• Title/Summary/Keyword: 에피스

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Epimerization of L-Arabinose for Producing L-Ribose (L-리보스 생산을 위한 L-아라비노스의 에피머반응)

  • Jeon, Young Ju;Song, Sung Moon;Lee, Chang Soo;Kim, In Ho
    • Korean Chemical Engineering Research
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    • v.49 no.5
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    • pp.628-632
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    • 2011
  • L-ribose has recently attracted interest as a starting material for antiviral drug. It could be obtained from L-arabinose by epimerization reaction. Epimerization reaction was carried out with molybdenium oxide or molybdic acid catalyst and methanol/water solution. Reaction temperature, methanol percentage, and catalyst kind were selected to find an optimum reaction condition. Ion exhange chromatography was used for separating epimerization reaction mixture, and then HPLC chromatogram of L-ribose fraction obtained to calculate the yield of the reaction. Shodex ion exchange HPLC column(Model SC1011) and Phenomenex Luna $NH_2$ HPLC column were compared to employ a convenient HPLC analysis. It was found that the usage of 20% methanol, $60^{\circ}C$, and 40 g/L molybdic acid gives the best reaction condition with a yield of 21%.

Formation and Growth of Epitaxial $CoSi_2$ Layer by Reactive Chemical Vapor Deposition (반응성 화학기상증착법을 이용한 에피택셜 $CoSi_2$ 박막의 형성 및 성장에 관한 연구)

  • Lee, Hwa-Seong;Lee, Hui-Seung;An, Byeong-Tae
    • Korean Journal of Materials Research
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    • v.10 no.11
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    • pp.738-741
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    • 2000
  • Univorm epitaxial $CoSi_2$layers have been grown in situ on a (100) Si substrate at temperatures near$ 600^{\circ}C$ by reactive chemical vapor deposition of cyclopentadienyl dicarbonyl cobalt, (Co(η(sup)5-C(sub)5H(sub)5) ($CO_2$). The growth kinetics of an epitaxial $CoSi_2$layer on al Si(100) substrate was investigated at temperatures ranging from 575 to $650^{\circ}C$. In initial deposition stage, plate-like discrete $CoSi_2$spikes were nucleated along the <111> directions in (100) Si substrate with a twinned structure. The discrete $CoSi_2$plates with both {111} and (100) planes grew into an epitaxial layer with a flat interface on (100) Si. For epitaxial $CoSi_2$growth on (100) Si, the activation energy of the parabolic growth was found to be 2.82 eV. The growth rate seems to be controlled by the diffusion of Co through the $CoSi_2$layer.

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이현순 현대.기아자동차 연구개발총괄본부 사장

  • Korean Federation of Science and Technology Societies
    • The Science & Technology
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    • no.10 s.449
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    • pp.86-89
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    • 2006
  • 1984년 현대자동차에 입사한 이후 알파, 베타, 델타, 엔진에 이어 최근의 세타엔진에 이르기까지 20년 넘게 자동차 엔진 개발을 이끌며 한국 자동차 엔진의 기술독립을 일궈낸 승부사로 통하는 이현순 현대∙기아자동차 연구개발총괄본부 사장. 이번호에는 그를 만나 그 동안의 기술개발 에피소드와 최근동향에 대해 들어봤다. 이 사장은 서울대학교 기계공학과를 졸업, 뉴욕주립대에서 기계공학 석사∙박사학위를 받은 후, 세계 최대 자동차 회사인 제네럴모터스 자동차연구소에 근무한 바 있다.

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Suppression of misfit dislocations in heavily boron-doped silicon layers for micro-machining (마이크로 머시닝을 위한 고농도로 붕소가 도핑된 실리콘 층의 부정합 전위의 억제)

  • 이호준;김하수;한철희;김충기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.2
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    • pp.96-113
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    • 1996
  • It has been found that the misfit dislocations in heavily boron-doped layers originate from wafer edges. Moreover, the propagation of the misfit dislocation into a heavily boron-doped region can be suppressed by placing a surrounding undoped region. Using a surrounding undoped region the disloction-free heavily boron-deoped silicon membranes have been fabricated. The measured surface roughness, fracture strength, and residual tensile stress of the membrane are 20.angs. peak-to-peak, 1.39${\times}$10$^{10}$ and 2.7${\times}$10$^{9}$dyn/cm$^{2}$, while those of the conventional heavily boron-doped silicon membrane with high density of misfit dislocations are 500 peak-to-peak, 8.27${\times}$10$^{9}$ and 9.3${\times}$10$^{8}$dyn/cm$^{2}$ respectively. The differences between these two membranes are due to the misfit dislocations. Young's modulus has been extracted as 1.45${\times}$10$^{12}$dyn/cm$^{2}$ for both membranes. Also, the effective lattice constant of heavily boron-doped silicon, the in-plane lattice constant of the conventional membrane, and the density of misfit dislocation contained in the conventional membrane have been extracted as density of misfit dislocation contained in the conventional membrane have been extracted as density of misfit dislocation contained in the conventional membrane have been extracted as 5.424.angs. 5.426.angs. and 2.3${\times}$10$^{4}$/cm for the average boron concentration of 1.3${\times}$10$^{20}$/cm$^{-23}$ cm$^{3}$/atom. Without any buffer layers, a disloction-free lightly boron-doped epitaxial layer with good crsytalline quality has been directly grown on the dislocation-free heavily boron-doped silicon layer. X-ray diffraction analysis revealed that the epitaxial silicon has good crystallinity, similar to that grown on lightly doped silicon substrate. The leakage current of the n+/p gated diode fabricated in the epitaxial silicon has been measured to be 0.6nA/cm$^{2}$ at the reverse bias of 5V.

