• Title/Summary/Keyword: reference parameter

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Noninformative priors for the common mean in log-normal distributions

  • Kang, Sang-Gil
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.6
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    • pp.1241-1250
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    • 2011
  • In this paper, we develop noninformative priors for the log-normal distributions when the parameter of interest is the common mean. We developed Jeffreys' prior, th reference priors and the first order matching priors. It turns out that the reference prior and Jeffreys' prior do not satisfy a first order matching criterion, and Jeffreys' pri the reference prior and the first order matching prior are different. Some simulation study is performed and a real example is given.

Objective Bayesian Estimation of Two-Parameter Pareto Distribution (2-모수 파레토분포의 객관적 베이지안 추정)

  • Son, Young Sook
    • The Korean Journal of Applied Statistics
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    • v.26 no.5
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    • pp.713-723
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    • 2013
  • An objective Bayesian estimation procedure of the two-parameter Pareto distribution is presented under the reference prior and the noninformative prior. Bayesian estimators are obtained by Gibbs sampling. The steps to generate parameters in the Gibbs sampler are from the shape parameter of the gamma distribution and then the scale parameter by the adaptive rejection sampling algorism. A numerical study shows that the proposed objective Bayesian estimation outperforms other estimations in simulated bias and mean squared error.

LPD(Linear Parameter Dependent) System Modeling and Control of Mobile Soccer Robot

  • Kang, Jin-Shik;Rhim, Chul-Woo
    • International Journal of Control, Automation, and Systems
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    • v.1 no.2
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    • pp.243-251
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    • 2003
  • In this paper, a new model for mobile soccer robot, a type of linear system, is presented. A controller, consisting of two loops the one of which is the inner state feedback loop designed for stability and plant be well conditioned and the outer loop is a well-known PI controller designed for tracking the reference input, is suggested. Because the plant, the soccer robot, is parameter dependent, it requires the controller to be insensitive to the parameter variation. To achieve this objective, the pole-sensitivity as a pole-variation with respect to the parameter variation is defined and design algorithms for state-feedback controllers are suggested, consisting of two matrices one of which is for general pole-placement and other for parameter insensitive. This paper shows that the PI controller is equivalent to the state feedback and the cost function for reference tracking is equivalent to the LQ cost. By using these properties, we suggest a tuning procedure for the PI controller. We that the control algorithm in this paper, based on the linear system theory, is well work by simulation, and the LPD system modeling and control are more easy treatment for soccer robot.

Model Reference Adaptive Control of the Air Flow Rate of Centrifugal Compressor Using State Space Method (상태 공간 기법을 이용한 원심압축기 공기 유량 모델 기반 적응 제어)

  • Han, Jaeyoung;Jung, Mooncheong;Yu, Sangseok;Yi, Sun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.8
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    • pp.535-542
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    • 2016
  • In this study, a model reference adaptive controller is developed to regulate the outlet air flow rate of centrifugal compressor for automotive supercharger. The centrifugal compressor is developed using the analytical based method to predict the transient behavior of operating and the designed model is validated with experimental data to confirm the system accuracy. The model reference adaptive control structure consists of a compressor model and a MRAC(model reference adaptive control) mechanism. The feedback control do not robust with variation of system parameter but the applied adaptive control is robust even if the system parameter is changed. As a result, the MRAC was regulated to reference air flow rate. Also MRAC was found to be more robust control compared with the feedback control even if the system parameter is changed.

Noninformative priors for the log-logistic distribution

  • Kang, Sang Gil;Kim, Dal Ho;Lee, Woo Dong
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.1
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    • pp.227-235
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    • 2014
  • In this paper, we develop the noninformative priors for the scale parameter and the shape parameter in the log-logistic distribution. We developed the first and second order matching priors. It turns out that the second order matching prior matches the alternative coverage probabilities, and is a highest posterior density matching prior. Also we revealed that the derived reference prior is the second order matching prior for both parameters, but Jerffrey's prior is not a second order matching prior. We showed that the proposed reference prior matches the target coverage probabilities in a frequentist sense through simulation study, and an example based on real data is given.

