• Title/Summary/Keyword: Isotonic regression

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Bayesian estimation of ordered parameters (순서화 모수에 대한 베이지안 추정)

  • 정광모;정윤식
    • The Korean Journal of Applied Statistics
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    • v.9 no.1
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    • pp.153-164
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    • 1996
  • We discussed estimation of parameters using Gibbs sampler under order restriction on the parameters. Two well-knwon probability models, ordered exponential family and binomial distribution, are considered. We derived full conditional distributions(FCD) and also used one-for-one sampling algorithm to sample from the FCD's under order restrictions. Finally through two real data sets we compared three kinds of estimators; isotonic regression estimator, isotonic Bayesian estimator and the estimator using Gibbs sampler.

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Nonparametric Procedures for Comparing Ordered Treatment Effects with a Control in a Randomized Block Design

  • Lim, Dong-Hoon
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.89-100
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    • 1997
  • In this paper we are concerned with comparing ordered treatment effects with a control in a randomized block design with multiple observations per cell. Two nonparametric procedures for detecting which treatment are better than the control are proposed and compared. An example is given and the results of a Monte Carlo power study are discussed.

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Test of Symmetry against Near Type III Positive Biasedness

  • Oh, Myong-Sik
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.10a
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    • pp.63-68
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    • 2003
  • One of the widely accepted assumptions in many statistical problem is that the underlying distribution is symmetric. Though a large number of nonparametric test are available in the literature for this problem, very few procedures focuses on the distributional structure when the symmetry assumption is rejected. Yanagimoto and Sibuya (1972) provided the various types of asymmetric distributional structure, positive biasedness, namely. In this paper we consider the test of symmetry against several new positive biasedness restrictions which are stronger than Yanagimoto and Sibuya's type II bias but weaker than type IV (III) bias.

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ORDER RESTRICTED STATISTICAL INFERENCE ON LORENZ CURVES OF PARETO DISTRIBUTIONS

  • Oh, Myongsik
    • Journal of applied mathematics & informatics
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    • v.13 no.1_2
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    • pp.457-470
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    • 2003
  • The comparison of two or more Lorenz curves of Pareto distributions of first kind under arbitrary order restriction is studied. The problem is turned out to be a statistical inference problem concerning scale parameters under order restriction. We assume that the location parameters of Palate distributions are completely unknown. In this paper the maximum likelihood estimation and likelihood ratio tests for and against order restriction are proposed.

Statistical Inference for Peakedness Ordering Between Two Distributions

  • Oh, Myong-Sik
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.05a
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    • pp.109-114
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    • 2003
  • The concept of dispersion is intrinsic to the theory and practice of statistics. A formulation of the concept of dispersion can be obtained by comparing the probability of intervals centered about a location parameter, which is peakedness ordering introduced first by Birnbaum (1948). We consider statistical inference concerning peakedness ordering between two arbitrary distributions. We propose nonparametric maximum likelihood estimator of two distributions under peakedness ordering and a likelihood ratio test for equality of dispersion in the sense of peakedness ordering.

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ORDER RESTRICTED TESTS FOR SYMMETRY AGAINST POSITIVE BIASEDNESS

  • Oh, Myong-Sik
    • Journal of the Korean Statistical Society
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    • v.36 no.3
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    • pp.335-347
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    • 2007
  • Two new types of positive biasedness, which are closely related to Type III positive biasedness (Yanagimoto and Sibuya, 1972), are proposed. We call these near Type III positive biasedness. Though no implication between Type II and near Type III biasedness exists, near Type III seems to be less restrictive than Type II biasedness. Constrained maximum likelihood estimates of distribution functions under near Type III positive bisedness are obtained. The likelihood ratio tests of symmetry against new positive biasedness restrictions are proposed. A small simulation study is conducted to compare the performance of the tests.

