• Proceedings of the KSME Conference
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• 2005.11a
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• pp.161.1-161.1
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• 2005

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.5
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• pp.570-577
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• 2007

A micromachined convective accelerometer is a recently developed device. Typical micromachined accelerometers use a solid proof mass for measuring acceleration. But a micromachined convective accelerometer does not use a solid proof mass. A micromachined convective accelerometer is composed of a heating resistor and temperature sensors. This device measures acceleration by using convective heat transfer phenomenon. Therefore characteristics of a micromachined convective accelerometer are different as compared with typical micromachined accelerometer. In this research, we analyze the convective accelerometer by using transient convective heat transfer analysis. Based on the results of a convective accelerometer, we propose a new model which has improved performance.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.920-926
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• 2007

새로운 매체와 접촉 시 발생하는 거부감을 최소화 하고 별도의 학습 없이 사용 가능한 직관적 명령 전달 방식의 매개 인터페이스를 제안한다. 제안하는 매개 인터페이스는 3차원 공간에서 사용가능한 가상 마우스와 TV 리모트 컨트롤러의 기능적 결합을 목표로 하고 실버세대들에게 익숙한 매체인 펜을 형태로 삼아 개념적으로 설계되었다. 구체적인 구현은 가속도계의 신호를 분석하거나 펜촉에 레이저 포인터를 추가하여 레이저 포인터의 좌표 변화를 웹캠으로 추적, 인식하는 방법으로 구분하였고 본 논문에서는 가속도계의 경우를 소개한다. 가속도계 신호분석을 통해 마우스의 기능을 모사하고 동작을 감지하는데 발생하는 문제점과 이를 해결하기 위한 기존 연구를 분석하고 동작 중에 중력방향의 수직축이 바뀌면서 발생하는 가속도계 신호의 오류를 보상하기 위해 제안된 Zero Velocity Compensation 방법을 소개한다. ZVC의 결과에 필수적인 저주파의 시계열 신호 실시간 끝점 추출과 동시에 패턴인식을 위한 특징추출 기능을 수행하는 새로운 알고리즘을 제안하며 기존의 방법과 실험적으로 성능을 비교한다. 또한 입력된 가속도계 신호를 학습된 인식기를 통해 인식하는 기존의 연구에서 더 나아가, 마우스의 좌표변화를 짧은 시간동안 가속도 신호의 실시간 분석을 통해 모사하기 위해 변형시킨 알고리즘을 소개한다.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.76-78
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• 2007

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1951-1956
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• 2008

Various MEMS accelerometers are used in engineering applications including automobiles, mobile phones, military systems, and electronic devices. Among them, the thermal accelerometer employing the temperature difference induced by the convective flow inside the micro cavity has been a topic of interest. As the convective sensor does not utilize a solid proof mass, it is compact, lightweight, inexpensive to manufacture, sensitive and highly endurable to mechanical shock. However, the complexity of the convective flow and various design constraints make optimization of a device a crucial step before fabrication. In this work, optimization of a 2-axis thermal convective MEMS accelerometer is conducted based on 3-dimensional numerical simulation. Parametric studies are performed by varying the several design variables such as the heater shape/size, the cavity size and types of the gas medium and the position of temperature probes in the sensor. The results of optimal design are presented.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.100-104
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• 2000

This paper deals with finite element analyses of residual stresses causing popping up which are induced in micromachining processes of a mcroaccelerometers. After heating the tunnel gap up to 100 degree and get it through the cooling process and the additional bean up to 80 degree and get is through the cooling process. We learn the thermal internal stress of each shape and compare the results with each other after heating the tunnel gap up to 400 degree during the Pt deposition process. We want to seek after the real cause of this pop up phenomenon and diminish this by change manufacturing processes of microaccelerometer by electrostatic force.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.28-32
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• 1995

Bacause the chatter vibration is a main factor to damage on the quality and integrity, The cure is required peticurity in cykinderical plunge grinding. The chatter vibration relatied with wheel speed, workpiece and infeed rate. Therefore, we expressed more credible normal signal and chatter signal Pattern in accrdiance with wheel speed and acquired RMS signal of the accelerrometer. In thos study, after finding the chatter pattern, we applied two parameters, standard deviation and Kurtosis, to Neural Network.

• Journal of Power System Engineering
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• v.5 no.2
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• pp.36-42
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• 2001

This paper deals with finite element analyses of residual stresses causing popping up which are induced in micromachining processes of a microaccelerometer sensors. The paddle of the micro accelerometer sensor is designed symmetric with respect to the direction of the beam. After heating the tunnel gap up to 100 degree and get it through the cooling process and the additional beam up to 80 degree and get it through the cooling process. We learn the thermal internal stresses of each shape and compare the results with each other, after heating the tunnel gap up to 400 degree during the Pt deposition process. Finally we find the optimal shape which is able to minimize the internal stresses of microaccelerometer sensor. We want to seek after the real cause of this pop up phenomenon and diminish this by change manufacturing processes of microaccelerometer sensor by electrostatic force.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1371-1372
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• 2015

최근 대규모 지진으로 인해 세계적으로 많은 인명 피해와 경제적 손실이 발생 하고 있다. 특히 특고압의 전기를 사용자가 요구하는 저압의 전기로 바꾸는 수배전반이 파손 되는 경우 발생하는 2차 피해는 큰 편이다. 본 논문에서는 수배전반의 지진으로 인한 2차 피해를 줄이기 위해 저가형 가속도 센서를 사용해 자동 복귀형 내진 마운트 시스템을 개발하여 수배전반의 파손으로 인한 피해를 줄이고 기존 면진 마운트 설비의 수명을 늘리고자 한다.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.178-185
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• 2009

A signal processing algorithm is proposed for end point detection which is used commonly in accelerometers-based pattern recognition problem. In the conventional method, end points are detected by manual manipulation with an additive button or algorithm based on statistical computation and highpass filtering to cause critical time delay and difficulty for parameters optimization. As an solution, we propose a focused Time Lagged Feedforward Network(TLFN) with respect to a differential signal of acceleration, which is widely applied for time series forecasting. The simple experiment is conducted with handwriting and the detection performance and response characteristic of the proposed algorithm is tested and analyzed.