• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.421-431
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• 2007

The purpose of this study was to examine the characteristics of observation and measurement inquiry process in the Korean science textbooks. For the inquiry process of observation, the higher grade textbooks contained more 'comparative observation' rather than 'simple observation'. Students should express their observation results in written words rather than verbal descriptions in the higher grade. For the inquiry process of measurement, the temperature measurement was the most frequent measurement activity. 'Measurement design' was found more frequently in the lower grade textbooks. The uses of measurement tools were not presented systematically and were presented restrictively when the relevant experiment wanted to use these tools. The higher grade textbooks include 'quantitative measurements' rather than 'qualitative measurements' and 'operation measurement' rather than 'simple measurement'. In the application of measurement results, we had difficulty in finding the activities related with the usage of unit, unit conversion, significant figure, error and uncertainty.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.111-116
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• 2009

Process capability indices have been widely used in manufacturing industries to provide a quantitative measure of process performance. PCIs have been developed to represent process capability more exactly. In the previous studies, only one designated location on each part has been measured. But multiple measurement locations on each part are required to calculate the reliable process capability. In this paper, we propose a new process capability index dealing the multiple measurement locations on each part. Also we showed the relationship between the new index and sigma level according to the number of measurement locations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.129-135
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• 2012

Companies strive for quality improvement and use process data obtained through measurement process to monitor and control the process. Measurement data contain variation due to error of operator and instrument. The total variation is sum of product variation and measurement variation. Gage R&R is for repeatability and reproducibility of measurement system. Gage R&R study is usually conducted to analyze the measurement process. In performing the gage R&R study, several parameters such as the appropriate number of operators (o), sample size of parts (p), and replicate (r) are used. In this paper we propose how to determine the optimal combination of number of operators (o), sample size of parts (p), and replicates (r) considering measurement time and cost by statistical method.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.36-43
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• 2004

In-line measurement systems are preferred to those in analytical laboratories, since in-line systems provide rapid response to process upsets. If an in-line measurement system exhibits an unstable variation and if this instability in measurement variation goes undetected, it will make the process monitoring procedure invalid. This paper presents a stability evaluation procedure for the in-line measurement system using two independent readings from the in-line measurement system and one reading from the analytical laboratory, which requires less measurement cost and time.

• Knowledge Management Research
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• v.3 no.1
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• pp.41-60
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• 2002

This paper defines measurement index items and weight of the index for the purpose of developing a performance measurement index that balancedly measures performance of B2B electronic commerce. The deductive research is used for the development of measurement index items and Analytic Hierarchy Process(AHP) method for the development of weight of the index. This paper has four performance measurement perspectives-finance, partners, business process and human resources, which based the existing researches of balanced performance measurement. This researchers developed eleven second level criteria and twenty-six indexes under four perspectives through the deductive method and expert interviews, weighted on the perspectives, criteria and indexes in accordance with the forms of e-marketplace-vertical and horizontal. As a result, the most important indexes are the maintenance of partners and the efficiency of operation process in the vertical e-marketplace. In the horizontal e-marketplace, the collection of partners, development and prediction processes are more important than other indexes.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.117-126
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• 2009

We develop methods for propagating and analyzing EPCI(Extended Process Capability Index) by using the error type that classifies into accuracy and precision. EPCI developed in this study can be applied to the three combined processes that consist of production, measurement and calibration. Little calibration work discusses while a great deal has been studied about SPC(Statistical Process Contol) and MSA(Measurement System Analysis). EPCI can be decomposed into three indexes such as PPCI(Production Process Capability Index), PPPI(Production Process Performance Index), MPCI(Measurement PCD, and CPCI(Calibration PCI). These indexs based on the type of error classification can be used with various statistical techniques and principles such as SPC control charts, ANOVA(Analysis of Variance), MSA Gage R&R, Additivity-of-Variance, and RSSM(Root Sum of Square Method). As the method proposed is simple, any engineer in charge of SPC. MSA and calibration can use efficientily in industries. Numerical examples are presentsed. We recommed that the indexes can be used in conjunction with evaluation criteria.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.252-257
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• 1991

This paper proposed that the eddy-current measurement method can be used a means of in-process measuring the hardening depth in Laser surface treatment process. Also, this paper deal with the numerical analysis of magnetic flux distribution and experimental result of measurement. In Laser heat treatment process of steels, a thin layer of the substrate is rapidly heated to austenitizing temperature and subsequently cooled at a very fast rate due to the self-quenching by heat conduction into the bulk body, to produce a martensite structure which have low magnetic permeability. The eddy-current measurement method depends on the properties of material to be measured such as electric conductivity, magnetic permeability and geometry. In this paper, the hardening depth was measured by detecting relevant magnetic permeability changes caused by heat treatment of steels.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.607-612
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• 2000

Roundness measurement method using three displacement sensors makes in-process roundness measurement possible on the NC machine because it eliminates the vibration signal and eccentricity signal from measured roundness signal from the workpiece. But if measured signals contain noises, high precision measurement of the roundness isn't possible. In this study, a high precision in-process roundness measurement system is developed, which applies a Kalman filter to the roundness measurement method using three displacement sensors and can be used to measure vibration of the spindle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.28-34
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• 2014

A non-contact type measurement system is specially devised to measure the width of a piston ring groove in the grinding process. This system comprises a line camera with an imaging lens, collimated white light source, and a one axis translation stage. When the measurement system movesalong the diagonal direction of the cylinder, the line camera captures an image. By analyzing such images, the width of the piston ring groove can be determined. The experimental results prove that the proposed system is useful, especially as a monitoring system in grinding piston ring grooves on cylinders with accuracy of several micrometers in an area of dozens of millimeters.

• Design & Manufacturing
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• v.16 no.1
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• pp.21-26
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• 2022

In the CNC machining process, problems such as lowering of machine operation rate, setting errors, and machining precision occur due to the increase in setting time and preparation time. These machining errors cause delays in delivery and increase in cost due to an increase in the number of mounting and dismounting of the workpiece, an increase in measurement and reprocessing time, and an increase in the finishing time in the assembly process. Therefore, in this study, by automating the setting of the work piece using OMV (On Machine Verification), which is a meteorological measurement system, the preparation time for machining the work piece and the setting accuracy were improved, the rework rate was reduced, and the mold manufacturing process was shortened. Through the advancement, standardzation, and automation of the mold part manufacturing process, we have improved productivity by minimizing low-value-added repetitive tasks. In addition, the measurement time was reduced by more than 50% and the machining measurement rate was improved by more than 20%, eliminating repetitive work for correcting machining defects, and reducing the work preparation time by more than 15% through automatic setting.