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

검색결과 3,152건 처리시간 0.036초

Experimental Investigation of R(ω), T(ω) and L(ω) for Multi-Layer SRRs and Wires Metamaterials

  • Luo, Hao;Wang, Xian;Liao, Zhangqi;Wang, Tao;Gong, Rongzhou
    • Journal of electromagnetic engineering and science
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    • 제10권3호
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    • pp.186-189
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    • 2010
  • Reflection(R($\omega$)), transmission(T($\omega$)) and loss(L($\omega$)) characteristics of multi-layer metamaterials are investigated experimentally in free space with the incident EM waves perpendicular to the substrate plane. The sample is made of split-ring resonators(SRRs) and wires which are the typical model of metamaterials. The R($\omega$) and T($\omega$) of multi-layer metamaterials have been calculated from the measured S-parameters. In this paper, we got the impedance-matched result according to the curves of R($\omega$), meanwhile the T($\omega$) decreased with increasing number of layers. At last, we attained the result that the L($\omega$) gets to nearly 98% around 8 GHz, with R($\omega$)=T($\omega$)=0. The design presented in this paper achieves experimented loss near unity.

A report of 7 unrecorded bacterial species isolated from several Jeju soil samples in 2016

  • Kim, Ju-Young;Jang, Jun Hwee;Maeng, Soohyun;Kang, Myung-Suk;Kim, Myung Kyum
    • Journal of Species Research
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    • 제7권2호
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    • pp.151-160
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    • 2018
  • Seven bacterial strains, 15J4M-1, 15J13-8, 16MFM10, 15J1-8, SR1-5-4, 15J13-6, and 15J8-11 assigned to the phylum Actinobacteria, Bacteroidetes, and Firmicutes were isolated from soil samples collected from Jeju, Korea. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strains 15J4M-1, 15J13-8, 16MFM10, 15J1-8, SR1-5-4, 15J13-6, and 15J8-11 were most closely related to Bacillus selenatarsenatis $SF-1^T$ (with 99.4% similarity), Brevibacterium luteolum $CF87^T$ (99.5%), Carnobacterium iners CCUG $62000^T$ (99.6%), Exiguobacterium profundum $10C^T$ (99.3%), Larkinella insperata LMG $22510^T$ (99.3%), Pseudokineococcus lusitanus CECT $7306^T$ (99.4%), and Spirosoma endophyticum $EX36^T$ (99.3%), respectively. This is the first report of these seven species in Korea.

Application of cohesive zone model to large scale circumferential through-wall and 360° surface cracked pipes under static and dynamic loadings

  • Moon, Ji-Hee;Jang, Youn-Young;Huh, Nam-Su;Shim, Do-Jun;Park, Kyoungsoo
    • Nuclear Engineering and Technology
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    • 제53권3호
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    • pp.974-987
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    • 2021
  • This paper presents ductile fracture simulation of full-scale cracked pipe for nuclear piping materials using the cohesive zone model (CZM). The main objective of this study is to investigate the applicability of CZM to predict ductile fracture of cracked pipes with various crack shapes and under quasi-static/dynamic loadings. The transferability of the traction-separation (T-S) curve from a small-scale specimen to a full-scale pipe is demonstrated by simulating small- and full-scale tests. T-S curves are calibrated by comparing experimental data of compact tension specimens with finite element analysis results. The calibrated T-S curves are utilized to predict the fracture behavior of cracked pipes. Three types of full-scale pipe tests are considered: pipe with circumferential through-wall crack under quasistatic/dynamic loadings, and with 360° internal surface crack under quasi-static loading. Computational results using the calibrated T-S curves show a good agreement with experimental data, demonstrating the transferability of the T-S curves from small-scale specimen.

Soft X-ray Absorption Spectroscopy via Reflectivity

  • Jang, H.;Ko, K.T.;Lee, J.S.;Khim, T.Y.;Lee, H.;Kim, J.Y.;Park, J.H.
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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    • pp.30.1-30.1
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    • 2007
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과학기술 분야 박사학위자의 직업다변화 및 결정요인 분석 (Occupational Diversification of Doctorates in Science and Technology)

  • 조가원
    • 기술혁신연구
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    • 제28권3호
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    • pp.55-76
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    • 2020
  • 한국에서 전통적인 과학기술인력 직업군의 경계는 빠른 속도로 허물어지고 있다. 한편으로는 지식기반경제의 등장과 확장으로 과학기술이 전통적 활용영역을 넘어 확산됨에 따라 과학기술인력 역시 다양한 융합분야로 진출하고 있으며, 동시에 고학력 인구의 비중에 비해 고급 직종의 비중이 상대적으로 낮은 데에서 기인한 하향취업이 그러한 경향을 가속화시킨다. 이 논문에서는 박사급 이공계 인력에 초점을 맞추어 직업구성의 변화 추이를 살펴보고 그 결정요인을 실증적으로 분석하고자 한다. 구체적으로, 관련 직종을 전통적 과학기술직업군과 기타 직업군으로 나누어 그 비중의 변화를 도출하며, 이러한 직업구조의 변화에 대한 영향요인을 분석한다. 분석에는 과학기술정책연구원의 '2012 박사인력활동조사' 데이터를 활용하였다. 분석 결과는 이공계 박사인력의 직업구성에 뚜렷한 변화가 일어나고 있음을 보여준다. 직업다변화는 공학보다는 이학 분야에서, 공공보다는 민간 분야에서, 그리고 신규 세대일수록 더 빠르게 진행되고 있었다.

S&T Policy Trend Using Language Network Analysis: Focusing on Science and Technology Basic Plan

  • Kim, Yun Jong;Jeong, Dae-hyun;Oh, Hyunchul
    • Asian Journal of Innovation and Policy
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    • 제6권2호
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    • pp.111-137
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    • 2017
  • This study analyzes a language network of Science and Technology Basic Plan, which is the basis for science and technology policy in Korea, for the next Science and Technology Basic Plan. Language network analysis was adopted for a quantitative approach measuring the trend of policies. Several techniques such as keyword analysis, language network map analysis, quantitative characteristics analysis and keyword-related major-word analysis have been performed. Results show that there are common policies emphasized by all Science and Technology Basic Plans in the past, and there are also specific policies emphasized in each period of the Science and Technology Basic Plan. These specific policies come from a 'change of times' when the Science and Technology Basic Plans were established, as well as the philosophy of the national government.

Activation of Ontact Research Using Science & Technology Knowledge Infrastructure ScienceON

  • Han, Sangjun;Shin, Jaemin;Lee, Seokhyoung;Park, Junghun
    • Journal of Information Science Theory and Practice
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    • 제10권spc호
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    • pp.1-11
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    • 2022
  • As data-based research activities and outcomes increase and ontact or non-face-to-face activities become common, the demand for easy utilization of resources, tools, functions, and easily accessible information required for research in the R&D sector has increased accordingly. With the rapid increase in the demand for collaborative research based on online platforms, research support institutions strive to provide venues for research activities that merge various information and functions. ScienceON, an integrated science & technology (S&T) knowledge infrastructure service developed and operated by the Korea Institute of S&T Information (KISTI), supports open collaboration by connecting and merging all the information, functions, and infrastructure required for research activities. This paper describes the online research activity support tool provided by ScienceON and the remarkable results achieved through this activity. Specifically, the excellent creation of the following flow of meta-material research activities in the ontact space is elucidated. First, the papers required for a meta-material analysis are retrieved, virtual simulation is conducted with the experimental data extracted from the papers, and research data are accumulated. ScienceON's tools for supporting ontact research activity will play a role as an important service in the era of digital transformation and open science.