• Journal of the Korean Society for information Management
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• v.22 no.1 s.55
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• pp.105-123
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• 2005

The most of all, this study is planned to search an ideal methods to develop the digital library system for our korean ancient books for their safe preservation and, at the same time, for their perusal of transcendental time and space : first. to offer the various access points like traditional oriental Four parts Classics classification, current subject classification and index keyword, etc. : second, to program a digital library system using MARC or XML, but with all bibliographic descriptive elements as possible; third, to prepare the more easy annotated bibliography and index for users' better comprehension, and last, to build original text database for practical reading to avoid the damage of original text. This type of korean ancient books digital library will be developed to the real international bibliographic control by networking enter the same kinds of internal and external organizations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.307-313
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• 2019

The traveling wave tube amplifier (TWTA), which can be applied to the Ka-band millimeter-wave multi-mode seeker, consists of an high voltage power supply(HVPS), a grid modulator, a command and control, and an RF assembly. We designed a power supply that generates a -17.9 kV high voltage by synchronizing the pulse repetition frequency(PRF) and power supply switching frequency(i.e. synchronization frequency), and a high-speed grid-switching modulator for RF pulse modulation. The TWTA, which is fabricated through miniaturization with a volume of 3.18 L, has high pulse switching characteristics of up to 18.5 ns. The maximum rise/fall time of the grid on/bias signal and peak power is more than 564.9 W. Moreover, an excellent spurious performance of -68.4 dBc or less was confirmed within the range of PRF and PRF/2.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.574-578
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• 1992

고분자 전해질형 연료전지(PEMFC)는 전해질로서 수소이온 교환 특성을 갖는 폴리머를 사용한 연료전지로서 다른 유형의 연료전지에 비하여 에너지 변환 특성이 우수할 뿐만 아니라 전력밀도 특성이 우수한 유형의 연료전지이다. 전해질 폴리머로서는 Perfluorosulfonate 멤브레인이 사용되고 있으며, 전지의 작동 원리는 인산형 연료전지와 동일하다. 본 총설 논문에서는 PEMFC의 작동 원리 및 기능상의 설명은 지양하고 고전력 밀도가 가능한 이유와 지금까지의 개발 역사 및 향후 개발 방향 등에 대해서 설명하고자 한다.

• Information and Communications Magazine
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• v.33 no.7
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• pp.10-17
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• 2016

영상 기술의 발전과 TV화면의 대형화에 따라 고성능의 서비스 수요가 증가하고 있다. 본 고에서는 현재 상용화 단계에 있는 지상파 4K UHDTV에서 나아가 차세대 실감 방송인 8K UHDTV에 대한 이해를 돕기 위한 설명과 기술 동향을 알아본다. 이어서 8K UHDTV 서비스를 위해 요구되는 고전송효율을 위한 송수신 기술인 Dual-Polarized MIMO 기술에 대해 알아본다.

• Analytical Science and Technology
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• v.7 no.3
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• pp.293-299
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• 1994

Fifty ancient Korean coins originated in Choson period have been determined for 11 elements such as Sn, Fe, As, Au, Co, Sb, Ir, Os, Ru and Ni by destructive and non-destructive neutron activation analysis as well as for 3 elements such as Cu, Pb and Zn by atomic absorption spectroscopy. The multivariate data have been analyzed by principal component mapping method. The spread of sample points in the eigenvector polt has been attributed to common origins of some elements.

• Journal of Korean Classical Literature and Education
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• no.35
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• pp.195-219
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• 2017

The distinctive character of a self-written epitaph is that it assumes one's own death. While containing the elements of an epitaph, it is distinctive in that it reveals motive of writing and scolds rather than praises one's own self. The motive for writing a self-written epitaph is two-fold. First, it seeks to tell the truth about one's own self. Second, it is a response to external shocks. The Educational Value of Self-written epitaph lies in leading the elderly to reflect on their lives today, and it bears the appearance of cooperative writing.

