• 제목/요약/키워드: G-structure

검색결과 5,131건 처리시간 0.029초

ON GENERALIZED FINSLER STRUCTURES WITH A VANISHING hυ-TORSION

  • Ichijyo, Yoshihiro;Lee, Il-Yong;Park, Hong-Suh
    • 대한수학회지
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    • 제41권2호
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    • pp.369-378
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    • 2004
  • A canonical Finsler connection Nr is defined by a generalized Finsler structure called a (G, N)-structure, where G is a generalized Finsler metric and N is a nonlinear connection given in a differentiable manifold, respectively. If NT is linear, then the(G, N)-structure has a linearity in a sense and is called Berwaldian. In the present paper, we discuss what it means that NT is with a vanishing hv-torsion: ${P^{i}}\;_{jk}\;=\;0$ and introduce the notion of a stronger type for linearity of a (G, N)-structure. For important examples, we finally investigate the cases of a Finsler manifold and a Rizza manifold.

SEMIALGEBRAIC G CW COMPLEX STRUCTURE OF SEMIALGEBRAIC G SPACES

  • Park, Dae-Heui;Suh, Dong-Youp
    • 대한수학회지
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    • 제35권2호
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    • pp.371-386
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    • 1998
  • Let G be a compact Lie group and M a semialgebraic G space in some orthogonal representation space of G. We prove that if G is finite then M has an equivariant semialgebraic triangulation. Moreover this triangulation is unique. When G is not finite we show that M has a semialgebraic G CW complex structure, and this structure is unique. As a consequence compact semialgebraic G space has an equivariant simple homotopy type.

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IMBEDDINGS OF MANIFOLDS DEFINED ON AN 0-MINIMAL STRUCTURE ON (R,+,.,<)

  • Kawakami, Tomohiro
    • 대한수학회보
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    • 제36권1호
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    • pp.183-201
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    • 1999
  • Let M be an 0-minimal structure on the standard structure :=( , +, ,<) of the field of real numbers. We study Cr -G manifolds (0$\leq$r$\leq$w) which are generalizations of Nash manifolds and Nash G manifolds. We prove that if M is polynomially bounded, then every Cr -G (0$\leq$r<$\infty$) manifold is Cr -G imbeddable into some n, and that if M is exponential and G is a compact affine Cw -G group, then each compact $C\infty$ -G imbeddable into some representation of G.

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WEYL STRUCTURES ON COMPACT CONNECTED LIE GROUPS

  • Park, Joon-Sik;Pyo, Yong-Soo;Shin, Young-Lim
    • 충청수학회지
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    • 제24권3호
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    • pp.503-515
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    • 2011
  • Let G be a compact connected semisimple Lie group, B the Killing form of the algebra g of G, and g the invariant metric induced by B. Then, we obtain a necessary and sufficient condition for a left invariant linear connection D with a Weyl structure ($D,\;g,\;{\omega}$) on (G, g) to be projectively flat (resp. Einstein-Weyl). And, we also get that if a left invariant linear connection D with a Weyl structure ($D,\;g,\;{\omega}$) on (G, g) which has symmetric Ricci tensor $Ric^D$ is projectively flat, then the connection D is Einstein-Weyl; but the converse is not true. Moreover, we show that if a left invariant connection D with Weyl structure ($D,\;g,\;{\omega}$) on (G, g) is projectively flat (resp. Einstein-Weyl), then D is a Yang-Mills connection.

PROLONGATIONS OF G-STRUCTURES IMMERSED IN GENERALIZED ALMOST r-CONTACT STRUCTURE TO TANGENT BUNDLE OF ORDER 2

  • Khan, Mohammad Nazrul Islam;Jun, Jae-Bok
    • 충청수학회지
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    • 제31권4호
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    • pp.421-427
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    • 2018
  • The aim of this study is to investigate the prolongations of G-structures immersed in the generalized almost r-contact structure on a manifold M to its tangent bundle T(M) of order 2. Moreover, theorems on Hsu structure, integrability and (${F\limits^{\circ}},\;{{\xi}\limits^{\circ}}{{\omega}\limits^{\circ}}_p,\;a,\;{\epsilon}$)-structure have been established.

