• Smart Structures and Systems
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• v.5 no.6
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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.

• Fashion & Textile Research Journal
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• v.24 no.6
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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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1279-1284
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• 2012

This study is about the change of coastline through using ASTER images. ASTER image is a sensor loaded in earth resources satellite shoot in Japan on Dec. 1999. It has 15m, 30m, 90m coastline, three sensors of VNIR, TIR and WIR, therefore it's possible to obtain more information on the Earth than the existing satellite images cause it contains various a wavelength range in spite of relatively economic image. The coastline is changed according to topography shape because it's strongly localized. Besides, it's one of the most important factors in MGIS(Marine Geographic Information System). Therefore, this study is accomplished by analysing variation after abstraction the coastline automatically by Vector Line from ASTER satellite images. The study result will be used as an important basic data when analysis the change of e coastline hereafter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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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.

• Proceeding of EDISON Challenge
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• 2017.03a
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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.

• Proceedings of the KIEE Conference
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• 2000.07c
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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.

• Proceedings of the KIEE Conference
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• 2000.07b
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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.

• Proceedings of the KIPE Conference
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• 2001.07a
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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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• v.60 no.4
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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.

• Journal of Korean Society of societal Security
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• v.1 no.3
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• pp.77-81
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• 2008

In this paper, we introduce a multi purpose environmental monitoring system developed as a commercially available standard using the technique of hetero-core spliced fiber optic sensor. The monitoring system has been tested and evaluated in a possible outdoor condition in view of the full scaled operation at actual sites to be monitored. Additionally, the developed system in this work conveniently provides us with various options of sensor modules intended for monitoring such physical quantities as displacement, distortion, pressure, binary states, and liquid adhesion. Two channels of optical fiber line were monitored, in each of which three displacement sensor modules were connected in series, in order to examine the performance to a pseudo-cracking experiment in the outdoor situation, and to clarify temperature influences to the system in terms of the coupling of optical connectors and the OTDR stability. The pseudo-cracking experiment successfully observed the actually given cracks by means of calculation based on the detected displacement values and their geometrical arrangement of the used sensor modules. And the robustness to the temperature is verified in the various temperature change.