• 제목/요약/키워드: S-space form

검색결과 1,261건 처리시간 0.041초

THE STRUCTURE JACOBI OPERATOR ON REAL HYPERSURFACES IN A NONFLAT COMPLEX SPACE FORM

  • KI, U-HANG;KIM, SOO-JIN;LEE, SEONG-BAEK
    • 대한수학회보
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    • 제42권2호
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    • pp.337-358
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    • 2005
  • Let M be a real hypersurface with almost contact metric structure $(\phi,\;\xi,\;\eta,\;g)$ in a nonflat complex space form $M_n(c)$. In this paper, we prove that if the structure Jacobi operator $R_\xi$ commutes with both the structure tensor $\phi$ and the Ricc tensor S, then M is a Hopf hypersurface in $M_n(c)$ provided that the mean curvature of M is constant or $g(S\xi,\;\xi)$ is constant.

LINEAR WEINGARTEN HYPERSURFACES IN RIEMANNIAN SPACE FORMS

  • Chao, Xiaoli;Wang, Peijun
    • 대한수학회보
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    • 제51권2호
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    • pp.567-577
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    • 2014
  • In this note, we generalize the weak maximum principle in [4] to the case of complete linear Weingarten hypersurface in Riemannian space form $\mathbb{M}^{n+1}(c)$ (c = 1, 0,-1), and apply it to estimate the norm of the total umbilicity tensor. Furthermore, we will study the linear Weingarten hypersurface in $\mathbb{S}^{n+1}(1)$ with the aid of this weak maximum principle and extend the rigidity results in Li, Suh, Wei [13] and Shu [15] to the case of complete hypersurface.

SCREEN CONFORMAL EINSTEIN LIGHTLIKE HYPERSURFACES OF A LORENTZIAN SPACE FORM

  • Jin, Dae-Ho
    • 대한수학회논문집
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    • 제25권2호
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    • pp.225-234
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    • 2010
  • In this paper, we study the geometry of lightlike hypersurfaces of a semi-Riemannian manifold. We prove a classification theorem for Einstein lightlike hypersurfaces M of a Lorentzian space form subject such that the second fundamental forms of M and its screen distribution S(TM) are conformally related by some non-vanishing smooth function.

기능주의 관점에서의 이토 토요의 공간 및 건축 사례 분석 - 소규모 주거 공간 사례를 중심으로 - (Analysis on Space and Architecture Examples of Toyo Ito from the Viewpoint of Functionalism - Focusing on Small-Sized Residental Spaces -)

  • 한현석
    • 디자인융복합연구
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    • 제16권6호
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    • pp.59-74
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    • 2017
  • 루이스 설리번은 "형태는 기능을 따른다"라고 주장했다. 기능이라는 것은 사용자가 제품이나 공간을 사용함에 있어서 가장 원초적으로 필요한 요소 중에 하나이며, 공간 및 건축 분야에서의 "기능"은 그것의 형태를 결정하는 가장 중요한 요소의 의미를 가지고 있다. 이렇게 "기능주의"의 관점에서 기능주의가 추구하는 중요한 요소들이 어떻게 그것의 형태와 관계를 갖는 지를 확인하기 위해서 토요 이토의 작품을 선정하였다. 1970년 초반에서 현재까지 진행된 그의 작품 중에서 공간 및 건축의 구조, 재질 및 공간의 형식을 쉽게 파악할 수 있도록 소규모의 주거 공간 프로젝트를 선정하여 분석하였다. 공간 및 건축의 구조와 표피를 재질의 특성으로 분류하고 공간의 개방성의 강도에 따른 분류를 진행하였다. 결과적으로 기능을 추구하는 공간 및 건축은 기능이라는 요소를 부각하기 위해서 전체적인 장식을 배제하고 그 기능의 효율성을 최대한으로 추구할 수 있는 방법을 사용하였다. 이토 토요의 소규모 주거 공간에서 발견되는 특징은 형태의 정형화 및 단순화, 공간의 개방성, 각 요소의 다목적성 활용성으로 정의할 수 있다.

REAL HALF LIGHTLIKE SUBMANIFOLDS WITH TOTALLY UMBILICAL PROPERTIES

  • Jin, Dae-Ho
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제17권1호
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    • pp.51-63
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    • 2010
  • In this paper, we prove two characterization theorems for real half lightlike submanifold (M,g,S(TM)) of an indefinite Kaehler manifold $\bar{M}$ or an indefinite complex space form $\bar{M}$(c) subject to the conditions : (a) M is totally umbilical in $\bar{M}$, or (b) its screen distribution S(TM) is totally umbilical in M.

REAL HYPERSURFACES WITH ξ-PARALLEL RICCI TENSOR IN A COMPLEX SPACE FORM

  • Ahn, Seong-Soo;Han, Seung-Gook;Kim, Nam-Gil;Lee, Seong-Baek
    • 대한수학회논문집
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    • 제13권4호
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    • pp.825-838
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    • 1998
  • We prove that if a real hypersurface with constant mean curvature of a complex space form satisfying ▽$_{ξ/}$S = 0 and Sξ = $\sigma$ξ for a smooth function $\sigma$, then the structure vector field ξ is principal, where S denotes the Ricci tensor of the hypersurface.

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Certain Characterization of Real Hypersurfaces of type A in a Nonflat Complex Space Form

  • Ki, U-Hang
    • Kyungpook Mathematical Journal
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    • 제61권1호
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    • pp.181-190
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    • 2021
  • Let M be a real hypersurface with almost contact metric structure (ϕ, ��, η, g) in a nonflat complex space form Mn(c). We denote S and R�� by the Ricci tensor of M and by the structure Jacobi operator with respect to the vector field �� respectively. In this paper, we prove that M is a Hopf hypersurface of type A in Mn(c) if it satisfies R��ϕ = ϕR�� and at the same time R��(Sϕ - ϕS) = 0.

실내조경 수공간의 이용만족도 요인 평가 (A Study on User's Satisfaction of Water Space Design in Interior Landscape Architecture Space)

  • 진금해;최만봉;노재현
    • 한국조경학회지
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    • 제31권1호
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    • pp.23-33
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    • 2003
  • The purpose of this study is to analyse six different factors of water space that influence interior landscape architecture of officers and commercial spaces. Six different factors of water space that influence interior landscape architecture are the height of the water space, the design form, the blending with the location environment, location, general satisfaction with the water space, and general satisfaction with whole space. The results of this study are as follows: 1. Water space of commercial space was bigger than office space. The satisfaction is the highest in 0∼0.6M(B2) of office space and 3.5M(C6) of commercial space. The cascade form in the office space and large water volume design in commercial areas, which supplies abundant sound and water volume, were the highest. 2. In the analysis of preferences, the design form and the general design of the office space influences satisfaction levels. The height of the water space, and a combination of other factors influence general satisfaction. Water space influences commercial areas in higher degrees. 3. The items were most desired or satisfactory for interior landscape architecture were a cascade, water fall, and small water fountain. 4. A place introduced with water space had higher satisfaction levels. Water space produces higher than general satisfaction and indicates water, space alone cannot make general interior space satisfactory, although it can make interior landscape architecture space satisfactory. 5. There is more general satisfaction in commercial space than in office space. 6. The design of water space influences overall satisfaction: a rest area of office space needs an impressive and aggressive approach, while the office space should harmonize with its surroundings, as a commercial space.