГРАФІЧНИЙ МЕТОД ВИМІРЮВАННЯ ФАЗОВОГО ЗСУВУ НА БАЗІ ДВОНАПІВПЕРІОДНОГО ПЕРЕТВОРЕННЯ." RADIOELECTRONIC AND COMPUTER SYSTEMS, no. 4 (December 25, 2019): 47–54. http://dx.doi.org/10.32620/reks.2019.4.05.

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The subject matter of the article is the oscilloscope methods of measuring the phase shift of two harmonic signals, after carrying out their two-half-period transformation and summing. The goal is to develop ways to implement an oscilloscope method of measuring the phase shift of two harmonic signals, which will significantly reduce the component of measurement error caused by phase non-symmetry of the transmission channels, by reducing their length. Analyze the measurement error for each of the methods for determining the phase shift of two harmonic signals using their two-half-periodic transformation. The tasks: statement of measurement problem of determination of phase shift of two harmonic signals; analysis of known oscilloscope methods of phase shift measurement, development of methods for implementing the oscilloscope method based on the analysis of the characteristics of the total signal obtained during the two-half-period transformation; estimation of measurement errors for each method. The methods used are the methodology for estimating measurement errors in indirect measurements. The following results were obtained. Methods for implementing an oscilloscope measurement method using the total signal after a two-half-period transformation based on the analysis of temporal characteristics and local extrema of this signal are proposed. The list of measuring operations that implement each method is defined. The analysis of the components of measurement errors was performed and the degree of correlation was determined. Synthesized ratios for the calculation of measurement error. Conclusions. The scientific novelty of the obtained results is the following: an oscilloscopic method has been developed that will allow reducing substantially the component of the error caused by phase non-symmetry of the signal transmission channels; obtained ratios for the implementation of the oscilloscope measurement method using two-half-period conversion; obtained ratios to calculate the standard deviation of the total measurement error in each of the proposed methods.

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Cai, Yong Lin, Ning Ning Cui, Xiang Mo, Xiang Kai Yao, and Wei Qing Sun. "The Pre-Travel Error Study of Electrical Trigger Probe in On-Machine Measurement." Key Engineering Materials 693 (May 2016): 1466–73. http://dx.doi.org/10.4028/www.scientific.net/kem.693.1466.

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On-machine measurement is a high-efficient measure method in NC machining, and there are pre-travel errors during measurement. What is more, these errors tend to present anisotropy, and affect the measurement accuracy. This paper aimed at measuring the anisotropy of probe’s pre-travel error. First, the standard ball is measured by changing the probe angle with the same machine tool moving direction, and the pre-travel errors with different probe angles under the same machine tool errors are obtained. Then, the machine tool backlash errors are measured and compensated, and the pre-travel errors with different probe angle are obtained. Finally, the mathematical model of pre-travel error is established. The method proposed in this paper can be used to determine probe’s pre-travel error with anisotropy.

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Fowler, Austin G., David S. Wang, and Lloyd C. L. Hollenberg. "Surface code quantum error correction incorporating accurate error propagation." Quantum Information and Computation 11, no. 1&2 (January 2011): 8–18. http://dx.doi.org/10.26421/qic11.1-2-2.

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The surface code is a powerful quantum error correcting code that can be defined on a 2-D square lattice of qubits with only nearest neighbor interactions. Syndrome and data qubits form a checkerboard pattern. Information about errors is obtained by repeatedly measuring each syndrome qubit after appropriate interaction with its four nearest neighbor data qubits. Changes in the measurement value indicate the presence of chains of errors in space and time. The standard method of determining operations likely to return the code to its error-free state is to use the minimum weight matching algorithm to connect pairs of measurement changes with chains of corrections such that the minimum total number of corrections is used. Prior work has not taken into account the propagation of errors in space and time by the two-qubit interactions. We show that taking this into account leads to a quadratic improvement of the logical error rate.

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Song, Qian, Ri Hong Zhu, Rong Gang Zhu, and Jin Peng Li. "Study on Phase Measurement Profilometry with Optical Fiber Projection Grating." Advanced Materials Research 718-720 (July 2013): 561–66. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.561.

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This article proposed a way to reduce the error in the measurement of object morphology that based on the phase measurement profilometry with Optical Fiber Projection Grating. Some simulation of the actual light intensity distribution need to do first to get the error that caused by the aperiodic fringes, express the errors by phase. After that, compensate for this error based on the actual measurement results. There is a larger improvement in the accuracy of the recovery after the process proposed in this article than before through the simulation. The experiment verifies the correctness of this method through the measurement of given standard parts.

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Ritchie, Nicholas W. M. "Embracing Uncertainty: Modeling the Standard Uncertainty in Electron Probe Microanalysis—Part I." Microscopy and Microanalysis 26, no. 3 (May 21, 2020): 469–83. http://dx.doi.org/10.1017/s1431927620001555.

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AbstractThis is the first in a series of articles which present a new framework for computing the standard uncertainty in electron excited X-ray microanalysis measurements. This article will discuss the framework and apply it to a handful of simple, but useful, subcomponents of the larger problem. Subsequent articles will handle more complex aspects of the measurement model. The result will be a framework in which sophisticated and practical models of the uncertainty for real-world measurements. It will include many long overlooked contributions like surface roughness and coating thickness. The result provides more than just error bars for our measurements. It also provides a framework for measurement optimization and, ultimately, the development of an expert system to guide both the novice and expert to design more effective measurement protocols.

