• 조명전기설비학회논문지
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• 제27권2호
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• pp.95-101
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• 2013

This paper presents the comparison of the earth resistivity obtained from the measurements made with the three-electrode and four-electrode fall-of-potential techniques. The ${\rho}-a$ curve obtained from Wenner four-electrode method in undisturbed earth is in good agreement with the ${\rho}-l$ curve obtained from the three-electrode method based on the fall-of- potential method. However, The ${\rho}-a$ curve in disturbed earth with moisture and freezing is significantly different with the ${\rho}-l$ curve. The ${\rho}-a$ curve is considerably sensitive to the freezing and the moisture present in the earth surface compared to the ${\rho}-l$ curve. Thus to determine the actual earth resistivity, it is necessary to take into account the earth surface conditions when measuring the earth resistivity.

• 전기전자학회논문지
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• 제23권4호
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• pp.1122-1127
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• 2019

본 연구에서는 인체의 생체임피던스는 임상 및 생물학적 조직의 병적 및 생리적 상태를 모니터링 하여 많은 정보를 획득 가능하다. 생체임피던측정용 4 전극법시스템은 2개의 전극은 생체의 전위차를 측정하였고, 다른 두 전극은 전류를 흘러주는 전극으로 사용하였다. 새롭게 개발된 건식 Gold 전극은 1 Hz에서 50 kHz 까지 임피던스를 측정하였으며, 재현성 있는 결과를 얻었다. 건식전극의 임피던스 측정값을 검증하기 위해서 생체전극피부등가회로를 이용하여 피팅을 실시하였고 모델링을 통해서 실효성을 증명하였다. 고정 전극형태는 측정 시 부착되는 전극의 위치가 일정하므로 안정적인 측정값을 얻을 수 있어서 오류를 최소화할 수 있다.

• 대한의용생체공학회:의공학회지
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• 제35권6호
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• pp.234-241
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• 2014

This study was designed to investigate the effects of stimulation intensity and inter-electrode distance on the parameters of the measured sensory nerve signal. 30 healthy subjects participated in this study. Sensory nerve signals were elicited by four different pulse amplitudes, i.e., 3, 6, 9, 12 mA, with the pulse width fixed at $500{\mu}s$. The sensory nerve signals elicited by the four different pulse amplitudes were measured by four different inter-electrode distances (20, 30, 40, and 50 mm). We extracted four parameters (pulse amplitude, pulse width, pulse area, and latency time from stimulation) from the sensory nerve signals. The measured pulse amplitude and pulse width were increased when the measuring inter-electrode distance was increased while the stimulating pulse amplitude was fixed. The measured pulse amplitude was saturated with the stimulating pulse amplitudes of over 6 mA while measuring inter-electrode distance. Under the same condition, measured pulse width was increased, and sensory nerve signal was initiated early. Sensory nerve signals, specially those of pulse amplitude, were distorted by a differential amplification method that commonly measures the human body signal. The experimental results indicate that the differential amplification method is required to be replaced when measuring nerve signals. Our observations suggested that the hyperpolarization of the action potential of the sensory nerve signal for preventing distortion could be used to clarify the correlation between the parameters of the sensory nerve signals and quantification of sensations.

• 대한의용생체공학회:의공학회지
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• 제25권3호
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• pp.227-233
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• 2004

본 논문에서는 뇌전도 바이오피드백 시스템을 위한 4채널 전두엽 전극 배치 및 JADE를 사용한 잡음 제거 방법을 제안하였다. 망막-각막 쌍극자 모델을 기반하여 4채널 전두엽 전극 배치를 제안하였으며, 이 배치에 의해서 얻은 신호에 대해서 JADE를 적용하여 4개의 독립 성분을 획득하였다. 각 독립 성분들 중에서 순수 뇌전도 성분을 추정하기 위해서 전체 신호에 대한 알파파비를 측정하여 그 값이 가장 큰 독립 성분을 잡음이 제거된 순수한 뇌전도로 추정하였다. 그 실험 결과 제안한 방법이 뇌전도 획득 과정에서 효과적으로 잡음을 제거함을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권11호
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• pp.575-580
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• 2001

