• ETRI Journal
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• 제28권2호
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• pp.253-256
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• 2006

We propose a novel power metal oxide semiconductor field effect transistor (MOSFET) employing a strained-Si channel structure to improve the current drivability and on-resistance characteristic of the high-voltage MOSFET. A 20 nm thick strained-Si low field channel NMOSFET with a $0.75\;{\mu}m$ thick $Si_{0.8}Ge_{0.2}$ buffer layer improved the drive current by 20% with a 25% reduction in on-resistance compared with a conventional Si channel high-voltage NMOSFET, while suppressing the breakdown voltage and subthreshold slope characteristic degradation by 6% and 8%, respectively. Also, the strained-Si high-voltage NMOSFET improved the transconductance by 28% and 52% at the linear and saturation regimes.

• ETRI Journal
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• 제32권3호
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• pp.406-413
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• 2010

In order to guarantee the proper operation of a recessed channel array transistor (RCAT) pseudo SRAM, the back-bias voltage must be changed in response to changes in temperature. Due to cell drivability and leakage current, the obtainable back-bias range also changes with temperature. This paper presents a pseudo SRAM for mobile applications with an adaptive back-bias voltage generator with a negative temperature dependency (NTD) using an NTD VBB detector. The proposed scheme is implemented using the Samsung 100 nm RCAT pseudo SRAM process technology. Experimental results show that the proposed VBB generator has a negative temperature dependency of -0.85 $mV/^{\circ}C$, and its static current consumption is found to be only 0.83 ${\mu}A$@2.0 V.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.961-963
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• 2009

a-Si process-based advanced-SPC (a-SPC) TFT has been developed and verified by manufacturing an AMOLED panel having improved cost competitiveness by using the existing a-Si infrastructure. The a-SPC TFT had superior device reliability and current drivability to a-Si TFT to meet the requirements of AMOLED backplane.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.593-598
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• 2007

A new continuously variable transmission for bicycles(B-CVT) is developed by using a traction drive mechanism having inner and outer spherical rotors. The B-CVT has high power efficiency, large torque capacity, improved drivability and good packageability. The ratio change mechanism for the B-CVT is very simple, in contrast with other traction drive CVTs. After completing a conceptual design, a performance analysis and a detail design, a prototype of the B-CVT has been manufactured. The prototype has rated power of 100 watts, pedal speed of 6 rad/s and an overall speed ratio of 1.0-4.0. A bench test and an actual bicycle test have been performed to verify the practicability of the B-CVT.

• International Journal of Automotive Technology
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• 제6권5호
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• pp.529-536
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• 2005

This paper presents a novel design of a fuzzy control strategy (FCS) based on torque distribution for parallel hybrid electric vehicles (HEVs). An empirical load-regulating vehicle operation strategy is developed on the basis of analysis of the components efficiency map data and the overall energy conversion efficiency. The aim of the strategy is to optimize the fuel economy and balance the battery state-of-charge (SOC), while satisfying the vehicle performance and drivability requirements. In order to accomplish this strategy, a fuzzy inference engine with a rule-base extracted from the empirical strategy is designed, which works as the kernel of a fuzzy torque distribution controller to determine the optimal distribution of the driver torque request between the engine and the motor. Simulation results reveal that compared with the conventional strategy which uses precise threshold parameters the proposed FCS improves fuel economy as well as maintains better battery SOC within its operation range.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.191-197
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• 2001

Performance requirements for automatic transmission fluids have been changing to reflect the design changes of automatic transmission. The major purpose for these design changes is to improve fuel economy and drivability. The use of special base oils like API Group III and IV base oils has increased in order to formulate high performance ATF. In this study. the effect of base oils characteristics on ATF performance is investigated, mainly regarding differences in frictional characteristics with deterioration. Moreover, low-temperature fluidity. oxidation stability. and seal compatibility are also compared for four different ATFs. From the investigation, it was found that the use of Group III and IV base oils in ATF has several benefits in low temperature viscosity. oxidation stability and SAE No.2 friction characteristics.

