• 대한전자공학회논문지SD
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• 제42권5호
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• pp.47-54
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• 2005

본 논문에서는 Crosstalk에 의한 coupling capacitance의 변화량, ${\Delta}Cc$이 기본값인 Cc보다 더 커질 수 있음을 제안한 테스트 회로를 이용하여 실험적으로 증명하였다. 또한 ${\Delta}Cc$가 Aggressive line의 위상에 매우 의존함을 보였으며 위상이 같은 경우보다 반대인 경우에 ${\Delta}Cc$가 크게 됨을 보였다. 실험 결과의 타당성을 검증을 위해 HSPICE 시뮬레이션을 수행하여 실험치와 잘 맞음을 나타내었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.240-248
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• 2009

Moore's law has driven silicon technology scale down aggressively, and it results in significant increase of leakage current on nano-meter scale CMOS. Especially, in mobile devices, leakage current has been one of designers' main concerns, and thus many studies have introduced low power methodologies. However, there are few studies to minimize implementation cost in the mixed use of the methodologies to the best of our knowledge. In this paper, we introduce industrial applications of low power design methodologies for the decrease of leakage current. We focus on the design cost reduction of power gating and reverse body bias when used together. Also, we present voltage scale as an alternative to reverse body bias. To sustain gate leakage current, we discuss the adoption of high-$\kappa$ metal gate, which cuts gate leakage current by a factor of 10 in 32 nm CMOS technology. A 45 nm mobile SoC is shown as the case study of the mixed use of low power methodologies.

• 한국세라믹학회지
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• 제55권6호
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• pp.581-589
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• 2018

This work concentrated on the effect of different laser beams on the microstructure and dielectric properties of $BaTiO_3$ nanoparticles at different calcinations times during the gelling preparation step. The nanoparticles were prepared by the sol-gel method. A green (1000 mW, 532 nm) and red laser beam (500 mW, 808 nm), were applied vertically at the center of stirring raw materials. The samples were sintered at $1000^{\circ}C$ for 2, 4, and 6 h. X-ray diffraction (XRD) analysis showed that samples prepared under the green laser have the highest purity. The FT-IR spectra showed that the stretching and bending vibrations of TiO bond without any other bonds, which are compatible to the X-ray diffraction (XRD) results. Samples were characterized by transmission electron microscopy (TEM), Scan electron microscopy (SEM), and UV-Visible spectrophotometer. Characterization showed the samples prepared under the green laser to have the highest particle size (~ 50 nm) and transparency for all sintering durations. Laser beam effects on electrical characterization were studied. BT nanoparticles prepared under the green laser show the higher dielectric constant, which was found to increase with sintering temperature.

• 한국자기학회지
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• 제20권4호
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• pp.167-172
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• 2010

게놈 프로젝트 이후 급격하게 발전하고 있는 나노자성-바이오 의료 컨버젼스 기술은 신약 개발 프로세스, 임상 진단 등의 분야에 혁신적인 변화를 일으킬 것으로 주목을 받고 있다. 이 중에서 차세대 바이오 에세이 기술은 암, 임상 유전적 질병의 조기진단 및 현장진단(point-of-care)과 같은 유비쿼터스 진단(U-health care)시대에 부응하는 휴대화 자동화 고속화 저비용화 사용편의성뿐만 아니라 post-genome 시대의 요구에 맞는 대용량화 다중 감지화 요건을 충족하는 기술이다. 본 논고에서는 바이오 에세이용 자기센서 및 미세유체역학하에서 바이오 분자 이송용 온 칩 자석(on-chip magnet) 연구에 대해서 소개하고자 한다.

• 한국생산제조학회지
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• 제18권3호
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• pp.307-314
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• 2009

Large area micro pattern replication has promising application potential in many areas. Rolling imprint process has been demonstrated as one of the most competitive processes for such micro pattern replication, because it has advantages in low cost, high throughput and high efficiency. In this paper, we developed a prototype of roll-to-flat(R2F) thermal imprint system for large area micro pattern replication process, which is one of the key processes in the fabrication of flexible displays. Experimental tests were conducted to evaluate the feasibility of system and the parameters' effect on the process, such as flat mold temperature, loading pressure and rolling speed. 100mm $\times$ 100mm stainless steel flat mold and commercially available polycarbonate sheets were used for the tests. The experimental results showed that the developed R2F system is suitable for fabrication of various micro devices with micro pattern over large area.