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Analyzing animation techniques used in webtoons and their potential issues (웹툰 연출의 애니메이션 기법활용과 문제점 분석)

  • Kim, Yu-mi
    • Cartoon and Animation Studies
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    • s.46
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    • pp.85-106
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    • 2017
  • With the media's shift into the digital era in the 2000s, comic book publishers attempted a transition into the new medium by establishing a distribution structure using internet networks. But that effort shied from escaping the parallel-page reading structure of traditional comics. On the other hand, webtoons are showing divers changes by redesigning the structure of traditional sequential art media; they tend to separate and allot spaces according to the vertical scroll reading method of the internet browser and include animations, sound effects and background music. This trend is also in accordance with the preferences of modern readers. Modern society has complicated social structures with the development of various media; the public is therefore exposed to different stimuli and shows characteristics of differentiated perceptions. In other words, webtoons display more relevant and entertaining characteristics by inserting sounds and using moving texts and characters in specific frames, while traditional comics require an appreciation of withdrawal and immersion like other published media. Motions in webtoons are partially applied for dramatic tension or to create an effective expression of action. For example, hand-drawn animation is adopted to express motions by dividing motion images into many layers. Sounds are also utilized, such as background music with episode-related lyrics, melodies, ambient sounds and motion-related sound effects. In addition, webtoons provide readers with new amusement by giving tactile stimuli via the vibration of a smart phone. As stated above, the vertical direction, time-based nature of animation motions and tactile stimuli used in webtoons are differentiated from published comics. However, webtoons' utilization of innovative techniques hasn't yet reached its full potential. In addition to the fact that the software used for webtoon effects is operationally complex, this is a transitional phenomenon since there is still a lack of technical understanding of animation and sound application amongst the general public. For example, a sound might be programmed to play when a specific frame scrolls into view on the monitor, but the frame may be scrolled faster or slower than the author intended; in this case, sound can end before or after a reader sees the whole image. The motion of each frame is also programmed to start in a similar fashion. Therefore, a reader's scroll speed is related to the motion's speed. For this reason, motions might miss the intended timing and be unnatural because they are played out of context. Also, finished sound effects can disturb the concentration of readers. These problems come from a shortage of continuity; to solve these, naturally activated consecutive sounds or animations, like the simple rotation of joints when a character moves, is required.

Analysis of the Problem of College Entrance System in Webtoon : in , (웹툰에서 재현하는 입시문제 : <공부하기 좋은 날>, <입시명문사립 정글고등학교>를 중심으로)

A Proposal and Application of a Song Analysis Method for Musical Songs and Acting (뮤지컬 노래와 연기를 위한 노래 분석법의 제시와 적용)

  • Lee, Eun-Hye
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.3
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    • pp.27-40
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    • 2021
  • This study aims to propose and apply a song analysis method for musical songs and acting. Prior to rehearsing a musical on stage, students and actors practice diverse exercises ranging from singing, acting and dancing. Among them, singing a musical song requires the actor not only to learn the pitch, beat and melody of the music but also to express the story and scene of the character in combination. Previous studies on analysis focused on research from the perspective of individual elements of singing, acting, and dancing rather than the proposal of comprehensive analysis methods. It is time for comprehensive analysis methods to be developed to practice musical songs and demonstrate them on stage. This study selected "Epiphany" sung by Todd from the musical Sweeney Todd(1979) as the subject of analysis. The song was analyzed in five stages: synopsis, music analysis, lyrics analysis, Uta Hagen's The Six Steps analysis, and Michael Chekhov's Psychological Gesture analysis. Through proposing and applying this step-by-step analysis method, this study verifies the usefulness of musical song analysis for practising both musical theory and practical skills at the same time and provides a base for future studies.

A Study on the Utilization Status of the Interior Landscape Plants in Large Buildings in Seoul (우리나라 실내조경식물의 활용실태에 관한 연구 -서울지역 대형건물의 Lobby를 중심으로-)

  • 박상헌;심경구
    • Journal of the Korean Institute of Landscape Architecture
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    • v.17 no.1
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    • pp.43-54
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    • 1989
  • In recent years plants have increasingly become in inferior part of the interior designing of large buildings. In 28 large buildings selected at random in Seoul City have been subjected to studies on utilization status of fille interior landscape plants. The results obtained were as follows. 1. Plant class found in Interior of large buildings were 59 class, especially Dracaena were the most predominent plants among them, and then comes Monstera, Phiodendron, Schefflera, and Washingtonia in that order. 2. The most abundant ornamental plant cultivars were Monstera adansoii(Monstera perutusa cv.), and then comes Schefflera arboricora(Schefflera Hong Kong cv.), Washingionia rubusta (Washingtonia palm). Rhapis excelsa, and Diffenbachia(Hawaii Snow cv.) in that order. 3. Foliage plants among the interior landscape plants showed 99.5 percent and Woody plants and Bonsai plants showed each 0.4, 0.1 percent. 4. Climbing foliage plants found in 28 large building observed For the present study were 9 cultivar, and the most abundant plants were Hedera (pittsburgh cv.) and Epipremnum (Marble Queen cv.) pl anted to clustered planting. 5. A majority of plants used to plastic pot, and most of 71an1s place on the floor. 6. Height of plants ranging less then 50cm were more frequently found, but ranging from 50cm to 2.0m were 4.3 percent and the most predominent height of plants were Canariensis showed 4m in the large buildings. 7. Interior light intensity in large building were shortage, therefore artificial lamp for formal growing needed to be equipped. 8. Purpose growth of interior plants were to in order visitors. 9. 7he superintendents prefered to used pot-stand. 10. The most important environment factor for plant growing were light, humidity, and water.

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