• Title/Summary/Keyword: gamma functions

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ERROR BOUNDS FOR GAUSS-RADAU AND GAUSS-LOBATTO RULES OF ANALYTIC FUNCTIONS

  • Ko, Kwan-Pyo
    • Communications of the Korean Mathematical Society
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    • v.12 no.3
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    • pp.797-812
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    • 1997
  • For analytic functions we give an expression for the kernel $K_n$ of the remainder terms for the Gauss-Radau and the Gauss-Lobatto rules with end points of multiplicity r and prove the convergence of the kernel we obtained. The error bound are obtained for the type $$\mid$R_n(f)$\mid$ \leq \frac{1}{\pi}l(\Gamma) max_{z \in \Gamma} $\mid$K_n(z)$\mid$ max_{z \in \Gamma} $\mid$f(z)$\mid$$, where $l(\Gamma)$ denotes the length of contour $\Gamma$.

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ON THE COEFFICIENTS OF GAMMA-STARLIKE FUNCTIONS

  • Thomas, Derek K.
    • Journal of the Korean Mathematical Society
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    • v.55 no.1
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    • pp.175-184
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    • 2018
  • We give several sharp estimates for some initial coefficients problems for the so-called gamma starlike functions f, analytic and univalent in the unit disk ${\mathbb{D}}:=\{z{\in}{\mathbb{C}}:{\mid}z{\mid}<1\}$, and normalized so that f(0) = 0 = f'(0)-1, and satisfying Re $\left[\left(1+{\frac{zf^{{\prime}{\prime}}(z)}{f^{\prime}(z)}}\right)^{\gamma}\left({\frac{zf^{\prime}(z)}{f(z)}}\right)^{1-{\gamma}}\right]$ > 0.

A duplication formula for the double gamma function $Gamma_2$

  • Park, Junesang
    • Bulletin of the Korean Mathematical Society
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    • v.33 no.2
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    • pp.289-294
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    • 1996
  • The double Gamma function had been defined and studied by Barnes [4], [5], [6] and others in about 1900, not appearing in the tables of the most well-known special functions, cited in the exercise by Whittaker and Waston [25, pp. 264]. Recently this function has been revived according to the study of determinants of Laplacians [8], [11], [15], [16], [19], [20], [22] and [24]. Shintani [21] also uses this function to prove the classical Kronecker limit formula. Its p-adic analytic extension appeared in a formula of Casson Nogues [7] for the p-adic L-functions at the point 0.

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ON CERTAIN SUBCLASSES OF STARLIKE FUNCTIONS

  • Kwon, Oh-Sang
    • Communications of the Korean Mathematical Society
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    • v.10 no.2
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    • pp.305-315
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    • 1995
  • The class $R_{\gamma-1,p}(A,B,\alpha)$ for $-1 \leq B < A \leq 1,\gamma > (B -1)p+(A_B)(p-\alpha)/1-B$ and $0 \leq \alpha < p$ consisting of p-valently analytic functions in the open unit disc is defined with the help of convolution technique. We study containment property, integral transforms and a sufficient condition for an analytic function to be in $R_{\gamma-1,p}(A,B,\alpha)$.

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A CLASS OF SERIES INVOLVING THE ZETA FUNCTION

  • Lee, Hye-Rim;Cho, Young-Joon;Lee, Keum-Sik;Seo, Tae-Young
    • East Asian mathematical journal
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    • v.16 no.2
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    • pp.303-315
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    • 2000
  • The authors apply the theory of multiple Gamma functions, which was recently revived in the study of the determinants of the Laplacians, in order to present a class of closed-form evaluations of series involving the Zeta function by appealing only to the definitions of the double and triple Gamma functions.

