• Title, Summary, Keyword: Gamma distribution

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Derivation of Optimal Design Flood by Gamma and Generalized Gamma Distribution Models(II) -On the Generalized Gamma Distribution Model- (Gamma 및 Generalized Gamma 분포 모형에 의한 적정 설계홍수량의 유도(II) -Generalized Gamma 분포모형을 중심으로-)

  • 이순혁;박명근;맹승진;정연수;류경선
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.2
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    • pp.59-68
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    • 1998
  • This study was conducted to derive optimal design floods by generalized gamma distribution model of the annual maximum series at eight watersheds along Geum, Yeongsan and Seomjin river systems. Design floods obtained by different methods for evaluation of parameters and for plotting positions in the generalized gamma distribution model were compared by the relative mean errors and graphical fit along with 95% confidence limits plotted on gamma probability paper. The results were analyzed and summarized as follows. 1. Basic statistics and parameters were calculated by the generalized gamma distribution model using different methods for parameters. 2. Design floods according to the return periods were obtained by different methods for evaluation of parameters and for plotting positions in the generalized gamma distribution model. 3. It was found that design floods derived by sundry averages method for parameters and Cunnane method for plotting position in the generalized gamma distribution are much closer to those of the observed data in comparison with those obtained by the other methods for parameters and for plotting positions from the viewpoint of relative mean errors. 4. Reliability of design floods derived by sundry averages method in the generalized gamma distribution was acknowledged within 95% confidence interval.

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Derivation of Optimal Design Flood by Gamma and Generalized Gamma Distribution Models(I) - On the Gamma Distribution Models - (Gamma 및 Generalized Gamma 분포 모형에 의한 적정 설계홍수량의 유도 (I) -Gamma 분포 모형을 중심으로-)

  • 이순혁;박명근;정연수;맹승진;류경식
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.3
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    • pp.83-95
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    • 1997
  • This study was conducted to derive optimal design floods by Gamma distribution models of the annual maximum series at eight watersheds along Geum , Yeong San and Seom Jin river Systems, Design floods obtained by different methods for evaluation of parameters and for plotting positions in the Gamma distribution models were compared by the relative mean errors and graphical fit along with 95% confidence interval plotted on Gamma probability paper. The results were analyzed and summarized as follows. 1.Adequacy for the analysis of flood flow data used in this study was confirmed by the tests of Independence, Homogeneity and detection of Outliers. 2.Basic statistics and parameters were calculated by Gamma distribution models using Methods of Moments and Maximum Likelihood. 3.It was found that design floods derived by the method of maximum likelihood and Hazen plotting position formular of two parameter Gamma distribution are much closer to those of the observed data in comparison with those obtained by other methods for parameters and for plotting positions from the viewpoint of relative mean errors. 4.Reliability of derived design floods by both maximum likelihood and method of moments with two parameter Gamma distribution was acknowledged within 95% confidence interval.

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Stochastic Simulation of Monthly Streamflow by Gamma Distribution Model (Gamma 분포모델에 의한 하천유량의 Simulation에 관한 연구)

  • 이중석;이순택
    • Water for future
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    • v.13 no.4
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    • pp.41-50
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    • 1980
  • The prupose of this study are the theoretical examination of Gamma distribution function and its application to hydraulic engineering, that is studying the simulation of monthly streamflow by the Gamma distribtution function model(Gamma Model) based on Monte Carlo technique. In the analysis, monthly streamflow data in the Nak Dong River, the Han River, and the Keum River were used and the data were changed to modular coefficient in order to make the analysis convenient. At first, the fitness of monthly streamflow to 2-Parameter Gamma distribution was tested by Chi-square and Kolmogrov-Smironov test, by which it was found the monthly streamflow were fit well to this Gamma distribution function. Then, the Gamma Model based on the Gamma distribution and Monte Carlo Method was used in the simulation of monthly streamflow, and simulateddata showed that all their stastical characteristics were preserved well in the simulation. Consequently, it can be concluded that the Gamma Model is suitable for the simulation of monthly streamflow series directly by using the Mote Carlo technique.

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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.

Properties of Extended Gamma Distribution

  • Lee, In-Suk;Kim, Sang-Moon
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.4
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    • pp.753-758
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    • 2004
  • A generalization of gamma distribution is defined by slightly modifying the form of Kobayashi's generalized gamma function(1991). We define a new extended gamma distribution and study some properties of this distribution.

