• 제목/요약/키워드: 혼성성

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First Principles Calculations on Electronic Structure and Magnetism of Transition Metal Doped ZnO (전이금속이 도핑된 ZnO의 전자구조와 자성에 대한 제일원리계산)

  • Yun, Sun-Young;Cha, Gi-Beom;Hong, Sun-C.
    • Journal of the Korean Magnetics Society
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    • v.15 no.1
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    • pp.1-6
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    • 2005
  • In this study we investigate the electronic structure and magnetism of transition metal (TM = Ti, Cr, Mn, Fe, Co, Ni, Ru, Pd, Ag ) deped ZnO($TM_{0.25}Zn_{0.75}O$), which are expected to have Curie temperature. Full-potential Linearized Augmented Plane Wave(FLAPW) metod is adopted with exchange-correlation potential expressed as general gradient approximation(GGA). The calculated magnetic moments of ($TM_{0.25}Zn_{0.75}O$) are 0.83, 3.03, 4.03, 3.48, 2.47, 1.56, 0.43, 0.75, 0.01 ${\mu}_B$ for TM = Ti, Cr, Mn, Fe, Co, Ni, Ru, Pd, Ag, respectively. The nearest neighbor O atom to the transition metal is calculated to have a significant magnetic moment of about 0.1${\mu}_B$, ?? 새 strong hybridization between O-p and TM-d bands. As the results, the systems may have larger magnetic moments in total, compared to the corresponding isolated atoms. The 3d TM doped systems exhibit the half-metallic character except Co, wheres the 4d TM doped systems behave like normal metals and low spin polarization at the Fermi levels.

A Specific Characters of Products In viewpoint of Inter-combination with Human -Concentrated on Inter-Combined Products′Type and Feather- (인간과 인터컴비네이션 관점에서의 제품특성연구 -상호결합제품의 유형과 특징을 중심으로-)

  • 진선태;박영목
    • Archives of design research
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    • v.14 no.3
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    • pp.145-154
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    • 2001
  • These days, the products like Walkman, mobile phone, notebook PC, PDA are moving together with our body, and in the imaginary world like internet, our other self, Avatar is moving in place of our body on the cyber world. These products are related with our human body, and when considering the ones, attached to the human body, and having the meaning of mental combination like these, as the combination of the human and the products, it is necessary to examine these products in approaching them with respect to the combination relation between the human and the products. As a result of examining we can understand that the products, said to combine with the human body, are coming oui steadily. and recently, the inclination on the combination and the movement appears strongly. As this background, there are a breakdown of dichotomy thought, mixed sexual imitation, cyber culture, techno culture. concept of informative nomands, phenomenon which the division of human and machine becomes vague. and the miniaturization of products. imitation of human, phenomenon that the Inclination on the combination with human is more accelerated by networking. These products combine with human body at each wearing type in the various forms. Its functions become multi-layered, and closer to the human body physically. or its communication becomes high·graded and, they have the recombined form through the existing products which the human has And, they communicate each other. have the strong fashionable property, and the characteristics like the imaginary product to imitate the human body and substitute for the human behave.

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A Preliminary Study on the Exhumation Mechanism of the Paleozoic Gwangcheon Gneiss in the Southwestern Margin of the Gyeonggi Massif (경기육괴 남서 연변부에 발달하는 고생대 광천편마암의 노출기작에 대한 예비 연구)

  • Park, Seung-Ik
    • Economic and Environmental Geology
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    • v.50 no.6
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    • pp.525-535
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    • 2017
  • Exhumation mechanism of migmatite in orogenic belts provides insights into thermo-mechanical evolution of lithosphere in association with orogeny. This study deals with kinematics of structures in and around the Gwangcheon Gneiss, as a preliminary study on exhumation mechanism, which is a main constituent of a domal structure (viz., Oseosan Dome) in the Hongseong area, southwestern margin of the Gyeonggi massif. Geological structures in the Gwangcheon Gneiss, which mainly comprises southern and northwestern part of the Oseosan Dome, generally have kinematic component of top-outward shear. This feature is likely to represent diapiric dome-up movement. In addition, a high strain zone, by which the tectonic domain involving the Gwangcheon Gneiss is bounded on the west, show structural features with normal sense of shear component. Taking available (thermo)chronological data into account, it is interpreted that activation of the high strain zone and exhumation of the Gwangcheon Gneiss occurred during Late Triassic, when the Gyeonggi massif was widely affected by post-collisional processes. It means that the Gwangcheon Gneiss was diapirically moved up and exhumed in the footwall of extensional high strain zone in association with Triassic post-collisional processes.

