• 한국전자통신학회논문지
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• 제11권7호
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• pp.659-664
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• 2016

본 논문에서는 고속 동작과 저전력 동작을 요구하는 디지털 회로 시스템에 사용될 수 있는 Current-mode FIR Filter를 위한 OTA(:Operational Trans-conductance Amplifier) 회로를 제안한다. Current-mode 신호처리는 동작 주파수와 상관없이 일정한 전력을 유지하는 특징이 있기 때문에 고속 동작을 요구하는 디지털 회로 시스템의 저전력 동작에 매우 유용한 회로설계 기술이라고 할 수 있다. 0.35um CMOS 공정을 이용한 시뮬레이션 결과, Vdd=2V에서 전원 전압의 50%에 해당하는 약 1V의 Dynamic Range를 확보하였으며, 약 0~200uA의 출력전류를 확인하였다. 설계한 OTA 회로의 전력은 약 21uW가 계산되었으며, Active Layout 면적은 $71um{\times}166um$ 사이즈로 집적화에 유리할 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.315-318
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• 1988

PHOTO-RESIST 자체문제로인해 감소되는 최소해상력, 촛집심도여유 및 CRITICAL DIMENSION (C.D.) 조정여유도등을 연구하였다. 기존에 사용중인 PHOTO-RESIST(큰 분자량)와 PHOTO-RESIST자체내에 CONTRAST 촉진 물질(CEM)이 첨가된것(INNER CEM TYPE) 및 PHOTO-RESIST구성성분중 작은 분자량/좁은 분자량 산포가 형성된 RESIN 의 PHOTO-RESIST(LOW MOLECULAR WEIGHT CONTROL TYPE)등 세가지 PHOTO-RESIST를 사용 하여 상기의 항목을 분석하였다. INNER CEM TYPE 및 LOW MOLECULAR WEIGHT CONTROL TYPE의 PHOTO-RESIST는 기존에 사용중인 RESIST보다, 최소 RESOLUTION은 약 0.2 - 0.3 um, DEPOCUS MARGIN은 약 0.8 - 1.2 um 및 C.D. CONTROL LATITUDE 향상된 것 등이 우수하였다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.49.2-49.2
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• 2007

• 한국전자파학회논문지
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• 제20권10호
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• pp.1107-1113
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• 2009

본 논문에서는 K-Band에서 동작하는 1/2 주파수 분배기를 130 nm CMOS 공정을 이용하여 설계하고 제작한 결과를 보인다. 피드백 방식의 밀러 주파수 분배기는 20~25 GHz에서 동작하며 바이어스 전압 1.2 V에서 7.2 mW의 전력을 소모하고 코어 회로의 레이아웃 크기는 $315{\times}246\;um^2$이다. 밀러 주파수 분배기의 출력 신호를 2분 주시키기 위한 CML(Current Mode Logic) 주파수 분배기는 8.5~13 GHz에서 동작하며 5.7 mW의 전력을 소모하고, 코어 회로의 레이아웃 크기는 $91{\times}98\;um^2$이다. 또한 두 주파수 분배기를 결합하여 20~25 GHz의 입력 신호가 4분주되어 출력됨을 확인하였다.

• 대기
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• 제21권2호
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• pp.163-172
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• 2011

Numerical forecasting depends on the initial condition error strongly because numerical model is a chaotic system. To calculate the sensitivity of some forecast aspects to the initial condition in the Korea Meteorological Administration (KMA) Unified Model (UM) which is originated from United Kingdom (UK) Meteorological Office (MO), an algorithm to calculate adjoint sensitivities is developed by modifying the adjoint perturbation forecast model in the KMA UM. Then the new algorithm is used to calculate adjoint sensitivity distributions for typhoon DIANMU (201004). Major initial adjoint sensitivities calculated for the 48 h forecast error are located horizontally in the rear right quadrant relative to the typhoon motion, which is related with the inflow regions of the environmental flow into the typhoon, similar to the sensitive structures in the previous studies. Because of the upward wave energy propagation, the major sensitivities at the initial time located in the low to mid- troposphere propagate upward to the upper troposphere where the maximum of the forecast error is located. The kinetic energy is dominant for both the initial adjoint sensitivity and forecast error of the typhoon DIANMU. The horizontal and vertical energy distributions of the adjoint sensitivity for the typhoon DIANMU are consistent with those for other typhoons using other models, indicating that the tools for calculating the adjoint sensitivity in the KMA UM is credible.

