• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.452-455
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• 2000

Diamond thin films were synthesized on WC-Co substrate at various experimental parameters using 13.56MHz RF PACVD(radio frequency plasma-assisted chemical vapor deposition). In order to increase the nucleation density, the WC-Co substrate was polished with 3$\mu\textrm{m}$ diamond paste. And the WC-Co substrate was pretreated in HNO$_3$: H$_2$O = 1:1 and O$_2$ plasma. In H$_2$-CH$_4$gas mixture, the crystallinity of thin film increased with decreasing CH$_4$concentration at 800W discharge power and 20torr reaction pressure. In H$_2$-CH$_4$-O$_2$gas mixture, the crystallinity of thin film increased with increasing O$_2$concentration at 800W discharge power, 20torr reaction pressure and 4% CH$_4$concentration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.551-552
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• 2006

This study was attended to demonstrate synthesis of silver nanoparticles stabilized with polymer and their applicability to printed electronics. Silver nanoparticles were synthesized by reduction of silver nitrate in aqueous solution in the presence of polyvinyl pyrrolidone (PVP) as a stabilizer. The ink used here is composed of 50 wt% Ag NP, 15 wt% humectant and then were printed on polyimide film. Particle deposit morphologies were controlled by varying the ink compositions. Printed silver patterns and dots were cured on a convection oven in air at $300^{\circ}C$ for 60 min. The printed patterns show good shape definition and the resistivity of the printed films is about $5{\mu}{\Omega}{\cdot}cm$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.418-419
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• 2007

플라즈마 열화학기상 증착법으로 Fe-Ni-Co 3원계 측매합금을 이용하여 $442^{\circ}C$의 저온에서 다중벽 탄소나노튜브를 합성하였다. 수소의 유량이 일정할 때 아세틸렌의 유량이 감소함에 따라 성장속도가 증가하였다. 합성된 탄소나노튜브는 약 8.4 nm의 직경과 $5.5\;{\mu}m$의 길이를 보였으며, 기판에 대해 수직으로 성장되었다. 4인치 웨이퍼 위에서도 전면적에서 균일한 성장을 보였다.

• Fire Science and Engineering
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• v.10 no.2
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• pp.40-51
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• 1996

A synthesis process for PZT powder using NH$_3$ gas as a precipitator in a bubble column reactor was experimentally successful in develope a production process of Piezoelectric ceramic PZT powder. Also as a reaction by coprecipitation, the crystalized PZT ceramic powder at the condition of over pH 9 could be attained. The time needed for reaction on the condition of NH$_3$ gas flow rate=0.5 1/min, Ar gas flow rate=2.0 1/min, Feed flow rate=2.33 ml /sec was less than five minutes, so it could synthesize PZT powder for such a few moments. And the synthesized PZT powder was 0.17${\mu}{\textrm}{m}$ in diameter on an average.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05c
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• pp.1-5
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• 2002

본 논문에서는 UART(Universal Asynchronous Receiver-Transmitter)를 soft IP(Intellectual Property) 모듈 형태로써 VLSI 설계과정을 통하여 구현하였다. 이 모듈은 현재 각종 통신 디바이스에서 최하 말단에서 직렬 데이터를 시스템으로 받아들이거나 병렬 데이터를 직렬 라인에 실어 보내는 중요한 역할을 담당한다. 본 연구에서 설계한 UART는 간단한 모듈 형태로 제작되어 있어 Verilog-HDL을 사용하여 직렬 송ㆍ수신을 필요로 하는 시스템에 내장되어 사용될 수 있다. 본 논문에서는 설계 순서에 따라 UART를 설계하고 Simulation을 하고 Synopsys Tool을 사용하여 Compile 과 Synthesis 후 Gate Area 와 Belay를 검출해 내었다. 합성결과 0.25$\mu$m 공정의 CMOS Cell Library를 사용하였을 경우 전체 면적은 1,013 gate가 나왔다. 본 논문에서 설계한 UART의 최장경로가 최대 4.12ns로 나타났으며, 최대 동작 클럭 주파수는 200MHz 로써 150Mbps 이상의 전송 속도를 가진다.

• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.816-827
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• 2008

In this paper, two-stage pipelined floating-point arithmetic unit (FP-AU) is designed. The FP-AU processor supports seventeen operations to apply 3D graphics processor and has area-efficient and low-latency architecture that makes use of modified dual-path computation scheme, new normalization circuit, and modified compound adder based on flagged prefix adder. The FP-AU has about 4-ns delay time at logic synthesis condition using $0.18{\mu}m$ CMOS standard cell library and consists of about 5,930 gates. Because it has 250 MFLOPS execution rate and supports saturated arithmetic including a number of graphics-oriented operations, it is applicable to mobile 3D graphics accelerator efficiently.

• Journal of Surface Science and Engineering
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• v.32 no.3
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• pp.303-306
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• 1999

On the effect of substrate bias at first stage of diamond synthesis at lower substrate temperature(approximately 673K) using microwave plasma CVD and effect of reaction gas system for the bias enhanced nucleation were studied. The reaction gas was mixture of methane and hydrogen or carbon monoxide and hydrogen. The nucleation density of applied bias -150V using $CH_4-H_2$ reaction gas system, significantly higher than that of $C-H_2$ reaction gas system. When the $CH_4-H_2$ reaction was used, nucleation density was increased because of existence of SiC as a interface for diamond nucleation. By use of this negative bias effect for fabrication of CVD diamond film using two-step diamond growth without pre-treatment, fabrication of the diamond film consist of diamond grains $0.2\mu\textrm{m}$ in diameter was demonstrated

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.1021-1026
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• 1994

This paper proposes a filter structure suitable for speech synthesis applications. We first derive the lossy pole-zero model by employing the wave digital filter(WDF) adaptor formula, and by converting the fixed termination value - 1 into a loss factor $\mu$c$\in$(-1, 1). Then we discuss how to determine the reflection We employ the Durbin's method in estimating the numerator polynomial of the lossy pole-zero transfer function from the given speech sound, and then apply the step-down algorithm on the numerator to extract the reflection coefficients of the closed-termination tract. For determining the reflection coefficients of the other parts we employ a pre-calculated pole-estimator polynomial.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.71.5-71
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• 2001

This paper presents the vibration control of a flexible intelligent beam with added mass. The materials which is a glass fiber reinforced(GFR) thermoplastic composite is employed to achieve vibration characteristics according to added mass induced end of composite beam. In the experiments of forced vibration control, the -controller are employed to achieve vibration suppression in forced vibration situations. Also, in the controller design, 1st and 2nd´s natural frequencies are considered in the modeling, because robust control theory which has robustness to structured uncertainty is adopted to suppress the vibration. By designing a controller using mu-synthesis, robust performance against measurement noise, various modeling.

• Bulletin of the Korean Chemical Society
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• v.2 no.2
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• pp.66-71
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• 1981

The effects of cation on tRNA have been theoretically investigated using the semiempirical potential energy functions. The binding of $Mg^{2+}$ to the model compound and the hydration scheme of the anticodon loop have been determined, and their stabilization energies produced by the introduction of magnesium pentahydrate and water molecules in the first hydration shell were calculated. The results indicate that magnesium pentahydrate is important for decreasing the flexibility of the anticodon loop and satisfying the large Y37 stereochemically during the protein synthesis. The effects of $Mg^{2+}$ on the hydration scheme were also investigated.