scholarly journals A comparison of two methods for estimating measurement repeatability in morphometric studies

2021 ◽  
Author(s):  
Zachariah Wylde ◽  
Russell Bonduriansky
Keyword(s):  
Measurement Repeatability

Measurement Repeatability of Corneal Aberrations

2002 ◽  
Vol 18 (5) ◽  
Author(s):  
Marine Gobbe ◽  
Michel Guillon ◽  
Cecile Maissa
Keyword(s):  
Corneal Aberrations ◽  
Measurement Repeatability

scholarly journals Simultaneous Measurements of Temperature and Viscosity for Viscous Fluids Using an Ultrasonic Waveguide

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5543
Author(s):  
Jinrui Huang ◽  
Frederic Cegla ◽  
Andy Wickenden ◽  
Mike Coomber
Keyword(s):  
Viscous Liquid ◽  
Viscous Fluids ◽  
Fluid Temperature ◽  
Wave Propagation Velocity ◽  
Temperature Detector ◽  
Elastic Shear ◽  
Surrounding Fluid ◽  
Commercial Resistance ◽  
Measurement Repeatability ◽  
Better Than

The characterisation and monitoring of viscous fluids have many important applications. This paper reports a refined ‘dipstick’ method for ultrasonic measurement of the properties of viscous fluids. The presented method is based on the comparison of measurements of the ultrasonic properties of a waveguide that is immersed in a viscous liquid with the properties when it is immersed in a reference liquid. We can simultaneously determine the temperature and viscosity of a fluid based on the changes in the velocity and attenuation of the elastic shear waves in the waveguide. Attenuation is mainly dependent on the viscosity of the fluid that the waveguide is immersed in and the speed of the wave mainly depends on the surrounding fluid temperature. However, there is a small interdependency since the mass of the entrained viscous liquid adds to the inertia of the system and slows down the wave. The presented measurements have unprecedented precision so that the change due to the added viscous fluid mass becomes important and we propose a method to model such a ‘viscous effect’ on the wave propagation velocity. Furthermore, an algorithm to correct the velocity measurements is presented. With the proposed correction algorithm, the experimental results for kinematic viscosity and temperature show excellent agreement with measurements from a highly precise in-lab viscometer and a commercial resistance temperature detector (RTD) respectively. The measurement repeatability of the presented method is better than 2.0% in viscosity and 0.5% in temperature in the range from 8 to 300 cSt viscosity and 40 to 90 °C temperature.

scholarly journals Quantitative Sasang Constitution Diagnosis Method for Distinguishing between Tae-eumin and Soeumin Types Based on Elasticity Measurements of the Skin of the Human Hand

2009 ◽  
Vol 6 (s1) ◽  
pp. 93-98 ◽  
Author(s):  
Han Wook Song ◽  
SungJun Lee ◽  
Yon Kyu Park ◽  
Sam Yong Woo
Keyword(s):  
Human Hand ◽  
Oriental Medicine ◽  
Compression Method ◽  
Repeatability Error ◽  
Sasang Constitution ◽  
Diagnosis Method ◽  
Sasang Constitutional Medicine ◽  
Constitutional Medicine ◽  
Measurement Repeatability ◽  
Elasticity Measurements

The usefulness of constitutional diagnoses based on skin measurements has been established in oriental medicine. However, it is very difficult to standardize traditional diagnosis methods. According to Sasang constitutional medicine, humans can be distinguished based on properties of the skin, including its texture, roughness, hardness and elasticity. The elasticity of the skin was previously used to distinguish between people with Tae-eumin (TE) and Soeumin (SE) constitutions. The present study designed a system that uses a compression method to measure the elasticity of hand skin and evaluated its measurement repeatability. The proposed system was used to compare the skin elasticity between SE and TE subjects, which produced a measurement repeatability error of <3%. The proposed system is suitable for use as a quantitative constitution diagnosis method for distinguishing between TE and SE subjects with an acceptable level of uncertainty.

Study on Measuring System of Automatic Image Alignment Refractive Index Based on New Mathematical Model

2014 ◽  
Vol 609-610 ◽  
pp. 1319-1323
Author(s):  
Qing Hua Yao ◽  
Miao Cao ◽  
Chang Liu
Keyword(s):  
Refractive Index ◽  
Optical Transmission ◽  
Optical Glass ◽  
Measuring System ◽  
Practical Significance ◽  
High Demand ◽  
Accuracy Measurement ◽  
General Instrument ◽  
Measurement Repeatability ◽  
High Accuracy Measurement

With the development of measuring technology,the measuring accuracy of optical glass refractive index of the increasingly high demand,V prism refractometers is major general instrument for measuring the refractive index of optical glass,not only the simple device,convenient measurement,and this method has high precision performance,however,the accuracy is only attained ,which in the regulation of national metrology verification and the introduction of V prism refractometers in the literature,the classic formula calculation principle formula error caused by refractive index has more than .Based on the mechanical structure and optical transmission to improve the original V prism refractometers the refractive index of air,by considering the influence on measurement precision of V prism refractometer,to mathematical modeling of V prism refractometer the principle formula,V can be measured refractive prism refractometer rate accuracy increased to ,measurement repeatability less than ,has important practical significance for realizing high accuracy measurement of the refractive index of optical glass.

