• 제목/요약/키워드: LiGA

검색결과 188건 처리시간 0.032초

장갑표적 감지센서용 94GHz 도파관 하모닉 전압조정발진기 설계 기법 (A Design Method of the 94GHz(W-Band) Waveguide Harmonic Voltage Controlled Oscillator for the Armor Sensor)

  • 노진입;최재현;리준문;안병철
    • 한국군사과학기술학회지
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    • 제8권3호
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    • pp.64-72
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    • 2005
  • In this paper, we propose a design method of the millimeter-wave(W-Band) waveguide cavity harmonic voltage controlled oscillator(VCO) using a Gunn diode for the armor sensor. Using the 3-dimensional simulation tool(Ansoft $HFSS^{TM}$), we were able to find the impedance matching point between waveguide and Gunn diode and estimate the oscillation frequency. A varactor diode is used for the frequency tuning, and we find out the equation for the calculation of the tunable frequency range. The designed VCO shows good performances; 17dBm output power at 94GHz center frequency, 520MHz frequency tuning range similar to the estimated value(480MHz).

전면 발광 유기발광다이오드의 마이크로 캐비티 효과에 관한 연구 (A study on the effect of micro cavity of top emission organic light-emission diode)

  • 한가람;김일영;민상홍;김현수;홍진수;김창교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1513-1514
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    • 2011
  • 본 논문에서는 양극을 Ni, Au, Ag 등으로 하여 소자를 만들어 본 후에 가장 효율이 좋은 금속으로 양극을 정하고 유기물 층의 두께에 따른 마이크로 캐비티에 의한 스펙트럼의 이동효과를 시뮬레이션을 통해 살펴보았다. 소자의 기본 구조는 전면 발광 방식으로 양극/NPB/Alq3/LiF/Al이다. 음극을 LiF/Al과 Mg/Ag로 구조로 제작한 후에 기본 구조와 결과를 비교하였다. 실험결과를 시뮬레이션 결과와 비교 검토하였다.

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Floating zone 법에 의한 $LiNbO_3$ 단결정의 광학적 특성에 관한 연구 (A study on the optical properties of $LiNbO_3$ single crystal grown by Floating zone method)

  • 고정민;조현;김세훈;최종건;오근호
    • 한국결정성장학회지
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    • 제5권4호
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    • pp.318-331
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    • 1995
  • Hologen lamp를 열원으로 한 적외선 집중가열 방식의 Floating zone법을 이용하여 조화융해조성(48.6 mol% $Li_2O : 51.4 mol% LiNbO_3$)의 $LiNbO_3$ 단결정과 여기에 5 mol%의 MgO를 첨가한 $LiNbO_3$:5mod%MgO 단결정을 c-축으로 성장시켰다. 고품질의 광학용 $LiNbO_3$ 결정을 성장시키기 위해 원료봉의 최적 소결조건 및 성장 분위이게 따른 원료봉/융액 계면에 대한 고찰을 하였고, 이를 바탕으로 하여 ga s flow rate, pulling rate, 원료봉과 종자정의 회전속도 등에 대한 최적의 결정성장 조건을 확립하였다. 성장된 결정에 대해서 chemical etching을 통한 etch pattern과 ICP(Inductively Coupled Plasma) 분석을 통한 조성 변동 및 불순물 Fe 함량을 조사하였고, 5 mol% MgO의 첨가에 따른 투과율과 굴절율의 변화를 관찰하였다. 또한 $LiNbO_3$의 비선형 광학특성에 대해서는 측정한 굴절율 값을 data로 하여 비선형 광학 굴절율 $n_2$를 계산하여 다른 광학물질과 비교하였고, 이와 관련하여 비선형 광학특성에 대한 전반적인 고찰을 하였다.

