• 제목/요약/키워드: Science and Technology (S&T)

검색결과 3,166건 처리시간 0.052초

Magnetic relaxation measurement of infinite layer superconductor Sr$_{0.9}$La$_{0.1}$CuO$_2$

  • Kim, Heon-Jung;Kim, Mun-Seog;Cung, C.U.;Kim, Ji-Yeon;Lee, Sung-Ik
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.121-124
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    • 2000
  • The time dependence of irreversible magnetization of grain aligned infinite layer superconductor Sr$_{0.9}$La$_{0.1}$CuO$_2$ was measured in temperature range of 2 K < T < 30 K for H= 0.5 T, 1.0 T and 1.5 T parallel to c-axis. From this, we calculated normalized flux creep rate S(T) ${\equiv}$ dlnM/dlnt and found that the temperature independent region in S(T) is significantly wide in comparision with other cuprate superconductors. Using the method of Maley et al., we also deduce the current density dependence of pinning potential and glassy exponent ${\mu}$.

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Coherent X-ray Diffraction Imaging with Single-pulse Table-top Soft X-ray Laser

  • Kang, Hyon-Chol;Kim, H.T.;Lee, S.K.;Kim, C.M.;Choi, I.W.;Yu, T.J.;Sung, J.H.;Hafz, N.;Jeong, T.M.;Kang, S.W.;Jin, Y.Y.;Noh, Y.C.;Ko, D.K.;Kim, S.S.;Marathe, S.;Kim, S.N.;Kim, C.;Noh, D.Y.;Lee, J.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2008년도 동계학술발표회 논문집
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    • pp.429-430
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    • 2008
  • We demonstrate coherent x-ray diffraction imaging using table-top x-ray laser at a wavelength of 13.9nm driven by 10-Hz ti:Sapphire laser system at the Advanced Photonics Research Institute in Korea. Since the flux of x-ray photons reaches as high as $10^9$ photons/pulse in a $20{\times}20{\mu}m^2$ field of view, we measured a ingle-pulse diffraction pattern of a micrometer-scale object with high dynamic range of diffraction intensities and successfully reconstructed to the image using phase retrieval algorithm with an oversampling ratio of 1:6. the imaging resolution is $^{\sim}150$ nm, while that is much improved by stacking the many diffraction patterns. This demonstration can be extended to the biological sample with the diffraction limited resolution.

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과학기술인 복지 정책에 관한 이론적 고찰 - Soft Infra 구축을 중심으로 - (Theoretical Review on the Welfare Policy of Science & Technology Personnel)

  • 이종민;박정수;황두희;정선양
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 2005년도 27회 하계학술발표회 논문집
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    • pp.140-158
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    • 2005
  • Science & Technology (S&T) is the most important thing to attain competitiveness in the 21st century. Our traditional S&T policies have been focused on hardware infra structure. But, we should consider soft infra of S&T to enhance welfare development of S&T personnel. S&T should be had a correct understanding method of the creation for S&T culture. It implies that S&T policy in the 21st century should consider non-material factors which include social, human, environment and culture. Under this background. This paper defines the concept of welfare of S&T personnel. Also this paper deals with the change of S&T policy of Korea and analyzes the characteristic of each phase. This paper argues that all actors (for example S&T personnel, corporate using S&T, public) should participate in the process of S&T innovation since the 21st century is the generation of popularization of S&T. The purpose of this paper is to suggest a few methods of welfare improvement of S&T personnel to reinforce soft infra structure of S&T.

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Re-Direction 기법을 활용한 전자원문 연계시스템 설계 및 구현 (Design and Implementation of Digital Contents Service System using Re-Direction Technique)

  • 조성남;이상환;이상기;황종선;정택영
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2004년도 춘계학술발표대회
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    • pp.1389-1392
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    • 2004
  • 정보통신 및 인터넷의 급속한 발전으로 전자원문 서비스 등 웹 서비스가 활발하게 이루어지고 있으나, 기존 웹 서비스에 대한 연구는 웹 서비스를 차별화하기 위해 HTTP의 속도지연 문제해결이나 서비스 차별화 방안에 대해 이루어지고 있다. 그러나, 타 시스템의 웹 서비스와 연계시 해당 웹 문서에 대한 제어권 확보에 관한 연구는 미미하다. 따라서, 본 논문에서는 타 시스템의 웹 문서에 대해 제어권 확보를 위해 Re-Direction Agent를 활용하여 해외전자원문 연계시스템을 구현하고자 한다.

