• 한국소음진동공학회논문집
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• 제20권11호
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• pp.1033-1037
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• 2010

Accelerometer and laser vibrometers are widely used to measure vibration of structures like a building or piping. Recently, the research measuring vibration by using camera image is introduced. This method can measure multi-points simultaneously. Also, it is possible to measure in the long distance. When we measure the vibration using a camera, the parameter analysis is needed. Therefore, this paper took the experiment for the camera lens selection. An error by the camera images characteristic was theoretically analyzed and we verified through an experiment. And the accuracy of the method measuring the vibration displacement by using the camera images was analyzed.

• Journal of Welding and Joining
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• 제29권2호
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• pp.94-101
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• 2011

A lumped mass damped vibratory model was proposed for quantitative understanding of welding machine characteristics. An experimental setup was developed to determine the mechanical parameters (moving mass m, equivalent stiffness k and damping c) which govern the dynamic mechanical response of the resistance spot welding machine. During the test, acceleration of the electrodes for each level of applied load was measured by accelerometer, filtered and numerically integrated to find the corresponding velocity and displacement. The machine dynamic parameters were determined by finding the unknowns of the proposed model with experimental data. A Simulink model was proposed to investigate the influence of these mechanical parameters on the welding process. The electrode response was simulated by changing values of stiffness and damping. It was observed that both of the machine parameters(c, k) have significant effect on the response of electrode head.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.893-898
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• 2003

A new type of the Expanded Knee brace was developed to measure the human knee joint. This instrument was composed of six parts, four arranged for two hinge joints and two pin joint , and two hinge for the expanded system. With a developed instrument, the experimental results obtained the data of Accelerometer, the experimental results obtained of the data FEM, the experimental results obtained the data of Motion Analysis and Force platform. Compared to earlier developed sports type knee brace, new instrument shows its convenience in application and accuracy in measurement.

• Journal of Advanced Marine Engineering and Technology
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• 제33권6호
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• pp.903-911
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• 2009

During the past three or four decades, the characteristics of turbulent swirling flow have been studied extensively because of their scientific and academic importance. This research deal with the periodic flow oscillation with and without swirling flow in a 180 degree circular tube using hot wire anemometry, microphone and accelerometer. The frequency regions are observed through the structured oscillation from spectrum. This work carried out to measure the sound level by using hot wire anemometry, microphone and accelerometer for each Reynolds number, $6{\times}10^4$, $8{\times}10^4$ and $1{\times}10^5$ respectively at the entry of the test tube with and without swirl flow.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1073-1077
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• 2001

The objective of this paper is to apply an experimental method based on the principle of reciprocity to measuring the structural intensity. Since only one accelerometer is used in this method it has the advantages of shortening measurement time. reducing accelerometer phase error. overcoming the limitation that the situation should be stationary during the experiment. It has been used to measure the vibration intensity of an infinite beam (beam with damped ends) and a semi-infinite beam (beam with simply supported and damped ends). Results showed that the experiment method based on the principle of reciprocity can be effectively used to measure the structural intensity.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.1726-1728
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• 2015

최근 IT 발전이 급격한 상승세를 이루면서 사용자와 터치스크린을 통해 상호작용하는 다양한 스마트폰이 등장하였다. 스마트폰 사용자들이 기본적으로 사용하는 다양한 입력 스킴은 습득 지연 시간 및 오타가 빈번하게 나타나고 있다. 또한, 손가락 위주로 문자를 입력하는 터치스크린 기반의 스마트폰은 손가락을 자유롭게 사용하지 못하는 사용자들에게 도움이 되지 않는다. 따라서 가속도 센서와 자이로 센서를 이용하여 손가락이 불편한 사용자도 쉽게 문자를 작성하듯 입력이 가능한 효율적인 문자 입력 키패드인 MISGA (Message Input Scheme using Gyro-Accelerometer sensor)를 제안한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.475-478
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• 2004

