• 제목/요약/키워드: Finite ascent

검색결과 11건 처리시간 0.018초

ALGEBRAIC SPECTRAL SUBSPACES OF OPERATORS WITH FINITE ASCENT

  • Han, Hyuk
    • 충청수학회지
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    • 제29권4호
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    • pp.677-686
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    • 2016
  • Algebraic spectral subspaces were introduced by Johnson and Sinclair via a transnite sequence of spaces. Laursen simplified the definition of algebraic spectral subspace. Algebraic spectral subspaces are useful in automatic continuity theory of intertwining linear operators on Banach spaces. In this paper, we characterize algebraic spectral subspaces of operators with finite ascent. From this characterization we show that if T is a generalized scalar operator, then T has finite ascent.

LOCAL SPECTRAL THEORY

  • YOO, JONG-KWANG
    • Journal of applied mathematics & informatics
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    • 제38권3_4호
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    • pp.261-269
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    • 2020
  • For any Banach spaces X and Y, let L(X, Y) denote the set of all bounded linear operators from X to Y. Let A ∈ L(X, Y) and B, C ∈ L(Y, X) satisfying operator equation ABA = ACA. In this paper, we prove that AC and BA share the local spectral properties such as a finite ascent, a finite descent, property (K), localizable spectrum and invariant subspace.

INHERITED PROPERTIES THROUGH THE HELTON CLASS OF AN OPERATOR

  • Kim, In-Sook;Kim, Yoen-Ha;Ko, Eung-Il;Lee, Ji-Eun
    • 대한수학회보
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    • 제48권1호
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    • pp.183-195
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    • 2011
  • In this paper we show that Helton class preserves the nilpotent and finite ascent properties. Also, we show some relations on non-transitivity and decomposability between operators and their Helton classes. Finally, we give some applications in the Helton class of weighted shifts.

ASCENT AND DESCENT OF COMPOSITION OPERATORS ON LORENTZ SPACES

  • Bajaj, Daljeet Singh;Datt, Gopal
    • 대한수학회논문집
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    • 제37권1호
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    • pp.195-205
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    • 2022
  • In this paper, we provide various characterizations for the composition operator on Lorentz spaces L(p, q), 1 < p ≤ ∞, 1 ≤ q ≤ ∞ to have finite ascent (descent) in terms of its inducing measurable transformation. At the end, in order to demonstrate our outcomes, some examples are given.

Conditions on Operators Satisfying Weyl's Theorem

  • Kim, An-Hyun
    • 호남수학학술지
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    • 제25권1호
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    • pp.75-82
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    • 2003
  • In this note it is shown that if T satisfies ($G_{1}$)-condition with finite spectrum then Weyl's theorem holds for T. If T is totally *-paranormal then $T-{\lambda}$ has finite ascent for all ${\lambda}{\in}{\mathbb{C}},\;T$ is isoloid, and Weyl's theorem holds for T.

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ON BROWDER'S THEOREM

  • Lee, Dong Hark
    • Korean Journal of Mathematics
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    • 제10권1호
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    • pp.11-17
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    • 2002
  • In this paper we give several necessary and sufficient conditions for an operator on the Hilbert space to obey Browder's theorem. And it is shown that if S has totally finite ascent and $T{\prec}S$ then $f(T)$ obeys Browder's theorem for every $f{\in}H({\sigma}(T))$, where $H({\sigma}(T))$ denotes the set of all analytic functions on an open neighborhood of ${\sigma}(T)$.

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SGA 기반 강화학습 알고리즘을 이용한 로봇 제어 (Robot Control via SGA-based Reinforcement Learning Algorithms)

  • 박주영;김종호;신호근
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2004년도 추계학술대회 학술발표 논문집 제14권 제2호
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    • pp.63-66
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    • 2004
  • The SGA(stochastic gradient ascent) algorithm is one of the most important tools in the area of reinforcement learning, and has been applied to a wide range of practical problems. In particular, this learning method was successfully applied by Kimura et a1. [1] to the control of a simple creeping robot which has finite number of control input choices. In this paper, we considered the application of the SGA algorithm to Kimura's robot control problem for the case that the control input is not confined to a finite set but can be chosen from a infinite subset of the real numbers. We also developed a MATLAB-based robot animation program, which showed the effectiveness of the training algorithms vividly.

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STUDY ON BROWDER'S SPECTRUMS AND WEYL'S SPECTRUMS

  • Lee, Dong Hark
    • Korean Journal of Mathematics
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    • 제12권2호
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    • pp.147-154
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    • 2004
  • In this paper we give several necessary and sufficient conditions for an operator on the Hilbert space H to obey Browder's theorem. And it is shown that if S has totally finite ascent and $T{\prec}S$ then $f(T)$ obeys Browder's theorem for every $f{\in}H({\sigma}(T))$, where $H({\sigma}(T))$ denotes the set of all analytic functions on an open neighborhood of ${\sigma}(T)$. Furthermore, it is shown that if $T{\in}B(H)$ is a compact operator or a Riesz Operator then T obeys Browder's theorem and Weyl's theorem holds if and only if Browder's holds.

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리츠 법을 이용한 열방어 시스템 패널의 열 좌굴 특성 연구 (Thermal Buckling Characteristics for Thermal Protection System Panel Using Ritz Method)

  • 이희수;김용하;박정선
    • 항공우주시스템공학회지
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    • 제13권1호
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    • pp.18-28
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    • 2019
  • 초고속 비행체는 발사 및 재진입 시 공력 가열에 의해 높은 열 하중을 받는다. 초고속 비행체의 외피 구조물인 열방어 시스템 패널은 기계적으로 구속되어 있기 때문에 고온 가열 시 열 좌굴이 발생할 수도 있다. 이는 초고속 비행체의 유동장에 변화를 주어 공력특성을 불안정하게 한다. 따라서 열방어 시스템 패널은 초고속 비행에 의한 공력가열 시 비행안정성을 유지하기 위해 열 좌굴을 방지하도록 설계되어야 한다. 본 논문에서는 운용 시 안팎에 큰 온도차가 존재하는 열방어 시스템 패널에 대해 유한차분법을 사용하여 열전달 특성을 분석하였으며, 리츠 법을 사용하여 열 좌굴 특성에 대한 근사적 모델을 제안하였다. 또한 정의된 근사적 모델의 정확도를 검증하기 위해 유한요소 해석결과와 비교하였다. 마지막으로, 수립된 근사 기법을 바탕으로 열방어 시스템 패널의 좌굴 발생 온도에 대한 매개변수 분석을 수행하였다.