• 대한전자공학회논문지TC
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• 제44권12호
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• pp.8-15
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• 2007

본 논문에서는 기존의 Right/left-handed 전송선(RLH-TL)에 집중 직렬 캐패시터와 병렬 인덕터 구현으로 발생하는 방사 효과를 포함하여 단위 셀을 모델링한다. 방사 효과가 고려된 RLH-TL 단위셀의 등가 회로를 제공하고 갭 커패시터와 션트 인터터에서의 방사율에 따른 Bloch 임피던스와 복소 전파상수를 해석한다. 두 개의 방사율이 같을 때 RLH-TL의 Block 임피던스는 RH-TL의 특성임피던스와 같아짐을 보인다. 게다가, 주어진 주파수에서 특정한 위상 변화를 위한 단위 셀의 설계 공식을 유도하여 제공한다. 마지막으로, 안테나 응용을 위해 RLH-TL에서 다양한 방법으로 방사효과를 control할 수 있는 설계 공식을 제공한다.

• Journal of Electrochemical Science and Technology
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• 제13권3호
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• pp.354-361
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• 2022

In a direct methanol fuel cell system (DMFC), one of the drawbacks is methanol crossover. Methanol from the anode passes through the membrane and enters the cathode, causing mixed potential in the cell. Only Pt-based catalysts are capable of operating as cathode for oxygen reduction reaction (ORR) in a harsh acidic condition of DMFC. However, it causes mixed potential due to high activity toward methanol oxidation reaction of Pt. To overcome this situation, developing Pt-based catalyst that has methanol tolerance is significant, by controlling reactant adsorption or reaction kinetics. Pt/C decorated with phosphate ion was prepared by modified polyol method as cathode catalyst in DMFC. Phosphate ions, bonded to the carbon of Pt/C, surround free Pt surface and block only methanol adsorption on Pt, not oxygen. It leads to the suppression of methanol oxidation in an oxygen atmosphere, resulting in high DMFC performance compared to pristine Pt/C.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.53-53
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• 2003

The aim of this study was to determine the interactive effects of BSA and EGF on the viability and development of porcine diploid parthenotes developing in vitro. The addition of 0.1 and 0.4% BSA to the culture medium enhanced the development of 4-cell parthenotes to the blastocyst stage but EGF had no effect. However, while BSA also increased cell numbers, it did so only when EGF was also present. Either agent on its own had no effect. Similarly, apoptosis in the blastocysts was not influenced by either agent on its own but was reduced when both BSA and EGF were present. Furthermore, semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) revealed that EGF enhanced the mRNA expression of BclxL in the presence of 0.4% BSA but BSA and EGF alone had no effect. EGF and/or BSA did not influence Bak gene expression in the blastocyst stage parthenotes. These results suggest that BSA has both beneficial and detrimental effects on the viability of porcine diploid parthenotes developing in vitro and that exogenous EGF may block some of the detrimental effects of BSA, possibly by inhibiting the BSA-induced apoptosis by increasing Bcl-xL expression. This results in a net increase in cell numbers in porcine diploid parthenotes developing in vitro.

• 대한골관절종양학회지
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• 제13권2호
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• pp.67-74
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• 2007

목적: 골의 거대세포종양의 재발과 면역조직화학적 표지자와의 연관성을 연구하였다. 대상 및 방법: 골에서 유발된 거대세포종양 10례를 대상으로 하였다. 6명은 남자, 4명은 여자였다. 모든 환자는 수술 전 생검을 통해 확진 후 수술을 시행하였다. 방사선학적 분류는 Enneking grading system에 의하여 이루어졌다. 면역조직화학적 연구를 위해 MCM3, Ki-67 그리고 HH3 표지자가 사용되었다. 면역조직화학적 검사는 Microarray block을 사용하여 시행하였다. 결과: 10례 중 3례(30%)에서 같은 위치에서 재발되었다. 재발된 3례 중 2례는 방사선학적 단계 상 단계 2였고, 1례는 단계 1이었다. 면역조직화학적 표지자의 발현율이 방사선학적 단계 1보다 2, 3에서 증가되었다. 하지만 결과의 일관성이 없어 세포 증식율과 방사선학적 단계의 연관성은 판별하기 어렵다. 평균 MCM3 표지자의 발현율은 재발하지 않은 종양에서 11.2%, 재발한 종양에서 7.2%였다. Ki-67은 12%, 8.9% 였고, HH3는 66.9%, 75.4%였다. MCM3 와 Ki-67 표지자는 재발한 종양에서 오히려 감소된 결과를 보여 재발율과는 연관이 없을 것으로 생각된다. HH3표지자는 재발한 종양에서 증가된 소견을 보여 거대세포종양의 재발과 연관이 있음을 보여주었다. 결론: 본 연구는 면역조직화학적 표지자 중 HH3표지자가 거대세포종양의 재발 가능성을 판정하는데 기준이 될 수 있을 것으로 생각된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.91-94
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• 2012

본 논문에서는 국내 표준(KS)으로 제정된 블록암호 알고리듬 ARIA의 효율적인 하드웨어 구현을 제안한다. 제안된 ARIA 암 복호 프로세서는 표준에 제시된 세 가지 마스터 키 길이 128/192/256-비트를 모두 지원하도록 설계되었으며, 회로의 크기를 줄이기 위해 키 확장 초기화 과정과 암 복호 과정에 사용되는 라운드 함수가 공유되도록 설계를 최적화 하였으며, 이를 통해 게이트 수를 약 20% 감소시켰다. 설계된 ARIA 암 복호 프로세서를 FPGA로 구현하여 하드웨어 동작을 검증하였으며, 0.13-${\mu}m$ CMOS 셀 라이브러리로 합성한 결과 33,218 게이트로 구현되어 640 Mbps@100 MHz의 성능을 갖는 것으로 평가되었다.

