• 제목/요약/키워드: $S^1$-invariant function

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A Generalization of S. P. Singh's T-invariant Point Theorem to Approximation Theory

  • Cho, Yeol Je
    • 한국수학교육학회지시리즈A:수학교육
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    • 제18권1호
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    • pp.21-23
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    • 1980
  • In [3], an extension of B. Brosowski s T-invariant Point Theorem is given where the linearity of the function and the convexity of the set are relaxed. In this paper, our main purpose is to generalize S. P. Singh's T-invariant Point Theorem to Approximation Theory.

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DYNAMICAL PROPERTIES ON THE ITERATION OF CF-FUNCTIONS

  • Yoo, Seung-Jae
    • 충청수학회지
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    • 제12권1호
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    • pp.1-13
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    • 1999
  • The purpose of this paper is to show that if the Fatou set F(f) of a CF-meromorphic function f has two completely invariant components, then they are the only components of F(f) and that the Julia set of the entire transcendental function $E_{\lambda}(z)={\lambda}e^z$ for 0 < ${\lambda}$ < $\frac{1}{e}$ contains a Cantor bouquet by employing the Devaney and Tangerman's theorem[10].

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EXTREMELY MEASURABLE SUBALGEBRAS

  • Ayyaswamy, S.K.
    • 대한수학회보
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    • 제22권1호
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    • pp.7-10
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    • 1985
  • For each a.mem.S and f.mem.m(S), denote by $l_{a}$ f(s)=f(as) for all s.mem.S. If A is a norm closed left translation invariant subalgebra of m(S) (i.e. $l_{a}$ f.mem.A whenever f.mem.A and a.mem.S) containing 1, the constant ont function on S and .phi..mem. $A^{*}$, the dual of A, then .phi. is a mean on A if .phi.(f).geq.0 for f.geq.0 and .phi.(1) = 1, .phi. is multiplicative if .phi. (fg)=.phi.(f).phi.(g) for all f, g.mem.A; .phi. is left invariant if .phi.(1sf)=.phi.(f) for all s.mem.S and f.mem.A. It is well known that the set of multiplicative means on m(S) is precisely .betha.S, the Stone-Cech compactification of S[7]. A subalgebra of m(S) is (extremely) left amenable, denoted by (ELA)LA if it is nom closed, left translation invariant containing contants and has a multiplicative left invariant mean (LIM). A semigroup S is (ELA) LA, if m(S) is (ELA)LA. A subset E.contnd.S is left thick (T. Mitchell, [4]) if for any finite subser F.contnd.S, there exists s.mem.S such that $F_{s}$ .contnd.E or equivalently, the family { $s^{-1}$ E : s.mem.S} has finite intersection property.y.

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A NOTE ON THE BOUNDARY BEHAVIOUR OF THE SQUEEZING FUNCTION AND FRIDMAN INVARIANT

  • Kim, Hyeseon;Mai, Anh Duc;Nguyen, Thi Lan Huong;Ninh, Van Thu
    • 대한수학회보
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    • 제57권5호
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    • pp.1241-1249
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    • 2020
  • Let Ω be a domain in ℂn. Suppose that ∂Ω is smooth pseudoconvex of D'Angelo finite type near a boundary point ξ0 ∈ ∂Ω and the Levi form has corank at most 1 at ξ0. Our goal is to show that if the squeezing function s(𝜂j) tends to 1 or the Fridman invariant h(𝜂j) tends to 0 for some sequence {𝜂j} ⊂ Ω converging to ξ0, then this point must be strongly pseudoconvex.

STABILITY THEOREMS OF THE OPERATOR-VALUED FUNCTION SPACE INTEGRAL ON $C_0(B)$

  • Ryu, K.-S;Yoo, S.-C
    • 대한수학회보
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    • 제37권4호
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    • pp.791-802
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    • 2000
  • In 1968, Cameron and Storvick introduce the definition and the theories of the operator-valued function space integral. Since then, the stability theorems of the integral was developed by Johnson, Skoug, Chang etc [1, 2, 4, 5]. Recently, the authors establish the existence theorem of the operator-valued function space [8]. In this paper, we will prove the stability theorems of the operator-valued function space integral over paths in abstract Wiener space $C_0(B)$.

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광굴절 매질을 이용한 공간계 불변 광상관기에 관한 연구 (Deformation Invariant Optical Correlator Using Photorefractive Medium)

  • 김란숙;임종태;손현;박한규
    • 대한전자공학회논문지
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    • 제26권6호
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    • pp.97-101
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    • 1989
  • 변형불변 패턴인식을 실현하기 위하여 크기와 회전변위에 대해 불변인 극-로가리즘 좌표변환을 이용하였고, 좌표 변환을 수행하기 위하여 Lee 방식의 투과함수를 갖는 CGH를 CAD용 포토(UV light)패턴 발생기에 의해 마스크로 제작하였다. 광학적으로 좌표변환된 입력패턴은 본 논문에서 제시한 광상관기에 입력되었으며, 실시간 홀로그래피에 의한 기록매질로서 $BaTiO_3$ 단결정을 정합필터로 사용하였다. 본 논문에서 제시한 광상관기를 사용하여 크기와 입력에 대한 자기상관값의 변화를 실험적으로 제시함으로서 변형불변 패턴인식을 증명하였다.

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광웨이브렛 원형고조 정합필터를 이용한 회전불변 패턴인식 (Rotation-invariant pattern recognition using an optical wavelet circular harmonic matched filter)

  • 이하운;김철수;김정우;김수중
    • 전자공학회논문지S
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    • 제34S권1호
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    • pp.132-144
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    • 1997
  • The rotation-invariant pattern recognition filter using circular harmonic function of the wavelet transforme dsreference image by morlet, mexican-hat, and haar wavelt function is proposed. The rotated reference images, the images sililar to the reference image, and the images which are added by random noise are used for the inpt images, and in case of the input images with random noise, they are applied to the recognition after removing the random noise by the transformed moving average method with proper thresholding value and window size. The proposed optical wavelet circular harmonic matched filter (WCHMF) is a type of the matche dfilter, so that it can be applied to the 4f vander lugt optical correlation system. SNR and discrimination capability of the proposed filter are compared with those of the conventional HF, the POCHF, and the BPOCHF. The proper wavelet function for the reference image used in this paper is achieved by applying morlet, mexican-hat, and harr wavelet function ot the proposed filter, and the proposed filter has good SNR and discrimination capability with rotation-invariance in case of the morlet wavelet function.

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CHARACTERIZATIONS OF THE GAMMA DISTRIBUTION BY INDEPENDENCE PROPERTY OF RANDOM VARIABLES

  • Jin, Hyun-Woo;Lee, Min-Young
    • 충청수학회지
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    • 제27권2호
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    • pp.157-163
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    • 2014
  • Let {$X_i$, $1{\leq}i{\leq}n$} be a sequence of i.i.d. sequence of positive random variables with common absolutely continuous cumulative distribution function F(x) and probability density function f(x) and $E(X^2)$ < ${\infty}$. The random variables X + Y and $\frac{(X-Y)^2}{(X+Y)^2}$ are independent if and only if X and Y have gamma distributions. In addition, the random variables $S_n$ and $\frac{\sum_{i=1}^{m}(X_i)^2}{(S_n)^2}$ with $S_n=\sum_{i=1}^{n}X_i$ are independent for $1{\leq}m$ < n if and only if $X_i$ has gamma distribution for $i=1,{\cdots},n$.