• Title/Summary/Keyword: Science and technology

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Concentration optimization of Tb/Yb co-doped alumino-germanosilicate optical fiber for upconversion visible laser applications

  • Lin, Aoxiang;Watekar, Pramod R.;Liu, Xueming;Cho, Hye-Jin;Chung, Young-Joo;Han, Won-Taek
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.02a
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    • pp.249-250
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    • 2008
  • We report on the visible photoluminescence of the Tb/Yb co-doped alumino-germano-silicate fibers for visible fiber laser application. By changing the concentration ratios of $Tb^{3+}$ to $Yb^{3+}$, we optimized the solution doping conditions and obtained the highest emission efficiency at 546nm. The luminescence intensity at 546nm was found to increase with the relative increase of $Tb^{3+}$ ions.

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Molecular Characterization of a Bombyx mori LIM protein

  • Hwang, Jae-Sam;Go, Hyun-Jeong;Youn, Eun-Young;Goo, Tae-Won;Choi, Kwang-Ho;Kim, Ik-Soo;Ahn, Mi-Young;Lee, Pyung-Jae;Kang, Seok-Woo;Seong, Su-Il
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 2004.04a
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    • pp.60-60
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    • 2004
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Design and Implementation of Content Switching Network Processor and Scalable Switch Fabric

  • Chang, You-Sung;Yi, Ju-Hwan;Oh, Hun-Seung;Lee, Seung-Wang;Kang, Moo-Kyung;Chun, Jung-Bum;Lee, Jun-Hee;Kim, Jin-Seok;Kim, Sang-Ho;Jung, Hee-Jae;Hong, Il-Sung;Kim, Yong-Hwan;Lee, Yu-Sik;Kyung, Chong-Min
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.3 no.4
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    • pp.167-174
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    • 2003
  • This paper proposes a network processor especially optimized for content switching. With 2Gbps port capability, it integrates packet processor cluster, content-based classification engine and traffic manager on a single chip. A switch fabric architecture is also designed for scale-up of the network processor's capability over hundreds gigabit bandwidth. Applied in real network systems, the network processor shows wire-speed network address translator (NAT) and content-based switching performance.

Topomer-CoMFA Study of Tricyclic Azepine Derivatives-EGFR Inhibitors

  • Chung, Jae-Yoon;Pasha, F.A.;Chung, Hwan-Won;Yang, Beom-Seok;Lee, Cheol-Ju;Oh, Jung-Soo;Moon, Myoung-Woon;Cho, Seung-Joo;Cho, Art E.
    • Molecular & Cellular Toxicology
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    • v.4 no.1
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    • pp.78-84
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    • 2008
  • EGFR has been intensively investigated as a target to block the signal transduction pathway which stimulates cancer growth and metastasis. Studies about structure-activity relationship for tricyclic azepine derivatives were performed with topomer-CoMFA. The derived topomer-CoMFA model with steric and electrostatic field parameters based on fragment units gave reasonable statistics ($q^2$=0.561, $r^2$=0.679). The model explains why a halogen atom at the meta position of aniline is important to increases inhibitory activity. This comes from an electrostatically negative groups are favored near this region. The model also shows that there are sterically favored regions around methoxy group extended from oxazepine derivatives. The findings about steric and electrostatic effects can be utilized for designing new inhibitors.

High Repetition Wavelength-locked 878.6 nm LD Dual-end-pumped Nd:YVO4 1064 nm Laser

  • Li, Yue;Yu, Yong-Ji;Wang, Yu-Heng;Liu, Hang;Liu, He-Yan;Jin, Guang-Yong
    • Current Optics and Photonics
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    • v.2 no.6
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    • pp.582-588
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    • 2018
  • A $Nd:YVO_4$ laser dual-end-pumped by a wavelength-locked 878.6 nm laser diode is presented. At the repetition rate of 500 KHz, the absorbed pump power of 58 W, an output power of 26.1 W at 1064 nm is obtained, corresponding to an optical-optical efficiency of 45%. The pulse width is 44.2 ns. Meanwhile, the effects of traditional 808 nm pumping and 878.6 nm dual-end-pumping on the output laser beam quality and pulse width are compared and analyzed in an experiment.

A Study on the Cooperation between the Humanities & Social Sciences and Natural Science & Technology (인문.사회과학과 과학기술부분 협력 방안에 관한 연구)

  • 이종수
    • Journal of Korea Technology Innovation Society
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    • v.3 no.3
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    • pp.125-140
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    • 2000
  • The paper studies on the cooperation between the humanities & social sciences and natural science & technology in 1990's. The article showed policy alternatives about the crisis of humanities & social sciences. That was science wars and we heard that was announced by Sokal affair. In this article, the author inquired into the Korean research policy's crisis and presented the policy alternatives about the crisis of humanities & social sciences and natural science & technology in various ways. In the concrete, the policy alternatives are cultural critique of technology and science and science & development of domain about interdisciplinary studies at the humanities & social science and natural science & technology. In conclusion, First, the author showed the appraisal and institutionalization of interdisciplinary studies. Second, the researcher proposed few policy alternatives and developmental area of interdisciplinary studies between the humanities & social sciences and natural science & technology.

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Wide-Tunable Mid Infrared Intra-cavity Optical Parametric Oscillator Based on Multi-period MgO:PPLN

  • Wang, Xiao-Chan;Wang, Yu-Heng;Zheng, Hao;Liu, Hong-Zhi;Yu, Yong-Ji;Wang, Zi-Jian
    • Current Optics and Photonics
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    • v.5 no.1
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    • pp.59-65
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    • 2021
  • This paper reports a tunable diode-pumped folded intracavity Q-switched singly resonant optical parametric oscillator based on multi-period MgO:PPLN. A wide tuning mid-infrared parametric light from 2.78 ㎛ to 4.17 ㎛ was obtained in real time by changing the poled periods and temperatures. The maximum output power of 1.89 W at 3.2 ㎛, 1.53 W at 3.5 ㎛, 0.87 W at 3.8 ㎛ and 0.486 W at 4.1 ㎛ were achieved. The highest optical-optical conversion efficiency was 7.89%. During experiments, a range tunable output of 2.78-4.17 ㎛ in the mid-infrared range was achieved.