• 한국멀티미디어학회논문지
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• 제18권5호
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• pp.652-662
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• 2015

It is necessary to develop small, implantable bio-telemetry systems which can measure and transmit patients' bio-signals from internal body to external receiver. When measuring bio-signals, like electrical bio-signals, acoustic bio-signal measurement has also a big clinical usefulness. But, sound signal has larger frequency bandwidth than any other bio-signals. When considering these issues, a wireless telemetry system which has rapid data transmission rate proportional to wide frequency bandwidth is necessary to be developed. The bluetooth module is used to overcome the data rate limitation caused by the large frequency bandwidth. In this paper, a novel multimedia bluetooth biotelemetry system was developed which consists of transmitter module located in the body and receiver device located outside of the body. The transmitter consists of microphone, bluetooth, and wireless charging device. And the receiver consists of bluetooth and codec system. The sound inside the skin is captured by microphone and sent to receiver by bluetooth while charging. The wireless charging system constantly supplies the electric power to the system. To verify the performance of the developed system, an in vitro experiment has been performed. The results show that the proposed biotelemetry system has ability to acquire the sound signals under the skin.

• 감성과학
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• 제11권3호
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• pp.419-426
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• 2008

In order to develop "textile electrode - sensing clothing" which is a sort of smart clothing to measure electric activities of heart, we propose possible ways to develop textile electrode and design of sensing clothing, ultimately aiming to develop "ECG sensing clothing for lifestyle monitoring". Conventional sensors for measuring typical electric activities of heart keep certain distance between measuring electrodes to measure signals for electric activities of heart, but these sensors often cause inappropriate factors (e.g. motional artifacts, inconvenience of use, etc) for monitoring natural cardiac activities in our daily life. In addition, most of textile electrodes have made it difficult to collect data due to high impedance and unstable contact between skin and electrodes. To overcome these questions, we minimized distance between electrodes and skin to maximize convenience of use. And in order to complement contact between skin electrodes, we modified textile electrode's form and developed ways to design clothing. As a result, we could find out clinical significance by investigating possible associations of clinical electrocardiogram (ECG) with variation of distance between electrodes, and could also demonstrate clinically significant associations between textile electrode developed herein and clothing.

• 컴퓨터교육학회논문지
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• 제10권6호
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• pp.69-77
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• 2007

본 논문에서는 가상실험실 설계에 필수적인 전자계측장비의 주요기능을 자바애플릿을 이용하여 소프트웨어적으로 구현하였다. 구현된 가상전자계측장비는 가상아나로그 멀티미터, 가상신호발생기, 가상오실로스코프이며, 웹상에서 학습자가 간단한 마우스조작을 통해 가상실험이 가능하도록 하였다. 또한, 구현된 가상전자계측장비의 유효성을 입증하기 위해 주로 전자계측장비의 사용법에 대한 이해를 돕는 가상실험을 구성하였다. 가상아나로그 멀티미터는 OHM, ACV, DCV, DCA를 측정할 수 있는 4가지 실험이 구축되어 있고, 가상신호발생기의 경우 신호발생기에서 주로 다루는 주파수 값을 변화시키거나 삼각파, 구형파, 사인파를 발생시켜 가상오실로스코프로 확인할 수 있도록 하였다. 가상오실로스코프의 경우 두 개의 채널을 이용하여 측정할 수 있는 요소(전압, 전류)를 확대기능을 추가하여 좀 더 세밀하게 측정할 수 있도록 하였으며, 트리거, 커서, 파형의 합성등과 같은 여러 가지 유용한 기능들을 구현하였다. 구현된 가상전자계측장비는 자바클래스 형태로 구현하였기 때문에 가상실험실 구성형태에 따라 여러 가지 다양한 방법으로 활용이 가능하다.

• Progress in Superconductivity
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• 제13권1호
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• pp.1-6
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• 2011

Measurement of magnetic signals generated from electric activity of myocardium provides useful information for the functional diagnosis of heart diseases. Key technical component of the magnetocardiography (MCG) technology is SQUID. To measure MCG signals with high signal-to-noise ratio, sensitive SQUID magnetic field sensors are needed. Present magnetic field sensors based on Nb SQUIDs have field sensitivity good enough to measure most of MCG signals. However, for accurate measurement of fine signal pattern or detection of local atrial fibrillation signals, we may need higher field sensitivity. In addition to field sensitivity, economic aspect of the SQUID system is also important. To simplify the SQUID readout electronics, the output voltage or flux-to-voltage transfer of SQUID should be large enough so that direct measurement of SQUID output can be done using room-temperature preamplifiers. Double relaxation oscillation SQUID (DROS), having about 10 times larger flux-to-voltage transfers than those of DC-SQUIDs, was shown to be a good choice to make the electronics compact. For effective cancellation of external noise inside a thin economic shielded room, first-order axial gradiometer with high balance, simple structure and long-baseline is needed. We developed a technology to make the axial gradiometer compact using direct bonding of superconductive wires between pickup coil and input coil. Conventional insert has mechanical support to hold the gradiometer array, and the dewar neck has equal diameter with the dewar bottom. Boiling of the liquid He can generate mechanical vibrations in the gradiometer array due to mechanical connection structure. Elimination of the mechanical support, and direct mounting of the gradiometer array into the dewar bottom can reduce the dewar neck diameter, resulting in the reduction of liquid He consumption.