• Journal of the Korean Electrochemical Society
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• v.14 no.4
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• pp.219-224
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• 2011

Using an electrolyte additive, we examined, for the first time, a novel self-ordering regime of 160~200 V in high-field anodization which had been used for a fast fabrication of self-ordered anodic alumina nanotemplate. FE-SEM analyses conducted after the high-field anodization, pulse detachment and chemical widening of pores showed the relationship of 2.2 nm/V in this voltage range, which was identical to the previously reported one in the literature. The growth rate of the alumina film was about 60 um/hr, which was 30 times faster than that of phosphoric acid mild anodization. This study provides a new process for the fast fabrication of nanotemplates with interpore distances larger than 300 nm.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.373-378
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• 2019

In various cultures and civilizations, artists are trying new ideas of reinterpreting the beauty of classic and redefining it in the ways of modern times rather than creating something new. In other words, modern cultural trend is creating a new culture by combining sensibilities of classic amid the flood of information with modern senses of artists. This study tries to combine various cultures an designs in accordance with this cultural change. Based on the features of expressing emotions of individuals and the world of impossible experiences from the short story 'When Buckwheat Flowers Bloom' of Lee Hyoseok, an incomplete area of consciousness which is at the border line of the polarized world divided by existence and absence is the area which creates a new culture by arousing readers' imagination as a potential world of thought. In addition, based on language from the short story, a researcher tries to utilize symbolic and imaginal beauties inside of that language as a material of design, and formative analysis them with the composition of proper words for visualization.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.616-624
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• 2009

This paper presents a 3D stereoscopic TIP (Tour Into Picture) for Korean classical paintings being composed of persons, boat, and landscape. Unlike conventional TIP methods providing 2D image or video, our proposed TIP can provide users with 3D stereoscopic contents. Navigating a picture with stereoscopic viewing can deliver more realistic and immersive perception. The method firstly makes input data being composed of foreground mask, background image, and depth map. The second step is to navigate the picture and to obtain rendered images by orthographic or perspective projection. Then, two depth enhancement schemes such as depth template and Laws depth are utilized in order to reduce a cardboard effect and thus to enhance 3D perceived depth of the foreground objects. In experiments, the proposed method was tested on 'Danopungjun' and 'Muyigido' that are famous paintings made in Chosun Dynasty. The stereoscopic animation was proved to deliver new 3D perception compared with 2D video.

• Electronics and Telecommunications Trends
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• v.29 no.6
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• pp.53-62
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• 2014

본고는 최근 화두가 되고 있는 에너지 절감을 위해 고효율, 친환경의 WBG(Wide Band-Gap) 화합물반도체인 SiC(Silicon Carbide), GaN(Gallium Nitride) 전력반도체 소자 및 전력변환 모듈의 기술동향과 ETRI에서 연구개발 진행 중인 GaN 전력반도체 관련 기술에 대해 기술한다. WBG 전력반도체는 기존의 실리콘 전력반도체와 비교하여 열 특성 향상, 고속 스위칭, 고전압/고전류 특성 및 스위칭 손실 최소화 등이 가능하고 이에 따른 시스템의 소형화 및 전력효율 향상 효과를 얻을 수 있다. 특히, GaN 전력반도체 소자는 시장이 가장 넓게 형성되어 있는 900V 이하에 적용이 가능하며, 앞으로 시장이 커질 것으로 예상되는 HEV(Hybrid Electric Vehicle)/EV(Electric Vehicle)의 친환경 자동차에도 활용될 것으로 기대되고 있다. 본고는 최근의 일본과 미국에서의 WBG 전력반도체에 대한 관심 및 투자 방향과 GaN 전력반도체 소자에 대한 해외 기업의 업계동향에 대해서도 함께 살펴본다. 이러한 WBG 전력반도체에 대한 해외 선진업체의 산업동향과 더불어 ETRI에서 연구개발 중인 GaN 전력반도체 기술현황에 대해 전력소자 설계 및 제조공정, 패키징, 전력모듈 설계 제작 기술을 포함하여 기술한다.