• 디자인학연구
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• 제12권4호
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• pp.99-108
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• 1999

승용차의 실내공간은 다수의 부품들로 구성되어 있으며, 그들 중 인스트루먼트 패널은 그 디자인에 따라 실내공간의 활용과 이 , 그리고 운전자의 조작성과 실내공간의 안전도까지도 좌우하는 중요한 부품이다. 초기 자동차에서의 인스트루먼트 패널은 엔진실과 실내공간을 구분 짓는 벽체에 운전에 필요한 엔진의 상태를 알리기 위한 계기를 부탁하는 개념에 출발하였다. 그러므로 운전석의 좌우 위치에 관게없이 패널 중앙부에 계기류를 장착하는 개념이 주류를 이루었다. 차량의 기능 향상과 장착품의 증가로 운전석 중심의 독립된 계기판과 충격 흡수제를 부탁한 구조가 등장하였으며, 이것은 오늘날의 다양한 형태의 계기판의 출발점이 되었다. 최근의 승용차의 계기판은 차량 안전 법구의 강화와 신공법의 개발, 그리고 운전 편의성 향상 등을 위하여 중앙부에 클러스터를 장착한 유형이 몇몇 차종에서 다시 등장하고 있다. 이러한 승용차 인스트루먼트 패널의 디자인 특징과 기능성 특성들을 분석하면 다음과 같은 결과를 얻을수 있다. -전방 시인성의 향상을 위한 I/P 전체의 부피 감소 -강화된 충돌 규제를 위한 보조 장치와 완충 구조의 설정 -운전 편의성과 초점 거리 차이 감소를 통한 안전성 향상을 위한 중앙부 클러스터 장착 유형의 재등장유형의 재등장

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.1-4
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• 2008

The electrical characteristics of polycrystalline silicon (poly-Si) thin film transistor (TFT) crystallized by excimer laser annealing (ELA) method were evaluated, The polycrystalline silicon thin-film transistor (poly-Si TFT) has higher electric field-effect-mobility and larger drivability than the amorphous silicon TFT. However, to poly-Si TFT's using conventional processes, the temperature must be very high. For this reason, an amorphous silicon film on a buried oxide was crystallized by annealing with a KrF excimer laser (248 nm)to fabricate a poly-Si film at low temperature. Then, High permittivity $HfO_2$ of 20 nm as the gate-insulator was deposited by atomic layer deposition (ALD) to low temperature process. In addition, the solid phase crystallization (SPC) was compared to the ELA method as a crystallization technique of amorphous-silicon film. As a result, the crystallinity and surface roughness of poly-Si crystallized by ELA method was superior to the SPC method. Also, we obtained excellent device characteristics from the Poly-Si TFT fabricated by the ELA crystallization method.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.1029-1038
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• 2009

This paper proposes a gain switching algorithm for joint position control of a hydraulic humanoid robot. Accurate position control of the lower body is one of the basic requirements for robust balance and walking control. Joint position control is more difficult for hydraulic robots than it is for electric robots because of an absence of reduction gear and better back-drivability of hydraulic joints. Backdrivability causes external forces and torques to have a large effect on the position of the joints. External ground reaction forces therefore prevent a simple proportional-derivative (PD) controller from realizing accurate and fast joint position control. We propose a state feedback controller for joint position control of the lower body, define three modes of state feedback gains, and switch the gains according to the Zero Moment Point (ZMP) and linear interpolation. Dynamic equations of hydraulic actuators were experimentally derived and applied to a robot simulator. Finally, the performance of the algorithm is evaluated with dynamic simulations.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.351-359
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• 2010

Large PHC piles with a diameter of 1,000mm or larger were recently introduced for the first time in Korea. This paper presents full-scale static and dynamic pile load tests performed on two 1,000mm PHC piles and two composite piles with steel pipe piles of the same diameter in the upper portion, installed by driving and pre-boring. The objectives of the tests include evaluating pile drivability, load-settlement relation, allowable bearing capacity, and the stability of mechanical splicing element for the composite pile(a.k.a. non-welding joint). The performance of the large diameter PHC piles were thought to be satisfactory compared to that of middle sized PHC piles with a long history of successful applications in the domestic and foreign markets.