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Synthesis of Conductive Polymer Nano-wires by Porous Membrane Template (다공막 주형에 의한 전도성 고분자 나노와이어의 합성)

  • Shin, Hwa-Sup;Youm, Kyung-Ho
    • Membrane Journal
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    • v.22 no.1
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    • pp.35-45
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    • 2012
  • We prepared the highly ordered nano-wires of polypyrrole, polyaniline conductive polymers and polypyrrole/ polyaniline conductive copolymers by templating the anodic aluminum oxide (AAO) porous membrane, in which pore diameter was 20 nm, 100 nm and 200 nm. Those conductive polymers were grown from pore inner surface of AAO membrane forming hollow tubes and then wire structures were formed after 3 hour polymerization. By removing AAO membrane templates using sodium hydroxide solution, the conductive polymer nano-wires were successfully obtained, of which diameter and length were close to the ones of nano-pores in AAO membrane template. Crystallinity and thermal stability of the conductive polymer nano-wires were higher than irregular ones that prepared by solution polymerization. Furthermore, the electrical resistance of conductive polymer nano-wires were reduced by about 4~60% compared with that of the irregular polymers prepared by solution polymerization.

An Extraction Algorithm of Compound Field-associated Terms for Korean Document Classifications (한글문서 분류용으로 이용할 복합어로 구성된 분야연상어의 추출법)

  • Lee, Samuel Sang-kon
    • Journal of KIISE:Software and Applications
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    • v.32 no.7
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    • pp.636-649
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    • 2005
  • Field-associated Terms itself have field Information. So, they determine field of document just like when human being perceives field. In case of Korean, we organized and experimented them by collecting approximately IS,999 document banks that are classified into 180 fields. We obtained high precision of extraction that 88,782 single field-associated terms are contracted into 8,405 ones thus recording compression rate as approximately 9$\%$ and recall as above 0.77 (average 0.85), precision as above 0.90 (average 0.94). By applying established field-associated terms to initial determination for document classification and comparing it with filed determination by human being, we got correct answers above approximately 90$\%$. We can use results of research as fundamental research for initial stage and apply it document retrieval between multilingual environment thus utilizing it as fundamental research for multilingual information retrieval.

Elementary Studies on the Fabrication and Characteristics of One-dimensional Nanomaterials

  • Kim, Hyeon-U
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.150-150
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    • 2012
  • 본 연구는 1차원 나노 구조의 합성과 기초적 분석에 관한 연구로써 특히 무기 산화물 나노재료를 그 대상으로 하였다. 내용으로는 첫째, 1차원 코어 나노와이어의 합성을 하였고 Thermal evaporation, substrate의 가열, 그리고 MOCVD 를 사용한 결과들을 나열한다. 둘째, 코어-쉘 나노와이어를 제작하기 위하여 특히 쉘층의 제작방법을 연구하였는데 PECVD, ALD, 그리고 sputtering에 의한 결과들을 나열하고 간단히 설명한다. Thermal evaporation에 의한 1차원 나노와이어 합성의 경우는 MgO의 예를 들었는데 MgO 나노와이어는 Au가 증착된 기판을 열처리하여 Au dot를 형성하고 이의 morphology를 조절하여 최적의 나노와이어 합성조건을 선정하였다. 이로써 기판 morphology가 나노선의 성장및 형상에 영향을 준다는 사실을 알게 되었다. 이 사실은 In2O3기판을 사용하고 이의 표면거칠기를 열처리로 조절하므로써 역시 나노와이어의 성장을 촉진하는 방법을 찾아내었다. 또한 thermal evaporation공법은 source분말의 선택에 따라 다양한 소재를 제작가능하다는 결과를 제시하였다. 예를 들면 SiOx 층이 precoating된 chamber내에서 MgO 나노선을 합성하는 것과 동일한 조건으로 실험을 진행하면 Mg2SiO4 나노와이어가 형성된 것을 확인하였다. 또한 Sn과 MgB2 분말을 함께 적용할 경우 Sn tip을 가진 MgO 나노와이어를 얻을 수 있었다. 이는 Sn이 동시에 촉매의 역할을 하였기 때문일 것으로 추정된다. 한편 Sn과 Bi 혼합분말을 적용한 경우 Bi2Sn2O7 신소재 tip을 포함한 SnO2 나노와이어를 얻을 수 있었다. 이 경우 Bi원자가 적절한 촉매의 역할을 수행한 것으로 사료된다. Substrate의 가열공법에서는 Si wafer상에 각종 금속 즉 Au, Ag, Cu, Co, Mo, W, Pt, Pd등 초박막을 DC sputter 로 형성한후 annealing하는 기술을 사용하였다. 특기할 만한 것은 Co를 사용한 경우 나노와이어의 spring구조를 얻을 수 있었다는 점이다. MOCVD에 의하여는 Ga2O3및 Bi2O3 나노와이어를 비교적 저온에서 합성하였고 In2O3의 경우는 독특한 나노구조를 형성하였고 이의 결정학적 특성에 대하여 조사하였다.