Postprocessing of Inter-Frame Coded Images Based on Convex Projection and Regularization (POCS와 정규화를 기반으로한 프레임간 압출 영사의 후처리)

  • Kim, Seong-Jin;Jeong, Si-Chang;Hwang, In-Gyeong;Baek, Jun-Gi
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.3
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    • pp.58-65
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    • 2002
  • In order to reduce blocking artifacts in inter-frame coded images, we propose a new image restoration algorithm, which directly processes differential images before reconstruction. We note that blocking artifact in inter-frame coded images is caused by both 8$\times$8 DCT and 16$\times$16 macroblock based motion compensation, while that of intra-coded images is caused by 8$\times$8 DCT only. According to the observation, we Propose a new degradation model for differential images and the corresponding restoration algorithm that utilizes additional constraints and convex sets for discontinuity inside blocks. The proposed restoration algorithm is a modified version of standard regularization that incorporate!; spatially adaptive lowpass filtering with consideration of edge directions by utilizing a part of DCT coefficients. Most of video coding standard adopt a hybrid structure of block-based motion compensation and block discrete cosine transform (BDCT). By this reason, blocking artifacts are occurred on both block boundary and block interior For more complete removal of both kinds of blocking artifacts, the restored differential image must satisfy two constraints, such as, directional discontinuities on block boundary and block interior Those constraints have been used for defining convex sets for restoring differential images.

A Study of Contemporary Korean Painting's Expressions through the Reinterpretation of Folk Painting (민화의 재해석을 통한 현대한국화의 표현에 대한 연구)

  • Oh, Se-Kwon
    • Journal of Science of Art and Design
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    • v.10
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    • pp.51-72
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    • 2006
  • Reinterpretation of the visual characteristics of Korean folk painting in contemporary Korean painting is to seek directions of today's Korean painting. When examining expressions of contemporary painting we see that there is a reappearance of iconic images, a reinterpretation of both flatness and multi-perspectives, and an objectifying of pastiche folk icons with an experimental spirit. All of these techniques suggest methods of contemporary Korean painting through 'folk painting'. Although folk painting has been adopted in contemporary Korean painting for a long time, interest increased in the 1980s. With the prevailance of both national characteristic expressive techniques of realism and color painting, artists reinterpreted folk painting in their work, borrowing the traditional five colors, common contents, and iconic images. Particularly, an interest in 'Korean Beauty' drew people's interest back to folk painting which provided the significant 'Korean Beauty' of traditional expressive techniques. This study is to examine the characteristics of selected group of works that created a new expressive technique in today's Korean painting by either the reappearance or the reinterpreting of iconic images of the Chosun Dynasty's folk painting. To achieve these goals, the artists, who modify or reinterpret folk painting's visual characteristics with a contemporary sense, are divided into three categories in this study; 'The Readoption of the Folk Image', 'The Reinterpretation of Folk Characteristics', and 'Experimental Expressions'. As a result, it proves that folk painting is both a classical expression and national expression which was not only favored in the Chosun period, but also can be reinterpreted through today's visual methodology.

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A Simultaneous Improvement in $CO_2$ Flux and $CO_2/N_2$ Separation Factor of Sodium-type FAU Zeolite Membranes through 13X Zeolite Beads Embedding (13X 제올라이트 흡착제 충진에 의한 Na형 Faujasite 제올라이트 분리막의 $CO_2/N_2$ 선택도 및 $CO_2$ 투과도 동시 증가 현상)

  • Cho, Churl-Hee;Yeo, Jeong-Gu;Ahn, Young-Soo;Han, Moon-Hee;Moon, Jong-Ho;Lee, Chang-Ha
    • Membrane Journal
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    • v.17 no.3
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    • pp.269-275
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    • 2007
  • Sodium type faujasite(FAU) zeolite membranes with a thickness of 5${\mu}m$ and a Si/Al molar ratio of 1.5 were prepared by the secondary growth process. The $CO_2/N_2$ separation in the vacuum mode was investigated at $30^{\circ}C$ for an equimolar $CO_2-N_2$ mixed gas before and after embedding 13X zeolite beads in the permeate side. The embedded 13X zeolite beads improved both $CO_2$ permeance and $CO_2/N_2$ separation factor, simultaneously. The phenomenon was explained by an increment in the $CO_2$ desorption rate at the FAU zeolite/$\alpha-Al_2O_3$ phase boundary due to an enhanced $CO_2$ escaping through the pore channels of the $\alpha-Al_2O_3$ support layer. In the present paper, it will be emphasized that a hybridization of a membrane with an adsorbent can provide a key to break through the trade-off between permeance and separation factor, generally shown in a membrane separation.

