• 한국공간구조학회논문집
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• 제17권4호
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• pp.93-102
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• 2017

Wireless MEMS sensors have common features such as wireless communication, data measurement, embedded processing, battery-based self-power, and low cost, and increased measurement effectiveness. Wireless MEMS sensors enable efficient SHM without interfering with location because there is no requirement for triboelectric noise and cumbersome cables. However, there is little research on the communication distance with sensors and data. For instance, existing researches have limited communication distance experiments in civil engineering bridges. It is also necessary to investigate the characteristics of dynamic behavior and the communication distance of architectural structures with different wireless transmission/reception environments. Therefore, in a building structure with walls and slabs instead of open spaces, MEMS sensors and data loggers were used as distance experiments where communication disturbance between the vertical slab and the horizontal wall could actually be communicated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1503_1504
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• 2009

MEMS 구조물은 ${\mu}m$단위의 크기로 만들어지므로 각속도계와 같이 정밀한 센서를 만들 때에는 노이즈 문제를 해결하지 않으면 신호를 측정할 수가 없다. MEMS 구조물의 미세한 진동에 의해 발생되는 수 pico-coulomb의 전하를 측정해야하므로 구동 신호가 검출 전극에서 Feed-through되어 나타나는 경우 그 크기가 구동에 의한 신호보다 100배 이상 크기 때문에 원하는 신호를 검출할 수 없다. 본 논문에서는 이러한 Feed-through 현상에 의한 노이즈를 줄이기 위하여 Guard-ring을 이용한 blocking 방법과 dummy port를 이용한 canceling 방법을 고안하고 Feed-through reduction 회로를 설계, 제작, 실험하여 그 효과를 확인하였다. 그 결과 구동신호가 6Vpp, 30kHz일 때, -53.186dBm이었던 Feed-through 신호가 -77.107dBm으로 줄어드는 것을 확인하였다. 또한 노이즈를 제거하지 않은 경우 측정할 수 없었던 Q-factor를 Feed-through reduction 회로를 사용하여 측정한 결과 진공 패키징된 Si 기반 자이로스코프가 공진주파수 약 7.018kHz에서 Q-factor가 약 2500임을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1427-1428
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• 2015

MEMS(Micro Electro-mechanical System) are getting attention as promising industry in the 21st century. Car air bags, acceleration sensors, and medical, information appliances are being actively applied in MEMS. This paper suggest the electrical electrodes of brain signal applied MEMS model and the prototype design for EEG signal amplification circuit. Also, we suggest an independent BCI(Brain Computer Interface) system with brain electrical signal of electrode models and wireless communication platform.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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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.

• 한국공간구조학회논문집
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• 제18권2호
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• pp.51-58
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• 2018

Recently, measuring instruments for SHM of structures had being developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to its absence of triboelectric noise and elimination of the requirement for cumbersome cable. However, the research on the tall buildings with relatively small vibration levels is insufficient. Therefore, in this paper, we used the wireless MEMS sensor and iPad to compare and analyze the vibration measurements of three tall buildings and two towers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.360-361
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• 2006

This paper describes a wire and wireless network sensor for temperature and humidity measurements. The network sensor comprises PLC(Power Line Communication) and RF transmitter(433MHz) for acquiring an internal (on-board) sensor signal, and measured data is transmitted to a main processing unit. The network sensor module is consist of MEMS sensor, 10-bit A/D converter, pre-amp., gain-amp., ADUC812 one chip processor and PLC/RF transmitting unit. The temperature and humidity sensor is based on MEMS piezoelectric membrane structure and is implemented by using dual function sensor for smart home and smart building.

• 한국공간구조학회논문집
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• 제19권1호
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• pp.101-108
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• 2019

Recently, measuring instruments for SHM of structures has been developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to the absence of triboelectric noise and elimination of the requirement of a cumbersome cable. However, the low-cost wireless MEMS sensor has high noise density and transmits the signal wirelessly, so data transmission delay occurs during measurement. Therefore, the footbridges that was previously measured by a mobile phone in 2014 was remeasured using G-Link-200, iPad and iPhone to compare their performance.

• 전자공학회지
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• 제31권1호
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• pp.28-37
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• 2004

• E2M - 전기 전자와 첨단 소재
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• 제21권8호
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• pp.11-17
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• 2008

• 기계저널
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• 제41권12호
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• pp.49-59
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• 2001