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A Study of the Theoretical Ethics Approach to Bioethics - Based on the ethics of Singer, Kant, and Aristotle - (생명윤리에 대한 이론 윤리학 탐구 - 싱어, 칸트, 아리스토텔레스 윤리학을 중심으로 -)

  • Kwak, Young-kuen
    • Journal of Korean Philosophical Society
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    • v.146
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    • pp.1-24
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    • 2018
  • The purpose of this paper is to explore the meaning of theoretical ethics regarding bioethics. First, I explore the meanings and limitations of the bioethics domain for 'the principle of equal consideration of interests' and the 'preference utilitarianism' concepts Singer presents. Secondly, I emphasize the significance of Kant's ethics in the domain of bioethics. Lastly, I suggest that Aristotle's virtue ethics should be realized in the domain of bioethics. Furthermore, I would like to suggest the meaning of human life through this. Singer's argument brings up a new topic about the meaning of evolved life not considered in the history of traditional ethics. He presented undeniable opinions about human dignity that he took for granted. In addition, it is assessed that the scope extension for the life respect target has been reasonably achieved. Contrary to this, Kant's ethics explains the meaning of human dignity based on its metaphysical meaning. Furthermore, it provides an appropriate orientation for human life. Embracing their claims is not sufficient to explain the meaning of Good Life. The meaning of Good Life is likely to be resolved through the application of Aristotle's virtue ethics. The meaning of a being of substance is living and furthermore, it is inherent to being itself.

Study on Determining Core Journals and Network Analysis in the Field of Disaster & Safety (재난안전 분야 핵심 학술지 탐색 및 네트워크 분석 연구)

  • Kim, Byungkyu;You, Beom-Jong
    • Journal of the Korean Society for Library and Information Science
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    • v.53 no.4
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    • pp.373-397
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    • 2019
  • Recent disasters are a complex and growing trend. In order to effectively prepare for and respond to disasters that occur without notice, it is very important to use scientific information related to disaster and safety in addition to the standardized disaster safety information that is used. In this paper, we searched and selected major journals in the field of disaster & safety and conducted various network analysis studies using the classification scheme for development of integrated metadata for disaster & safety information developed through Disaster & Safety Information Sharing Platform R&D project as well as KSCD. Also, we have constructed and analyzed citation network, co-authorship network and keyword network through data identification and preprocessing of research paper contents. As a result of this study, based on the network constructed by information analysis unit, the network structure between core domestic and foreign journals, major research institutes, core keywords and individual information by disaster & safety type was identified in detail, and the analysis results were presented on a case-by-case basis.

Metadata for records management in the current and semi-current stages (현용·준현용 단계의 기록관리를 위한 메타데이터)

  • Kwag, Jeong
    • The Korean Journal of Archival Studies
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    • no.16
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    • pp.3-37
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    • 2007
  • The new environment for records managements requires the revolutionary transition from paper-record management to electric-record management. Capturing contents, contexts, and structure informations of the electric records to preserve the evidentiality, authenticity, and reliability is the outstanding issue. The recordkeeping metadata has been placed at the center of the current issue. This study focused on the establishment of the structures of recordkeeping metadata for current and semi-current stages in the life cycle of records. The reason concentrated on current and semi-current stages is that the authenticity of the record is concerned as the evidence of the business processes. Current and semi-current stages are where the records is able to be produced, captured and managed in the business context. The metadata can be collected and preserved with authenticity. This study explained the relations between entities concerned with producing records and proposed the metadata elements by establishing data model.

