• 센서학회지
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• 제5권3호
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• pp.9-16
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• 1996

본 논문에서는 고전압 임펄스전압 발생장치의 조작에 의하여 발생하는 과도전압을 측정할 수 있는 용량성분 압기를 실현하였다. 전장센서를 이용한 과도전압측정계는 고속응답의 평판형 전장센서와 광대역 전압버퍼로 구성되었으며, 사용된 전압버퍼(LH0033)의 입력임피던스는 $10^{12}{\Omega}$ 정도로 대단히 높다. 단위계단 응답특성을 파악하기 위하여 새로운 교정방법을 제안하고, 설치조건에 따른 분압비 오차를 검토하였으며, 분압비 오차를 0.5% 이내로 하기 위한 최적설치조건을 제시하였다. 교정실험으로부터 과도전압측정계의 응답시간은 약 15.78 ns이었으며, 주파수대역은 6.37 Hz에서 27.3MHz이다. 따라서 본 측정계로 과도과전압은 물론 상용주파수전압도 신호의 일그러짐 없이 측정이 가능하였다.

• 전기학회논문지
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• 제61권2호
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• pp.263-269
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• 2012

In order to present that the electromagnetic compatibility standards following the frequency goes up which is based automotive electronics, in this paper, a hybrid/electric vehicle battery which reflects the frequency of the equivalent circuit model is introduced. By using this circuit modeling, the impedance characteristics can be analysed and an analyze of battery one cell is finished. Using this model, each different from the discharging situation, the discharge characteristic curve could be led. Basic theoretical approaches and measuring results through MATLAB and experimental validation of the EIS measurement equipment was used.

• 전기학회논문지
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• 제61권2호
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• pp.251-256
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• 2012

This study deals with the location of partial discharges(PDs) for power cables and GIS using 2 PD sensors and long coaxial signal cables. Throughout the experiments by use of simulated PD pulses and corona discharges in the power cable system, it is found out that the impedance matching between the coaxial signal cable and the measuring equipment should be done for good S/N ratio and the on-site measurement using more than 100m-long coaxial signal cable is possible. In addition, new PD location algorithm with the polarities of PD pulses and the arrival time difference between two pulses was proposed and was proved through the partial discharge experiments for the cable joint defect and artificial void defect.

• 비파괴검사학회지
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• 제13권1호
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• pp.21-28
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• 1993

If the infinitesimal delamination exists and the two waves can hardly be distinguished from each other on account of being much closer, we cannot measure the thickness of delamination by the time difference method. On this study, we calculated the thickness of infinitesimal delamination model by means of measuring echo height due to the deflection of material particles and utilized Newton Ring for optical measurement as a delamination model. From the result of Newton Ring expressed in the delamination model, we can calculate the infinitesimal delamination thickness up to $0.2{\sim}0.3{\mu}m$ due to the difference of acoustic impedance by the ratio of the echo height to the total reflection.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1692-1693
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• 2011

본 논문에서는 전극칩에서 배양하는 세포의 활동성을 실시간으로 모니터링 하기 위해 AC 함수발생기와 Lock-in-amplifier (SR 830, Stanford Research System)를 이용하여 개발한 LabVIEW(National Instrument)기반 세포 임피던스 측정시스템을 제안하였다. 대장암 세포인 HT-29를 다 채널 전극칩에서 60시간동안 배양하는 동안 LabVIEW기반 세포 임피던스 측정시스템을 이용해서 인가하는 신호의 주파수와 세포의 배양시간에 따른 세포 임피던스 변화를 관찰하였다. 결과 HT-29 세포가 전극에 안착하고 증식하기 때문에 전극의 임피던스가 증가한다는 이전 연구결과와 일치하는 측정결과를 얻었고, 이 결과를 통해서 제안한 LabVIEW 기반 세포 임피던스 측정시스템이 암세포 연구에 적합하고, 앞으로 유용하게 사용될 수 있음을 확인하였다.

• Transactions on Electrical and Electronic Materials
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• 제14권4호
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• pp.182-186
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• 2013

We studied the possibility that an air capacitor can be used as a humidity sensor by measuring capacitance change. In order to investigate the possibility, the change of capacitance of an air capacitor due to moisture in air was first considered theoretically, and was then experimentally verified. The capacitance was measured by an LCR impedance meter with a 100-kHz and 1-V ac. The results revealed that the changes in the experimentally measured capacitances were greater than those in the theoretically calculated values. Based on this fact, we knew that an air capacitor could be used as part of a humidity sensing device. We expect the humidity sensor with an air capacitor has characteristics of fast response time, high reliability, and high durability compared with other conventional methods.

• 전기학회논문지P
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• 제62권2호
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• pp.95-97
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• 2013

$CaTiO_3$ thin films using silk screen printing technology were fabricated and their humidity sensitive characteristics have been investigated. The specimens were sintered at $1000^{\circ}C$, $1050^{\circ}C$, $1100^{\circ}C$ for 1 hour and the best humidity sensitivity was shown in the specimens sintered at $1000^{\circ}C$. The humidity sensitivity decreased with increasing measuring frequencies and was stable at different abient temperatures. Hysteresis of impedance variation with increasing and decreasing relative humidity were negligible.

• 한국군사과학기술학회지
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• 제11권6호
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• pp.74-80
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• 2008

Analysis of the electromagnetic environment on topside of a ship is needed for optimal arrangement of all kinds of antennas to be installed on the shipboard in order to minimize the probability of EMI of equipment and subsystems in real ship after construction phase. In this paper we analyze the characteristics of electric-fields such as radiation patterns and near E-fields of V/UHF antennas installed on a shipboard. We compare simulated results with measurements on the real ship for near E-fields to verify the reliability of the computed electromagnetic environment. Although there are various factors causing errors such as cable loss and impedance mismatching etc. when measuring near E-field, both data show similar trends in the range of the acceptable tolerance.

• 대한의용생체공학회:의공학회지
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• 제33권3호
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• pp.114-127
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• 2012

Recent technical advancement allows noninvasive measurement of blood glucose. In this literature, we reviewed various noninvasive techniques for measuring glucose concentration. Optical or electrical methods have been investigated. Optical techniques include near-infrared spectroscopy, Raman spectroscopy, optical coherence technique, polarization, fluorescence, occlusion spectroscopy, and photoacoustic spectroscopy. Electrical methods include reverse iontophoresis, impedance spectroscopy, and electromagnetic sensing. Ultrasound, detection from breath, or fluid harvesting technique can be used to measure blood glucose level. Combination of various methods is also promising. Although there are many interesting and promising technologies and devices, there need further researches until a commercially available non-invasive glucometer is popular.

• 제어로봇시스템학회논문지
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• 제20권8호
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• pp.789-794
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• 2014

This paper presents some real performance of two typical bilateral teleoperation benchmark tasks: peg-in-hole and surface tracking tasks. The tasks are performed by an energy-bounding algorithm in the master control and position-based impedance algorithm in the slave control. Performance is analyzed for the position-force tracking capabilities from free space motion to surface contacting motion. In addition, preliminary user performance is evaluated by measuring the completion time and maximum/average contact forces. The quality of the measured performance is also compared with that of other existing approaches.