• Title/Summary/Keyword: Gamma-type function

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Hydrological Studies on the best fitting distribution and probable minimum flow for the extreme values of discharge (極値流量의 最適分布型과 極値確率 流量에 關한 水文學的 硏究 -錦江流域의 渴水量을 中心으로-)

  • Lee, Soon-Hyuk;Han, Chung-Suck
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.21 no.4
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    • pp.108-117
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    • 1979
  • In order to obtain the basic data for design of water structures which can be contributed to the planning of water use. Best fitted distribution function and the equations for the probable minimum flow were derived to the annual minimum flow of five subwatersheds along Geum River basin. The result were analyzed and summarized as follows. 1. Type III extremal distribution was considered as a best fit one among some other distributions such as exponential and two parameter lognormal distribution by $x^2$-goodness of fit test. 2. The minimum flow are analyzed by Type III extremal distribution which contains a shape parameter $\lambda$, a location parameter ${\beta}$ and a minimum drought $\gamma$. If a minimum drought $\gamma=0$, equations for the probable minimum flow, $D_T$, were derived as $D_T={\beta}e^{\lambda}1^{y'}$, with two parameters and as $D_T=\gamma+(\^{\beta}-\gamma)e^{{\lambda}y'}$ with three parameters in case of a minimum drought ${\gamma}>0$ respectively. 3. Probable minimum flow following the return periods for each stations were also obtained by above mentioned equations. Frequency curves for each station are drawn in the text. 4. Mathematical equation with three parameters is more suitable one than that of two parameters if much difference exist between the maximum and the minimum value among observed data.

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Effects of Peroxisome Proliferator-Activated $Receptor-{\gamma}2$ Pro12Ala Polymorphism on Body Fat Distribution in Female Korean Subjects (Peroxisome Proliferator-Activated $Receptor-{\gamma}$ 2 $(PPAR{\gamma}2)$ Pro12Ala (P12A) 유전자 다형성이 한국여성의 체지방분포에 미치는 영향)

  • Kim, Kil-Soo;Choi, Sun-Mi;Yang, Hyun-Sung;Yoon, Yoo-Sik;Shin, Seun-Uoo
    • Journal of Korean Medicine for Obesity Research
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    • v.4 no.1
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    • pp.1-11
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    • 2004
  • Objectives: The effects of peroxisome proliferator-activated receptor ${\gamma}2\;(PPAR{\gamma}2)$ Pro12Ala (P12A) polymorphism on body mass index (BMI) and type 2 diabetes are well documented; however, until now, only a few studies have evaluated the effects of this polymorphism on body fat distribution. This study was conducted to elucidate the effects of this polymorphism on computed tomography (CT)-measured body fat distribution and other obesity-related parameters in Korean female subjects. Methods & Results: The frequencies of $PPAR{\gamma}2$ genotypes were: PP type, 93.0%; PA type, 6.8%; and AA type, 0.2%. The frequency of the A allele was 0.035. Body weight (P .012), BMI (P .012), and waist-to-hip ratio (WHR) (P .001) were significantly higher in subjects with PA/AA compared with subjects with PP. When body composition was analyzed by bioimpedance analysis, lean body mass and body water content were similar between the 2 groups. However, body fat mass (P .003) and body fat percent (P .025) were significantly higher in subjects with PA/AA compared with subjects with PP. Among overweight subjects with BMI of greater than 25, PA/AA was associated with significantly higher abdominal subcutaneous fat (P .000), abdominal visceral fat (P .031), and subcutaneous upper and lower thigh adipose tissue (P .010 and .013). However, among lean subjects with BMI of less than 25, no significant differences associated with $PPAR{\gamma}2$ genotype were found, suggesting that the fat-accumulating effects of the PA/AA genotype were evident only among overweight subjects, but not among lean subjects. When serum lipid profiles, glucose, and liver function indicators were compared among overweight subjects, no significant difference associated with $PPAR{\gamma}2$ genotype was found. Changes in body weight, BMI, WHR, and body fat mass were measured among overweight subjects who finished a 1-month weight lose program of a hypocaloric diet and exercise; no significant differences associated with $PPAR{\gamma}2$ genotype were found. Conclusions: The results of this study suggest that the $PPAR{\gamma}2$ PA/AA genotype is associated with increased subcutaneous and visceral fat areas in overweight Korean female subjects, but does not significantly affect serum biochemical parameters and outcomes of weight loss programs.

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APPROXIMATE PEXIDERIZED EXPONENTIAL TYPE FUNCTIONS

  • Lee, Young-Whan
    • The Pure and Applied Mathematics
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    • v.19 no.2
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    • pp.193-198
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    • 2012
  • We show that every unbounded approximate Pexiderized exponential type function has the exponential type. That is, we obtain the superstability of the Pexiderized exponential type functional equation $$f(x+y)=e(x,y)g(x)h(y)$$. From this result, we have the superstability of the exponential functional equation $$f(x+y)=f(x)f(y)$$.

STABILIZATION FOR THE VISCOELASTIC KIRCHHOFF TYPE EQUATION WITH A NONLINEAR SOURCE

  • Kim, Daewook
    • East Asian mathematical journal
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    • v.32 no.1
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    • pp.117-128
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    • 2016
  • In this paper, we study the viscoelastic Kirchhoff type equation with a nonlinear source $$u^{{\prime}{\prime}}-M(x,t,{\parallel}{\bigtriangledown}u(t){\parallel}^2){\bigtriangleup}u+{\int}_0^th(t-{\tau})div[a(x){\bigtriangledown}u({\tau})]d{\tau}+{\mid}u{\mid}^{\gamma}u=0$$. Under the smallness condition with respect to Kirchhoff coefficient and the relaxation function and other assumptions, we prove the uniform decay rate of the Kirchhoff type energy.

