• Title/Summary/Keyword: Finite ascent

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ALGEBRAIC SPECTRAL SUBSPACES OF OPERATORS WITH FINITE ASCENT

  • Han, Hyuk
    • Journal of the Chungcheong Mathematical Society
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    • v.29 no.4
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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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    • v.38 no.3_4
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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
    • Bulletin of the Korean Mathematical Society
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    • v.48 no.1
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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
    • Communications of the Korean Mathematical Society
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    • v.37 no.1
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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
    • Honam Mathematical Journal
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    • v.25 no.1
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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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    • v.10 no.1
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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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Robot Control via SGA-based Reinforcement Learning Algorithms (SGA 기반 강화학습 알고리즘을 이용한 로봇 제어)

  • 박주영;김종호;신호근
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2004.10a
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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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    • v.12 no.2
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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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Thermal Buckling Characteristics for Thermal Protection System Panel Using Ritz Method (리츠 법을 이용한 열방어 시스템 패널의 열 좌굴 특성 연구)

  • Lee, Heesoo;Kim, Yongha;Park, Jungsun
    • Journal of Aerospace System Engineering
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    • v.13 no.1
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    • pp.18-28
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    • 2019
  • High speed vehicles are subjected to high thermal loadings due to aerodynamic heating during ascent and reentry. Since a thermal protection system panel is mechanically constrained, it may cause thermal buckling under excessive thermal loadings. The thermal buckling could disturb the field of flow and make aerodynamic characteristics unstable. It is thus necessary to design the thermal protection system panel to prevent thermal buckling. This study defines the analytical model of temperature distribution using the finite difference method for the thermal protection system panel with large temperature differences inside and outside. This paper proposes the approximate model of the thermal buckling characteristics for the thermal protection system panel through the use of the Ritz method. The validity of the present method was verified by comparing the results of the finite element analysis. Furthermore, this research performs the parametric analysis of the thermal buckling characteristics for the thermal protection system panel by using the approximate model.