• 한국자기학회지
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• 제9권5호
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• pp.227-233
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• 1999

단층 솔레노이드의 길이 1.02m, 평균방경 0.11497m, 단위길이당 권선수 1000turns/m에서 Eooiptical 함수와 Legendre 다항식, Biot-Savart 법칙을 이용하여 단층 솔레노이드에 다전류를 인가하여 중심부근에서 자장균일도를 향상시키는 계산방법, 자장분포도 및 반지름 변화에 따른 자장균일도의 차이를 구하였다. 단전류 방법의 경우 1$\times$10-8의 자장균일도 공간이 중심에서 0.1cm 미만이지만, 5-current 방법은 8cm 정도로 80배정도 확대됨을 알 수 있고, 단층 단전류를 사용한 솔레노이드와 비교하였을 때 길이가 0.16km인 경우와 같은 효과를 얻었다. 또한 각각의 계산방법에 대한 자장오차를 비교분석하였다.

• 한국표면공학회지
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• 제18권3호
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• pp.105-115
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• 1985

Lead-tin-copper ternary alloy electrodeposition is conducted onto the inner bore surface of plain bearings as an overlay in order to investigate the effect of slot width, current density and fluoboric acid concentration on the uniformity of overlay. The thickness of overlay is analyzed by means of current distribution resulting from the overvoltage of plating bath and the apparent distance between cathode and anode. The result demonstrate that the uniformity of overlay is remarkably dependent of the slot size and current density, but has little bearing on the fluoboric acid concentration over 100g/L. This present study indicates that uniform overlay is obtainable within the tolerable thickness of ${\pm}2{\mu}m$ by using the slot width of 22mm. The surface morphology examination also shows the important role of concentration polarization of the micro-uniformity of overlay. The micro-uniformity has improved at the low concentration polarization which resulted from operating at the low current density and high fluoboric acid concentration. The surface morphology of deposits exhibits the vivid pyramid crystalline in the plating condition of low concentration polarizatio and all deposits have columnar structure parallel to the applied electric field regardless of the electroplating condition used.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1436-1439
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• 2005

A novel current-type data driver for active matrix organic light emitting diode (AMOLED) is proposed for current uniformity enhancement among its output channels. New architecture is composed of shadow DACs that precharge output stages, a single-real DAC that correct the output level to a real target current level and output stages that operate in 3 states of sampling, correcting and driving. Simulation results show that the proposed driving method and circuits improve the current uniformity among output channels of a current-type driver IC.

• 전기화학회지
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• 제12권4호
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• pp.317-323
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• 2009

돌출부를 지니고 있는 전극의 전기도금 공정에 대한 이론적 이차 전류분포에 대하여 고찰하였다. 전극이 모두 전도체인 경우(Case 1)와 돌출부위만 전도체인 경우(Case 2) 두 가지 경우에 대하여 인가전위, 이온교환 전류밀도와 용액의 비전도도의 비인 $\xi$값, aspect ratio의 영향 등에 대하여 살펴보았다. 그 결과 인가 전위와 $\xi$값이 증가할수록 전류분포는 불균등화가 심화됨을 알 수 있었다. Aspect ratio가 작아질수록 전류분포가 보다 균등화되며 Case 2의 경우가 Case 1의 경우 보다 균등도가 좋아짐을 알 수 있었다. 돌출부위가 다양한 모양으로 이루진 전극에 대해서도 이 모델을 적용한 결과 전극 표면에 따른 국부 전류분포를 동시에 계산할 수 있음을 알 수 있었고 이 경우에도 이전과 마찬가지로 $\xi$값이 감소할수록 전류분포의 균등도가 좋아짐을 알 수 있었다.

• 한국초전도ㆍ저온공학회논문지
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• 제9권3호
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• pp.41-45
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• 2007

This paper presents transport current non-uniformity in a joint for superconducting multistage cable-in-conduit conductor (CICC) and relaxation in the CICC. The joint is considered to have a current loop linked to an external magnetic field so that it becomes an emf voltage source. It is numerically analyzed using an electrical transmission line model. The inductive current in a resistive joint is compared to that of a non-resistive joint when the ramping field is applied vertically to the joints. Regarding the parameter values of the model. a full scale $Nb_3Sn$ CICC and a strand-to-strand (STS) joint for the toroidal field magnet of the KSTAR (Korea Superconducting Tokamak Advanced Research) device are referenced to. It is found that the resistive joint prevents the current from rising too much and enhances decaying the current when the ramping stops. The 'flattop' current is found to be proportional to the ramp rate of the field (dB/dt). The relaxation length, which is defined as the length within which the maximum induced current falls by 1/e. is found to saturate within 0.27m.

• 한국재료학회지
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• 제14권3호
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• pp.196-202
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• 2004

A numerical simulation based on the finite element method is used to investigate the effect of a reciprocal paddle on the uniformity of deposition rates at a patterned electrode. The calculated deposition rates agreed well with the measured values. The influences of the paddle velocity, the gap between cathodes and paddles, anode size and the distance between the anode and cathode have been studied. The optimum conditions on the paddle and geometric factors for electrodeposit uniformity could be obtained.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.285-286
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• 2007

Current distributions according to electrode patterns in vertical structured InGaN/GaN LED (light emitting diode) were investigated quantitatively by utilizing three dimensional electrical circuit modeling method. The uniformity of the injected current density in the active layer was compared among different electrode patterns. It was found that the current uniformity was greatly dependent on the electrode pattern in vertical InGaN/GaN LEDs.

• Journal of Information Display
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• 제3권3호
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• pp.35-43
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• 2002

Silicon-based 0.69-inch AMOEL microdisplay with integrated driver and timing controller circuits for microdisplay applications has been developed using 0.35 ${\mu}m$ l-poly 4-metal standard CMOS process with 5 V CMOS devices and CMP (Chemical Mechanical Polishing) technology. To reduce the large data programming time consumed in a conventional current programming pixel circuit technique and to achieve uniform display, de-amplifying current mirror pixel circuit and the current-mode data driver circuit with threshold roltage compensation are proposed. The proposed current-mode data driver circuit is inherently immune to the ground-bouncing effect. The Monte-Carlo simulation results show that the proposed current-mode data driver circuit has channel-to-channel non-uniformity of less than ${\pm}$0.6 LSB under ${\pm}$70 mV threshold voltage variaions for both NMOS and PMOS transistors, which gives very good display uniformity.

• 전기학회논문지
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• 제60권4호
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• pp.753-758
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• 2011

Magnetic field and Electric field of High Temperature Superconducting magnet are very important to analysis of superconducting magnet. The maximum perpendicular magnetic field was applied to the outermost pancake windings. The critical current of all the magnet windings is limited by the critical current of the outermost pancake windings. The E-J relation was used to determine the critical current, and an evolution s trategy was adopted for the optimization of gap length between each pancake windins. The results of calculations show that the critical current and the central magnetic field and uniformity increased by 82.6% and 31.6% and 50.8%, respectively, for a magnet consisting of ten pancake windings. This paper did an analysis the cause of increase the critical current and central magnetic field and uniformity in no gap and optimal gap model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.100-102
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• 2005

This paper presents evaluation of the electrical uniformity of zinc oxide varistors for lightning arresters. Two types of varistors were prepared which are a domestic varistor destroyed in the long duration current impulse withstand test and a new imported varistor. The domestic varistor exhibited good electrical uniformity except destroyed parts, but the imported varistor showed the worse results.