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잉글리쉬 라벤다의 종자발아(種子發芽)에 대한 온도(溫度), 광(光) 및 생육조절물질(生長調節物質)의 영향(影響) (Effects of Temperature, Light and Plant Growth Regulators on the Seed Germination of Lavandula angustifolia Mill)

  • 이현일;강원희;유창연;김일섭
    • 한국약용작물학회지
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    • 제6권4호
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    • pp.258-264
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    • 1998
  • 본(本) 연구(硏究)는 잉글리쉬 라벤다의 실생번식(實生繁殖)을 통한 대량증식(大量增殖) 체계확립(體系確立)을 위하여 종자발아(種子發芽)에 미치는 온도(溫度), 광(光), 및 생장조절물질(生長調節物質)의 효과(效果)를 조사(調査)하였는던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. $4^{\circ}C$ 항온기(恒溫器)에 건조보관(乾燥保管)한 종자(種子)는 4% 정도(程度)의 극히 낮은 발아율(發芽率)을 보였다. 2. 광의 효과는 9주간 층적처리(層積處理)한 종자에서 명발아(明發芽)가 암발아(暗發芽)에 비해 발아율(發芽率)이 15%이상 증가(增加)하였고, 이러한 차이는 암상태(暗狀態)에서 $GA_3$ 1000mg/L 처리에 의하여 극복(克服)되어 $GA_3$가 부분적으로 광대체(光代替) 효과(效果)가 있는 것으로 나타났다. 3. $GA_3$ 용액(溶液)을 처리한 종자(種子)에서 발아적온(發芽適溫)은 $25^{\circ}C$인 것으로 나타났다. 4. 발아율(發芽率) 향상(向上)을 위한 방법(方法)으로, $GA_3$ 처리는 $500{\sim}2000mg/L$ 농도(濃度)에서 75% 정도(程度)의 높은 발아율(發芽率)을 보였고, $GA_3$와 BA의 조합처리(組合處理)는 $GA_3$ 1000mg/L+BA 10mg/L가 $GA_3$, 단독처리(單獨處理)에 비해 10%정도의 발아율(發芽率) 향상(向上)을 보였다. 저온층적처리(低溫層積處理)는 $4^{\circ}C$에서 $9{\sim}12$주간 모래 습윤저장(濕潤貯藏)한 종자가 발아율(發芽率)이 70% 이상으로 가장 높았고, 평균발아일교(平均發芽日敎)도 3日 이내(以內)로 단축(短縮)되었다. 또한 층적처리(層積處理) 종자에 대한 $GA_3$ 처리는 6주 이내(以內)의 층적처리(層積處理) 종자가 효과적(效果的)인 것으로 나타났다. 5. $GA_3$처리에 의한 종자(種子)의 출아율(出芽率)은 vermiculite : peatmoss (1 : 1, v/v) 혼합상토(混合床土)에서 무처리 0.7%에 비해 $GA_3$ 1000mg/L처리는 65%로 높게나타났다.

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Non-Benzoquinone Geldanamycin Analog, WK-88-1, Induces Apoptosis in Human Breast Cancer Cell Lines

  • Zhao, Yu-Ru;Li, Hong-Mei;Zhu, Meilin;Li, Jing;Ma, Tao;Huo, Qiang;Hong, Young-Soo;Wu, Cheng-Zhu
    • Journal of Microbiology and Biotechnology
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    • 제28권4호
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    • pp.542-550
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    • 2018
  • Heat shock protein 90 (Hsp90) is treated as a molecular therapeutic target for the prevention and treatment of cancer. Geldanamycin (GA) was the first identified natural Hsp90 inhibitor, but hepatotoxicity has limited its clinical application. Nevertheless, a new GA analog (WK-88-1) with the non-benzoquinone skeleton, obtained from genetically engineered Streptomyces hygroscopicus, was found to have anticancer activity against two human breast cancer cell lines. WK-88-1 produced concentration-dependent inhibition of cell proliferation, cell cycle arrest, and apoptosis in estrogen receptor (ER)-positive MCF-7 and ER-negative MDA-MB-231 cell lines. Detailed analysis showed that WK-88-1 downregulated some key cell cycle molecules (CDK1 and cyclin B1) and lead to $G_2/M$ cell cycle arrest. Further studies also showed that WK-88-1 could induce human breast cancer cell apoptosis by downregulating Hsp90 client proteins (Akt, p-Akt, IKK, c-Raf, and Bcl-2), decreasing the ATP level, increasing reactive oxygen species production, and lowering the mitochondrial membrane potential. Meanwhile, we discovered that WK-88-1 significantly decreased the levels of Her-2 and $ER-{\alpha}$ in MCF-7 cells but not in MDA-MB-231 cells. In addition, WK-88-1 significantly increased caspase-3, -8, and -9 activities and the cleavage of PARP in a concentration-dependent manner (with the exception of caspase-3 and PARP in MCF-7 cells). Taken together, our preliminary results suggest that WK-88-1 has the potential to play a role in breast cancer therapy.

