• 제목/요약/키워드: Special functions

검색결과 849건 처리시간 0.031초

새로운 p진 Bent 수열의 생성 (New Constructions of p-ary Bent Sequences)

  • 김영식;장지웅;노종선
    • 한국통신학회논문지
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    • 제28권10C호
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    • pp.930-935
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    • 2003
  • 본 논문에서는 소수 p에 대해 Kumar와 Moreno가 소개한 유한체 상에시 정의된 bent 함수를 이용하여 균형성과 최적의 상관성질을 갖는 p진 bent 수열군의 일반화된 생성방법을 소개한다[3]. 이렇게 생성된 수열군을 일반화된 p진 수열이라 부르기로 한다. Moriuchi와 Imamura가 [6]에서 소개한 균형성과 최적의 상관특성을 갖는 p진 수열군은 일반화된 bent 수열의 특별한 예임을 보인다.

유도 초음파 이용 결함 진단을 위한 정합추적 기법 (Matching Pursuit Approach for Guided Wave-Based Damage Inspection)

  • 홍진철;선경호;김윤영
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.615-618
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    • 2004
  • For successful guided-wave damage inspection, the appropriate signal processing of measured wave signals is very important. The objective of this paper is to introduce an efficient signal processing technique especially suitable for the guided-waves used for damage detection. The key idea of this technique is to model guided-waves by chirp functions of special form considering the dispersion phenomenon. To determine the parameter of the chirp functions simulating guided-waves, the matching pursuit algorithm is employed. The damage information in waveguides can be extracted by pulse-characterizing parameters. The effectiveness of present method is checked with the longitudinal wave-based damage inspection.

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A CLASS OF MULTIVALENT FUNCTIONS WITH NEGATIVE COEFFICIENTS DEFINED BY CONVOLUTION

  • Ali Rosihan M.;Khan M. Hussain;Ravichandran V.;Subramanian K.G.
    • 대한수학회보
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    • 제43권1호
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    • pp.179-188
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    • 2006
  • For a given p-valent analytic function g with positive coefficients in the open unit disk $\Delta$, we study a class of functions $f(z) = z^p - \sum\limits{_{n=m}}{^\infty} a_nz^n(a_n{\geq}0)$ satisfying $$\frac 1 {p}{\Re}\;(\frac {z(f*g)'(z)} {(f*g)(z)})\;>\;\alpha\;(0{\leq}\;\alpha\;<\;1;z{\in}{\Delta})$$ Coefficient inequalities, distortion and covering theorems, as well as closure theorems are determined. The results obtained extend several known results as special cases.

THE SPACE OF FOURIER HYPERFUNCTIONS AS AN INDUCTIVE LIMIT OF HILBERT SPACES

  • Kim, Kwang-Whoi
    • 대한수학회논문집
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    • 제19권4호
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    • pp.661-681
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    • 2004
  • We research properties of the space of measurable functions square integrable with weight exp$2\nu $\mid$x$\mid$$, and those of the space of Fourier hyperfunctions. Also we show that the several embedding theorems hold true, and that the Fourier-Lapace operator is an isomorphism of the space of strongly decreasing Fourier hyperfunctions onto the space of analytic functions extended to any strip in $C^n$ which are estimated with the aid of a special exponential function exp($\mu$|x|).

CERTAIN SUMMATION FORMULAS FOR HUMBERT'S DOUBLE HYPERGEOMETRIC SERIES Ψ2 AND Φ2

  • CHOI, JUNESANG;RATHIE, ARJUN KUMAR
    • 대한수학회논문집
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    • 제30권4호
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    • pp.439-446
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    • 2015
  • The main objective of this paper is to establish certain explicit expressions for the Humbert functions ${\Phi}_2$(a, a + i ; c ; x, -x) and ${\Psi}_2$(a ; c, c + i ; x, -x) for i = 0, ${\pm}1$, ${\pm}2$, ..., ${\pm}5$. Several new and known summation formulas for ${\Phi}_2$ and ${\Psi}_2$ are considered as special cases of our main identities.