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20(S)-Ginsenoside Rh2 displays efficacy against T-cell acute lymphoblastic leukemia through the PI3K/Akt/mTOR signal pathway

  • Xia, Ting;Zhang, Jin;Zhou, Chuanxin;Li, Yu;Duan, Wenhui;Zhang, Bo;Wang, Min;Fang, Jianpei
    • Journal of Ginseng Research
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    • 제44권5호
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    • pp.725-737
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    • 2020
  • Background: T-cell acute lymphoblastic leukemia (T-ALL) is a kind of aggressive hematological cancer, and the PI3K/Akt/mTOR signaling pathway is activated in most patients with T-ALL and responsible for poor prognosis. 20(S)-Ginsenoside Rh2 (20(S)-GRh2) is a major active compound extracted from ginseng, which exhibits anti-cancer effects. However, the underlying anticancer mechanisms of 20(S)-GRh2 targeting the PI3K/Akt/mTOR pathway in T-ALL have not been explored. Methods: Cell growth and cell cycle were determined to investigate the effect of 20(S)-GRh2 on ALL cells. PI3K/Akt/mTOR pathway-related proteins were detected in 20(S)-GRh2-treated Jurkat cells by immunoblotting. Antitumor effect of 20(S)-GRh2 against T-ALL was investigated in xenograft mice. The mechanisms of 20(S)-GRh2 against T-ALL were examined by cell proliferation, apoptosis, and autophagy. Results: In the present study, the results showed that 20(S)-GRh2 decreased cell growth and arrested cell cycle at the G1 phase in ALL cells. 20(S)-GRh2 induced apoptosis through enhancing reactive oxygen species generation and upregulating apoptosis-related proteins. 20(S)-GRh2 significantly elevated the levels of pEGFP-LC3 and autophagy-related proteins in Jurkat cells. Furthermore, the PI3K/Akt/mTOR signaling pathway was effectively blocked by 20(S)-GRh2. 20(S)-GRh2 suppressed cell proliferation and promoted apoptosis and autophagy by suppressing the PI3K/Akt/mTOR pathway in Jurkat cells. Finally, 20(S)-GRh2 alleviated symptoms of leukemia and reduced the number of white blood cells and CD3 staining in the spleen of xenograft mice, indicating antitumor effects against T-ALL in vivo. Conclusion: These findings indicate that 20(S)-GRh2 exhibits beneficial effects against T-ALL through the PI3K/Akt/mTOR pathway and could be a natural product of novel target for T-ALL therapy.

과학기술 전문용어의 다국어 의미망 생성과 분석 (Building and Analysis of Semantic Network on S&T Multilingual Terminology)

  • 정도헌;최희윤
    • 정보관리연구
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    • 제37권4호
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    • pp.25-47
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    • 2006
  • 다국어로 구축된 학술정보 시스템의 통합검색 환경을 구현하기 위해서는 다국어 전문용어에 대한 해석을 제공하고 전문용어의 분야별 분류정보를 제공할 수 있는 시스템이 필요하다. 본 연구는 이러한 다국어 환경의 통합 정보검색 시스템을 운용할 수 있도록 기반시스템을 구축하는 것을 목적으로 한다. 다국어 의미망으로 상호 연결된 과학기술 전문용어 체계를 구축하는 방법과 다단계 연결노드에 대한 최단거리 탐색 기법을 소개하였다. 또한, 생성된 용어군집 결과를 해석하기 위한 기초분석을 수행하여 향후 심도있는 분석연구를 수행하기 위한 기반을 마련하고자 하였다.