휴대폰용 2인치 LCD-BLU의 광특성에 미치는 광학패턴 세장비의 영향 연구 : I. 광학 해석 및 설계 (A Study on the Effect of Optical Characteristics in 2 inch LCD-BLU by Aspect Ratio of Optical Pattern : I. Optical Analysis and Design)

  • 황철진;고영배;김종선;윤경환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.239-242
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    • 2006
  • LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LGP (Light Guiding Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50{\sim}200$ um in diameter on it by etching process. But the surface of the etched dots of LGP is very rough due to the characteristics of the etching process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched dot patterned LGP, optical pattern design with 50um micro-lens was applied in the present study. The micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different aspect ratio (i.e. $0.2{\sim}0.5$) of optical pattern conditions to the brightness distribution of BLU with micro-lens patterned LGP. Finally, high aspect ratio micro-lens patterned LGP showed superior results to the one made by low aspect ratio in average luminance.

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The CCND1 G870A Gene Polymorphism and Brain Tumor Risk: a Meta-analysis

  • Qin, Ling-Yan;Zhao, Li-Gang;Chen, Xu;Li, Ping;Yang, Zheng;Mo, Wu-Ning
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3607-3612
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    • 2014
  • Background: In recent years, numerous studies have been performed to investigate the CCND1 G870A gene polymorphism impact on brain tumors susceptibility. Unfortunately, the results of previous studies were inconsistent. Therefore, we performed a meta-analysis to derive a more precise estimation of any association. Materials and Methods: We conducted a search in PubMed, Embase and CNKI covering all published papers up to November, 2013. Odds ratios (ORs) and their 95% confidence intervals (95%CIs) were applied to assess associations. Results: A total of 6 publications including 9 case-control studies met the inclusion criteria. The pooled ORs for the total included studies showed significant association among comparison A vs G (OR= 1.246, 95%CI= 1.092-1.423, p= 0.001), homozygote comparison AA vs GG (OR= 1.566, 95%CI= 1.194-2.054, p= 0.001), heterozygote comparison AG vs GG (OR= 1.290, 95%CI= 0.934-1.782, p= 0.122), dominant model AA/GA vs GG (OR= 1.381, 95%CI= 1.048-1.821, p= 0.022) and recessive model AA vs GA/GG (OR= 1.323, 95%CI= 1.057-1.657, p= 0.015) especially in glioma. Conclusions: CCND1 G870A polymorphism may increase brain tumor risk, especially for gliomas. However, more primary large scale and well-designed studies are still required to evaluate the interaction of CCND1 G870A polymorphism with brain tumor risk.

휴대폰용 2 인치 LCD-BLU의 광특성에 미치는 음각 및 양각 광학패턴의 영향 연구 :I. 광학 해석 및 설계 (A Study on the Effect of Optical Characteristic in 2 inch LCD-BLU by Negative and Positive Optical Pattern :I. Optical Analysis and Design)

  • 황철진;고영배;김종선;윤경환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.75-76
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    • 2006
  • LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50{\sim}200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current dot patterned LGP, optical pattern design with $50{\mu}m$ micro-lens was applied in the present study. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different pattern conditions to the brightness distribution of BLU with micro-lens patterned LGP. Finally, negative micro-lens patterned LGP showed superior results to the one made by positive in average luminance.

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