Repeated measurements of facial skin characteristics using the Janus‐Ⅲ measurement system

2019 ◽  
Vol 26 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Sangseob Leem ◽  
Junghwa Chang ◽  
Yunkwan Kim ◽  
Joong‐Gon Shin ◽  
Hae Jung Song ◽  
...  
Keyword(s):  
Measurement System ◽  
Repeated Measurements ◽  
Facial Skin

scholarly journals Development of an image‐based measurement system for human facial skin colour

2021 ◽  
Author(s):  
Ruili He ◽  
Kaida Xiao ◽  
Michael Pointer ◽  
Yoav Bressler ◽  
Zhen Liu ◽  
...  
Keyword(s):  
Measurement System ◽  
Skin Colour ◽  
Facial Skin

Gage Repeatability and Reproducibility Investigations of a Test Rig Using ANOVA/Xbar-R Method

2011 ◽  
Author(s):  
Berna Balta ◽  
Fazıl O¨nder So¨nmez ◽  
Abdu¨lkadir Cengiz
Keyword(s):  
Experimental Study ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Measurement System ◽  
System Analysis ◽  
Experimental Studies ◽  
Repeated Measurements ◽  
Test Rig ◽  
Experimental Conditions ◽  
Repeatability And Reproducibility

In an experimental study, good measurement systems are important for approaching successful decisions. The assessment of a measurement system is known as “Gage Repeatability and Reproducibility” (GR&R). “Measurement System Analysis” (MSA) should be performed at the beginning of an experimental study to ensure that the information to be collected are true representation of what is occurring in the experiment. Experimental data collected under the same condition usually show variation, which arises partly from the experimental system, partly from the measurement devices and partly from the operator who makes the measurements. MSA helps to differentiate the contribution of each source to the randomness of the data. In this way, one may see whether there is a need to reduce the measurement variation so that the data reflects basically the experimental variation. Besides, MSA gives quantitative measures for repeatability and reproducibility. Repeatability is the variation in repeated measurements taken by the same operator under the same experimental conditions. Reproducibility is the variation in data obtained by different operators taking the measurement with the same setup under the same conditions. These are measures of the consistency and precision of the data. GR&R is the most common MSA tool that analyzes the viability of an experimental set-up. Resultant GR&R will indicate overall measurement system variation as the sum of repeatability variation and reproducibility variation. Generally, GR&R % gives a measure of the suitability of the measurement system to yield acceptable data for statistical studies such as “Design Of Experiments” (DOE), “One Factor At a Time” (OFAT), “Response Surface Methodology”, etc. [1, 2]. In this paper, “Analysis of Variance” (ANOVA) and the “Average and Range” (Xbar & R) methods are used to assess the capability of a laboratory made measurement device, which is used for the investigations of a belt drive system efficiency. GR&R is applied at the design stages of the construction of the test rig and final application is presented in this study. The results prove that the test rig is capable of making experimental studies using statistical methods such as DOE and Response Surface Methodology.

Modeling Intraindividual Variability in Three-Level Multilevel Models

Methodology ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 95-108 ◽  
Author(s):  
Steffen Nestler ◽  
Katharina Geukes ◽  
Mitja D. Back
Keyword(s):  
Multilevel Model ◽  
Multilevel Models ◽  
Mixed Effects ◽  
Repeated Measurements ◽  
Scale Model ◽  
Suggested Approach ◽  
Psychological Study ◽  
Level Data ◽  
Ecological Momentary ◽  
Momentary Assessment

Abstract. The mixed-effects location scale model is an extension of a multilevel model for longitudinal data. It allows covariates to affect both the within-subject variance and the between-subject variance (i.e., the intercept variance) beyond their influence on the means. Typically, the model is applied to two-level data (e.g., the repeated measurements of persons), although researchers are often faced with three-level data (e.g., the repeated measurements of persons within specific situations). Here, we describe an extension of the two-level mixed-effects location scale model to such three-level data. Furthermore, we show how the suggested model can be estimated with Bayesian software, and we present the results of a small simulation study that was conducted to investigate the statistical properties of the suggested approach. Finally, we illustrate the approach by presenting an example from a psychological study that employed ecological momentary assessment.

CCD flux measurement system PROHERMES

1999 ◽  
Vol 09 (PR3) ◽  
pp. Pr3-649-Pr3-654 ◽  
Author(s):  
A. Kröger-Vodde ◽  
A. Holländer
Keyword(s):  
Measurement System ◽  
Flux Measurement

Use of a Lyophilized Reference Plasma to Compare Coagulation Test Procedures

1975 ◽  
Vol 34 (02) ◽  
pp. 426-444 ◽  
Author(s):  
J Kahan ◽  
I Nohén
Keyword(s):  
Oral Anticoagulant Therapy ◽  
Repeated Measurements ◽  
Test Procedures ◽  
Coagulation Activity ◽  
Close Relationship ◽  
Measured Activity ◽  
Test Materials ◽  
The Difference ◽  
The Stability ◽  
The One

SummaryIn 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy.Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers’ procedures used to set “normal percentage activity”, as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents.The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents.The assigned coagulation activity of different batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.

Sign in / Sign up

Export Citation Format

Share Document