• Journal of Korean Society for Quality Management
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• v.42 no.4
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• pp.607-616
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• 2014

Purpose: This paper reviews popular measurement system indices and proposes a procedure for assessing a measurement system using two parameters with intraclass correlation and a factor for process capability. Methods: Gage Repeatability and Reproducibility(GR&R), precision-to-tolerance ratio(PTR), number of distinct categories, producer's and consumer's risks are employed to assess the measurement capabilities and discuss the relationships between measurement system metrics. Results: Two-dimensional plot by two parameters is presented to assess adequacy of the measurement system and process capability. A numerical example and previously studied case study are provided for illustration. Conclusion: The procedure proposed in this paper using two-dimension parameters provides a valuable procedure and helpful guidelines to quality and production managers in assessing the capabilities of a measurement system and choosing the needed actions to be the most benefit.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.37-41
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• 2002

Thermal characteristics of hydrostatic guideway is largely depended on the temperature of supplied oil. For improving the positioning accuracy of hydrostatic guideway, relationship between setting temperature of oil cooler and thermal characteristics is analyzed, and influence of thermal characteristics on positioning accuracy is also analyzed experimental1y in this paper. Laser scale which has 0.01 $\mu\textrm{m}$ of resolution is used as feed-back unit. From the experimental results, it is confirmed that positioning error and repeatability is minimize upto 0.21 $\mu\textrm{m}$ and 0.18 $\mu\textrm{m}$ when the temperature of supplied oil is setting equal to temperature of atmosphere, and also confirmed that thermal deformation, which occurs by the temperature deviation between table and rail or scale supporter, works as limit of repeatability in long time operation.

• Korean Journal of Optics and Photonics
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• v.12 no.2
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• pp.77-82
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• 2001

Error characteristics of a mirror loss measurement system using an exponential decay method were studied, with the two samples having about 200-ppm-loss and 30-ppm-loss, respectively. In order to minimize the decay signal deviation from an exponential curve due to cavity length fluctuation, a data average method was tried. The data average method significantly improved the exponential curve fitting error of the decay signal, so that for a 6 decay signal data average the loss measurement error was reduced by about 2.4 times for the 200-ppm-loss mirror and 1.3 times for the 30-ppm-loss mirror compared with a single shot measurement. Day-to-day mirror loss repeatability error for the two samples was investigated. The repeatability error was measured to be about 5% for the 200-ppm-loss mirror and about 26.4% for the 30-ppm-loss mirror. Low decay signal average effect and high repeatability error in the low loss mirror measurement were explained with non-uniform spatial loss distribution of the sample and contamination from the environment, in addition to the error sources of the mirror loss measurement system itself. The influence of cavity length fluctuation and cavity length measurement error on the mirror loss measurement system performance was theoretically calculated. It confirmed that the requirement for the cavity length parameters was not so strict in the mirror loss measurement system of several ppm resolution. ution.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.34-42
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• 1998

This paper describes an analysis of measuring error of on the machine measuring(OMM) system which directly measures machined surface dimensions using scanning probe on a CNC milling machine. 21 inch TV shadow mask mould clamped to a pallet was measured using PTP(point to point) measuring algorithm in OMM system and the results were compared with those using coordinate measuring machine(CMM). The OMM error was evaluated by probe error, stylus contact error, center shift error, repeatability, work-piece clamping error and etc. The results show that elastic deformation of the pallet is most affecting factor on the measuring error, thus pallet design and clamping method need very careful cosiderations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.466-471
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• 1994

To make a dynamic system a given desired motion trajectory, a new feedback error learning scheme is proposed which is based on the repeatability of dynamic system motion. This method is composed of feedforward and feedback control laws. A benefit of this control scheme is that the input pattern that generates the desired motion can be formed without estimating the physical parameters of system dynamics. The numerical simulations show the good performance of the proposed scheme

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.73-77
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• 1997

This paper describes the analysis of measuring error of on the machine measuring(OMM) system which can directly measure the three dimensional machined free surface dimension using scanning probe on milling machine. 21 inch TV shadow mask mould was measured using PTP(point to point)measurement algorithm at pallet clamped and unclamped state on OMM system, and using coordinate measuring machine(CMM) one after another. The OMM system was evaluated probe error, stylus contact error, center shift error, repeatability and so on. Consequencely, the conclusion derived that elastic displacement of pallet had effect on measuring error mainly, and pallet design and setup method would be important.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.1
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• pp.47-53
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• 1988

Daily milk yield estimates were obtained on 74 lactations of 35 Japanese Black cows on weeks 1 to 9, 11, 13, 17, 21 and 26 postpartum using the weigh-suckle-weigh method. The data obtained were analyzed by least-squares procedures according to the models including the following effects; dam, lactation number, season of calving, week of experiment and partial regressions on the lactation number. The overall mean and standard error for daily milk yield was $4.55{\pm}0.04\;kg$. The milk yield declined essentially linearly throughout the experimental period. The main effects of lactation number, season of calving and week of experiment were highly significant. Differences in daily milk yield among cows were significant, and the repeatability was estimated as $0.60{\pm}0.06$. The overall means(kg) and repeat-abilities of cumulative milk yield for 1, 4, 9, 13, 17, 21 and 26 weeks postpartum were 41, 0.08; 166, 0.40; 361, 0.61; 503, 0.66; 632, 0.67; 749, 0.65 and 884, 0.58; respectively. The means of calf weight at birth and 26 weeks weight for different lactations ranged from 25.5 to 33.6 kg and 145.6 to 185.4 kg, respectively. Calf daily gains between experiment weeks were low in earlier stages of lactation.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.293-298
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• 2006

For this study, Clinical evaluation of the diverse Autorefractors was performed to examine validity and repeatability compared with subjective refraction. Measurements of refractive error were performed on 212 eyes of 106 subjects subjectivly noncycloplegic. Intersession repeatability of the Autorefractors were also assessed on all 106 subjects together with intersession repeatability on 7 to 14 days intervals. Spherical powers of subjective refraction and autorefractions by Autorefractors were analyzed by paired T-test.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.60-67
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• 2011

In this paper, the structure of a gravity compensator(GC) was studied, and the 6-axis robot manipulator which is newly developed by applying the GC is presented to improve the torque performance and repeatability error of the robot joint. The kinematics analysis on the robot was presented. Also, experiments of the performance of the joint actuator of robot adopting the gravity compensator were presented by the GC to $1^{st}$ and $2^{nd}$ joints of the robot arm. According to the experiment results, it was validated that the position errors and load torque of the robot joint actuator adopting the GC are reduced significantly.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.389-392
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• 1996

We propose a method to improve repeatability positioning precision of a linear pulse motor. By using this method the systematic error which may make the precision worse can be suppressed easily. And also we show that Power OP-Amp drive system enables the accidental error to be suppressed in comparison with PWM control drive system using IGBT inverter. As a result of the suppression of systematic and accidental error, improved performance of a linear pulse motor with repetitive positioning control is shown by experimental results.