In this paper, using $500\mum-thickness\; (100)\; silicon\; wafer,\; flat\; 65\mum-thickness$ silicon mirror plates were fabricated through dry etching and wet etching, and $45\mum-depth$ grooved driving electrodes were fabricated through UV-LIGA process. Four shapes of the driving electrode were fabricated: twenty four grooves of the $50\mum-width$, twelve grooves of the $100\mum-width$, six grooves of the $200\mum-width$, and no grooves on the driving electrode. Fabricated mirror plate size and spring size are $2400\times2400\times65\mum3\; and \;500\times10\times65\mum3,$ respectively. Mirror plate parts and driving electrodes were assembled into the scanning mirrors. Measured natural resonance frequencies were about 600Hz which have error within $\pm 2%$ to calculated value. Due to the squeeze effect in the narrow gap between the mirror plate and the driving electrode, measured resonance frequencies were reduced as raising the amplitude of the mirror plate. In a case of driving electrode without grooves, the resonance frequency was reduced largely, compared with a case of driving electrode with grooves. According to the experimental results, squeeze effect was smaller in the driving electrode with smaller-width and many grooves. Therefore, the driving electrode with smaller-width and many grooves was effective in low voltage and high speed operation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.207-212
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• 2001

Electro-Rheological(ER) fluid are suspensions which show an abrupt increase in rheological properties under electric fields. ER effects arise from electrostatic forces between the starch particles dispersed in the electrically insulating silicone oil, induced when an electric field is applied. Yield stress of the fluids were measured on the couette cell type rheometer as a function of electric fields. This paper presents performance analyses of four types of the two parallel-plate. Which have different electrode length and width but same electrode area. On the basis of the pressure drop and flow rate analysis. Four types of the two parallel-plate are designed and manufactured. Using ER fluid, it is possible to directly interface between electric signals and fluid power without moving parts.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1024-1026
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• 2004

We have developed the five mask $PMOS^1$ and the six mask CMOS process architecture for poly-Si TFT. In order to have a competitive process with that for a-Si TFT, the simple co-planar electrode structure whose data line electrode and pixel electrode are on the same plane was adopted. In addition, RGB + White four color $technology^2$ were applied to achieve high aperture ratio and transmittance. Using the aforementioned process architecture and four color technology, 2.0 inch qCIF transmissive micro-reflectance (TMR) device was successfully fabricated.

• 대한화학회지
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• 제20권2호
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• pp.129-135
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• 1976

4-전극 측정 용기와 정전위 전자회로를 써서 직독식 전기전도도 측정장치를 고안하여 KCl, HCl등 전해질 용액의 전기전도도를 측정하였다. 이 장치는 상용되고 있는 브릿지회로와 2-전극 용기를 쓰는 방법에서 당면하는 어려운 문제들, 특히 전극에서의 전기 이중층의 존재와 파라디임피던스 등으로 나타나는 전기화학적으로 복잡한 성질들로 인한 문제들을 피하여 정밀하고 간편한 측정에 쓰이도록 만들었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 추계학술대회
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• pp.98-100
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• 1991

We studied the characteristics of the compound electrode and found that the compound electrode provides the four-electrode method in a compact form. We developed a new method of measuring the skin impedance using simple electrodes at low frequencies. At high frequencies where the effect of internal tissue impedance is not negligible, we used the compensation method using compound electrodes since they measure the voltage right under the skin. At 50 kHz, we measured the real part of the skin impedance of less than $80\;{\Omega}$ on the thorax.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.100-100
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• 2009

$TiO_2$ is widely being used as a semiconductor electrode for DSSC. Anti-recombination property and surface area of $TiO_2$ give an important influence to the DSSC efficiency. In this study, $TiO_2$ electrode was fabricated on FTO using screen printing method. Various overlayers were coated on them by dip coating in solution of saturated $Ba(NO_3)_2$, $Mg(NO_3)_2$ and $N_{2}O_{6}Sr$. They reduced the recombination of electrons from photo excited state of Ru dye. The atmospheric plasma treatment was applied to both the $TiO_2$ and each overlayer coated $TiO_2$ surfaces to improve contact ability with dye. We prepared four samples, one sample has bare $TiO_2$ surfaces to improve contact ability with dye. We prepared four samples, one sample has bare $TiO_2$ electrode and the other samples consist of each overlayer coated $TiO_2$ electrodes. We used XRD, FE-SEM, J-V, IPCE and EIS in order to investigate characteristic.