Technical Repeatability and Reproducibility of the Stress Radiographs Performed with the Vezzoni-Modified Badertscher Hip Distension Device

2019 ◽  
Vol 32 (01) ◽  
pp. 067-072 ◽  
Author(s):  
Lieve De Rycke ◽  
Aldo Vezzoni ◽  
Ingeborgh Polis ◽  
Jimmy Saunders ◽  
Bart Broeckx ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Hip Joint ◽  
Evaluation Method ◽  
Limits Of Agreement ◽  
Stress Radiographs ◽  
Technical Reproducibility ◽  
Repeatability And Reproducibility ◽  
Measurement Repeatability

Objective The aim of this study was to evaluate the repeatability and reproducibility of the radiographical stress technique using the Vezzoni-modified Badertscher distension device (VMBDD). Materials and Methods Stress radiographs of 10 dogs obtained with the VMBDD were performed consecutively by two different operators and then measured twice by a third veterinarian. The technical repeatability was first assessed individually for the two operators who took the stress radiographs, followed by the technical reproducibility. The obtained variances were used to calculate the 95% limits of agreement for the measurement repeatability, the technical repeatability and the technical reproducibility. Results Both the technical repeatability and reproducibility of the VMBDD technique were good, with the 95% limits of agreement of the measurement repeatability and technical repeatability equalling ± 0.07 overall, and the 95% limits of agreement of the technical reproducibility being ± 0.09. Clinical Significance These results, in combination with the previous results for the measurement of the laxity index, support the use of the VMBDD as a reliable in-house evaluation method to assess the hip joint by trained clinicians. For screening purposes, however, we suggest to limit the number of evaluators, to limit the variability.

scholarly journals Particulate Emissions of Euro 4 Motorcycles and Sampling Considerations

Atmosphere ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 421 ◽  
Author(s):  
Barouch Giechaskiel ◽  
Alessandro A. Zardini ◽  
Tero Lähde ◽  
Adolfo Perujo ◽  
Anastasios Kontses ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Particle Number ◽  
Scientific Literature ◽  
Regulatory Control ◽  
Small Displacement ◽  
Particulate Emissions ◽  
Passenger Cars ◽  
State Tests ◽  
The Mean ◽  
Measurement Repeatability

The scientific literature indicates that solid particle number (SPN) emissions of motorcycles are usually higher than that of passenger cars. The L-category (e.g., mopeds, motorcycles) Euro 4 and 5 environmental steps were designed to reduce the emissions of particulate matter and ozone precursors such as nitrogen oxides and hydrocarbons. In this study the SPN emissions of one moped and eight motorcycles, all fulfilling the Euro 4 standards, were measured with a SPN measurement system employing a catalytic stripper to minimize volatile artefacts. Although the particulate matter mass emissions were <1.5 mg/km for all vehicles tested, two motorcycles and the moped were close to the SPN limit for passenger cars (6 × 1011 particles/km with sizes larger than 23 nm) and four motorcycles exceeded the limit by a factor of up to four. The measurement repeatability was satisfactory (deviation from the mean 10%) and concentration differences between tailpipe and dilution tunnel were small, indicating that performing robust SPN measurements for regulatory control purposes is feasible. However, steady state tests with the moped showed major differences between the tailpipe and the dilution tunnel sampling points for sub-23 nm particles. Thus, the measurement procedures of particles for small displacement engine mopeds and motorcycles need to be better defined for a possible future introduction in regulations.

scholarly journals The effect of image quality on the reliability of OCT angiography measurements in patients with diabetes

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Cecília Czakó ◽  
Lilla István ◽  
Mónika Ecsedy ◽  
Zsuzsa Récsán ◽  
Gábor Sándor ◽  
...  
Keyword(s):  
Image Quality ◽  
Measurement Errors ◽  
Vessel Density ◽  
Foveal Avascular Zone ◽  
Flow Area ◽  
Retinal Capillary ◽  
Unit Increase ◽  
Patients With Diabetes ◽  
Density Values ◽  
Measurement Repeatability

Abstract Background This study aimed to determine the relationship between image quality and measurement repeatability of optical coherence tomography angiography (OCTA) parameters in patients with non-proliferative diabetic retinopathy. Methods A total of 100 eyes of 50 patients were included in the study. Three OCTA images were obtained consecutively during one session of imaging in all patients using the RTVue AngioVue OCTA device. We applied the signal strength index (SSI) provided by the RTVue system to define scan quality. Superficial vessel density (VD) in the central 3 × 3 mm macular and in the perifoveal region, as well as foveal avascular zone (FAZ) area were evaluated by the AngioAnalytics software for each scan from three consecutive measurements, whereby measurement repeatability of the OCTA parameters were calculated. The effect of SSI value on OCTA parameters, as well as on measurement errors was assessed. Results Values of SSI ranged from 30 to 85 with an overall mean of 61.79 ± 10.38. Mean SSI values showed significant positive correlation with the mean retinal capillary vessel density values, but not with non-flow area. Repeatability of OCTA parameters was generally improved with higher SSI values. We calculated a mean correction factor of 0.22% (95% CI 0.20–0.24 µm; p < 0.001) for VD at the 3 × 3 mm macular scan, 0.23% (95% CI 0.21–0.26%; p < 0.001) for perifoveal VD and − 0.001 mm2 (95% CI − 0.001 to 0.002; p = 0.001) for the non-flow area for each unit increase in SSI for the comparison of images with different SSI values. Conclusions The influence of image quality on OCTA metrics should be considered for image comparisons during follow-up to avoid misinterpretation of small changes in OCTA parameters in patients with diabetes.

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