• Title, Summary, Keyword: Parameter

Search Result 21,591, Processing Time 0.082 seconds

Bayesian Parameter Estimation of the Four-Parameter Gamma Distribution

  • Oh, Mi-Ra;Kim, Kyung-Sook;Cho, Wan-Hyun;Son, Young-Sook
    • Communications for Statistical Applications and Methods
    • /
    • v.14 no.1
    • /
    • pp.255-266
    • /
    • 2007
  • A Bayesian estimation of the four-parameter gamma distribution is considered under the noninformative prior. The Bayesian estimators are obtained by the Gibbs sampling. The generation of the shape/power parameter and the power parameter in the Gibbs sampler is implemented using the adaptive rejection sampling algorithm of Gilks and Wild (1992). Also, the location parameter is generated using the adaptive rejection Metropolis sampling algorithm of Gilks, Best and Tan (1995). Finally, the simulation result is presented.

Development of Fretting Fatigue Parameter (접촉피로 파라미터의 개발)

  • Lee, Hyuk-Jae
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.14 no.1
    • /
    • pp.92-99
    • /
    • 2011
  • In this study, new multi-axial, critical plane based, fretting fatigue crack initiation parameter is developed by the addition of a new term into the Modified Shear Stress Range(MSSR) parameter. The newly developed parameter (MSSR') is then used to evaluate fretting fatigue life of titanium alloy, Ti-6A1-4V with various contact conditions. Finite element analysis is also used in order to obtain stress distribution on the contact surface during fretting fatigue test, which is then used for the calculation of fretting fatigue parameter. The MSSR' parameter shows better performance in predicting fretting fatigue lives from the conventional fatigue data, and less scattering within fretting fatigue data with different contact geometries.

Estimation of Defect Clustering Parameter Using Markov Chain Monte Carlo (Markov Chain Monte Carlo를 이용한 반도체 결함 클러스터링 파라미터의 추정)

  • Ha, Chung-Hun;Chang, Jun-Hyun;Kim, Joon-Hyun
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.32 no.3
    • /
    • pp.99-109
    • /
    • 2009
  • Negative binomial yield model for semiconductor manufacturing consists of two parameters which are the average number of defects per die and the clustering parameter. Estimating the clustering parameter is quite complex because the parameter has not clear closed form. In this paper, a Bayesian approach using Markov Chain Monte Carlo is proposed to estimate the clustering parameter. To find an appropriate estimation method for the clustering parameter, two typical estimators, the method of moments estimator and the maximum likelihood estimator, and the proposed Bayesian estimator are compared with respect to the mean absolute deviation between the real yield and the estimated yield. Experimental results show that both the proposed Bayesian estimator and the maximum likelihood estimator have excellent performance and the choice of method depends on the purpose of use.

AN AVERAGE OF SURFACES AS FUNCTIONS IN THE TWO-PARAMETER WIENER SPACE FOR A PROBABILISTIC 3D SHAPE MODEL

  • Kim, Jeong-Gyoo
    • Bulletin of the Korean Mathematical Society
    • /
    • v.57 no.3
    • /
    • pp.751-762
    • /
    • 2020
  • We define the average of a set of continuous functions of two variables (surfaces) using the structure of the two-parameter Wiener space that constitutes a probability space. The average of a sample set in the two-parameter Wiener space is defined employing the two-parameter Wiener process, which provides the concept of distribution over the two-parameter Wiener space. The average defined in our work, called an average function, also turns out to be a continuous function which is very desirable. It is proved that the average function also lies within the range of the sample set. The average function can be applied to model 3D shapes, which are regarded as their boundaries (surfaces), and serve as the average shape of them.

