• 제목/요약/키워드: and symmetry

검색결과 1,979건 처리시간 0.031초

Chemical and Electrochemical Intercalation of Lithium in 2D-FeMoO$_4Cl^1$

  • 조진호;장순호;노동윤;손경아
    • Bulletin of the Korean Chemical Society
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    • 제10권1호
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    • pp.27-30
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    • 1989
  • Lithium has been intercalated into $FeMoO_4Cl$, and deintercalated from $LixFeMoO_4Cl$ both electrochemically and chemically. The inserted $Li^+$ ions are stabilized in the distorted octahedral field in interlayer space of $FeMoO_4Cl$. The crystal symmetry is reduced from tetragonal to monoclinic due to the reduction of ferric to ferrous ions in $LixFeMoO_4Cl$ upon lithium intercalation. From the magnetic and structural data, it has been concluded that the high-spin electronic configuration of $Fe^{2+}(d_{xz}^2{d_{y2}^1}{d_1}{2d_z^12}{\cdot}_y2)$, corresponding to $^5E_g$, group term in $D_{4h}$ symmetry, can be stabilized by the elongation of $FeO_4Cl_{2-}$octahedra in a weak ligand field.

MO Theoretical Studies on the Effect of Bond Angle Distortion in Pyrazine

  • Lee, Ik-Choon;Kim, Ho-Soon
    • Bulletin of the Korean Chemical Society
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    • 제5권2호
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    • pp.68-73
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    • 1984
  • An enhancement of through-bond interaction by bond angle distortion in pyrazine was examined using various MO methods. Results of MINDO/3 geometry optimization with an angle (${\alpha}$) at $C_2$ atom fixed to 120∼90$^{\circ}$ lead to distorted structures in which the distorted bond is brought closer toward lone pair orbital n of N atom. It was also found that the bond angle distortion increased the P character at the atom $C_2$, resulting in an increased vicinal overlap between n and the $C_2-C_3$ bond. The FMO patterns of ${\sigma}$ framework showed three-fold degeneracy, one of which was of different symmetry which mixes in the symmetry adapted pair, $n_+\;and\;n_-;\;both\;n_+\;and\;n_-$ orbitals thus can interact with both FMOs of the ${\sigma}$ framework. The LCBO-MO analysis with partial elimination of bonds, antibonds or both, however, revealed that the main interaction of $n_+$ was with the HO-${\sigma}$ and that of $n_-$ was with the LU-${\sigma}^{\ast}$ orbital of the ${\sigma}$ framework.

PSEUDO SYMMETRY OF M(R) AND N(R)

  • JUNG, EUN-SUK
    • 호남수학학술지
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    • 제23권1호
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    • pp.15-20
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    • 2001
  • Reduced Von Neumann Regular ring is pseudo symmetric and N(R) is reduced. Thus N(R) is pseudo symmetric and M(R) is reduced if and only if M(R) = N(R).

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화상처리를 이용한 연삭공구 인식 및 안면인식 응용 (Grinding disk detection with image processing and application to face recognition)

  • 백재용;송무건;유송민
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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    • pp.115-118
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    • 2001
  • An image processing method was applied to characterize a shape of the flexible grinding disk. A disk surface image was taken by CCD camera. Depth of cut was changed to be 2 and 4mm. Circles marked on the disk were captured to extract the key features of the deflection. Notable correlation has been observed between the intervals and the process conditions. Same methodology has been applied to check the symmetry of the human face. Tentative results revealed that symmetry could be checked using the filtered face image.

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Póincare Sphere Analysis of the Pretilt Angle Effect on the Viewing Angle of a Single-Domain FFS Liquid-Crystal Mode

  • Lee, Dong-Jin;Oh, Seong-Woo;Shim, Gyu-Yeop;Choi, Jun-Chan;Lee, Joun-Ho;Kim, Byeong Koo;Kim, Hak-Rin
    • Journal of the Optical Society of Korea
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    • 제20권1호
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    • pp.156-164
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    • 2016
  • We demonstrated the pretilt angle effect on the viewing angle properties of a single-domain fringe-field switching (FFS) liquid crystal (LC) mode. By performing the Póincare sphere analysis, we investigated, in detail, the origin of the viewing angle asymmetry that exists in the single-domain FFS LC mode both in the field-on and field-off states. Using this analysis, we confirmed that the pretilt angle reduces the viewing angle symmetry in the single-domain FFS LC mode. Finally, we examined the effect of a zero pretilt angle on the viewing angle symmetry by evaluating real single-domain FFS LC cells.

