• Archives of Pharmacal Research
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• 제17권6호
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• pp.480-482
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• 1994

A number of 5-substituted pyrimidine acyclic nucleosides were synthesized and tested for invitor cytotoxicity against four cell lines (j-82 cell, p-388 cell, FM-3A cell and U-938 cell lines). Synthesis of 1-cyanomethyl-5-substituted pyrimidines (1a-e) and 1-(4-cyanobutyl)-5-substituted pyrimidines (2a-e) was acomplished from the series of alkylation reactions ofl 5-substituted uracils with the corresponding chloacetonitrile and 5-chlorovaleronitile in DMSO under $50^{\circ}C$ temperature. These 5-substituted pyrimidine acylic nucleosides (1a-e and 2a-e) exhibited moderate to significant acitivity aginst four cell lines.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권1호
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• pp.15-21
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• 2013

In this paper, a MEMS tunable capacitor was successfully designed and fabricated using an aluminum nitride film and a gold suspended membrane with two air gap structure for commercial RF applications. Unlike conventional two-parallel-plate tunable capacitors, the proposed tunable capacitor consists of one air suspended top electrode and two fixed bottom electrodes. One fixed and the top movable electrodes form a variable capacitor, while the other one provides necessary electrostatic actuation. The fabricated tunable capacitor exhibited a capacitance tuning range of 375% at 2 GHz, exceeding the theoretical limit of conventional two-parallel-plate tunable capacitors. In case of the contact state, the maximal quality factor was approximately 25 at 1.5 GHz. The developed fabrication process is also compatible with the existing standard IC (integrated circuit) technology, which makes it suitable for on chip intelligent transceivers and radios.

• 전자통신동향분석
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• 제4권3호
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• pp.106-120
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• 1989

반도체 집적회로(IC)가 고집적화됨에 따라 소자는 계속 축소화되고 이에 따른 소자 제조공정은 더욱 엄격하고 복잡해지고 있다. 그 중 절연막 분야에서는 MOSFET(metal-oxide-semiconductor field-effect transistor) 소자의 절연막과 기억소자에서의 capacitor 절연막의 초박막화와 고신뢰화가 매우 주목 받고 있는 분야이다. 본 고에서는 지난 1989년 5월 Kyoto에서 IEEE Electron Device Society와 일본 응용물리학회가 공동주최로 개최된 '1989 Symposium on VLSI Technology' 에서 발표된 논문 중에서 절연막에 관련된 논문을 분석 정리함으로써 절연막에 대한 최근 기술 동향을 파악하고자 하였다.

• 전자통신동향분석
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• 제20권1호통권91호
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• pp.84-92
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• 2005

생체인식 기술은 다양한 온라인 서비스의 보급에 의해 비대면상에서의 안전한 개인 인증 수단이 요구됨에 따라 신뢰성을 제공하는 사용자 인증의 수단으로 부각되었다. 그러나, 생체인식의 실제 응용에 있어 기대되는 성능을 만족시킬 수 없는 경우가 발생할 수 있으며 이에 따라 여러 종류의 생체인식 기술을 함께 사용하여 성능을 향상시키고 신뢰도를 높이는 다중 생체인식(multi-modal biometrics) 기술이 활발하게 연구되고 있다. 본 고에서는 다중 생체인식 기술의 동향을 살펴보고 IC 카드 기반 다중 생체인식시스템에 대해 논의한다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권3호
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• pp.149-167
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• 2004

Passive components are indispensable in the design and development of microchips for high-frequency applications. Inductors in particular are used frequently in radio frequency (RF) IC's such as low-noise amplifiers and oscillators. This paper gives a broad overview on the on-chip spiral inductors. The design concept and modeling approach of the typical square-shaped spiral inductor are first addressed. This is followed by the discussions of advanced structures for the enhancement of inductor performance. Research works reported in the literature are summarized to aid the understanding of the recent development of such devices.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1146-1152
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• 2011

The discovery of 2'-spirocyclopropyl-ribocytidine (J. Med. Chem. 2010, 53, 8150-8160) as a potent inhibitor of RNA synthesis by NS5B ($IC_{50}=7.3{\mu}M$), the RNA polymerase encoded by hepatitis C Virus (HCV), has led to the synthesis and biological evaluation of several carbocyclic versions of 2'-spiropropyl-nucleosides. The cyclopentenol intermediate 7 was successfully constructed via ring-closing metathesis (RCM) from divinyl 6. Spirocyclopropanation of enone 8 was effected by using (2-chloroethyl)-dimethylsulfonium iodide and potassium tert-butoxide to form the desired intermediate 9. The synthesized nucleoside analogues 21-24 were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line. Among them, the cytosine nucleoside analogue 22 exhibited significant anti-HCV activity ($EC_{50}= 8.2{\mu}M$).

• 한국전산유체공학회지
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• 제7권2호
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• pp.17-24
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• 2002

The transient flow fields in a direct injection engine was analyzed by using the STAR-CD CFD code doting the intake/compression processes. The analyses were focused on the computation grid generation by using the IC3M code which is a pre-developed and especially well adapted for the analyses of internal combustion engine. The results showed that the used grid generation technique was well suited for the flow analyses on any internal combustion engine.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2001년도 추계 학술대회논문집
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• pp.63-69
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• 2001

The transient flow fields in direct injection engines were analyzed by using the STAR-CD CFD code during the intake/compression processes. The analyses were focused on the computation grid generation by using the IC3M code which is a pre-developed and especially well adapted for the analyses of internal combustion engines. The results showed that the used grid generation technique was well suited for the flow analyses on any internal combustion engines.

• Journal of Advanced Marine Engineering and Technology
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• 제29권8호
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• pp.855-861
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• 2005

Fracture toughness defined near the initiation of stable crack growth is investigated by R-curve and Direct Current electric Potential Determination(DCPD) under mode I plane strain conditions for CT specimen with 25.4mm thickness of SS400 steel. Fracture toughness. $J_{IC}$lit near crack tip of CT specimen by R-curve is 17.14 $kg_{f}/mm$ and however. its value by DCPD is 22.82 $Rg_{f} mm$ The value of fracture toughness by DCPD is larger than that by R-curve. Therefore, it is suggested that the evaluation of fracture toughness by R-curve is optimum than by DCPD, when considering amount of crack growth about each of fracture toughness.

• 전자통신동향분석
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• 제22권5호
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• pp.46-56
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• 2007

투명전자소자는 투명한 특성을 이용하여 기존의 전자기기가 가지고 있는 공간적/시각적 제약을 해소하려는 목적을 가진 소자이며 투명트랜지스터를 기반으로 한다. 투명 트랜지스터는 투명반도체(주로 산화물), 투명절연체, 투명전도체로 구성되어 있다. 투명 트랜지스터와 투명 OLED를 결합한 투명디스플레이에 정보 인식/정보 처리 기능이 추가로 구현되어 있는 공간 임베디드 정보 단말기를 스마트 창이라고 부른다. 투명전자소자는 초기에는 투명하지 않은 형태의 산화물 트랜지스터를 이용한 디스플레이 분야에 주로 이용될 가능성이 높고 2010년 이후에 투명 IC, 스마트 창 형태의 신규 시장이 창출될 것으로 예측된다. 또한, 투명전자소자 분야는 세계적으로 개발 초기단계이기 때문에 원천 특허 확보 등에 주력할 필요가 있다.