• Smart Structures and Systems
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• 제5권6호
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• pp.663-679
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• 2009

The use of Micro-Electro-Mechanical Systems (MEMS) accelerometers in geotechnical instrumentation is relatively new but on the rise. This paper describes a new MEMS-based system for in situ deformation and vibration monitoring. The system has been developed in an effort to combine recent advances in the miniaturization of sensors and electronics with an established wireless infrastructure for on-line geotechnical monitoring. The concept is based on triaxial MEMS accelerometer measurements of static acceleration (angles relative to gravity) and dynamic accelerations. The dynamic acceleration sensitivity range provides signals proportional to vibration during earthquakes or construction activities. This MEMS-based in-place inclinometer system utilizes the measurements to obtain three-dimensional (3D) ground acceleration and permanent deformation profiles up to a depth of one hundred meters. Each sensor array or group of arrays can be connected to a wireless earth station to enable real-time monitoring as well as remote sensor configuration. This paper provides a technical assessment of MEMS-based in-place inclinometer systems for geotechnical instrumentation applications by reviewing the sensor characteristics and providing small- and full-scale laboratory calibration tests. A description and validation of recorded field data from an instrumented unstable slope in California is also presented.

• 한국의류산업학회지
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• 제24권6호
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• pp.694-706
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• 2022

This study focusses on the development of a motion-sensing smart leggings prototype with the help of a module that monitors motion using a fiber-type stretch sensor. Additionally, it acquires data on Electrocardiogram (ECG), respiration, and body temperature signals, for the development of smart clothing used in online exercise coaching and customized healthcare systems. The research process was conducted in the following order: 1) Fabrication of a fiber-type elastic strain sensor for motion monitoring, 2) Positioning and attaching the sensor, 3) Pattern development and three-dimensional (3D) design, 4) Prototyping 5) Wearability test, and 6) Expert evaluation. The 3D design method was used to develop an aesthetic design, and for sensing accurate signal acquisition functions, wearability tests, and expert evaluation. As a result, first, the selection or manufacturing of an appropriate sensor for the function is of utmost importance. Second, the selection and attachment method of a location that can maximize the function of the sensor without interfering with any activity should be studied. Third, the signal line selection and connection method should be considered, and fourth, the aesthetic design should be reflected along with functional verification. In addition, the selection of an appropriate material is important, and tests for washability and durability must be made. This study presented a manufacturing method to improve the functionality and design of smart clothing, through the process of developing a prototype of motion-sensing smart leggings.

• 한국정보통신학회논문지
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• 제16권6호
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• pp.1279-1284
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• 2012

본 연구는 ASTER영상을 이용한 해안선 변화에 관한 연구이다. ASTER영상은 1999년 12월에 일본에서 발사된 지구탐사위성에 탑재된 센서이다. ASTER 영상은 15m, 30m, 90m의 해상도와 VNIR, TIR, WIR의 3개의 센서를 가지고 있으나 비교적 영상이 저렴하다. 특히 다양한 파장대를 분포하고 있어 기존의 위성영상보다 지구상의 많은 정보의 획득이 가능하다. 해안선은 국지성이 강하므로 지형 형상에 따라서 변화하게 된다. 그리고 해양지리정보구축에서 가장 중요한 요소 중의 하나다. 따라서 본 연구에서는 ASTER 위성영상으로부터 해안선을 Vector Line으로 자동추출 후 변화량을 분석하였다. 연구결과는 향후 해안선 변화를 분석하는데 중요한 기초자료로 활용될 것이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.594-601
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• 1997

Propeller fans are commonly equipped in outdoor units of air-conditioners to provide effective cooling in a dried heat exchanger. A new design technique was developed to satisfy requirements of aerodynamic and aeroacoustic performance, which employs the intersection method of two cylinders for mean camber line. Three proto-types of propeller fan including Palm-Shaped, Highly-Swept(PSHS) fan (proto 3)were not only to provide low lift forces for dipole sound, but also to reduce the organized tip vortices interacting with the fan guide causing narrow-banded rotating instabilities. Cross-correlation technique was applied to study flow noise source characteristics for three proto-type fans designed. The cross-correlations between a microphone at far field and a hot-wire sensor at near field show that flows near hub region of proto 3 fan are less organized and the flow structures especially at high flow rate coefficients for proto 3 fan are less correlated with noise generated than other proto-types fans.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.534-538
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• 2017