INFERENCE FOR PEAKEDNESS ORDERING BETWEEN TWO DISTRIBUTIONS

  • Oh, Myong-Sik
    • Journal of the Korean Statistical Society
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    • v.33 no.3
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    • pp.303-312
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    • 2004
  • The concept of dispersion is intrinsic to the theory and practice of statistics. A formulation of the concept of dispersion can be obtained by comparing the probability of intervals centered about a location parameter. This is the peakedness ordering introduced first by Birnbaum (1948). We consider statistical inference concerning peakedness ordering between two arbitrary distributions. We propose non parametric maximum likelihood estimators of two distributions under peakedness ordering and a likelihood ratio test for equality of dispersion in the sense of peakedness ordering.

Statistical Inference Concerning Peakedness Ordering between Two Symmetric Distributions

  • Oh, Myong-Sik
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.1
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    • pp.201-210
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    • 2004
  • The peakedness ordering is closely related to dispersive ordering. In this paper we consider the statistical inference concerning peakedness ordering between two arbitrary symmetric distributions. Nonparametric maximum likelihood estimates of two distribution functions under symmetry and peakedness ordering are given. The likelihood ratio test for equality of two symmetric discrete distributions in the sense of peakedness ordering is studied.

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The Effect of Increased Dilution Volume and Prolonged Infusion Time of Vancomycin on Incidence of Adverse Reactions through Peripheral Venous Cannulae (말초정맥을 통한 반코마이신희석과 주입시간연장이 부작용발생에 미치는 영향)

  • Oh, Myeong Ju;Kim, Mae Ja
    • Korean Journal of Adult Nursing
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    • v.12 no.2
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    • pp.196-208
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    • 2000
  • The purpose of the study was to explore the effect of 2 hour infusion of vancomycin(1g) in 200ml of isotonic saline every 12 hour on the frequency of "red man syndrome", phlebitis and length of peripheral catheter placement of infected patients, in order to provide safe infusion method for reducing vancomycinin-duced RMS and phlebitis. The subjects of the study consisted of 16 hospitalized patients; 3 oncology and gastro-intestinal patients, 1 neurological patient, 6 thoracic surgical patients and 6 orthopedic patients, who had received vancomycin from July to October in 1999 at S-hospital. The dependent variables were the incidence of RMS, phlebitis and the length of peripheral catheter placement. The incidence of RMS was checked by an inspector at the first night whenever the infusion method of vancomycin was changed. RMS was observed every 15 minutes during an hour for symptoms of RMS such as itching, erythema, chest pain and systolic blood pressure. Incidence of phlebitis was assessed by inspector twice a day from the insertion of peripheral catheter to the removal of the catheter. The data were analyzed by percentage, mean, $X^2$-test, t-test, repeated ANOVA, and logistic regression analysis using the SPSSWIN program. The results are summarized as follows; 1. No significant difference was identified in frequency of RMS between the experimental group and control group. 2. There was no significant difference in the change of systolic blood pressure as the time goes on between the experimental group and control group. 3. The incidence of phlebitis was significantly lower in the experimental group than in the control group. 4. The length of peripheral catheter placement was significantly longer in the experimental group than in the control group. 5. Other drugs administrated with vancomycin didn't influence the occurrence of phlebitis. However, the infusion method of vancomycin influenced the occurrence of phlebitis. The results suggest that 2 hour infusion of vancomycin(1g) in 200ml of isotonic saline every 12 hours may decrease the incidence of phlebitis and increase the length of peripheral catheter placement compared to 1 hour infusion of vancomycin(1g) in 100ml of isotonic saline every 12 hours. However, it does not reduce the incidence of RMS.

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Estimation from Incomplete Data in Multivariate Distributions under Stochastic Ordering (확률적 순서를 갖는 다변량분포에서 불완전자료에 의한 추정)

  • Kwang Mo Jeoung
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.145-157
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    • 1994
  • For multivariate distributions satisfying stochastic ordering, we suggest maximum likelihood estimation with incomplete data via an EM algorithm. In this paper we restrict our attention to the contingency tables with partially cross-classified observations. We may use the existing isotonic regression program to implement EM algorithm, and we illustrate the estimation process through an example.

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