In this paper, a magnet-type automatic pipe cutting machine that binds itself to the surface of the pipe using magnetic force and executes unmanned cutting process is proposed. During pipe cutting process when the machine moves around the pipe laid vertical to the gravitational field, the gravity acting on the pipe cutting machine widely varies as the position of the machine varies. That is, with same driving force from the driving motor the cutting machine moves faster when it climbs down the surface of the pipe and moves slower when it climbs up to the top of the pipe. To maintain a constant velocity of the pipe cutting machine and improve the cutting quality, the authors adopted a conventional PID controller with a feedforward effort designed based on the encoder measurement of the driving motor. It is, however, impossible for the encoder at the motor to measure the absolute position and consequently the absolute velocity of the cutting machine in the case where the slip between the surface of the pipe and wheel of the cutting machine is not negligible. As an attempt to obtain a better estimation of the absolution angular position/velocity of the machine the authors proposes the use of the MEMS-type accelerometer which can measure static acceleration as well as dynamic acceleration. The estimated angular velocity of the cutting machine using the MEMS-type accelerometer measurement is experimentally obtained and it indicates the significant slipping of the machine during the cutting process.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.243-247
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• 2007

가상현실을 구축하는데 있어서 사용자 인터페이스는 몰입감을 증대시키기 위한 중요한 요소 중 하나이다. 하드웨어 성능의 향상으로 가상현실 시스템이 게임, 방송, 교육, 문화 콘텐츠 등에 대중적으로 널리 활용되면서, 사용자의 자유로운 움직임을 보장하면서 가상현실을 제어할 수 있는 무선 인터페이스에 대한 연구의 필요성이 증대되고 있다. 본 논문에서는 가상현실과 상호작용을 위해 지그비(Zigbee)와 가속도 센서(Accelerometer)로 구성된 ZA센서를 개발하고, ZA센서와 무선통신 모듈로 가상현실 시스템과 통신을 하면서 상호작용하는 가상현실 시스템의 구축 방안을 제안한다. 또한 센서의 움직임에 따른 가상환경 제어 응용을 구현함으로써 개발된 시스템의 활용방안을 제시한다.

• 한국전자통신학회논문지
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• 제15권3호
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• pp.603-610
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• 2020

본 논문에서는 수면하는 동안 신체 움직임을 감지하여 수면의 질을 측정하기 위한 스마트 베개를 제안한다. 제안된 스마트 베개는 9개의 가속도 센서를 내장하여 수면하는 동안 머리 또는 몸의 움직임을 감지할 수 있다. 스마트 베개의 효용성을 알아보기 위해서 총 7명의 사용자를 선발하여 5일 동안 개발된 수면 베개를 사용하도록 하고 이들의 수면 모습을 카메라로 녹화하는 한편 설문 조사를 실시하였다. 스피어만 상관관계를 이용하여 수면 중 분당 신체 움직임과 수면품질의 상관관계를 분석한 결과 수면 중 분당 신체 움직임이 많을수록 수면의 질이 저하되는 것을 확인할 수 있었다. 본 논문의 결과는 향후 수면 장애를 신속히 진단하여 치료하는데 활용될 수 있다.

• 대한의용생체공학회:의공학회지
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• 제30권3호
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• pp.213-220
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• 2009

In this study, we have developed a novel step detection algorithm for gait evaluation of patients with hemiplegia based on trunk accelerometry device. For this, we have used a bandpass filter and a least square acceleration (LSA) filter which is characterized by emphasizing the peak or valley point of the acceleration signals for each 3-axis accelerometer signals. To evaluate the algorithm, the detected steps by developed algorithm and real steps by the motion analysis system were compared. As a result, we could obtain the sensitivity of 96.44%, the specificity of 99.94% and the accuracy of 99.90% for the patients' data sets and the sensitivity of 100%, the specificity of 99.93% and the accuracy of 99.93% for the normal data sets. In conclusion, the developed algorithm is useful for the step detection for patients with hemiplegia as well as normal subjects.