• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.137-142
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• 1996

Magnetic-electrolytic-abrasive polishing system(MEAPS) was developed for machining national standard electrode and its finishing characteristics was analyzed. The paper describes the operational principle of MEAP system by experimental results. The finishing characteristics and optimal finishing condition for national standard electrodes were experimented and analyzed. As a result, MEAPS can improve straightness as well as surface roughness.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.475-478
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• 1992

Series of study were conducted to investigated the condition of wet polishing and quality of wet polished rice. The optimal condition for wet polishing was determined to be 0.5% added water after removal bran layer of 95% by normal milling. Its polishing yield was 0.75% lower than normal polishing, and the moisture content of wet and normal polished rice was the same, but the whiteness of wet polished rice was higher by 3.5% than that of normal polished rice and the lightness was very good. The total solid as washing wet polished rice in water and the total solid in residual liquid of cooked wet polished rice was about 0.30 and 2% lower than those of normal polished rice, respectively. The storability of wet polished rice was better than that of normal polished rice.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.468-472
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• 2005

This paper is to investigate the influence of the endface quality on the loss characteristics of a plastic optical fiber connector for in-car network service. Using the parameters of the surface roughness and applied load, insertion loss of connector is measured. Due to scattering and change of refractive index, an optimal condition for low-loss coupling exists. We present the optimal condition as surface roughness $R_{rms}$ = 8 nm and contact load up to 50 N.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.157-165
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• 1999

Production and measurement of a super-polished few-ppm-scattering mirror substrate are investigated. In order to improve the surface roughness directly determining scattering, the super-polishing process using Bowl-Feed technique is tried. The surface quality of the super-polished substrate is estimated by the phase-measuring interferometer. For the reliable roughness measurement using the interferometer, data averaging method is applied so that the optimal data averaging condition, 30 phase-data averaging and 20 intensity-data averaging, minimizing the measurement error is experimently searched. Based on the optimal data averaging condition, surface roughness of home-made mirror substrate is measured to be less than $0.5{\AA}$ rms corresponding to 2-ppm total-integrated-scattering.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.3
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• pp.31-38
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• 1995

Magnetic-electrolytic-abrasive polishing(MEAP) system was newly developed and the finishing characteristics of Cr-coated roller was analyzed. The paper describes the operational principle of MEAP system and magnetic field effect on the MEAP process by experimental results. The finishing characteristics and optimal finishing condition for Cr-coated roller was experimented and analyzed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.4
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• pp.131-134
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• 2016

The conditions for chemical polishing and etching technique were investigated to reveal surface defects in RE : YAG ($RE=Nd^{3+},\;Er^{3+},\;Yb^{3+}$) single crystals grown by Czochralski method. The optimal condition for chemical polishing was in 85 % $H_3PO_4$ solution at $330^{\circ}C$ for 30 minutes with a specimen fixed in the vertical direction. In addition, the optimal condition for chemical etching was in 85 % $H_3PO_4$ solution at $260^{\circ}C$ for 1 hour, and $70{\sim}80{\mu}m$ sized triangular etch pits were observed on (111) face. As a result of defect density analysis, $1.9{\times}10^3/cm^2$ for Nd(1 %) : YAG, $4.3{\times}10^2/cm^2$ for Er(7.3 %) : YAG, and $5.1{\times}10^2/cm^2$ for Yb(15 %) : YAG were measured.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.10a
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• pp.82-85
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• 1995

Magnetic-electrolytic-abrasive polishign(MEAP) systemwas newly developed and the finishing characteristics of Cr-coated roller was analyzed. The paper describes the operational principle of MEAP system and magnetic field effect on the MEAP process by experimental results. The finishing characteristics and optimal finishing condition for Cr-coated roller were experimented and analyzed.

• Journal of Korean Society for Quality Management
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• v.42 no.3
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• pp.325-338
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• 2014

Purpose: The purpose of this study was to explain de-painting phenomenon of KUH-1 tail blade and to propose useful solution of it by test. The proposed solution was evaluated by real flight, and then it applied to mass product to improve the paint qual ity of KUH-1 tail blade. Methods: This study investigated an adhesive ability of primer following surface sanding condition. The cross cut and scratch test were conducted to evaluate the adhesive strength. And the water flow test was designed to simulate a real flight condition under rain. Through water flow test, an optimal condition of tail blade to prevent a de-painting phenomenon was deduced. Finally, the improvement method was evaluated by real flight under rain. Results: The results of this study are as follows; The sequential polishing was most excellent method in primer painting quality. The results of test including cross cut, scratch and water flow showed that MIL-DTL-53039 paint with epoxy primer has excellent adhesive ability. To proof the effect of improvement, a real flight during a rain condition was conducted. Finally, the comparison between original and improved configuration was conducted. Conclusion: The painting quality of KUH-1 tail blade was improved through deriving an optimal painting condition. In detail, a condition of optimal sanding and a sort of primer and paint was showed. Finally, the reliability of tail blade was guaranteed through improving the quality of painting.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.61-68
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• 2006

This paper is to investigate the influence of the endface quality on the loss characteristics of a plastic optical fiber(POF) connector and the stability of new designed sleeve for in-car network service. Using the parameters of the surface roughness and applied load, insertion loss of connector is measured. Endface condition for optimizing the connection is presented by the surface roughness satisfying loss criteria and the stress for minimizing the loss, $R_{rms}=8nm$ and 19 MPa, respectively. By vibration test and dynamic loss measurement, we show the stability of the new designed sleeve.

• Corrosion Science and Technology
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• v.22 no.6
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• pp.457-465
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• 2023

Irradiation-assisted stress corrosion cracking (IASCC) is one of the main degradation mechanisms of austenitic stainless steels, which are used as reactor internal materials. Slow strain rate testing (SSRT) has been widely applied to evaluate the IASCC initiation characteristics of proton-irradiated tensile specimens. Tensile specimens require low surface roughness for micro-crack observation, and electropolishing is the most important specimen pre-treatment process used for this. In this study, optimal electropolishing conditions were examined through analyzing results of polarization experiments and surface roughness measurements after electropolishing. Corrosion cell and electropolishing equipment were fabricated for polarization tests and electropolishing experiments using SSRT specimens. The experimental parameters were electropolishing time, current density, electrolyte temperature, and stirring speed. The optimal electropolishing conditions for SSRT tensile specimens made of type 316 stainless steel were evaluated as a polishing time of 180 seconds, a current density of 0.15 A/cm², an electrolyte temperature of 60 ℃, and a stirring speed of 200 RPM.