Symmetry and depth-dependent orders of subsurface defects in Mn-doped Sb(111) studied by using STM

  • Cho, Doo-Hee;Kim, Min-Seong;Lyo, In-Whan
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.57-57
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    • 2010
  • Sb(111) is a spin textured surface due to the strong spin-orbit coupling, often viewed as a proto-type topological insulator. We used scanning tunneling microscopy (STM) to characterize various Mn-induced subsurface defects existing at the surface of Mn-doped Sb at 50 K. Our STM images show that every defect exhibits 3-fold symmetry with a single rotational orientation and can be categorized by their shapes and sizes. We found more than 10 types of subsurface defects with distinctive orders, which allows the resolution of the vertical positions of the magnetic dopants lying more than 10 layers down from the surface. We will discuss about our findings in comparison with theoretical results.

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신경망 기반의 효율적인 얼굴 검출 (Efficient face detection based on Neural Network)

  • 강창호;최종무;김문현
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2000년도 추계학술발표논문집 (상)
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    • pp.243-246
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    • 2000
  • 얼굴 영역 검출은 주어진 영상에서 얼굴의 유.무, 개수 및 위치를 검출하는 것으로 본 논문은 영상에서 얼굴을 검출하는 방법으로 신경망(Neural Network)을 적용하였다. 검출률의 향상 및 오검출률의 감소, 계산량을 최대한 줄이기 위해 후보 영역의 최적화와 얼굴의 대칭성(symmetry of face)을 이용한 좌우 평균 명암도 비교방법, 평균 얼굴 (average face)을 이용한 템플릿 매칭을 사용하였고, 실험을 통해서 제안한 방법이 효과적으로 수행됨을 보였다.

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Josephson Tunneling and Pairing Symmetry of High Tc Superconductor

  • Shin, E.J.;Nahm, Kyun;Chung, M.H;Kim, M.D.;Kim, C.K.;Noh, H.S.
    • Progress in Superconductivity
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    • 제1권2호
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    • pp.85-88
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    • 2000
  • The temperature dependent Josephson critical current $J_c(T)/J_c(0)$ between high $T_c$ superconductors along the a-axis is theoretically studied. The interface influence on the wave functions of quasi-particles is included in the theory within the framework of the two-dimensional t-J model. It is found that the experimental results can be satisfactorily explained by the present model with d wave pairing symmetry.

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Pairing symmetry analyzed by a peak shape of density of states in an Bi2Sr2CaCu2O8+x superconductor

  • Kim, Hyun-Tak;Kang, Kwang-Yong
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 추계학술대회 논문집
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    • pp.30-34
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    • 2003
  • For an inhomogeneous superconductor, we reveal a relation of an observed superconducting gap, $\Delta$$_{obs}$ and the intrinsic true gap, $\Delta$$_{i}$, $\Delta$$_{obs}$(equation omitted) where band filling, 0<$\rho$<$\leq$1. $\Delta$$_{obs}$ is the effect of measurement when 0<$\rho$<1. The true gap is observed only when $\rho$=1. Parring symmetry analyzed by a coherence-peak shape of density of states, observed in B $i_2$S $r_2$CaC $u_2$ $O_{8}$$\chi$ superconductors, is s- wave.X> $O_{8}$$\chi$ superconductors, is s- wave. wave.

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해주반 판각의 조형분석에 관한 연구 (Study on formal analysis of carving boards in 'Haejuban')

  • 이유진;임승택
    • 한국가구학회지
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    • 제20권5호
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    • pp.414-430
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    • 2009
  • This paper is designed for the purpose of suggesting Figurative data applicable to modern furniture designs through doing research on Haejuban's engraving that includes excellent Figurative beauty among Korean traditional lighted-floor type furnitures. As a result of the analysis, Haejuban's(Traditional Korean dining table) engraving pattern type was mainly divided into independent patterns and combined patterns. The patterns expressed the most among them are peony patterns. The patterns expressed by the engraving mostly showed the Figurative characteristics of symmetry. The patterns shown in Haejuban's engraving wish or stand for richness, long life, lucky, fidelity, divinity, happiness, success and so on. The species of trees used for Haejuban were a total of 8 kinds such as ginkgo trees, zelkova trees, walnut trees, wild-walnut trees, chinaberry trees and other scrub trees. Ginkgo trees were used the most among them.

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