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Vach, Werner, and Oke Gerke. "How Replicates Can Inform Potential Users of a Measurement Procedure about Measurement Error: Basic Concepts and Methods." Diagnostics 11, no. 2 (January 22, 2021): 162. http://dx.doi.org/10.3390/diagnostics11020162.

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Measurement procedures are not error-free. Potential users of a measurement procedure need to know the expected magnitude of the measurement error in order to justify its use, in particular in health care settings. Gold standard procedures providing exact measurements for comparisons are often lacking. Consequently, scientific investigations of the measurement error are often based on using replicates. However, a standardized terminology (and partially also methodology) for such investigations is lacking. In this paper, we explain the basic conceptual approach of such investigations with minimal reference to existing terminology and describe the link to the existing general statistical methodology. This way, some of the key measures used in such investigations can be explained in a simple manner and some light can be shed on existing terminology. We encourage clearly conceptually distinguishing between investigations of the measurement error of a single measurement procedure and the comparison between different measurement procedures or observers. We also identify an unused potential for more advanced statistical analyses in scientific investigations of the measurement error.

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El Alani, Omaima, Hicham Ghennioui, Abdellatif Ghennioui, Yves-Marie Saint-Drenan, Philippe Blanc, Natalie Hanrieder, and Fatima-Ezzahra Dahr. "A Visual Support of Standard Procedures for Solar Radiation Quality Control." International Journal of Renewable Energy Development 10, no. 3 (February 5, 2021): 401–14. http://dx.doi.org/10.14710/ijred.2021.34806.

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Solar irradiance data from high-quality ground-based measurements are primordial for different solar energy applications. In order to achieve the required accuracy, quality control procedures are of great benefit. A variety of approaches have been proposed. In this sense, some approaches propose a visual representation of the routine, while others only provide a time series of binary flag values, and do not propose any specific visualization of the flagged data as opposed to non-flagged ones. In this regard, the present paper puts forward a complete routine including several quality control procedures for solar irradiance measurements by providing visual support for these different approaches. The visual tool in question was validated using five years research data with 10 minutes resolution of the global, diffuse and direct components of solar irradiation collected from three ground-based weather stations in Morocco. This visual tool puts forth a more precise idea of the measurement quality by detecting various errors, such as time shifts, outliers identification; either with one or two components, or consistency tests between the three components of solar radiation when available. The proposed tool can be regarded as a means of improving the detection rate of abnormal data as a first step in diagnosing the prominent causes of error.

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Linnet, Kristian. "Performance of Deming regression analysis in case of misspecified analytical error ratio in method comparison studies." Clinical Chemistry 44, no. 5 (May 1, 1998): 1024–31. http://dx.doi.org/10.1093/clinchem/44.5.1024.

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Abstract Application of Deming regression analysis to interpret method comparison data presupposes specification of the squared analytical error ratio (λ), but in cases involving only single measurements by each method, this ratio may be unknown and is often assigned a default value of one. On the basis of simulations, this practice was evaluated in situations with real error ratios deviating from one. Comparisons of two electrolyte methods and two glucose methods were simulated. In the first case, misspecification of λ produced a bias that amounted to two-thirds of the maximum bias of the ordinary least-squares regression method. Standard errors and the results of hypothesis-testing also became misleading. In the second situation, a misspecified error ratio resulted only in a negligible bias. Thus, given a short range of values in relation to the measurement errors, it is important that λ is correctly estimated either from duplicate sets of measurements or, in the case of single measurement sets, specified from quality-control data. However, even with a misspecified error ratio, Deming regression analysis is likely to perform better than least-squares regression analysis.

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Hess, Sonja Y., Guy-Marino Hinnouho, Maxwell A. Barffour, Bangone Bounheuang, Charles D. Arnold, David Bell, Tola H. Marts, and Sengchanh Kounnavong. "First Field Test of an Innovative, Wider Tape to Measure Mid-Upper Arm Circumference in Young Laotian Children." Food and Nutrition Bulletin 39, no. 1 (December 19, 2017): 28–38. http://dx.doi.org/10.1177/0379572117742502.

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Background: Measurements of mid-upper arm circumference (MUAC) may result in measurement error due to incorrect placement along the arm or tight pulling of tape. To reduce the risk of these measurement errors, a new wider tape was developed. Objective: To compare the measurement agreement and precision and the ease of use of the standard and wide MUAC tapes. Methods: Mid-upper arm circumference was measured in 814 children aged 9 to 32 months with both tapes. The midpoint of the upper arm was measured with the standard tape and estimated with the wide tape. Standardization sessions were implemented to assess intra- and interobserver precision. Results: Mid-upper arm circumference with the wide MUAC tape was significantly larger than the standard tape (mean [standard deviation]: 14.3 [1.0] cm vs 13.9 [1.0] cm; P < .001), resulting in a consistent bias of +0.41 cm. Forty-six (5.7%) children were identified with low MUAC <12.5 cm by standard tape compared with 10 (1.2%) by the wide tape ( P <.001). Because a new tape could be reproduced by correcting for this bias, we corrected measured results by subtracting 0.41 cm and mean MUAC by tape type was no longer significantly different. Intra- and interobserver technical error of measurement suggested a better precision with the wide MUAC tape. Conclusions: Despite simplifying the measurement by approximating the midpoint of the upper arm, the wide MUAC tape tended to have better precision than the standard MUAC tape. However, there was a consistent measurement bias of +0.41 cm in mean MUAC. This first field test yielded promising results and led to further product adjustments.

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Journal articles on the topic 'Standard error of measurement'

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