• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.455-458
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• 2002

In recent years, precision positioning stage is demanded fur some industrial fields such as semi conductor lithography, ultra precision machining and fabricating of nano structure. In this research, precision multi-axis positioning stage, which consists of pzt actuator, flexure, and capacitance gauge, is designed and developed. The performance of it such as 3-axis positioning, characteristic of motion and resolution is verified.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.214-218
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• 2002

In recent years, precision positioning stage is demanded for some industrial fields such as semi-conductor lithography, ultra precision machining, and fabricating of nano structure. In this research, precision multi-axis positioning stage, which consists of pzt actuator, flexure, and capacitance gauge, is designed and developed. The performance of 3-axis positioning, characteristics of motion and resolution are verified.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.304-307
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• 2004

As optical fiber communication grows, the fiber alignment become the focus of industrial attention. This greatly influence the overall production rates for the opto-electric products. We proposed multi-axis nano positioning stage for optical fiber alignment. This device has 3 DOF translation and sub nanometer resolution. This nano stage consist of 3 PZT-driven flexure stages which are stacked parallel. The displacement of it is measured with capacitance gauge and is controlled by computer-embedded main controller. The design process of flexure stage using FEM is proposed and the performance evaluation of this system is verified with experiments.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.213-218
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• 2004

As optical fiber communication grows, the fiber alignment become the focus of industrial attention. This greatly influence the overall production rates for the opto-electric products. We proposed multi-axis nano positioning stage for optical fiber alignment. This device has 3 DOF translation and sub nanometer resolution. This nano stage consist of 3 PZT-driven flexure stages which are stacked parallel. The displacement of it is measured with capacitance gauge and is controlled by computer-embedded main controller. The design process of flexure stage using FEM is proposed and the performance evaluation of this system is verified with experiments.

• 한국자동차공학회논문집
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• 제25권1호
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• pp.60-65
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• 2017

We designed and fabricated the engine oil monitoring sensor to measure engine oil deterioration through increased vehicle mileage. Since the condition of the engine oil can be affected by the state of the vehicle and its operating conditions, it should be directly measured and determined in every vehicle. The fabricated sensor has an aluminum parallel capacitor structure that measures capacitance related with the dielectric constant, which is one of the indices of oil deterioration. The size of the capacitor is small enough that it could be easily adapted on the oil level gauge without introducing any change in the design. The fabricated device is installed in the diesel engine to measure the change in capacitance accurately as the vehicle moved from 0 km (new engine oil state) to 11,364 km. The results showed the maximum value at around 5,000 km, and the values plateaued as mileage increased, corresponding with the measurement result of the TAN (Total Acid Number). Based on the results, the condition of the oil must be monitored regularly though oil change is recommended once the vehicle has traveled the distance of around 10,000 km.

• 한국진공학회지
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• 제5권3호
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• pp.181-187
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• 1996

The Ultrasonic Interferometer Manometer(UIM) which can calibrae from1 Pa to $10^5$Pa has been developed, and its uncertainty is evaluated less than $\pm$(30ppm of pressure+12mPa). We can calibrate Capacitance Diaphragm Gauge(DCG) used as a transfer standard gauge in the low vacuum field. TheUIM enables to maintain the measurement traceability for industries. In order to improve the UIM's accracy, we will perform the international intercomparison withother national standards laboratories.

• 한국진공학회지
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• 제14권2호
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• pp.59-68
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• 2005

부피가 다른 세 개의 진공용기를 조합하여 정적법 (static expansion method)을 이용한 중진공영역의 국가표준기를 개발하였다. 이 장치를 이용하여 133pa 범위의 용량형 진공게이지 (capacitance diaphragm gauge)를 교정하여 국제표준화기구의 측정불확도 표현지침에 따라 분석하였다. 그 결과 표준압력 0.553Pa에서의 확장불확도 (expanded uncertainty)가 95% 신뢰수준 (confidence level), 포함인자 (coverage factor) k=2에서 $2.628\times10^{-3}Pa$로 우수한 성능을 보였다.

• 한국진공학회지
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• 제10권2호
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• pp.173-181
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• 2001

1,333 Pa 용량의 용량형진공계를 저진공 국가표준기인 초음파간섭 수은주압력계(ultrasonic interferometer manometer)를 이용하여 교정하였다. 이 결과의 불확도를 국제표준화기구의 권고안의 A형 불확도, B형 불확도, 합성표준불확도, 확장불확도 등으로 구분하여 평가하였다. 표준압력 1.76 Pa~1.31$\times$$10^3$Pa에서의 합성표준불확도는 $1.38 \times10^{-2}\; Pa\sim3.03 \times10^{-1} $Pa이었으며, 상대불확도(합성표준불확도/표준압력)는 $2.3 \times 10^{-4}\;Pa\sim7.9 X\times10^{-3} $Pa 이었다.

• 한국진공학회지
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• 제12권3호
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• pp.151-156
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• 2003

저진공 국가표준기인 초음파간섭 수은주압력계를 이용하여 두 개의 용량형 격막식 게이지와 두 개의 공진형 실리콘 게이지를 교정하였다. 용량형 격막식 게이지의 센서부는 금속으로 되어 있으므로 견고하고 과압에 잘 견딜 뿐만 아니라 우수한 분해능을 가지고 있으며, 공진형 실리콘 게이지는 우수한 안정성과 기계적인 충격에 강한 특성을 가지고 있다. 이들의 교정 불확도를 국제표준화기구에서 제정한 측정불확도 표현지침서에 따라 분석하여 비교하였으며, 그 결과 확장불확도의 최대 차이는 교정압력 100 Pa에서 $9\times10^{-3}$Pa 이었다. 또한 공진형 실리콘 게이지의 표준압력에 대한 압력비의 차이가 0.5 % 이내이었으므로 저진공 영역의 전달표준기로 사용이 가능함을 알 수 있었다.

• 동력기계공학회지
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• 제7권2호
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• pp.36-43
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• 2003

In this paper, the strain-gauge type accelerometer is developed. This type of accelerometer has simple structure and cost for manufacturing is cheap, compared with other types of accelerometer such as piezoelectric, capacitance and servo, etc. Also it is very sensitive to the low frequency vibration which is the prominent characteristics of the vibration occurring by vehicles moving across a bridge. Two prototype accelerometers are designed and manufactured based upon the FE(Finite Element) method and static and dynamic calibration tests are performed to check out the linearity, sensitivity and cross sensitivity, etc. Experimental results designate that the proposed accelerometer show reasonable performances compared to the commercial one.