• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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• pp.15-18
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• 2003

In this paper, We explained the best shape design of electrode for discharge on the water. Electrode with rounding was reduced maximum electric field of over 40% to electrode without rounding for discharge on the water and the best shape of electrode for discharge on the water designed when shape of electrode had a curve radius of over $60^{\circ}$ at electrode's face to electrode's face with minimum distance and a curve radius of under $120^{\circ}$ at electrode's side face to electrode's front face. And When dielectric beads are used between electrodes, the life of electrodes is improved by lower stress of electric field on surface of electrodes.

• Journal of Welding and Joining
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• 제35권2호
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• pp.52-57
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• 2017

In this study, resistance spot weldability of lightweight steel with high Al contents was evaluated using various electrode shapes. The six types of electrode shape were prepared with different electrode face diameter and radius. The tensile shear tests were carried out to investigate the failure behaviors. Also, the nugget size and hardness were measured and compared with various electrode shapes. The experimental results show that the acceptable weld current region for low density lightweight steel could be obtained with 10mm electrode face diameter and 76mm electrode face radius.

• Journal of Information Display
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• 제8권3호
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• pp.29-33
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• 2007

The temporal dark image sticking phenomena are examined and compared for the two different electrode structures such as the face-to-face and coplanar sustain electrode structure. To compare the temporal dark image sticking phenomena for both structures, the differences in the infrared emission profile, luminance, and perceived luminance of the image sticking cells and the non image sticking cells were measured. It is observed that the temporal dark image sticking is mitigated for the face-to-face structure. The mitigation of the temporal dark image sticking for the face-to-face structure is due to the slight increase in the panel temperature induced by the ITO-less electrode structure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.617-620
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• 2007

The temporal dark image sticking phenomena for both the face-to-face and coplanar sustain electrode structures were compared. For both structures, the temporal dark image sticking phenomena were examined by measuring the difference in the IR emission, display luminance, perceived luminance, and temperature between the image sticking and the no image sticking cells. For the face-to-face structure, the 10-min sustain discharge causes a small increment of the panel temperature thanks to the ITO-less electrode structure, thereby resulting in mitigating the temporal dark image sticking phenomenon.

• Geomechanics and Engineering
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• 제19권1호
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• pp.93-104
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• 2019

Anomalies and/or fractured grounds not detected by the surface geophysical and geological survey performed during design stage may cause significant problems during tunnel excavation. Many studies on prediction methods of the ground condition ahead of the tunnel face have been conducted and applied in tunneling construction sites, such as tunnel seismic profiling and probe drilling. However, most such applications have focused on the drill and blast tunneling method. Few studies have been conducted for mechanized tunneling because of the limitation in the available space to perform prediction tests. This study aims to predict the ground condition ahead of the tunnel face in TBM tunneling by using an electrical resistivity tomography survey. It compared the characteristics of each electrode array and performed an investigation on in-situ tunnel boring machine TBM construction site environments. Numerical simulations for each electrode array were performed, to determine the proper electrode array to predict anomalies ahead of the tunnel face. The results showed that the modified dipole-dipole array is, compared to other arrays, the best for predicting the location and condition of an anomaly. As the borehole becomes longer, the measured data increase accordingly. Therefore, longer boreholes allow a more accurate prediction of the location and status of anomalies and complex grounds.

• Geomechanics and Engineering
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• 제29권3호
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• pp.301-310
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• 2022

Accurate prediction of mixed ground conditions ahead of a tunnel face is of vital importance for safe excavation using tunnel boring machines (TBMs). Previous studies have primarily focused on electrical resistivity surveys from the ground surface for geotechnical investigation. In this study, an FE (finite element) numerical model was developed to simulate electrical resistivity surveys for the prediction of risky mixed ground conditions in front of a tunnel face. The proposed FE model is validated by comparing with the apparent electrical resistivity values obtained from the analytical solution corresponding to a vertical fault on the ground surface (i.e., a simplified model). A series of parametric studies was performed with the FE model to analyze the effect of geological and sensor geometric conditions on the electrical resistivity survey. The parametric study revealed that the interface slope between two different ground formations affects the electrical resistivity measurements during TBM excavation. In addition, a large difference in electrical resistivity between two different ground formations represented the dramatic effect of the mixed ground conditions on the electrical resistivity values. The parametric studies of the electrode array showed that the proper selection of the electrode spacing and the location of the electrode array on the tunnel face of TBM is very important. Thus, it is concluded that the developed FE numerical model can successfully predict the presence of a mixed ground zone, which enables optimal management of potential risks.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.707-710
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• 2004