Comparison of methods of approximating option prices with Variance gamma processes (Variance gamma 확률과정에서 근사적 옵션가격 결정방법의 비교)

  • Lee, Jaejoong;Song, Seongjoo
    • The Korean Journal of Applied Statistics
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    • v.29 no.1
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    • pp.181-192
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    • 2016
  • We consider several methods to approximate option prices with correction terms to the Black-Scholes option price. These methods are able to compute option prices from various risk-neutral distributions using relatively small data and simple computation. In this paper, we compare the performance of Edgeworth expansion, A-type and C-type Gram-Charlier expansions, a method of using Normal inverse gaussian distribution, and an asymptotic method of using nonlinear regression through simulation experiments and real KOSPI200 option data. We assume the variance gamma model in the simulation experiment, which has a closed-form solution for the option price among the pure jump $L{\acute{e}}vy$ processes. As a result, we found that methods to approximate an option price directly from the approximate price formula are better than methods to approximate option prices through the approximate risk-neutral density function. The method to approximate option prices by nonlinear regression showed relatively better performance among those compared.

An Indirect Approach Determining Parameters of Clark's Model Based on Model Fitting to the Gamma Distribution function (Gamma분포형 함수 적합을 이용한 Clark 모형의 매개변수 간접추정)

  • Seong, Kee-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.2
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    • pp.223-235
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    • 2003
  • An indirect or supplementary approach is proposed for determining the parameters of the Clark's model in order to improve existing defect in estimating the parameters. The gamma-distribution type function is employed to represent the Clark's model, which takes the same form as the Nash's model, so that parameter estimation is not difficult since it can be performed with a simple optimization process. Analytic forms of Clark's models parameters are introduced using parameters of the proposed methodology to give traditional form of Clark's. An application to a watershed has shown that the proposed approach can preserve the properties of observed data. Based the application, the new approach is recommended as an alternative to the existing parameter estimating methodology.

The p-deformed Generalized Humbert Polynomials and Their Properties

  • Savalia, Rajesh V.;Dave, B.I.
    • Kyungpook Mathematical Journal
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    • v.60 no.4
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    • pp.731-752
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    • 2020
  • We introduce the p-deformation of generalized Humbert polynomials. For these polynomials, we derive the differential equation, generating function relations, Fibonacci-type representations, and recurrence relations and state the companion matrix. These properties are illustrated for certain polynomials belonging to p-deformed generalized Humbert polynomials.

Context-Dependent Regulation of Type17 Immunity by Microbiota at the Intestinal Barrier

  • Begum Akuzum;June-Yong Lee
    • IMMUNE NETWORK
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    • v.22 no.6
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    • pp.46.1-46.25
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    • 2022
  • T-helper-17 (Th17) cells and related IL-17-producing (type17) lymphocytes are abundant at the epithelial barrier. In response to bacterial and fungal infection, the signature cytokines IL-17A/F and IL-22 mediate the antimicrobial immune response and contribute to wound healing of injured tissues. Despite their protective function, type17 lymphocytes are also responsible for various chronic inflammatory disorders, including inflammatory bowel disease (IBD) and colitis associated cancer (CAC). A deeper understanding of type17 regulatory mechanisms could ultimately lead to the discovery of therapeutic strategies for the treatment of chronic inflammatory disorders and the prevention of cancer. In this review, we discuss the current understanding of the development and function of type17 immune cells at the intestinal barrier, focusing on the impact of microbiota-immune interactions on intestinal barrier homeostasis and disease etiology.

Diagnostics of Diffuse Two-Phase Matter Using Techniques of Positron Annihilation Spectroscopy in Gamma-Ray and Optical Spectra

  • Doikov, Dmytry;Yushchenko, Alexander;Jeong, Yeuncheol
    • Journal of Astronomy and Space Sciences
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    • v.36 no.3
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    • pp.115-119
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    • 2019
  • This paper is a part of the series on positron annihilation spectroscopy of two-phase diffuse gas-and-dust aggregates, such as interstellar medium and the young remnants of type II supernovae. The results obtained from prior studies were applied here to detect the relationship between the processes of the annihilation of the K-shell electrons and incident positrons, and the effects of these processes on the optical spectra of their respective atoms. Particular attention was paid to the Doppler broadening of their optical lines. The relationship between the atomic mass of the elements and the Doppler broadening, ${\Delta}{\lambda}_D$ (${\AA}$), of their emission lines as produced in these processes was established. This relationship is also illustrated for isotope sets of light elements, namely $^3_2He$, $^6_3Li$, $^7_3Be$, $^{10}_5B$ and $^{11}_5B$. A direct correlation between the ${\gamma}-line$ luminosity ( $E_{\gamma}=1.022MeV$) and ${\Delta}{\lambda}_D$ (${\AA}$) was proved virtually. Qualitative estimates of the structure of such lines depending on the positron velocity distribution function, f(E), were made. The results are presented in tabular form and can be used to set up the objectives of further studies on active galactic nuclei and young remnants of type II supernovae.

Integral Formulas Involving Product of Srivastava's Polynomials and Galué type Struve Functions

  • Suthar, Daya Lal;Andualem, Mitku
    • Kyungpook Mathematical Journal
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    • v.59 no.4
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    • pp.725-734
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    • 2019
  • The aim of this paper is to establish two general finite integral formulas involving the product of Galué type Struve functions and Srivastava's polynomials. The results are given in terms of generalized (Wright's) hypergeometric functions. These results are obtained with the help of finite integrals due to Oberhettinger and Lavoie-Trottier. Some interesting special cases of the main results are also considered. The results presented here are of general character and easily reducible to new and known integral formulae.