Preoperative Radiological Parameters to Predict Clinical and Radiological Outcomes after Laminoplasty

  • Lee, Su Hun;Son, Dong Wuk;Shin, Jun Jae;Ha, Yoon;Song, Geun Sung;Lee, Jun Seok;Lee, Sang Weon
    • Journal of Korean Neurosurgical Society
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    • 제64권5호
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    • pp.677-692
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    • 2021
  • Many studies have focused on pre-operative sagittal alignment parameters which could predict poor clinical or radiological outcomes after laminoplasty. However, the influx of too many new factors causes confusion. This study reviewed sagittal alignment parameters, predictive of clinical or radiological outcomes, in the literature. Preoperative kyphotic alignment was initially proposed as a predictor of clinical outcomes. The clinical significance of the K-line and K-line variants also has been studied. Sagittal vertical axis, T1 slope (T1s), T1s-cervical lordosis (CL), anterolisthesis, local kyphosis, the longitudinal distance index, and range of motion were proposed to have relationships with clinical outcomes. The relationship between loss of cervical lordosis (LCL) and T1s has been widely studied, but controversy remains. Extension function, the ratio of CL to T1s (CL/T1s), and Sharma classification were recently proposed as LCL predictors. In predicting postoperative kyphosis, T1s cannot predict postoperative kyphosis, but a low CL/T1s ratio was associated with postoperative kyphosis.

복숭아 농장 토양에서 Nematodes와 연관된 Lactobacillus spp.의 분리 및 동정 (Identification of Lactobacillus spp. associated with nematodes in peach farm soil)

  • 이우현;최재임;이진일;이원표;윤성식
    • 미생물학회지
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    • 제53권3호
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    • pp.163-169
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    • 2017
  • 복숭아 수확시기에 낙과한 토양에서 Lactobacillus sp. D4와 D5 균주를 분리하였다. 분리한 Lactobacillus sp. D4와 D5 균주를 동정하기 위하여 형태학적 동정, 생화학적 동정 및 16S rRNA 유전자서열 분석을 수행하였다. 16S rRNA 유전자서열 분석 결과 Lactobacillus sp. D4는 Lactobacillus plantarum subsp. plantarum ATCC $14917^T$과 Lactobacillus pentosus ATCC $40997^T$에 각각 99.05%, 98.98% 일치하였으며, Lactobacillus sp. D5는 Lactobacillus pentosus ATCC $40997^T$, Lactobacillus plantarum subsp. plantarum ATCC $14917^T$에 각각 98.71%, 98.64% 일치하였다. Lactobacillus sp. D4와 D5 균주는 당 이용성 비교에서 Lactobacillus plantarum ATCC $14917^T$과 Lactobacillus pentosus ATCC $8041^T$에 비교하여 다른 결과를 나타내었다. 정확한 동정을 위하여 VITEK MS matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) 분석, multiplex PCR, random amplified polymorphic DNA (RAPD)-PCR을 수행하였다. 이러한 결과에 근거하여 Lactobacillus sp. D4와 D5 균주는 Lactobacillus plantarum으로 동정되었다.

과학기술문화 하부구조에 관한 통계지표 분석 (An Analysis of Statistical Indicators on the Infrastructure of Science and Technology Culture in Korea)

  • 송성수
    • 과학기술학연구
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    • 제6권2호
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    • pp.185-205
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    • 2006
  • 이 글에서는 과학기술국민이해도조사를 비롯한 다양한 자료를 활용하여 우리나라의 과학기술문화 하부구조에 관한 통계지표를 분석하였다. 유형적 하부구조의 경우에는 인터넷을 제외하면 과학관, 과학기술 TV 프로그램, 과학기술도서 등 유형적 하부구조의 확보율은 매우 낮은 수준이며, 이에 대한 활용도는 전반적으로 저조하지만 약간 증가하고 있는 추세를 보이고 있다. 무형적 하부구조와 관련해서는 일반 국민의 과학 기술에 대한 관심 및 이해가 아직 저조하고 과학기술자의 사회적 중요성에 비해 사회적 대우가 낮으며, 과학기술정책에 대한 과학기술자와 시민단체의 참여가 제한적인 것으로 나타나고 있다. 과학기술문화 통계지표의 발전을 위해서는 개인적 제도적 사회적 맥락을 고려한 조사, 특정한 집단에 대한 조사, 과학기술문화백서의 발간 등이 필요하다.

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