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A design on model following optimal boiler-turbine H$\infty$control system using genetic algorithm (유전 알고리즘을 이용한 모델 추종형 최적 보일러-터빈 H$\infty$ 제어시스템의 설계)

  • 황현준;김동완;박준호;황창선
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1460-1463
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    • 1997
  • The aim of this paper is to suggest a design method of the model following optimal boiler-turbine H.inf. control system using genetic algorithm. This boiler-turbine H.inf. control system is designed by applying genetic algortihm with reference model to the optimal determination of weighting functions and design parameter .gamma. that are given by Glover-Doyle algornithm whch can design H.inf. contrlaaer in the sate. space. The first method to do this is ghat the gains of weightinf functions and .gamma. are optimized simultaneously by genetic algroithm. And the second method is that not only the gains and .gamma. but also the dynamics of weighting functions are optimized at the same time by genetic algonithm. The effectiveness of this boiler-turbine H.inf. control system is verified and compared with LQG/LTR control system by computer simulation.

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Application of GA to Design on Optimal Multivariable $H_{\infty}$ Control System (최적 다변수 $H_{\infty}$ 제어 시스템의 설계를 위한 GA의 적용)

  • 황현준;김동완;정호성;박준호;황창선
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.3
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    • pp.257-266
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    • 1999
  • The aim of this paper is to suggest a design method of the optimal multivariable $H_{\infty}$ control system using genetic algorithm (GA). This $H_{\infty}$ control system is designed by applying GA to the optimal determination of weighting functions and design parameter $\gamma$ that are given by Glover-Doyle algorithm which can design $H_{\infty}$ controller in the state space. The first method to do this is that the gains of weighting functions and $\gamma$ are optimized simultaneously by GA with tournament method. And the second method is that not only the gains and $\gamma$ but also the dynamics of weighting functions are optimized at the same time by eA with roulette-wheel method. The effectiveness of this $H_{\infty}$ control system is verified by computer simulation.

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A NOTE ON THE q-ANALOGUE OF KIM'S p-ADIC log GAMMA TYPE FUNCTIONS ASSOCIATED WITH q-EXTENSION OF GENOCCHI AND EULER NUMBERS WITH WEIGHT α

  • Araci, Serkan;Acikgoz, Mehmet;Park, Kyoung Ho
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.2
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    • pp.583-588
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    • 2013
  • In this paper, we introduce the $q$-analogue of $p$-adic log gamma functions with weight alpha. Moreover, we give a relationship between weighted $p$-adic $q$-log gamma functions and $q$-extension of Genocchi and Euler numbers with weight alpha.

MONOTONICITY CRITERION AND FUNCTIONAL INEQUALITIES FOR SOME q-SPECIAL FUNCTIONS

  • Mehrez, Khaled
    • Journal of the Korean Mathematical Society
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    • v.58 no.1
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    • pp.133-147
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    • 2021
  • Our aim in this paper is to derive several new monotonicity properties and functional inequalities of some functions involving the q-gamma, q-digamma and q-polygamma functions. More precisely, some classes of functions involving the q-gamma function are proved to be logarithmically completely monotonic and a class of functions involving the q-digamma function is showed to be completely monotonic. As applications of these, we offer upper and lower bounds for this special functions and new sharp upper and lower bounds for the q-analogue harmonic number harmonic are derived. Moreover, a number of two-sided exponential bounding inequalities are given for the q-digamma function and two-sided exponential bounding inequalities are then obtained for the q-tetragamma function.

EXTENSIONS OF MULTIPLE LAURICELLA AND HUMBERT'S CONFLUENT HYPERGEOMETRIC FUNCTIONS THROUGH A HIGHLY GENERALIZED POCHHAMMER SYMBOL AND THEIR RELATED PROPERTIES

  • Ritu Agarwal;Junesang Choi;Naveen Kumar;Rakesh K. Parmar
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.3
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    • pp.575-591
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    • 2023
  • Motivated by several generalizations of the Pochhammer symbol and their associated families of hypergeometric functions and hypergeometric polynomials, by choosing to use a very generalized Pochhammer symbol, we aim to introduce certain extensions of the generalized Lauricella function F(n)A and the Humbert's confluent hypergeometric function Ψ(n) of n variables with, as their respective particular cases, the second Appell hypergeometric function F2 and the generalized Humbert's confluent hypergeometric functions Ψ2 and investigate their several properties including, for example, various integral representations, finite summation formulas with an s-fold sum and integral representations involving the Laguerre polynomials, the incomplete gamma functions, and the Bessel and modified Bessel functions. Also, pertinent links between the major identities discussed in this article and different (existing or novel) findings are revealed.