• 한국진공학회지
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• 제16권1호
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• pp.58-64
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• 2007

조직공학재생의학(조재학)은 생명과학과공학의 기본개념을 응용하여 생체조직을 만들고, 복원시키고, 변형시키기 위하여 새로운 디바이스나 생체조직 대용품을 만드는 학문분야이다. 조재학은 다학제간 연구개발하는 분야로써 매우 혁신적인 건강관리 및 치료 학문분야이다. 조재학의 큰 특징은 발전 속도가 빠른 첨단 과학 기술을 바탕으로 하고 있기 때문에 발전 속도가 빠르다는 점과 여러 분야의 지식과 기술을 함께 이용하기 때문에 다른 학문보다 관련 분야에 대하여 더욱 더 폭 넓은 이해를 필요로 하게 되므로 서로 다른 분야의 지식을 가진 과학자들의 협동 연구가 요구된다. 본 총설에서는 현재의 연구개발 동향 및 결과와 미래 가능성의 이해를 돕기위해 고찰하였다.

• 한국군사과학기술학회지
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• 제18권2호
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• pp.139-145
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• 2015

In this paper, the flexible piezoelectric nanocomposite generator(NCG) device based on $BaTiO_3$ nanostructures was fabricated via simple and low-cost spin coating method. The $BaTiO_3$ nanostructures synthesized by self-assembly reaction showed dendrite morphologies. To produce the piezoelectric nanocomposite(p-NC layer) which acts as an electric energy source in NCG device, the piezoelectric nanopowders($BaTiO_3$) were dispersed in polydimethylsiloxane(PDMS). Sequently, the p-NC layer was inserted in two dielectric layer of PDMS; these layers enabled the NCG device flexibility as well as durability prohibiting detachment(exfoliation) for significantly mechanical bending motions. The fabricated NCG device shows average maximum open circuit voltage of 6.2 V and average maximum current signals of 300 nA at 20 wt% composition of $BaTiO_3$ nanostructures in p-NC layer. Finally, the flexible energy harvester generates stable output signals at any rate of frequency which were used to operate LCD device without any external energy supply.

• 한국정보통신학회논문지
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• 제14권10호
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• pp.2305-2309
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• 2010

본 연구에서는 상단게이트와 하단게이트를 갖는 더블게이트 MOSFET에서 채널길이와 채널두께의 비에 따른 문턱전압의 변화에 대하여 분석하였다. 더블게이트 MOSFET는 두개의 게이트를 가지고 있기 때문에 전류제어 능력이 기존 MOSFET의 두배에 가깝고 나노소자에서 단채널효과를 감소시킬 수 있다는 장점이 있다. MOSFET에서 채널길이와 채널두께는 소자의 크기를 결정하며 단채널효과에 커다란 영향을 미치고 있다. 채널길이가 짧아지면 서 채널두께와의 비에 따라 단채널효과 중 문턱전압의 변화가 크게 영향을 받고 있다. 그러므로 이 연구에서는 DGMOSFET에서 채널길이와 채널두께의 비를 변화시키면서 문턱전압의 변화와 드레인 유기장벽감소현상을 분석할 것이다.

• 한국소음진동공학회논문집
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• 제18권4호
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• pp.411-423
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• 2008

Pneumatic vibration isolator has a wide application for ground-vibration isolation of vibration-sensitive equipments. Recent advances In precision machine tools and instruments such as nano-technology or medical devices require a better isolation performance, which can be efficiently done by precise modeling- and design- of the isolation system. This paper will discuss an efficient transmissibility design method for pneumatic vibration isolator by employing the complex stiffness model of dual-chamber pneumatic spring developed in our previous research. Three design parameters of volume ratio between the two pneumatic chambers, the geometry of capillary tube connecting the two pneumatic chambers and finally the stiffness of diaphragm necessarily employed for prevention of air leakage were found to be important factors in transmissibility design. Based on design technique that maximizes damping of dual-chamber pneumatic spring, trade-off among the resonance frequency of transmissibility, peak transmissibility and transmissibility in high frequency range was found, which was not ever stated in previous researches. Furthermore this paper will discuss about negative role of diaphragm in transmissibility design. Then the design method proposed in this paper will be illustrated through experiment at measurements.

• Steel and Composite Structures
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• 제35권6호
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• pp.779-788
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• 2020

Multi-Walled Carbon nanotubes (MWCNT) coupled with Silicone Rubber (SR) can represent applicable strain sensors with accessible materials, which result in good stretchability and great sensitivity. Employing these materials and given the fact that the combination of these two has been addressed in few studies, this study is trying to represent a low-cost, durable and stretchable strain sensor that can perform excellently in a high number of repeated cycles. Great stability was observed during the cyclic test after 2000 cycles. Ultrahigh sensitivity (GF>1227) along with good extensibility (ε>120%) was observed while testing the sensor at different strain rates and the various number of cycles. Further investigation is dedicated to sensor performance in the detection of human body movements. Not only the sensor performance in detecting the small strains like the vibrations on the throat was tested, but also the larger strains as observed in extension/bending of the muscle joints like knee were monitored and recorded. Bearing in mind the applicability and low-cost features, this sensor may become promising in skin-mountable devices to detect the human body motions.