We have proposed on dual-drive & -emission (DDE) panel based on organic light-emitting diodes (OLEDs). The device is composed on independent operation of two OLED structures with two transparent electrodes for data signals and an intermediate reflective electrode for common scan signal. Typical device structure is ITO / organic electroluminescent layer (1) /intermediate reflective electrode / organic electroluminescent layer (2) /transparent electrode. Symmetric bright emission could be obtained by applying AlNd as the intermediate reflective electrode and $MoO_3$ as a hole injection layer for upper device structure. The proposed panel is useful for emissive face-to-face panel exhibited for different images.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.605-608
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• 2007

The discharge characteristics of the face-to-face sustain electrode structure employing auxiliary address pulse are investigated under a sustain driving frequency of 20 kHz and various auxiliary address pulse widths (500 ns, $1{\mu}s$, $2\;{\mu}s$) in the 6-in. test panel (42-in. Full HD grade) with a pressure of 450 Torr and a 4 % Xe-content. The luminance and the luminous efficiency at the auxiliary address pulse width of 500 ns are improved more than these of $1\;{\mu}s$ and $2\;{\mu}s$. At the auxiliary address pulse width of 500 ns, the luminous efficiency shows about 0.96 lm/W at the auxiliary pulse of 90 V and the sustain voltage of 260 V.

• 센서학회지
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• 제19권1호
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• pp.1-7
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• 2010

Electrostatic capacitance measurement method in a fine hose was proposed, in which two ring-type electrodes were disposed on the hose in the direction of fluid flow instead of the conventional face-to-face electrodes. With the proposed electrode structure, we realized a Ringer's solution exhaustion detector for an IV(invasive vein) injection set. On a 4 mm-diameter hose of IV set, we disposed two ring-type electrodes of 10 mm width at a distance of 5 mm each other and obtained 0.72 pF and 2.51 pF for air and 10 % dextrose Ringer's solution in the hose, respectively. The capacitance between the two electrodes varied with the hose-wraparound coverage of electrode as well as the width of electrode and the distance between the electrodes. For hose-wraparound electrode coverage of 75 %, the capacitance varied from 0.62 pF to 1.98 pF with the Ringer's solution level between the two electrodes. A charge amplifier converted the capacitance. variation into electric signal and a comparator was used to detect whether Ringer's solution was exhausted or not. The result was delivered to a host using a RF transmitter with 320 MHz carrier frequency.

• 한국터널지하공간학회 논문집
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• 제16권6호
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• pp.599-614
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• 2014

TBM으로 시공되는 터널은 기계에 의해 전단면 굴착(full face tunnelling)이 이루어지므로, 굴착면에 접근하는 것이 매우 제한적이다. 이러한 한계를 극복하고 TBM 터널에서 굴착면 전방의 지반상태를 정확히 예측할 수 있는 기술은 매우 드물다. 본 연구는 TBM에서 전기비저항을 사용하여 굴착면 전방의 이상지반을 예측할 수 있는 TBM 비저항 예측(TRP)시스템을 개발하고, TBM 현장에서의 적용성과 예측 정확성을 검증하기 위해 EPB 쉴드 TBM으로 시공 중인 지하철 터널에서 현장 실험을 수행하였다. TBM 비저항 예측 시스템은 전극을 사용하여 지반의 전기비저항을 측정하고, 이를 바탕으로 역해석을 수행하여, 이상지반의 위치와 두께 및 전기적 특성을 예측한다. 전극이 부착된 강관을 유압으로 굴착면에 압입하여, 전극이 지반과 완전히 접촉하도록 장치를 제작하였다. 또한, 전극이 챔버 내부를 관통하여 나아가도록 하는 동시에 토사유출을 방지하도록 설계하여 현장에서의 전방예측을 가능하게 하였다. 1차 실험 결과, 굴착면 근접 지반과 굴착면 전방 지반의 전기비저항 및 유전율이 동일하게 나타나 이상지반이 존재하지 않음을 예측하였다. 2차 실험 결과, 굴착면 전방 약 1 m 지점부터 상대적으로 낮은 유전율 비를 가지는 이상지반 구간이 약 5 m 길이로 존재함을 예측하였다. 이는 각각 지표에서 물리탐사 또는 시추를 통해 조사된 지반상태 및 TBM 굴착 중 예측 구간에서 반출되었던 버력을 관찰한 기록과 잘 일치하였다.