• 대한토목학회논문집
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• 제30권3A호
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• pp.257-264
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• 2010

일반적으로 대형구조물의 건전성평가에 있어 중요한 인자인 변위를 추정함으로써 구조물의 성능 저하 및 노후도를 판단하는 근거가 된다. 그러나 변위응답의 계측이 중요함에도 불구하고 계측 방법의 부재로 말미암아 현수교와 같은 대형구조물의 변위응답을 측정하는 방법이 용이치 않은 것이 현실이다. 본 논문에서는 변형률신호로부터 변위응답을 추정하는 방법인 모드분해기법을 제시하였다. 모드분해기법은 등가정적 변위응답과 구조물의 주요거동을 나타내는 저차모드의 변위응답을 합하여 최종변위응답을 추정하는 방법이다. 변형률신호의 계측시 전기저항식 변형률센서를 사용할 경우 전기적 노이즈 문제가 발생할 소지가 크며, 측점이 많아질수록 경제적 부담감이 커진다. 이런 문제점을 극복하기 위하여 전기적 노이즈의 영향이 없고 다중측정이 가능한 광섬유 브래그 격자 센서를 사용하였다. 현수교와 플레이트거더교의 동재하실험을 통하여 모드분해기법의 사용성을 검토하였다.

• 센서학회지
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• 제24권4호
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• pp.215-218
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• 2015

As several innovative technologies for flexible electric devices are being realized, demand for in-situ strain monitoring for flexible electric devices is being emphasized. Because flexible devices are commonly influenced by substrate strain, suitable strain sensors for flexible devices are essential for the sophisticated maneuvering of flexible devices. In this study, a flexible strain sensor based on an Ag electrode is prepared on a polyimide substrate using the LDW (laser direct writing) process. In this process, first, the Ag nanoparticles are coated on the substrate and selectively sintered using a focused laser. Because of the advantages of the LDW process (such as being mask-less, using low temperatures, and having non-vacuum characteristics), the entire fabrication process has been dramatically simplified; as a final outcome, a highly reliable strain sensor has been fabricated. Using this strain sensor, various strain conditions that arise from different bending radii can be detected by measuring real-time electrical signals.

• 대한임베디드공학회논문지
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• 제17권5호
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• pp.257-263
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• 2022

Active stabilizers use signals such as steering angle, yaw rate, and lateral acceleration to vary the roll stiffness of the front and rear suspension depending on the vehicle's driving conditions, and are attracting attention as RSC (Roll Stability Control) system that suppresses roll when turning and improves ride comfort when going straight. Various studies have been conducted in relation to active stabilizer bars and RSC systems. However, accurate modeling of passive stabilizer model and active stabilizer model and vehicle dynamics analysis result verification are insufficient, and performance result analysis related to vehicle roll angle estimation and electric motor control is insufficient. Therefore, in this study, an accurate vehicle dynamics model was constructed by measuring the passive/active stabilizer bar model and component parameters. Based on this, the analysis result with high reliability was derived by comparing the roll angle estimation algorithm based on the lateral acceleration and suspension of the vehicle with the actual vehicle driving test result. In addition, it was intended to accurately analyze the motor torque characteristics and roll reduction effects of the electric motor-driven RSC system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.756-759
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• 2003

In this study, an ultrasonic transducer is fabricated with a 1-3 type composite resonator. Pulse-echo responses of an ultrasonic transducer are investigated in underwater with the designated water-levels. LED output signals of a level limit switch with changing a water level are obtained by using the currently developed self-made 1-3 type composite transducer and electric measuring unit. LED is turned on at above the up-limit level with increasing a water level, and LED is turned on at less than the down-limit level with decreasing a water level.

• 분석과학
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• 제8권4호
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• pp.411-418
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• 1995

A method for the direct determination of elemental content in each of aerosol particles by inductively coupled plasma atomic emission (ICP-AES) or mass spectrometry (ICP-MS) is described. This method is based upon the introduction of diluted aerosol into an ICP and the measurement of either the flash emission intensities of an atomic spectral line or ion intensities. A pulse-height analyzer is used for the measurement of the distribution of the elemental content. In order to calibrate the measuring system, monodisperse aerosols are used. The potentials of the method are shown by demonstrating the copper emission signals from the aerosols generated at a small electric switch, a study of the relation between the decreasing rate of particle number density and particle size, and measurements of calcium contents in the individual biological cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.3-4
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• 2007

Orientational ordering of polar molecules and excess charges at the interface are main origins of surface polarization. For organic electronics, probing and control of these two surface polarization phenomena are key issues. In this presentation, I report a novel electrical measurement that can directly probe orientational dipolar motion in surface monolayers by Maxwell-displacement-current, and also report a novel optical technique that allows carrier motions in organic materials by measuring the optical second harmonic signals activated by the electric field. Then I discuss how the control of dipolar motions and carrier motions are linked to organic electronics applications such as organic field effect transistors.