Wavelet-based Pitch Detector for 2.4 kbps Harmonic-CELP Coder (2.4 kbps 하모닉-CELP 코더를 위한 웨이블렛 피치 검출기)

  • 방상운;이인성;권오주
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.8
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    • pp.717-726
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    • 2003
  • This paper presents the methods that design the Wavelet-based pitch detector for 2,4 kbps Harmonic-CELP Coder, and that achieve the effective waveform interpolation by decision window shape of the transition region, Waveform interpolation coder operates by encoding one pitch-period-sized segment, a prototype segment, of speech for each frame, generate the smooth waveform interpolation between the prototype segments for voiced frame, But, harmonic synthesis of the prototype waveforms between previous frame and current frame occur not only waveform errors but also discontinuity at frame boundary on that case of pitch halving or doubling, In addtion, in transition region since waveform interpolation coder synthesizes the excitation waveform by using overlap-add with triangularity window, therefore, Harmonic-CELP fail to model the instantaneous increasing speech and synthesis waveform linearly increases, First of all, in order to detect the precise pitch period, we use the hybrid 1st pitch detector, and increse the precision by using 2nd ACF-pitch detector, Next, in order to modify excitation window, we detect the onset, offset of frame by GCI, As the result, pitch doubling is removed and pitch error rate is decreased 5.4% in comparison with ACF, and is decreased 2,66% in comparison with wavelet detector, MOS test improve 0.13 at transition region.

Distribution of Available Soil Phosphorus and Effect of Phosphorus Application on Appearance of Algal Waterbloom and Rice Yield in Honam Area (호남지역(湖南地域) 논 토양(土壤)의 유효인산함량(有效燐酸含量) 및 인산시비(燐酸施肥)에 따른 괴불발생(發生)과 수량(收量))

  • Yoo, Chul-Hyun;Choi, Jeong-Weon;Shin, Bog-Woo;Lee, Sang-Bokg;Jeong, Ji-Ho;Kim, Seong-Jo;Han, Seong-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.29 no.3
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    • pp.270-274
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    • 1996
  • To estimate the suitable method of phosphorus application in puddled-soil drill seeding of rice, available phosphorus, appearance of algal water bloom, and rice yield were investigated in paddy soil of Honam area from 1994 to 1995. Available phosphorus content with different regions was the highest in the east-west inland region of Noryeong mountain range and the inland region of Honam area and it was the lowest in the Charyeong south plains region. Available phosphorus content was the highest in the alluvial plains. and it was the lowest in dilluvial terrace. Frations of phosphorus in Jeonbug series were high in the order of Ca-P, Fe-P, and Al-P, respectively. Algal water bloom occurred highly in 100% and 70% basal applications before seeding, and slightly in no-fertilizer and 100% application of 3-leaf stage in puddled-soil drill seeding of rice. Suitable amount of phosphorus application was 21kg/ha in the single cropping paddy field of Fluvio-marine plain, and rice yield was increased 6% at 50% basal application.

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The Effect of ${\pi}$ Bonds on the Calculated Dipole Moments for Tetrahedral and Square Planar [M(Ⅱ)$O_2S_2$] Type Complexes [M(II) = Co(II), Ni(II), Cu(II) and Zn(II)] (사면체 및 사각형 [M(II)$O_2S_2$]형태 착물의 쌍극자 모멘트에 대한 ${\pi}$결합의 영향 [M(II) = Co(II), Ni(II), Cu(II) 및 Zn])

