• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.11
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• pp.1622-1625
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• 2014

The main measurement uncertainty factors in DC high-voltage dividers for a national high-voltage standard are the measurement uncertainty of low-voltage arm and the stability of a high-voltage supply. In this study, the uncertainties by the two factors are greatly improved. As a result the measurement uncertainty for the DC high-voltage divider is reduced from $16{\times}10^{-6}(k=2)$ to $8{\times}10^{-6}(k=2)$ which is at international level.

• Journal of Astronomy and Space Sciences
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• v.9 no.2
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• pp.193-202
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• 1992

The fist sounding rocket in Korea, KSR-420S has been under the development at Korea Aerospace Research Institute (KARI), and is expected to be launched in 1993 to measure the vertical ozone profile over the Korean Peninsula. The KSR-420S is expected to provide the fist in situ measurement of ozone concentrations over the Korean Peninsula. An optical ozone detector has been developed at Korea Research Institute of Standards and Science (KRISS), and its calibration has been completed recently. In this paper, measurement principles of the ozone detector in KSR-420S, its calibration data, ozone measurement procedure and data reduction algorithm are presented with sample calculations.

• Journal of Sensor Science and Technology
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• v.18 no.2
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• pp.103-109
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• 2009

Thermal time constant measurement system was designed and fabricated to measure the thermal time constant, which shows a dynamic property of the thermocouple. Type K thermocouple samples were fabricated with variable shape each other and the thermal time constants of thermocouples were measured using the home-made thermal time constant measurement system. Thermal time constants of 12 type K thermocouple samples were distributed from 0.03 s to 8.2 s. It showed experimentally that the thermal time constant of thermocouple was increased linearly for the increase of the sheath diameter of thermocouple.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.671-672
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• 2006

We have investigated the behavior of the ultrafast laser ablation of chromium films (200nm) on the silicon and pyrex-glass(corning 7740) substrate with respect to the laser fluence and the number of laser pulses. In addition, several experiments about ITO thin film were carried out with femto-second Ti:Sapphire laser (150fs). Finally, we introduce the ablation characteristic in accordance with materials of thin film and substrate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.503-504
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• 2006

Determination of elastic properties of nano-scale materials using nano-indentation tests is well established, but that of plastic properties is not yet clear. This paper presents a method to extract plastic properties from nano-indentation test, together with results from detailed elastic-plastic FE analysis. It shows that the plastic properties determined from this method are not unique, in the sense that a number of different plastic properties can give the same load-displacement response from nano-indentation test. possible ways to overcome such problems are discussed.

• Progress in Superconductivity
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• v.4 no.1
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• pp.80-85
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• 2002

In order to disseminate the IEC international standard of RRR measurement of Cu／Nb／-Ti composite superconductors, a measuring system was developed at KRISS. The system consisted of helium reservoir, base plate, thermometer, voltmeter and current source. The helium reservoir and base plate provided a stable temperature of a range from 4.2 K to 300 K and the voltmeter measured several order of $mutextrm{V}$ on specimen for obtaining RRR of the Cu／Nb-Ti composite superconductor. Three specimens of the Cu／Nb-Ti composite superconductors were measured using this system for characterizing their RRR. The resistance-temperature curves ortho specimens showed 10／sup -6／ to 10／sup -5／ Ohms near transition temperature and 10／sup -4／ to 10／sup -3／ Ohms at 293 K. The RRR values of the specimens were 145, 71 and 140, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.143-143
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• 2011

발표자는 본 발표를 통해 현재 표준연구원에서 진행되고 있는 플라즈마 연구들 간단히 소개하는 시간을 가질까 한다. 표준연구원/진공센터내의 플라즈마팀은 진공기반구축사업,반도체진공공정실시간측정기술개발 사업등의 후원을 받아 지난 10년각 국내 최대의 플라즈마 연구 인프라를 갖추는데 성공하였으며 이를 바탕으로 해외 우주기관과 견줄만한 플라즈마 발생장치, 진단장치, 전산모사시스템 등을 확보한 상태이다. 본발표를 통해 그간 표준연구원에서 진행하고 있는 플라즈마 진단시스템, 모니터링 시스템, 플라즈마원개발, 시뮬레이션 연구, 공정해석 연구등을 간략하게 소개드릴려고 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.151-151
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• 2011

Atmospheric-pressure plasmas are used in a variety of materials processes. The lifetime of most atmospheric-pressure plasma sources is limits by electrode erosion due to energetic ion bombardment. These drawbacks were solved recently by several microplasma sources based on microstrip structure, which are more efficient and less prone to perturbations than other microplasma sources. In this work, we propose microplasma sources based on strip line and microstrip line, developed for the generation of microplasmas even in atmospheric air and analyzes these systems with microwave field simulation via comparative study with two previous microwave sources (Microstrip Spit Ring Resonator (MSRR), Microstrip Structure Source (MSS)).

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.144-144
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• 2011

Diagnostics of plasma density and temperature play an important role for monitoring plasma processing and Laser Thomson scattering is a one of the most accurate diagnostic technique for measuring plasma density and temperature because of none-perturbation to plasma among various diagnostic techniques invented to measure plasma density and temperature. I will briefly review Laser Thomson scattering experiment performed in KRISS and difficulties for measuring the electron velocity distribution such as Gaussian due to low signal-to-noise ratio with showing results that we got until now. This work is an intermediate step in a process that we will get a reliable data which shows physical phenomenon of plasma compared with other diagnostic techniques and results.

• The KSFM Journal of Fluid Machinery
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• v.7 no.1 s.22
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• pp.24-29
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• 2004

The inter-comparison of standards is required to be recognized the calibration results. The sonic nozzle package is developed to do inter-comparison of the bell preyer used to calibrate many gas flow meters for industries. Four national metrology institutes (KRISS, CMS, CENAM, NEL) were participated in this inter-comparison. The deviation of calibration data from the average value was small at the low flow rate and large at the high flow rate, respectively At the high flow rate, the deviation was larger than the expected value from uncertainties asserted by NMIs. This means there are some problems in the uncertainty evaluation and experiment procedures in some of the participated NMIs.