• Title/Summary/Keyword: parameter estimating

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Inference about Measure of Agreement in the General Mixture Model via Parameter Orthogonalization

  • Um, Jongseok
    • Communications for Statistical Applications and Methods
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    • v.10 no.2
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    • pp.341-352
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    • 2003
  • Collecting data through experiment, the observers are an import source of measurement error and the inference on the measure of agreement, say kappa, is necessary. The models commonly used are complicated general mixture model, which have many nuisance parameters. Orthogonalization of parameters reduce the effect of nuisance parameter. Orthogonalization of estimating function gives the same effect as the parameter orthogonalization. In this study, the method for orthogonalization of estimating equation is studied and applied to the Beta-binomial model to examine the properties of the estimate of kappa. As a result, the likelihood function is insensitive to the change of the nuisance parameter and bias is smaller than the result of m.1.e. when kappa has extreme values

Estimating the Regularizing Parameters for Belief Propagation Based Stereo Matching Algorithm (Belief Propagation 기반 스테레오 정합을 위한 정합 파라미터의 추정방식 제안)

  • Oh, Kwang-Hee;Lim, Sun-Young;Hahn, Hee-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.1
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    • pp.112-119
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    • 2010
  • This paper defines the probability models for determining the disparity map given stereo images and derives the methods for solving the problem, which is proven to be equivalent to an energy-based stereo matching. Under the assumptions the difference between the pixel on the left image and the corresponding pixel on the right image and the difference between the disparities of the neighboring pixels are exponentially distributed, a recursive approach for estimating the MRF regularizing parameter is proposed. Usually energy-based stereo matching methods are so sensitive to the parameter that it should be carefully determined. The proposed method alternates between estimating the parameter with the intermediate disparity map and estimating the disparity map with the estimated parameter, after computing it with random initial parameter. It is shown that the parameter estimated by the proposed method converges to the optimum and its performance can be improved significantly by adjusting the parameter and modifying the energy term.

A Study on the Parameter Estimation Algorithm for Nonlinear Systems (비선형 시스템의 계수추정 알고리즘 연구)

  • Lee, Dal-Ho;Seong, Sang-Man
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.7
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    • pp.898-902
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    • 1999
  • In this paper, we proposed an algorithm for estimating parameters of nonlinear continuous-discrete state-space system. This algorithm uses the conventional extended Kalman filter(EKF) for estimating state variables, and modifies the recursive prediction error method for parameter estimation of the nonlinear system. Simulation results for both linear and nonlinear measurements under the environment of process and measurement noises show a convincing performance of the proposed algorithm.

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Likelihood ratio in estimating Chi-square parameter

  • Rahman, Mezbahur
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.3
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    • pp.587-592
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    • 2009
  • The most frequent use of the chi-square distribution is in the area of goodness-of-t of a distribution. The likelihood ratio test is a commonly used test statistic as the maximum likelihood estimate in statistical inferences. The recently revised versions of the likelihood ratio test statistics are used in estimating the parameter in the chi-square distribution. The estimates are compared with the commonly used method of moments and the maximum likelihood estimate.

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Comparison of Bayesian Methods for Estimating Parameters and Uncertainties of Probability Rainfall Distribution (확률강우분포의 매개변수 및 불확실성 추정을 위한 베이지안 기법의 비교)

  • Seo, Youngmin;Park, Jaeho;Choi, Yunyoung
    • Journal of Environmental Science International
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    • v.28 no.1
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    • pp.19-35
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    • 2019
  • This study investigates the performance of four Bayesian methods, Random Walk Metropolis (RWM), Hit-And-Run Metropolis (HARM), Adaptive Mixture Metropolis (AMM), and Population Monte Carlo (PMC), for estimating the parameters and uncertainties of probability rainfall distribution, and the results are compared with those of conventional parameter estimation methods; namely, the Method Of Moment (MOM), Maximum Likelihood Method (MLM), and Probability Weighted Method (PWM). As a result, Bayesian methods yield similar or slightly better results in parameter estimations compared with conventional methods. In particular, PMC can reduce parameter uncertainty greatly compared with RWM, HARM, and AMM methods although the Bayesian methods produce similar results in parameter estimations. Overall, the Bayesian methods produce better accuracy for scale parameters compared with the conventional methods and this characteristic improves the accuracy of probability rainfall. Therefore, Bayesian methods can be effective tools for estimating the parameters and uncertainties of probability rainfall distribution in hydrological practices, flood risk assessment, and decision-making support.

Estimating Parameters in Overdispersed Binary Data

  • Lee, Sunho
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.269-276
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    • 2000
  • there are several methods available for estimating parameters in overdispersed binary response data with the litter effect. Simulations are performed to compare methods for estimating an overall mean and an overdispersion parameter using moments a maximum likelihood under a beta-binomial distribution a maximum quasi-likelihood and a maximum extended quasi-likelihood.

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Theoretical Basis of PERT Formula and a New Estimation Method (PERT 공식의 이론적 근거와 새로운 추정방법)

  • Kim, Se-Hun;Won, Y.K.;Chae, Kyung-C.
    • Journal of Korean Institute of Industrial Engineers
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    • v.15 no.2
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    • pp.103-108
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    • 1989
  • PERT formulae for the mean and variance of activity time are near exact only over a short interval of the concentration parameter which is defined as the sum of the two shape parameters of the beta distribution. Aiming a better estimation of the mean and variance of activity time, we propose a method of subjectively estimating this concentration parameter via estimating the probability of completing the activity within a specified time interval.

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Simultaneous Estimation of the Birth and Death Rate of the Linear Growth Birth and Death Process Based on Discrete Time Observation

  • ChangHyuck Oh
    • Communications for Statistical Applications and Methods
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    • v.3 no.1
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    • pp.235-242
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    • 1996
  • When the linear growth birth and death process observed at a set of equidistant time points, McNeil and Weiss (1997) present a method for simultaneously estimating the Malthusian parameter and the sum of the two parameters under wery restricted assumptions using a diffusion approximation. This article suggests a method, which does not require the restrictions given by Weiss, for estimating simultaneously the Malthusian parameter and the sum of the two parameters.

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On Estimating Burr Type XII Parameter Based on General Type II Progressive Censoring

  • Kim Chan-Soo
    • Communications for Statistical Applications and Methods
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    • v.13 no.1
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    • pp.89-99
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    • 2006
  • This article deals with the problem of estimating parameters of Burr Type XII distribution, on the basis of a general progressive Type II censored sample using Bayesian viewpoints. The maximum likelihood estimator does not admit closed form but explicit sharp lower and upper bounds are provided. Assuming squared error loss and linex loss functions, Bayes estimators of the parameter k, the reliability function, and the failure rate function are obtained in closed form. Finally, a simulation study is also included.