• Title/Summary/Keyword: gamma function

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SOME GENERALIZED GAMMA DISTRIBUTION

  • Nadarajah Saralees;Gupta Arjun K.
    • Journal of the Korean Statistical Society
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    • v.36 no.1
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    • pp.93-109
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    • 2007
  • Gamma distributions are some of the most popular models for hydrological processes. In this paper, a very flexible family which contains the gamma distribution as a particular case is introduced. Evidence of flexibility is shown by examining the shape of its pdf and the associated hazard rate function. A comprehensive treatment of the mathematical properties is provided by deriving expressions for the nth moment, moment generating function, characteristic function, Renyi entropy and the asymptotic distribution of the extreme order statistics. Estimation and simulation issues are also considered. Finally, a detailed application to drought data from the State of Nebraska is illustrated.

THE q-DEFORMED GAMMA FUNCTION AND q-DEFORMED POLYGAMMA FUNCTION

  • Chung, Won Sang;Kim, Taekyun;Mansour, Toufik
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.4
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    • pp.1155-1161
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    • 2014
  • In this paper, we rederive the identity ${\Gamma}_q(x){\Gamma}_q(1-x)={\frac{{\pi}_q}{sin_q({\pi}_qx)}$. Then, we give q-analogue of Gauss' multiplication formula and study representation of q-oscillator algebra in terms of the q-factorial polynomials.

FOUR LOGARITHMICALLY COMPLETELY MONOTONIC FUNCTIONS INVOLVING GAMMA FUNCTION

  • Qi, Feng;Niu, Da-Wei;Cao, Jian;Chen, Shou-Xin
    • Journal of the Korean Mathematical Society
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    • v.45 no.2
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    • pp.559-573
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    • 2008
  • In this paper, two classes of functions, involving a parameter and the classical Euler gamma function, and two functions, involving the classical Euler gamma function, are verified to be logarithmically completely monotonic in $(-\frac{1}{2},\infty)$ or $(0,\infty)$; some inequalities involving the classical Euler gamma function are deduced and compared with those originating from certain problems of traffic flow, due to J. Wendel and A. Laforgia, and relating to the well known Stirling's formula.

SOME LOGARITHMICALLY COMPLETELY MONOTONIC FUNCTIONS RELATED TO THE GAMMA FUNCTION

  • Qi, Feng;Guo, Bai-Ni
    • Journal of the Korean Mathematical Society
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    • v.47 no.6
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    • pp.1283-1297
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    • 2010
  • In this article, the logarithmically complete monotonicity of some functions such as $\frac{1}{[\Gamma(x+1)]^{1/x}$, $\frac{[\Gamma(x+1)]^{1/x}}{x^\alpha}$, $\frac{[\Gamma(x+1)]^{1/x}}{(x+1)^\alpha}$ and $\frac{[\Gamma(x+\alpha+1)]^{1/(x+\alpha})}{[\Gamma(x+1)^{1/x}}$ for $\alpha{\in}\mathbb{R}$ on ($-1,\infty$) or ($0,\infty$) are obtained, some known results are recovered, extended and generalized. Moreover, some basic properties of the logarithmically completely monotonic functions are established.

STABILITY OF THE G-FUNCTIONAL EQUATION

  • Kim, Gwang-Hui
    • Journal of applied mathematics & informatics
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    • v.9 no.2
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    • pp.837-844
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    • 2002
  • In this paper, we obtain the Hyers-Ulam Stability for the difference equations of the form f(x + 1) = $\Gamma$(x)f(x), which is the reciprocal functional equation of the double gamma function.

A PROOF OF THE LEGENDRE DUPLICATION FORMULA FOR THE GAMMA FUNCTION

  • Park, In-Hyok;Seo, Tae-Young
    • East Asian mathematical journal
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    • v.14 no.2
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    • pp.321-327
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    • 1998
  • There have been various proofs of the Legendre duplication formula for the Gamma function. Another proof of the formula is given here and a brief history of the Gamma function is also provided.

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CERTAIN INTEGRAL REPRESENTATIONS OF GENERALIZED STIELTJES CONSTANTS γk(a)

  • Shin, Jong Moon
    • East Asian mathematical journal
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    • v.31 no.1
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    • pp.41-53
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    • 2015
  • A large number of series and integral representations for the Stieltjes constants (or generalized Euler-Mascheroni constants) ${\gamma}_k$ and the generalized Stieltjes constants ${\gamma}_k(a)$ have been investigated. Here we aim at presenting certain integral representations for the generalized Stieltjes constants ${\gamma}_k(a)$ by choosing to use four known integral representations for the generalized zeta function ${\zeta}(s,a)$. As a by-product, our main results are easily seen to specialize to yield those corresponding integral representations for the Stieltjes constants ${\gamma}_k$. Some relevant connections of certain special cases of our results presented here with those in earlier works are also pointed out.

Loss-of-function and Gain-of-function Rice Mutants from Gamma-Ray Mutagenesis

  • Lee, Seon-Woo;Park, Gyung-Ja;Kim, Jin-Cheol;Kim, Heung-Tae;Park, Yong-Ho;Cho, Kwang-Yun
    • The Plant Pathology Journal
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    • v.19 no.6
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    • pp.301-304
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    • 2003
  • Gamma-ray irradiation is known to induce various mutations in plants caused by chromosome alterations. This study investigated disease responses of selected gamma-ray induced rice mutants generated from seven Japonica-type rice cultivars against three plant diseases. Among the tested 22 mutants, three gain-of-function mutants and six loss-of-function mutants against rice blast were obtained, as well as three loss-of-function mutants against bacterial leaf blight (BLB). Two of the loss-of-function mutants were susceptible to both rice blast and BLB. Gain-of-function mutation has not been frequently observed in rice plants, thus, the mutants can be used to identify loci of novel genes for the regulation of disease resistant response.

Inference on the reliability P(Y < X) in the gamma case

  • Moon, Yeung-Gil;Lee, Chang-Soo
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.1
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    • pp.219-223
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    • 2009
  • We shall derive a quotient distribution of two independent gamma variables and its moment and reliability are represented by hypergeometric function and Wittaker's function. And we shall consider an inference on the reliability in two independent gamma random variables.

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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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