One-pot Synthesis of Hydrous MnO2 Nanowires for Selective Oxidative Transformation of Furfuryl Alcohol (Furfuryl 알코올의 선택적 산화 전환에 대한 수화 이산화망간 나노와이어의 One-pot 합성)

  • Mobina, Irshad;Choi, Bong Gill;Kim, Jung Won
    • Applied Chemistry for Engineering
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    • v.30 no.1
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    • pp.49-53
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    • 2019
  • Hydrous $MnO_2$ nanowires were easily synthesized by an one-pot synthesis with a simple hydrothermal method. As prepared hydrous $MnO_2$ nanowires were characterized with scanning emission microscopy (SEM), transmit emission microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET). They showed a good catalytic activity with the suitable nano-size of 4-5 nm and morphology. The furfuryl alcohol was selected as a substrate and the reaction was carried out in a toluene solvent at $100^{\circ}C$ under the atmospheric pressure of oxygen. The hydrous $MnO_2$ nanowire catalyst exhibited an excellent yield of furfural with the first-rate selectivity and conversion. The catalytic performance during recycle tests was also carried out and the catalyst showed a good mechanical strength with a negligible loss in the activity over five reaction cycles.

Prediction of 123I production using the monte Carlo code MCNPX (몬테 칼로 전산코드 MCNPX를 이용한 I-123 생산량 예측)

  • Yoo, Jae jun;Kim, Gyehong;Kim, Byung il;Lee, Donghoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.816-818
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    • 2014
  • Gas target chamber has been developed for producing $^{123}I$ which is radiopharmaceuticals for diagnosis of thyroid cancer, and modeled how to occur nuclear reaction between chamber and $^{124}Xe$ with energy 30MeV inside the gas target chamber by using the MCNPX. The beam energy was lost as the beam spread when beam hit inside the gas target chamber. The cooling water was used not to change the gas target chamber as loss of energy transfer to the thermal energy. Spiral cooling line was designed for cooling the target chamber efficiently. By using the c30 cyclotron, $^{124}Xe(p,2n)$, $^{124}Xe(p,n)$, $^{124}Xe(p,pn)$ nuclear reactions were studied. In this study, we predict the production yield.

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High aspect-ratio InGaN nanowire photocatalyst grown by molecular beam epitaxy (MBE 법에 의해 성장된 고종횡비 InGaN 나노와이어 광촉매)

  • An, Soyeon;Jeon, Dae-Woo;Hwang, Jonghee;Ra, Yong-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.4
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    • pp.143-148
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    • 2019
  • We have successfully fabricated high aspect-ratio GaN-based nanowires on Si substrates using molecular beam epitaxy (MBE) system for high-efficiency hydrogen generation of photoelectrochemical water splitting. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) demonstrated that p-GaN:Mg and p-InGaN nanowires were grown vertically on the substrate with high density. Furthermore, it was also confirmed that the emission wavelength of p-InGaN nanowire can be adjusted from 552 nm to 590 nm. Such high-aspect ratio p-InGaN nanowire structure will be a solid foundation for the realization of ultrahigh-efficiency photoelectrochemical water splitting through sunlight.

A Study on USA, Japan and India Stock Market Integration - Focused on Transmission Mechanism - (미국, 일본, 인도 증권시장 통합에 관한 연구 - 정보전달 메카니즘을 중심으로 -)

  • Yi, Dong-Wook
    • International Area Studies Review
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    • v.13 no.2
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    • pp.255-276
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    • 2009
  • This article has examined the international transmission of returns among S&P500, Nikkei225 and SENSEX stock index cash markets using the daily closing prices covered from January 4, 2002 to February 6, 2009. For this purpose we employed dynamic time series models such as the Granger causality analysis and variance decomposition analysis based on VAR model. The main empirical results are as follows; First, according to Granger causality tests we find that S&P500 stock index has a significant prediction power on the changes of SENSEX and Nikkei225 stock index market and vice versa. However, US stock market's influence is dominant to the other stock markets at a significant level statistically. Second, according to variance decomposition, SENSEX stock index is more sensitive to the movement of S&P500 than that of Nikkei225 stock index. These kinds of empirical results shows that the three stock markets are integrated over times and these results will be informative for the international investors to build the world-wide investment portfolio and risk management strategies, etc.