Structural Aspects of GPCR-G Protein Coupling

  • Chung, Ka Young
    • Toxicological Research
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    • 제29권3호
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    • pp.149-155
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    • 2013
  • G protein-coupled receptors (GPCRs) are membrane receptors; approximately 40% of drugs on the market target GPCRs. A precise understanding of the activation mechanism of GPCRs would facilitate the development of more effective and less toxic drugs. Heterotrimeric G proteins are important molecular switches in GPCR-mediated signal transduction. An agonist-activated receptor interacts with specific sites on G proteins and promotes the release of GDP from the $G{\alpha}$ subunit. Because of the important biological role of the GPCR-G protein coupling, conformational changes in the G protein upon receptor coupling have been of great interest. One of the most important questions was the interface between the GPCR and G proteins and the structural mechanism of GPCR-induced G protein activation. A number of biochemical and biophysical studies have been performed since the late 80s to address these questions; there was a significant breakthrough in 2011 when the crystal structure of a GPCR-G protein complex was solved. This review discusses the structural aspects of GPCR-G protein coupling by comparing the results of previous biochemical and biophysical studies to the GPCR-G protein crystal structure.

FORM 신뢰성 기반 항타강관말뚝 저항계수 산정 (FORM Reliability-based Resistance Factors for Driven Steel Pipe Piles)

  • 박재현;허정원;이주형;정문경;곽기석
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.779-783
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    • 2008
  • LRFD Resistance factors for static bearing capacity of driven steel pipe piles were calibrated in the freamework of reliability theory. Reliability analysis was performed by the First Order Reliability Method (FORM) using resistance bias factor statistics.The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, based on the reliability level of the current design practice and considering redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure.

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CRITICAL METRICS ON NEARLY KAEHLERIAN MANIFOLDS

  • Pak, Jin-Suk;Yoo, Hwal-Lan
    • 대한수학회보
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    • 제29권1호
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    • pp.9-13
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    • 1992
  • In this paper, we consider the function related with almost hermitian structure on a copact complex manifold. More precisely, on a 2n-diminsional complex manifold M admitting 2-form .ohm. of rank 2n everywhere, assume that M admits a metric g such that g(JX, JY)=g(X,Y), that is, assume that g defines an hermitian structure on M admitting .ohm. as fundamental 2-form-the 'almost complex structure' J being determined by g and .ohm.:g(X,Y)=.ohm.(X,JY). We consider the function I(g):=.int.$_{M}$ $N^{2}$d $V_{g}$, where N is the norm of Nijenhuis tensor N defined by (J,g). by (J,g).

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ALMOST EINSTEIN MANIFOLDS WITH CIRCULANT STRUCTURES

  • Dokuzova, Iva
    • 대한수학회지
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    • 제54권5호
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    • pp.1441-1456
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    • 2017
  • We consider a 3-dimensional Riemannian manifold M with a circulant metric g and a circulant structure q satisfying $q^3=id$. The structure q is compatible with g such that an isometry is induced in any tangent space of M. We introduce three classes of such manifolds. Two of them are determined by special properties of the curvature tensor. The third class is composed by manifolds whose structure q is parallel with respect to the Levi-Civita connection of g. We obtain some curvature properties of these manifolds (M, g, q) and give some explicit examples of such manifolds.

Note on Cellular Structure of Edge Colored Partition Algebras

  • Kennedy, A. Joseph;Muniasamy, G.
    • Kyungpook Mathematical Journal
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    • 제56권3호
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    • pp.669-682
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    • 2016
  • In this paper, we study the cellular structure of the G-edge colored partition algebras, when G is a finite group. Further, we classified all the irreducible representations of these algebras using their cellular structure whenever G is a finite cyclic group. Also we prove that the ${\mathbb{Z}}/r{\mathbb{Z}}$-Edge colored partition algebras are quasi-hereditary over a field of characteristic zero which contains a primitive $r^{th}$ root of unity.