• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.4
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• pp.55-61
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• 2012

Very important content in performance evaluation of machine tool is positioning accuracy and repeatability precision measurements of feed mechanism. A study analyses the measurement method and uncertainty factors by ISO-based test method. Reliable results can't be derived without the notion of measurement uncertainty. The reason is that the measured value includes a lot of uncertain factors. Finding the factor that affects the measurement of parameter is important for estimation of measurement precision. In this paper, the evaluation of uncertainty analysis about positioning accuracy and repeatability precision measurements of high precision feed mechanism is presented to evaluate the important factors of uncertainty.

• Fashion & Textile Research Journal
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• v.1 no.1
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• pp.50-55
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• 1999

The repeatability of fabric drape was studied. Two methods for draping were used and the relation between node distributions was investigated using statistical analysis. With this, the relationship between node distribution and fabric mechanical properties was studied. The repeated measurements showed that there was no evidence that fabric has intrinsic node number and the mechanical properties influence on the number of nodes.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.209-213
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• 2012

Purpose: To assess the repeatability of the monocular spherical endpoints, a test was performed with four methods which are the retinoscopy, the MPMVA (maximum plus maximum visual acuity) method, the R/G duochrome method, and the crossed cylinder method. Methods: The monocular spherical endpoints was measured by four kinds of method (Retinoscopy, MPMVA method, R/G duochrome method, Crossed cylinder method) on 20 subjects (40 eyes) of average age 23.0 year-old men and women. After a week, retest was performed by same procedure and the test-retest repeatability was assessed by using the Bland-Altman plot analysis. Results: The test-retest mean difference of retinoscopy was the smallest diopters of -0.03 and that of R/G duochrome method was the largest diopters of -0.19. The upper/lower 95% limits of agreement for repeatability was the narrowest in retinoscopy and was the widest in crossed cylinder method. When compared the spherical endpoints of each eye between by retinoscopy and by other three methods, the error rate of ${\pm}0.25D$ in total eyes was 85% in MPMVA method, 80% in R/G duochrome method, and 24% in crossed cylinder method. Conclusions: Test-retest repeatability is the highest in the retinoscopy, and the retinoscopy, the MPMVA method, and R/G duochrome method are suitable for monocular spherical endpoints test.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.269-274
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• 2010

Purpose: The repeatability of a new Red-Blue phoria chart test (Red-Blue phoria chart; RBP) was appreciated. Methods: Distance (5 m) and near (40 cm) heterophoria was measured in 38 visually normal subjects. Phoria tests using RBP, Howell phoria card (HP), and MIM card (MIM) were done and the repeatability of each phoria test was compared with one another. Results: The mean of horizontal deviations was that RBP was $-0.602{\pm}0.727{\Delta}$, HP was $-0.865{\pm}1.051{\Delta}$, and MIM was $-1.501{\pm}1.346{\Delta}$, at distance, and that RBP was $-2.566{\pm}2.352{\Delta}$, HP was $-2.804{\pm}2.411{\Delta}$, MIM was $-3.838{\pm}2.603{\Delta}$, at near. The repeatability was RBP>MIM>HP in distance tests and MIM>RBP>HP in near tests. Conclusions:RBP test is identified as a reliable phoria test having high repeatability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.607-608
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• 2009

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.55
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• pp.13-24
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• 2000

6 sigma movement is the most prominent quality improvement methodology in practice. Measurement plays an important role in helping any organization improve quality. Therefore, the measurement systems analysis is the first step for the quality improvement of manufacturing process in 6 sigma movement. In this study, we investigate the effect of Gage Repeatability and Reproducibility(Gage R&R) in view of defect rate and process capability indices, and provide guidelines for acceptance of gage repeatability and reproducibility(%R&R) for six sigma quality.

• Journal of Technologic Dentistry
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• v.35 no.1
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• pp.37-42
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• 2013

Purpose: The purpose of this study was to evaluate the repeatability of dental white light scanner. Methods: The impression(Zerosil, Dreve, Germany) were digitized in white light scanner(Identica, Medit, Korea) to create 3-dimensional surface-models. The distribution of the discrepancies between the number of points in the corresponding CRM models and the point clouds in the others were measured by a matching-software(PowerInspect 2012, Delcam Plc, UK). The discriptive statistics were used for statistical analysis(SPSS 20.0). Results: The measurement of repeatablity showed very good reliability. The mean(SD) discrepancy value on the white light scanner digital models was 8.7(0.67) ${\mu}m$, based on SD and absolute mean values. Conclusion: These in vitro studies showed that repeatability of dental white light scanner is high reliability. These results can be confirmed in further clinical studies.

• Journal of the Korean Vacuum Society
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• v.20 no.5
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• pp.322-326
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• 2011

Etch process of silicon dioxide layer by using capacitively coupled plasma (CCP) is currently being used to manufacture semiconductor devices with nano-scale feature size below 50 nm. In typical CCP plasma etcher system, plasmas are generated by applying the RF power on upper electrode and ion bombardment energy is controlled by applying RF power to the bottom electrode with the Si wafer. In this case, however, etch results often drift due to heating of the electrode during etching process. Therefore, controlling the temperature of the upper electrode is required to obtain improvement of etch repeatability. In this work, we report repeatability improvement during the silicon dioxide etching under extreme process conditions with very high RF power and close gap between upper and bottom electrodes. Under this severe etch condition, it is difficult to obtain reproducible oxide etch results due to drifts in etch rate, critical dimension, profile, and selectivity caused by unexpected problems in the upper electrode. It was found that reproducible etch results of silicon dioxide layer could be obtained by controlling temperature of the upper electrode. Methods of controlling the upper electrode and the correlation with etch repeatability will be discussed in detail.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.774-787
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• 2011

This paper deals with quantitative analysis about the characteristics of GNSS(Global Navigation Satellite System) signals contaminated with multipath signals and day-to-day repeatability of the navigation solution and SNR(Signal to Noise Ratio) caused by multipath signals using the collected data from GPS receiver installed on KSLV-I which was on standby on the launch pad at Naro Space Center. Since the GPS antennas, surrounding environments and GPS satellite orbits were very slightly changed with respect to the day, the repeating pattern of the solution and SNR caused by the multipath signals was verified from the collected data. Analytic result of the multipath effects and day-to-day repeatability of the navigation solution and SNR observed at the launch pad would be used for obtaining more stable performance of the GPS receiver when the satellite launch vehicles are on standby.

• Journal of Sasang Constitutional Medicine
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• v.24 no.3
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• pp.34-41
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• 2012

Objectives In this study, we developed a mock-up of the system for Sasang Constitutional (SC) diagnosis. This system consists of 5 devices which are the face analyzer, the voice analyzer, the skin analyzer, the pulse analyzer, and the computer-based questionnaire. Our goal is to evaluate the repeatability of the system. Methods Each device is capable of classifying SC types. The classification probability of the integrated system for the SC types was obtained by summing the probability from each device. For evaluating the repeatability of the system, we collected data for 5 subjects, and repeated the measurement three times for each individual. The average and standard deviation were used for calculating the Coefficient of Variation. Results The results showed that the repeatability of the classification probability of the integrated system is about 8%, which implies the system is repeatable. Conclusions To increase usability of this system, it is desirable for the system to offer information on health condition of the user. The integrated constitutional diagnosis system will be upgraded to complement the convenience and to develop the diagnostic algorithm for the user's health condition.