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The Statistical Design of CV Control Charts for the Gamma Distribution Processes (감마분포 공정을 위한 변동계수 관리도의 통계적 설계)

  • Lee, Dong-Won;Paik, Jae-Won;Kang, Chang-Wook
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.29 no.2
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    • pp.97-103
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    • 2006
  • Recently, the control chart is developed for monitoring processes with normal short production runs by the coefficient of variation(CV) characteristic for a normal distribution. This control chart does not work well in non-normal short production runs. And most of industrial processes are known to follow the non-normal distribution. Therefore, the control chart is required to be developed for monitoring the processes with non-normal short production runs by the CV characteristics for a non-normal distribution. In this paper, we suggest the control chart for monitoring the processes with a gamma short runs by the CV characteristics for a gamma distribution. This control chart is denoted by the gamma CV control chart. Futhermore evaluated the performance of the gamma CV control chart by average run length(ARL).

Selecting probability distribution of event mean concentrations from paddy fields (논으로부터 배출되는 유량가중평균 수질농도의 적정 확률분포 선정)

  • Jung, Jaewoon;Choi, Dongho;Yoon, Kwangsik
    • Journal of Environmental Impact Assessment
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    • v.23 no.4
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    • pp.285-295
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    • 2014
  • In this study, we analyzed probability distribution of EMCs (Event Mean Concentration) of COD, TOC, T-N, T-P and SS from rice paddy fields and compared the mean values of observed EMCs and the median values of estimated EMCs ($EMC_{50}$) through probability distribution. The field monitoring was conducted during a period of four crop-years (from May 1, 2008, to September 30. 2011) in a rice cultivation area located in Emda-myun, Hampyeong gun, Jeollanam-do, Korea. Four probability distributions such as Normal, Log-normal, Gamma, and Weibull distribution were used to fit values of EMCs from rice paddy fields. Our results showed that the applicable probability distributions were Normal, Log-normal, and Gamma distribution for COD, and Normal, Log- Normal, Gamma and Weibull distribution for T-N, and Log-normal, Gamma and Weibull distribution for T-P and TOC, and Log-normal and Gamma distribution for SS. Log-normal and Gamma distributions were acceptable for EMCs of all water quality constituents(COD, TOC, T-N, T-P and SS). Meanwhile, mean value of observed COD was similar to median value estimated by the gamma distribution, and TOC, T-N, T-P, and SS were similar to median value estimated by log-normal distribution, respectively.

Speech Estimators Based on Generalized Gamma Distribution and Spectral Gain Floor Applied to an Automatic Speech Recognition (잡음에 강인한 음성인식을 위한 Generalized Gamma 분포기반과 Spectral Gain Floor를 결합한 음성향상기법)

  • Kim, Hyoung-Gook;Shin, Dong;Lee, Jin-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.3
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    • pp.64-70
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    • 2009
  • This paper presents a speech enhancement technique based on generalized Gamma distribution in order to obtain robust speech recognition performance. For robust speech enhancement, the noise estimation based on a spectral noise floor controled recursive averaging spectral values is applied to speech estimation under the generalized Gamma distribution and spectral gain floor. The proposed speech enhancement technique is based on spectral component, spectral amplitude, and log spectral amplitude. The performance of three different methods is measured by recognition accuracy of automatic speech recognition (ASR).

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Statistical Properties of Kumaraswamy Exponentiated Gamma Distribution

  • Diab, L.S.;Muhammed, Hiba Z.
    • International Journal of Reliability and Applications
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    • v.16 no.2
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    • pp.81-98
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    • 2015
  • The Exponentiated Gamma (EG) distribution is one of the important families of distributions in lifetime tests. In this paper, a new generalized version of this distribution which is called kumaraswamy Exponentiated Gamma (KEG) distribution is introduced. A new distribution is more flexible and has some interesting properties. A comprehensive mathematical treatment of the KEG distribution is provided. We derive the $r^{th}$ moment and moment generating function of this distribution. Moreover, we discuss the maximum likelihood estimation of the distribution parameters. Finally, an application to real data sets is illustrated.

Analysis on the Relations of Droplet Size Distribution and Optical Depth in Water Curtain (워터커튼에서 액적의 크기 분포와 광학 두께의 상관관계 분석)

  • You, Woo Jun;Ryou, Hong-Sun
    • Fire Science and Engineering
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    • v.30 no.2
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    • pp.62-67
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    • 2016
  • In this study, the optical depth is analyzed with the effects of droplet size distribution of the water curtain nozzle to attenuate the radiative heat transfer. The HELOS/VARIO equipment is used for the measurement of the droplet size distributions. The spray characteristics are quantified by the investigation of Deirmenjian's modified gamma distribution function. The distribution constant of the nozzle can be obtained as ${\alpha}=1$ and ${\gamma}=5.2$. The generalized equation of the optical depth related with the droplet size distribution is introduced. These results will be applicable to the analysis of the design condition of the water curtain nozzle.