• Title/Summary/Keyword: assistant professor

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A Comparative Study of the GPAC Method and the 3-pattern Method for Identifying ARMA Processes

  • Chul Eung KIM;ByoungSeon CHOI
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.47-58
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    • 1996
  • The generalized partial autocorrelation (GPAC) method of Woodward and Gray (1981) and the 3-pattern method of Choi (1991) have been used for identifying ARMA processes. The methods are based on the extended Yule-Walker equations. The purpose of this paper is to show the 3-pattern method is superior to the GPAC method through theoretical analysis and computer simulations.

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Influence in Fitting an Equicorrelation Model

  • Kim, Myung Geun;Jung, Kang-Mo
    • Communications for Statistical Applications and Methods
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    • v.8 no.3
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    • pp.841-849
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    • 2001
  • The influence in fitting an equicorrelation model is investigated using the influence function. The influence functions for the model parameters are derived and its sample versions are used for investigating the influence of observations on the estimators of the parameters. Some relationships among the sample versions are found. We will derive a measure for identifying observations that have a large influence on the test of fitting the equicorrelation model using the influence function method. An example is given for illustration.

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Test of Normality Based on the Normalized Sample Lorenz Curve

  • Kang, Suk-Bok;Cho, Young-Suk
    • Communications for Statistical Applications and Methods
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    • v.8 no.3
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    • pp.851-858
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    • 2001
  • Using the normalized sample Lorenz curve which is introduced by Kang and Cho (2001), we propose the test statistics for testing of normality that is very important test in statistical analysis and compare the proposed test with the other tests in terms of the power of test through by Monte Carlo method. The proposed test is more power than the other tests except some cases

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Robustness in the Hierarchical Bayes Estimation of Normal Means

  • Kim, Dal-Ho;Park, Jin -Kap
    • Communications for Statistical Applications and Methods
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    • v.6 no.2
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    • pp.511-522
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    • 1999
  • The paper considers the problem of robustness in hierarchical bayesian models. In specific we address Bayesian robustness in the estimation of normal means. We provide the ranges of the posterior means under $\varepsilon$-contamination class as well as the density ratio class of priors. For the class of priors that are uniform over a specified interval we investigate the sensitivity as to the choice of the intervals. The methods are illustrated using the famous baseball data of Efron and Morris(1975).

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Fuzzy Hypergraph

  • Lee, Hyung kwang;Oh, Gil-Rok;Cho, Choong-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • v.4 no.2
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    • pp.3-8
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    • 1994
  • In this paper, the hypergraph is fuzzified. In a hypoergraph, there are 3types of sets which can be fuzzified. According to the fuzzificatioin level, 7 types of fuzzy hypergraphs can be obtained. After defining the 7 thpes of hypergraphs, some interesting concepts are developed such as the order, size and degree of such as the order, size and degree of the fuzzy hypergraph.

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Goodness-of-Fit Test for the Exponential Distribution Based on the Transformed Sample Lorenz curve

  • Suk-Bok;Young-Suk
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.277-284
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    • 2000
  • The transformed sample Lorenz curve provides a powerful and easily computed goodness-of-fit test for exponentiality which does not depend on the unknown scale parameter. We compare the power of the transformed sample Lorenz curve statistic with the other goodness-of-fit tests for exponentiality against various alternatives through Monte Carlo methods and discuss the results.

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On the strong law of large numbers for pairwise negative quadrant dependent random variables

  • T. S.;J. I.;H. Y.
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.291-296
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    • 2000
  • Petrov(1996) examined the connection between general moment conditions and the applicability of the strong law lf large numbers to a sequence of pairwise independnt and identically distributed random variables. In this note wee generalize Theorem 1 of Petrov(1996) and also show that still holds under assumption of pairwise negative quadrant dependence(NQD).

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Factors and Developments in Grading Cut Flowers

  • Bae, Yeong-Hwan;Koo, Hyun-Mo
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.746-754
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    • 1996
  • Grading and sorting fresh cut flowers are time consuming process. In Korea, cut flowers are sorted mostly by human inspection due to the lack of adequate machinery. In this paper, quality evaluation factors of cut flowers are discussed, and types of sorting machines existing in the market are introduced . Aspects of computer image processing in evaluation the quality of cut flowers are also discussed.

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MASS TRANSPORT IN FINITE AMPLITUDE WAVES

  • ;Robert T. Hudspeth
    • Proceedings of the Korea Water Resources Association Conference
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    • 1988.07a
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    • pp.29-36
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    • 1988
  • A general scheme is developed which determines the Lagrangian motions of water particles by the Eulerian velocity at their mean positions by use of Taylor's theorem. Utilizing the Stokes finite-amplitude wave theory, the mass transport velocity which includes the effects of higher-order wave components is determined. The fifth-order theory predicts the mass transport velocity less than that given by the existing second-order theory over the whole depth. Limited experimental data for changes in wave celerity in closed wave flumes are compared with the theoretical predictions.

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Test of Normality Based on the Transformed Lorenz Curve

  • Kang, Suk-Bok;Cho, Young-Suk
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.901-908
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    • 1999
  • Using the Transformed Lorenz curve which is introduced by Cho et al.(1999) we propose the test statistic for testing of normality that is very important test in statistical analysis and compare the proposed test statistic with the Shapiro and Wilk's W test statistic in terms of the power of test through by Monte Carlo method.

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