A unified method for stresses in FGM sphere with exponentially-varying properties

  • Celebi, Kerimcan;Yarimpabuc, Durmus;Keles, Ibrahim
    • Structural Engineering and Mechanics
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    • 제57권5호
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    • pp.823-835
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    • 2016
  • Using the Complementary Functions Method (CFM), a general solution for the one-dimensional steady-state thermal and mechanical stresses in a hollow thick sphere made of functionally graded material (FGM) is presented. The mechanical properties are assumed to obey the exponential variations in the radial direction, and the Poisson's ratio is assumed to be constant, with general thermal and mechanical boundary conditions on the inside and outside surfaces of the sphere. In the present paper, a semi-analytical iterative technique, one of the most efficient unified method, is employed to solve the heat conduction equation and the Navier equation. For different values of inhomogeneity constant, distributions of radial displacement, radial stress, circumferential stress, and effective stress, as a function of radial direction, are obtained. Various material models from the literature are used and corresponding temperature distributions and stress distributions are computed. Verification of the proposed method is done using benchmark solutions available in the literature for some special cases and virtually exact results are obtained.

EVALUATION OF INTEGRAL FORMULAS ASSOCIATED WITH THE PRODUCT OF GENERALIZED BESSEL FUNCTION WITH ORTHOGONAL POLYNOMIALS

  • Khan, Nabiullah;Nadeem, Raghib;Usman, Talha;Khan, Abdul Hakim
    • 호남수학학술지
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    • 제41권1호
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    • pp.135-152
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    • 2019
  • In the last decades, various integral formulas associated with Bessel functions of different kinds as well as Bessel functions themselves, have been studied and a noteworthy amount of work can be found in the literature. Following up, we present two definite integral formulas involving the product of generalized Bessel function associated with orthogonal polynomials. Also, some intriguing special cases of our main results have been discussed.

CHARACTERIZING FUNCTIONS FIXED BY A WEIGHTED BEREZIN TRANSFORM IN THE BIDISC

  • Lee, Jaesung
    • Korean Journal of Mathematics
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    • 제27권2호
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    • pp.437-444
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    • 2019
  • For c > -1, let ${\nu}_c$ denote a weighted radial measure on ${\mathbb{C}}$ normalized so that ${\nu}_c(D)=1$. For $c_1,c_2>-1$ and $f{\in}L^1(D^2,\;{\nu}_{c_1}{\times}{\nu}_{c_2})$, we define the weighted Berezin transform $B_{c_1,c_2}f$ on $D^2$ by $$(B_{c_1,c_2})f(z,w)={\displaystyle{\smashmargin2{\int\nolimits_D}{\int\nolimits_D}}}f({\varphi}_z(x),\;{\varphi}_w(y))\;d{\nu}_{c_1}(x)d{\upsilon}_{c_2}(y)$$. This paper is about the space $M^p_{c_1,c_2}$ of function $f{\in}L^p(D^2,\;{\nu}_{c_1}{\times}{\nu}_{c_2})$ ) satisfying $B_{c_1,c_2}f=f$ for $1{\leq}p<{\infty}$. We find the identity operator on $M^p_{c_1,c_2}$ by using invariant Laplacians and we characterize some special type of functions in $M^p_{c_1,c_2}$.

RAY CLASS INVARIANTS IN TERMS OF EXTENDED FORM CLASS GROUPS

  • Yoon, Dong Sung
    • East Asian mathematical journal
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    • 제37권1호
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    • pp.87-95
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    • 2021
  • Let K be an imaginary quadratic field with ��K its ring of integers. For a positive integer N, let K(N) be the ray class field of K modulo N��K, and let ��N be the field of meromorphic modular functions of level N whose Fourier coefficients lie in the Nth cyclotomic field. For each h ∈ ��N, we construct a ray class invariant as its special value in terms of the extended form class group, and show that the invariant satisfies the natural transformation formula via the Artin map in the sense of Siegel and Stark. Finally, we establish an isomorphism between the extended form class group and Gal(K(N)/K) without any restriction on K.

ON PARTIAL SUMS OF FOUR PARAMETRIC WRIGHT FUNCTION

  • Din, Muhey U
    • 대한수학회논문집
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    • 제37권3호
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    • pp.681-692
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    • 2022
  • Special functions and Geometric function theory are close related to each other due to the surprise use of hypergeometric function in the solution of the Bieberbach conjecture. The purpose of this paper is to provide a set of sufficient conditions under which the normalized four parametric Wright function has lower bounds for the ratios to its partial sums and as well as for their derivatives. The sufficient conditions are also obtained by using Alexander transform. The results of this paper are generalized and also improved the work of M. Din et al. [15]. Some examples are also discussed for the sake of better understanding of this article.