Hall and Ion-Slip effects on magneto-micropolar fluid with combined forced and free convection in boundary layer flow over a horizontal plate

  • Seddeek, M.A.;Abdelmeguid, M.S.
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.8 no.2
    • /
    • pp.51-73
    • /
    • 2004
  • A boundary layer analysis is used to study the effects of Hall and ion-slip currents on the steady magneto-micropolar of a viscous incompressible and electrically conducting fluid over a horizontal plate. By means of similarity solutions, deviation of fundamental equations on the assumption of small magnetic Reynolds number are solved numerically by using the shooting method. The effects of various parameters of the problem, e.g. the magnetic parameter, Hall parameter, ion-slip parameter, buoyancy parameter and material parameter are discussed and shown graphically.

  • PDF

Decentralized Controller Design for Nonlinear Systems using LPV technique

  • Lee, Sangmoon;Kim, Sungjin;Sangchul Won
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.68.5-68
    • /
    • 2001
  • This paper investigates the problem of linear parameter-dependent output feedback controllers design for interconnected linear parameter-varying(LPV) plant. By using a parameter-independent common Lyapunov function, sucient conditions for solving the problems are established, which allow us to design linear parameter dependent decentralized controllers in terms of scaled H-infinite control problems for related linear systems without interconnections. The solvability conditions are expressed in terms of finite-dimensional linear matrix inequalities(LMI´s) evaluated at the extreme points of the admissible parameter set.

  • PDF

Robust control of nonlinear system by using pole sensitivity (극점감도를 고려한 비선형 시스팀의 강인한 제어)

  • 서병설;강진식;임동균
    • 제어로봇시스템학회:학술대회논문집
    • /
    • /
    • pp.185-190
    • /
    • 1991
  • In this paper, we present a method of analising a system with nonlinear parameter by pole sensitivity defined by the rate of pole movement with respect of non-linear parameter variation. Pole sensitivity give us not only the rate of pole movement but also the directional information. We present a method of design of a state feedback for a system with nonlinear system parameter by considering the pole sensitivity and show that the suggested method guarantee the stability robustness for a system with nonlinear parameter, parameter perturbation and urimodelled dynamics.

  • PDF

Robust Controller Design in Parameter Space (플랜트 매개 변수 공간상의 강인 안정화 제어기 설계)

  • Hwang, Hu-Mor
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.285-287
    • /
    • 1992
  • This paper considers the design of robust stabilizing controller of a linear time-invariant digital system subject to variations of parameter vector. For a given controller the radius of the largest stability hypersphere in this parameter space is calculated. This radius is a measure of the stability Margin of the closed-loop system. Based on this calculation a design procedure is proposed to robustify a given stabilizing controller. This algorithm iteratively enlarges the stability hypersphere in parameter space and can be used to design a controller to stabilize a plant subject to given ranges of parameter perturbations. These results are illustrated by an example.

  • PDF

Sequential Test for Parameter Changes in Time Series Models

  • Lee Sangyeol;Ha Jeongcheol
    • Proceedings of the Korean Statistical Society Conference
    • /
    • /
    • pp.185-189
    • /
    • 2001
  • In this paper, we consider the problem of testing for parameter changes in time series models based on a sequential test. Although the test procedure is well-established for the mean and variance change, a general parameter case has not been discussed in the literature. Therefore, we develop a sequential test for parameter changes in a more general framework.

  • PDF

A Parameter Extraction Method for BJT Gummel-Poon Model (BJT Gummel-Poon 모델 파라미터 추출 방법)

  • 윤신섭;이성현
    • Proceedings of the IEEK Conference
    • /
    • /
    • pp.763-766
    • /
    • 2003
  • A direct parameter extraction method using several two-port parameter equations derived in cutoff and active bias modes has been studied to obtain an accurate Gummel-Poon BJT model. First, dc model parameters were extracted from slopes and y-axis intercepts of I-V curve and Gummel plot. The pad capacitances and junction capacitance parameters were determined by using measured S-parameter sets in the cutoff bias. The resistance and transit time parameters were extracted by using measured S-parameter sets in the active bias.

  • PDF