• 제목/요약/키워드: a-invariant

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HARMONIC HOMOMORPHISMS BETWEEN TWO LIE GROUPS

  • Son, Heui-Sang;Kim, Hyun Woong;Park, Joon-Sik
    • 호남수학학술지
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    • 제38권1호
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    • pp.1-8
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    • 2016
  • In this paper, we get a complete condition for a group homomorphism of a compact Lie group with an arbitrarily given left invariant Riemannian metric into another Lie group with a left invariant metric to be a harmonic map, and then obtain a necessary and sufficient condition for a group homomorphism of (SU(2), g) with a left invariant metric g into the Heisenberg group (H, $h_0$) to be a harmonic map.

ON SEMI-INVARIANT SUBMANIFOLDS OF A NEARLY KENMOTSU MANIFOLD WITH A QUARTER SYMMETRIC NON-METRIC CONNECTION

  • Ahmad, Mobin;Jun, Jae-Bok
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제18권1호
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    • pp.1-11
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    • 2011
  • We define a quarter symmetric non-metric connection in a nearly Ken-motsu manifold and we study semi-invariant submanifolds of a nearly Kenmotsu manifold endowed with a quarter symmetric non-metric connection. Moreover, we discuss the integrability of the distributions on semi-invariant submanifolds of a nearly Kenmotsu manifold with a quarter symmetric non-metric connection.

ON SEMI-INVARIANT SUBMANIFOLDS OF A NEARLY KENMOTSU MANIFOLD WITH A SEMI-SYMMETRIC NON-METRIC CONNECTION

  • Ahmad, Mobin;Jun, Jae-Bok
    • 충청수학회지
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    • 제23권2호
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    • pp.257-266
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    • 2010
  • We define a semi-symmetric non-metric connection in a nearly Kenmotsu manifold and we study semi-invariant submanifolds of a nearly Kenmotsu manifold endowed with a semi-symmetric non-metric connection. Moreover, we discuss the integrability of distributions on semi-invariant submanifolds of a nearly Kenmotsu manifold with a semi-symmetric non-metric connection.

OBLIQUE PROJECTIONS AND SHIFT-INVARIANT SPACES

  • Park, Sang-Don;Kang, Chul
    • Journal of applied mathematics & informatics
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    • 제26권5_6호
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    • pp.1207-1214
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    • 2008
  • We give an elementary proof of one of the main results in [H.O. Kim, R.Y. Kim, J.K. Lim, The infimum cosine angle between two finitely generated shift-invariant spaces and its applications, Appl. Comput. Har-mon. Anal. 19 (2005) 253-281] concerning the existence of an oblique projection onto a finitely generated shift-invariant space along the orthogonal complement of another finitely generated shift-invariant space under the assumption that the generators generate Riesz bases.

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CLAIRAUT ANTI-INVARIANT SUBMERSIONS FROM COSYMPLECTIC MANIFOLDS

  • Tastan, Hakan Mete;Aydin, Sibel Gerdan
    • 호남수학학술지
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    • 제41권4호
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    • pp.707-724
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    • 2019
  • We investigate the new Clairaut conditions for anti-invariant submersions whose total manifolds are cosymplectic. In particular, we prove the fibers of a proper Clairaut Lagrangian submersion admitting horizontal Reeb vector field are one dimensional and classify such submersions. We also check the existence of the proper Clairaut anti-invariant submersions in the case of the Reeb vector field is vertical. Moreover, illustrative examples for both trivial and proper Clairaut anti-invariant submersions are given.

ON SOME PROPERTIES OF SEMI-INVARIANT SUBMANIFOLDS OF A NEARLY TRANS-SASAKIAN MANIFOLD ADMITTING A QUARTER-SYMMETRIC NON-METRIC CONNECTION

  • Ahmad, Mobin;Jun, Jae-Bok;Siddiqi, Mohd Danish
    • 충청수학회지
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    • 제25권1호
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    • pp.73-90
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    • 2012
  • We define a quarter-symmetric non-metric connection in a nearly trans-Sasakian manifold and we consider semi-invariant submanifolds of a nearly trans-Sasakian manifold endowed with a quarter-symmetric non-metric connection. Moreover, we also obtain integrability conditions of the distributions on semi-invariant submanifolds.

CENTROAFFINE GEOMETRY OF RULED SURFACES AND CENTERED CYCLIC SURFACES IN ℝ4

  • Yang, Yun;Yu, Yanhua
    • 대한수학회지
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    • 제55권4호
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    • pp.987-1004
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    • 2018
  • In this paper, we get several centroaffine invariant properties for a ruled surface in ${\mathbb{R}}^4$ with centroaffine theories of codimension two. Then by solving certain partial differential equations and studying a centroaffine surface with some centroaffine invariant properties in ${\mathbb{R}}^4$, we obtain such a surface is centroaffinely equivalent to a ruled surface or one of the flat centered cyclic surfaces. Furthermore, some centroaffine invariant properties for centered cyclic surfaces are considered.

INFINITELY MANY SOLUTIONS FOR A CLASS OF THE ELLIPTIC SYSTEMS WITH EVEN FUNCTIONALS

  • Choi, Q-Heung;Jung, Tacksun
    • 대한수학회지
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    • 제54권3호
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    • pp.821-833
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    • 2017
  • We get a result that shows the existence of infinitely many solutions for a class of the elliptic systems involving subcritical Sobolev exponents nonlinear terms with even functionals on the bounded domain with smooth boundary. We get this result by variational method and critical point theory induced from invariant subspaces and invariant functional.

A BIFURCATION PROBLEM FOR THE BIHARMONIC OPERATOR

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • 제20권2호
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    • pp.263-271
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    • 2012
  • We investigate the number of the solutions for the biharmonic boundary value problem with a variable coefficient nonlinear term. We get a theorem which shows the existence of $m$ weak solutions for the biharmonic problem with variable coefficient. We obtain this result by using the critical point theory induced from the invariant function and invariant linear subspace.

Fourier Transform을 이용한 3차원 폐곡면 객체의 특징 벡터 추출 (Feature Extraction in 3-Dimensional Object with Closed-surface using Fourier Transform)

  • 이준복;김문화;장동식
    • 융합신호처리학회논문지
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    • 제4권3호
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    • pp.21-26
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    • 2003
  • 본 논문은 퓨리에 변환을 이용한 3차원 폐곡면 객체의 특징 벡터 추출 기법을 제시한다. 특징 벡터는 3차원극좌표계를 이용하여 폐곡면 객체의 회전각도별 내측거리값을 퓨리에 변환을 통해 주파수 영역으로 변환하여 추출한다. 특징 벡터는 폐곡면 표면점과 중심점과의 관계를 나타내는 내측거리값을 활용하므로 위치 이동에 불변이고 내측거리값은 퓨리에 변환 전 정규화되기 때문에 크기 변화에 불변이며 퓨리에 변환 후 파워 스펙트럼을 적용하여 회전 변화 불변임을 보여주고 있다. 실험 결과 위치 이동, 크기 변화, 회전 변화에 불변임을 알 수 있고 서로 상이한 객체간에 변별력이 있어 객체 고유의 특징 벡터로써 활용이 가능함을 제시한다.

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