• Restorative Dentistry and Endodontics
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• 제27권5호
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• pp.488-492
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• 2002

The purpose of this study was to evaluate the effectiveness of plasma arc curing (PAC) unit for composite and compomer curing. To compare its effectiveness with conventional quartz tungsten halogen (QTH) light curing unit, the polymerization shrinkage rates and amounts of three composites (Z100, Z250, Synergy Duo Shade) and one compomer, that had been light cured by PAC unit or QTH unit, was compared using a custome made linometer. The measurement of polymerization shrinkage was peformed after polymerization with either QTH unit or PAC unit. In case of curing with the PAC unit, the composite was light cured with Apollo 95E for 6s, the power density of which was recorded as 1350 mW/$\textrm{cm}^2$ by Coltolux Light Meter. For light curing with QTH unit, the composite was light cured for 30s with the XL2500, the power density of which was recorded as 800 mW/$\textrm{cm}^2$ by Coltolux Light Meter. The amount of linear polymerization shrinkage was recorded in the computer every 0.5s for 60s. Ten measurements were made for each material. The amount of linear polymerization shrinkage for each material in 10s and 60s which were cured with PAC or QTH unit were compared with t test. The amount of polymerization shrinkage in the tested materials were compared with 1way ANOVA with Duncan's multiple range test. As for the amounts of polymerization shrinkage in 60s, there was no difference between PAC unit and QTH unit in Z250 and Synergy Duo Shade. In Z100 and Dyract AP, it was lower when it was cured with PAC unit than when it was cured with QTH unit (p<0.05). As for the amounts of polymerization shrinkage in 10s, there was no difference between PAC unit and QTH unit in Z100 and Dyract AP. The amounts of polymerization shrinkage was significantly higher when it was cured with PAC unit in Z250 and Synergy Duo Shade (p<0.05). The amounts of polymerization shrinkage in the tested materials when they were cured with QTH unit were Z250 (6.6um) < Z100 (9.3um), Dyract AP (9.7um) < Synergy Duo Shade (11.2um) (p<0.05). The amount of polymerization shrinkage when the materials were cured with PAC unit were Dyract AP (5.6um) < Z100 (8.1um), Z250(7.0um) < Synergy Duo Shade (11.2um) (p<0.05).

• 센서학회지
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• 제10권4호
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• pp.207-213
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• 2001

A Schottky type GaN ultraviolet photodetector with a mesa structure was fabricated by depositing an Al ohmic contact on an $n^+$-GaN layer and a Pt Schottky contact on a GaN layer. The undoped GaN(0.5um)/$n^-$-GaN(0.1 um)/$n^+$-GaN(1.5 um) multi-layer structure was grown on a sapphire substrate using MOCVD. The Schottky contact properties were characterized for different passivation conditions. The leakage current of the fabricated Schottky diode was 2 nA at a reverse voltage of 5V. Plus the photocurrent was 120uA using a hydrargyrum lamp with an optical power of 1mW at a wavelength of 365 nm. The diode exhibited an ultraviolet-visible rejection ratio of $10^2$.

• 한국전기전자재료학회논문지
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• 제22권2호
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• pp.123-127
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• 2009

In order to get more higher integration density of devices, it is getting to be used more and more micro via interconnection lines for interconnecting layers or devices. However, it is very important to enhance the electrical characteristic by reducing the electrical resistivity of micro via interconnection line because it affects the reliability of packaging. In this paper, Micro vias were patterned with a diameter from 10 to 100 um by increasing the step of 10 um and 100 um height and were fabricated by micromachining technology to investigate the electrical characteristic of micro via interconnection lines. These micro vias were filled with copper by electroplating process with appling pulse current mode. And the electrical characteristics of micro via interconnection lines were measured. The measured value of electrical resistivity shows with a range from 20 to $26\;m{\Omega}$. This value from micro via interconnection lines fabricated by pulse current mode electroplating process shows better result than the resistivity from than micro via interconnection lines fabricated by DC mode ($31\;m{\Omega}$).

• 한국가스학회:학술대회논문집
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• 한국가스학회 1997년도 추계학술발표회 논문집
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• pp.177-182
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• 1997

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2009년도 춘계학술대회
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• pp.45-45
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• 2009