• Journal of Pharmaceutical Investigation
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• 제41권2호
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• pp.111-115
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• 2011

pH-sensitive cross-linked polymeric micelles were synthesized by using block ionomer complexes of poly(ethylene oxide)-b-poly(methacrylic acid) (PEO-b-PMA) with calcium ions as micellar templates. An anticancer drug, doxorubicin (DOX) was conjugated on the cross-linked ionic cores of micelles via acid-labile hydrozone bonds. The resulting DOX-conjugated, pH-sensitive micelles are stable at physiological conditions, whereas the release of DOX was significantly increased at the acidic pH. Such micelles were internalized to lysosomes, and acidic pH in lysosomes triggers the release of DOX upon internalization in MCF-7 breast cancer cells. The released DOX entered the cell nucleus and eventually killed cancer cells. Therefore, these data demonstrate that the pH-sensitive micelles could be a promising nanocarrier for delivery of anticancer drug, DOX.

• Progress in Superconductivity
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• 제6권1호
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• pp.7-12
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• 2004

Due to the very fast switching speed of Josephson junctions, superconductive digital circuit has been a very good candidate fur future electronic devices. High-speed and Low-power microprocessor can be developed with Josephson junctions. As a part of an effort to develop superconductive microprocessor, we have designed an RSFQ 4-bit ALU (Arithmetic Logic Unit) in a pipelined structure. To make the circuit work faster, we used a forward clocking scheme. This required a careful design of timing between clock and data pulses in ALU. The RSFQ 1-bit block of ALU used in this work consisted of three DC current driven SFQ switches and a half-adder. We successfully tested the half adder cell at clock frequency up to 20 GHz. The switches were commutating output ports of the half adder to produce AND, OR, XOR, or ADD functions. For a high-speed test, we attached switches at the input ports to control the high-speed input data by low-frequency pattern generators. The output in this measurement was an eye-diagram. Using this setup, 1-bit block of ALU was successfully tested up to 40 GHz. An RSFQ 4-bit ALU was fabricated and tested. The circuit worked at 5 GHz. The circuit size of the 4-bit ALU was 3 mm ${\times}$ 1.5 mm, fitting in a 5 mm ${\times}$ 5 mm chip.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.254-254
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• 2006

The sensitivity of plasmid DNA (pDNA) to S1 nuclease, an enzyme to cleave a single-strand DNA, was dramatically modulated through a supramolecular assembly (polyion complex micelle) with a synthetic block copolymer, poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL). The pDNA condensed in stoichiometric charge ratio was cleaved into 7 fragments each being 10/12, 9/12, 8/12, 6/12, 4/12, 3/12, and 2/12 of the original DNA length, on the other hand, the pDNA condensed in higher charge ratios (>4), were digested into non-specific manner. Condensation of the pDNA was investigated from two viewpoints that how does the rigid DNA molecules fold and condense and how does the condensation influence their biological activity.

• 한국전산유체공학회지
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• 제2권1호
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• pp.46-53
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• 1997

The flow field around a three dimensional minivan-like body has been simulated. This study solves 3-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system using second-order accurate schemes for the time derivatives, and third/second-order scheme for the spatial derivatives. The Marker-and-Cell concept is applied to efficiently solve continuity equation. A H-H type of multi-block grid system is generated around a three dimensional minivan-like body. Turbulent flows have been modeled by the Baldwin-Lomax turbulent model. To validate present procedure, the flows around the Ahmed body with 12.5° of slant angle are simulated. A good agreement with other numerical results is achived. After code validation, the flows around a mimivan-like body are simulated. The simulation shows three dimensional vortex-pair just behind body. The flow separation is also observed on the rear of the body. It has concluded that the results of present study properly agreed with physical flow phenomena.

• Applied Microscopy
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• 제35권4호
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• pp.10-15
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• 2005

신경연접 구조 관찰을 위한 방법으로 hydrofluoric acid 용액을 이용하여 유리 커버글라스 위에 배양된 신경세포의 전자현미경 관찰을 위한 편리한 시료제작법을 제시하였다. 배양된 신경세포의 TEM관찰을 위한 전체적인 시편제작 방법은 일반적인 전자현미경 시편 준비법과 큰 차이가 없으나 시료 블록을 제작한 후 유리 커버글라스를 효과적으로 제거하는 것이 가장 큰 차이점이다. 유리 커버글라스의 제거를 위해 열중합 반응이 끝난 시료 블록은 유리 커버글라스를 완전히 노출시켜 48% hydrofluoric acid 용액이 들어있는 플라스틱 비이커에 넣어 $5{\sim}10$분간 처리하여 유리 커버글라스를 완전히 제거한 후, 흐르는 물로 충분히 세척하고 상온에서 건조하여 사용하였다. 유리 커버글라스가 제거된 시료 블록은 실체 현미경을 이용하여 관찰하고자 하는 부위를 선정한 후 절삭하여 절편을 제작하였다.