Noninformative Priors for the Ratio of Means of Two Poisson Distributions

  • Kang, Sang-Gil;Lee, Woo-Dong;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.2
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    • pp.201-207
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    • 2002
  • In this paper, Jeffrey's and reference priors are derived when the parameter of interest is the ratio of means of two in dependent Poisson distribution. To achieve the parameter orthogonality in the sense of Cox and Reid (1987), non-trivial orthogonal transformation is provided. The orthogonal transformation makes to find noninformative priors easy. Our simulation study indicates that the reference prior meet very well the target coverage probabilities in a frequentist sense. Using the real data, we compute Bayes estimator and MLE for the ratio of means based on the reference prior.

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DC Servo Motor Control using Model Reference PID Genetic Controller (모델기준 PID 유전 제어기를 이용한 DC 서보 전동기 제어)

  • Son, Jae-Hyun;Cho, Yang-Heang;Kim, Jae-Hong
    • Proceedings of the KIEE Conference
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    • 2001.07e
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    • pp.141-145
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    • 2001
  • In this paper, model reference PID genetic controller was proposed in order to overcome the difficulty of reflecting control performance required in the overall control system and defects of the adaptation performance in the PID genetic controller. The proposed controller comprised Inner feedback loop consisting of the PID controller and plant, and outer loop consisting of an genetic algorithm which was designed for tuning a parameter of the controller. A reference model was used for design criteria of a PID controller which characterizes and quantizes the control performance required in the overall control system. Tuning parameter of the controller is performed by the genetic algorithm. The performance of proposed algorithm was verified through experiment for the DC servo motor.

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A New Approach for Accurate RTL Power Macro-Modeling

  • Kawauchi, Hirofumi;Taniguchi, Ittetsu;Fukui, Masahiro
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.10 no.1
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    • pp.11-19
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    • 2010
  • Register transfer level power macromodeling is well known as a promising technique for accurate and efficient power estimation. This paper proposes effective approaches based on the tablebased method for the RTL power macro-modeling. The new parameter SD, which characterizes the distribution of switching activities for each gate in the circuit, is one of the contributions. The new parameter SD has strong correlation with power consumption. We also propose an accurate table reference method considering the circuit characteristics. The table reference method is applicable for every table-based method and outputs more accurate power value. The experimental results show that the combination of the proposed methods reduces max error 30.36% in the best case, comparing conventional methods. The RMS error is also improved 1.70% in the best case.

A Novel Parameter Estimation Algorithm for Interior Permanent-Magnet Synchronous Motors (매입형 영구자석 동기전동기를 위한 새로운 전동기 상수 추정 방법)

  • Lim, Dong-Chan;Lee, Dong-Myung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.3
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    • pp.289-295
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    • 2013
  • It is important to know exact values of Interior Permanent Magnet Synchronous Motors(IPMSM)' parameters such as stator resistance and inductance in order to have their high performance. This paper proposes a novel motor parameter(stator resistance, d&q axis inductance) estimation algorithm for IPMSM. The proposed estimation method utilizes back-EMF equations and model reference adaptive system(MRAS). The algorithm using back-EMF estimates d and q axis inductances in the constant torque region, and the stator resistance is estimated by using MRAS with the estimated inductance regardless of speed regions. The validity of the proposed algorithm is verified by simulations and experiments.

Bayesian One-Sided Hypothesis Testing for Shape Parameter in Inverse Gaussian Distribution

  • Kang, Sang-Gil;Kim, Dal-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.3
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    • pp.995-1006
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    • 2008
  • This article deals with the one-sided hypothesis testing problem in inverse Gaussian distribution. We propose Bayesian hypothesis testing procedures for the one-sided hypotheses of the shape parameter under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian hypothesis testing procedures based on the fractional Bayes factor, the median intrinsic Bayes factor and the encompassing intrinsic Bayes factor under the reference prior. Simulation study and a real data example are provided.

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