  • Sangwoon Ahn;Jin Ha Park;Chang Jin Choi
    • Journal of the Korean Chemical Society
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    • v.26 no.5
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    • pp.265-273
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    • 1982
  • The effect of ${\pi}$ bonds on the calculated dipole moments for square planar and tetrahedral [M(II)$O_2S_2$]] type complexes has been investigated by two different approaches. One is the approximate molecular orbital method based on the assumption that the mixing coefficient CM of the valence basis sets for the central metal ion and the appropriate ligand orbitals is equal for all ${\sigma}$ and ${\pi}$ bonding molecular orbitals. The other is the more refined calculation based on the semiempirical LCAO-MO method. If ${\sigma}$ bonds only are assumed to be formed, the calculated dipole moments for square planar and tetrahedral complexes are lower than those of the experimental values. If the contribution of ${\pi}$ bonds to the calculated dipole moments are fully considered, the calculated dipole moments for both square planar and tetrahedral [M(II)$O_2S_2$]] type complexes are higher than the experimental values. However if ${\pi}$ bonds are assumed to be delocalzed, the calculated dipole moments for tetrahedral [M(II$O_2S_2$]] type complexes fall in the range of the experimental values, but those for square planar complexes deviate from the experimental values. These results suggest that [M(II)$O_2S_2$]] type complexes may have the tetrahedral structure in inert solvent solution. This structure is in agreement with the experimental one. The calculated dipole moments for tetrahedral [M(II)$O_2S_2$]] type complexes indicate that the contribution of ${\pi}$ bonds to the calculated dipole moments may not be neglected.

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Microelectromechnical system 소자를 위한 박막형 2차 전지용 TEX>$SnO_2$ 음극 박막의 충, 방전 특성 평가

  • 윤영수;전은정;신영화;남상철;조원일
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.50-50
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    • 1999
  • 마이크로 공정을 이용한 초소형 정밀 기계는 공정 기술과 재료 기술의 발전에 의하여 더욱 소형화되고 있으며 특히 기능을 갖는 부분과 이 부분을 제어하는 주변회로의 on-chip화의 요구가 증가되기 시작하였다. 이와 같은 추세에 있어서의 문제점은 초소형 정밀기계 부품 소자의 구동을 위한 에너지원의 개발이다. 즉, 소자의 크기가 작아진 것에 부합되는 초소형의 전지가 필요하게 된 것이다. 따라서 보다 완전한 초소형 정밀 기계 및 마이크로 소자의 구현을 위하여 마이크로 소자와 혼성 (Hybrid) 되어 이용될 수 있는 고성능 및 초소형의 전지의 개발이 필수적이다. 초소형 전지의 구현을 위하여 Li계의 2차 전지를 선택하여 이를 박막화하고 반도체 공정을 도입할 수 있다. 이러한 전지를 박막형 2차 전지 또는 박막형 마이크로 전지(thin film Secondary Battery : TFSB or Thin Film Micro-Battery : TFMB)라 하며 이러한 2차 전지는 일반적인 벌크 전지와 동일하게 cathode/Electolyte/Anode의 구조를 갖는다. 박막의 특성상 전해질은 고상의 물질을 사용하는 것이 벌크형 2차 전지와 다른 점이다. TFSB의 성능은 주로 cathode에 의하여 결정되며 지금까지 많은 cathode 물질에 대한 연구 보고가 발표되고 있다. 반도체 공정을 이용한 TFMB의 제작시 무엇보다 중요한 점은 우수한 고상 전해질 및 anode 물질의 선택에 있다. 최근에 2차 전지를 위한 carbon계 anode를 대체할 수 있는 SnO에 대한 보고가 있는데 이는 한 개의 Sn 원자당 2개 이사의 Li가 반응하여 높은 용량을 갖는 전지의 제작이 가능하기 때문이다. Sno2의 anode는 매우 높은 충전용량을 갖는데 첫 번째 방전시에 Li2O를 생성하여 비가역적 반응을 나타내고 계속되는 충방전 동안 Li-Sn 합금이 생성되어 2차전지의 가역적 반응을 가능하게 한다. SnO2 는 대기중에서 Li 금속보다 안정하기 때문에 전지의 제작 공정 및 사용 면에서 매우 우수한 물질이지만 아직까지 SnO2 구조적 특성과 전지의 충, 방전 특성에 대한 관계의 규명을 위한 정확한 정설은 제시되고 있지 못하다. 본 연구에서는 TFSB anode 물질로써 SnOx박막을 상온에서 여러 전도성 콜렉터 위에 증착하여 그 충, 방전 특성을 보고하였다. 증착된 SnOx박막의 표면은 SEM, AFM으로 분석하였으며 구조의 분석은 XR와 Auger electron spectroscope로 하였다. 충, 방전 특성을 분석하기 위하여 리늄 foil을 대극과 참조 전극으로 하여 EC:DMC=1:1, 1M LiPF6 액체 전해질을 사용한 Half-Cell를 구성하여 100회 이상의 정전류 충, 방전 시험을 행하였다. Half-Cell test 결과 박막의 구조, 콜렉터의 종류 및 Sn/O비에 따라 서로 다른 충, 방전 거동을 나타내었다.

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