• Title/Summary/Keyword: Minimum Variance

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Self-tuning Control of DC Servo Motor Taking into Account of Load Variation (부하변동을 고려한 직류 서어보전동기의 자기동조제어에 관한 연구)

  • Lee, Yoon-Jong;Oh, Won-Seok;Kim, Young-Tae
    • Proceedings of the KIEE Conference
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    • 1988.11a
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    • pp.430-433
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    • 1988
  • An adaptive control system for D.C servo drive is developed via minimum variance control theory. The problem of designing this controller under varying load conditions is discussed. A robust self tuning controller that can track a constant reference and reject constant load disturbance is developed. Simulation study shows that the controller has excellent adaptation, capability as well as transient recovery under load changes.

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A METHOD FOR ADJUSTING ADAPTIVELY THE WEIGHT OF FEATURE IN MULTI-DIMENSIONAL FEATURE VECTOR MATCHING

  • Ye, Chul-Soo
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.772-775
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    • 2006
  • Muilti-dimensional feature vector matching algorithm uses multiple features such as intensity, gradient, variance, first or second derivative of a pixel to find correspondence pixels in stereo images. In this paper, we proposed a new method for adjusting automatically the weight of feature in multi-dimensional feature vector matching considering sharpeness of a pixel in feature vector distance curve. The sharpeness consists of minimum and maximum vector distances of a small window mask. In the experiment we used IKONOS satellite stereo imagery and obtained accurate matching results comparable to the manual weight-adjusting method.

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Estimation of the Lorenz Curve of the Pareto Distribution

  • Kang, Suk-Bok;Cho, Young-Suk
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.285-292
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    • 1999
  • In this paper we propose the several estimators of the Lorenz curve in the Pareto distribution and obtain the bias and the mean squared error for each estimator. We compare the proposed estimators with the uniformly minimum variance unbiased estimator (UMVUE) and the maximum likelihood estimator (MLE) in terms of the mean squared error (MSE) through Monte Carlo methods and discuss the results.

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Satellite's orbit tracking with batch estimation

  • Kim, Jong-Ah;Kim, Jin-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.224-228
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    • 1994
  • This paper deals with a Batch processor application to determine orbit trajectories from satellite tracking data. The purpose of this paper is to find the initial state vectors. In order to determine the better estimation process, several different cases are compared. Here we adapt a minimum variance concept to develop estimation and prediction techniques. These results are compared with by SEP, Spherical Error Probable, values.

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Reliability Estimation for a Shared-Load System Based on Freund Model

  • Hong, Yeon-Woong;Lee, Jae-Man;Cha, Young-Joon
    • Journal of the Korean Data and Information Science Society
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    • v.6 no.2
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    • pp.1-7
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    • 1995
  • This paper considers the reliability estimation of a two-component shared-load system based on Freund model. Maximum likelihood estimator, order restricted maximum likelihood estimator and uniformly minimum variance unbiased estimator of the reliability function for the system are obtained. Performance of three estimators for moderate sample sizes is studied by simulation.

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Adaptive Control for Discrete Process with Time Varying Delay (시변 지연시간을 갖는 이산형 프로세스의 적응제어)

  • 김영철;김국헌;정찬수;양흥석
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.11
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    • pp.503-510
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    • 1986
  • A new algorithm based on the concept of prediction error minimization is suggested to estimate the time varying delay in discrete processes. In spite of the existence of the stochastic noise, this algorithm can estimate time varying delay accurately. Computation time of this algorithm is far less than that of the previous extended parameter methods. With the use of this algorithm, generalized minimum variance control shows good control behavior in simulations.

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Rule Based Auto-Tuning PID Controller with Feedforward Path (피드포워드 경로를 갖는 규칙 기반 자동동조 PID제어기)

  • 윤양웅;박왈서
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.4
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    • pp.355-361
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    • 1992
  • In this paper, some rules for auto- tuning of feedback-feedforward controller in variable load and disturbance are presented. The parameters of feedback PID controller are determined by heuristic rules based on input regulation experiment, and the parameters of feedforward controller are determined by result rules based on spectral factorization, minimum variance, and polynomial equation. These heuristic and result rules are used as an element of the feedback loop in an auto-tuning feedback-feedforward controller. The robust and accurate control performance is demonstrated by computer simulation.

On the Estimation of Reliability Functions for the Freund Model

  • Hong, Yeon-Woong;Lee, Jae-Man;Cha, Young-Joon
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.1
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    • pp.79-83
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    • 1997
  • This paper considers the problem of estimating the model parameters and reliability functions for Freund bivariate exponential distribution. Uniformly minimum variance unbiased estimators for model parameters, joint reliability and marginal reliability functions are obtained in the both case of non-identically distributed marginals and identically distributed marginals.

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Modelling of a pH titration process and design of a self-tuning pH controller (pH 적정공정의 모델링 및 자기동조 제어기 설계)

  • 김우태;이혁희;최태호;이지태
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.476-481
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    • 1988
  • In this paper a pH process of a weak acid with a strong base is modeled into a bilinear form, and a self-tuning pH control algorithm which is robust against initial values of solution and disturbances is presented. The control algorithm employs the recursive least square method for the parameter estimation and the generalised minimum variance criterion as the objective function. The computer simulation shows that the tracking of desired pH values is obtained in satisfactory manner regardless of the initial values chosen for the process.

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On the Estimation of Fraction Defectives

  • Kim, Seong-in
    • Journal of Korean Society for Quality Management
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    • v.8 no.2
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    • pp.3-14
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    • 1980
  • This paper is concerned with the design of an appropriate sampling plan or stopping rule and the construction of estimate for the estimation of process or lot fraction defective. Various sampling plans which are well known or have potential applications are unified into a generalized sampling plan. Under this sampling plan sufficient statistic, probability distribution, moment, and minimum variance unbiased estimate are obtained. Results for various sampling plans can be derived as special cases. Then, under given parameter values, the relative efficiencies of the various sampling plans are compared with respect to expected sample sizes and variances of estimates.

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