• Title/Summary/Keyword: Science and Technology (S&T)

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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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    • v.10 no.3
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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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    • v.7 no.2
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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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    • v.53 no.3
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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.

Occupational Diversification of Doctorates in Science and Technology (과학기술 분야 박사학위자의 직업다변화 및 결정요인 분석)

  • Cho, Kawon
    • Journal of Technology Innovation
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    • v.28 no.3
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    • pp.55-76
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    • 2020
  • The traditional occupational boundaries of human resources in science and technology (S&T) have quickly blurred in Korea. On the one hand, the knowledge-based economy has emerged and S&T proliferated beyond conventional areas, leading scientists and engineers to advance into various convergence fields. On the other hand, Korea's labor market is characterized by a higher percentage of highly-educated human resources and a relatively smaller number of high-quality jobs. As a result, the highly educated in S&T have flowed over the traditional careers into non-S&T careers. Focusing on doctorates in S&T, this paper analyzes changes in their career patterns and identifies main determinants. Specifically, jobs are categorized into traditional STEM occupations and the others in order to identify fluctuations in their share and to analyze factors affecting such changes. The analyses are based on data from the 'Survey on Careers and Mobility of Doctorate Holders 2012' conducted by the Science and Technology Policy Institute. The results exhibit marked changes in the occupational composition of doctorates in S&T. Occupational diversification has been proceeded faster in natural sciences, the private sector, and the younger generation than in engineering, the public sector, and the older generation.

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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    • v.6 no.2
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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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    • v.10 no.spc
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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.