There are three types of robots that move on the ground classified as drivetrain. Wheels, tracks and Legs. Wheels and tracks are much easier to construct and control, but they have problems passing through obstacles like people. This paper discusses the design of line tracing using Theo Jansen, one of multi-legged walking mechanism. In order to increase the moving speed, the Jansen mechanism is designed by maximizing the objective variable as GL (Ground Length), GAC (Ground Angle Coefficient). In this project, only three sensors were attached and Arduino was used for optimal control of the motor using the sensor values.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1951-1953
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• 2000

Partial Discharge is non-disruptive discharge, which can be discriminated to 3 kinds as firstly, internal discharge which is caused by internal voids inside of insulator, secondly, surface discharge which occurs from the surface of insulator and finally, corona discharge which is from the surface of an electrode. In this thesis, three kinds of defects are artificially made to the inside and the surface of the epoxy resine busing with internal voltage detection sensor, which is practically equipped into SF6 gas insulated switchgear for 22.9kV distribution line, so that discrimination of three kinds of PD signals by means of phi-q-n pattern analysis method was performed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1233-1235
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• 2000

A new control method of three phase converter without measuring input phase-voltage and DC-link voltage is proposed. Input phase-voltage of these required voltages is estimated using EKF(Extended Kalman Filter) and DC-link voltage is estimated from the measured line currents and the estimated input phase-voltage. This control method is achieved without PLL(Phase Locked Loop) which senses the angle of input phase-voltage and DC-link voltage sensor. In addition, the proposed method controls high power factor and DC-link voltage utilizing the estimated phase angle. This paper describes the effectiveness of the proposed estimated algorithm through simulations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.227-230
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• 2001

A new control method of three phase converter without measuring input Phase-voltage and DC-link voltage is Proposed. Input Phase-voltage of these required voltages is estimated using EKF(Extended Kalman Filter) and DC-link voltage is estimated from the measured line currents and the estimated input phase-voltage. This control method is achieved without PLL(Phase Locked Loop) which senses the angle of input phase-voltage and DC-link voltage sensor. In additon, the proposed method controls high power factor and DC-link voltage utilizing the estimated phase angle. This paper describes the effectiveness of the proposed estimated algorithm through simulations.

• Journal of Korean Neurosurgical Society
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• 제60권4호
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• pp.471-474
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• 2017

Objective : The thromboembolic events during neuroendovascular therapy (NET) are the major complications of concern that can be occasionally fatal. The thrombotic occlusion of the guide catheter for NET is thought to be the risk of the thromboembolic events. We have developed an idea for inventing the monitoring system of the continuous irrigation through the guide catheter. We herein present a unique invention of the guide catheter irrigation monitoring device. Methods : We have developed ideas for preventing the thrombotic occlusion of the guide catheter. In order to design a convenient device working in the practical use, we have consulted and shared the ideas with the electrical engineers about putting the invention. Results : The guide catheter irrigation monitoring device (GCIMD) consisted of three parts of optical sensor, main body and electric adapter. In brief, the basic principles of working of the GCIMD are as follows. The optical sensor is attached to the dripping chamber of the line to irrigation solution. The main body had the small light and speaker to make an alarm sounds. The sensor monitors the dripping of flush solution. If the dripping stops more than three seconds, a warning alarm has been activated. So, the operating physicians can concentrate and check the guide catheter irrigation. After the use of the GCIMD, there was no major thromboembolic complication in conjunction with the thrombotic occlusion of the guide catheter in our institute. Conclusion : We have developed a brilliant invention of the GCIMD for NET.

• 한국재난관리표준학회지
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• 제1권3호
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• pp.77-81
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• 2008

본 논문에서는 기존 광파이버센서가 갖는 문제점을 보완할 수 있는 새로운 형태의 광파이버 센서에 대해 소개한다. 저자 등이 개발한 헤테로코어형 광파이버센서는 비교적 간단하면서도 큰 곡률 반경에 있어서 전달손실이 발생하며 민감한 손실특성을 나타내는 원리를 이용한 것이다. 또한 원리상 온도의존성이 거의 없어 온도보상이 필요 없고, 마크로벤딩에 의한 광량변화를 검출하는 방식이므로 파단우려가 없는 것도 가장 큰 장점 중의 하나이다. 이러한 특징을 갖는 센서에 대한 내환경특성을 분석하고 평가하기 위해, 본 논문에서는 헤테로코어 형 광파이버센서를 이용하여 각종 환경정보를 모니터링하는 광네트워크형 멀티환경 모니터링 시스템을 구성 할 경우 고려해야 할 특성에 대해 검토하였다. 즉, 온도변화에 대한 센싱 시스템의 강인성을 실험을 통해 확인하였다. 이것은 실용적 관점에서 계측시스템 전체의 환경변화에 대한 종합적인 평가를 수행하는 것을 의미하며 그 결과를 본 논문에 소개한다.