• Title/Summary/Keyword: Statistical Hypothesis Test

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UMP Unbiased Test for the Infection Rate in Group Testing

  • Kwon, Se-hyug
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.293-303
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    • 1999
  • When test outcomes of units are dichotomous and he infection rate is small group testing is more efficient that noe-to-one testing in estimating the true p and classifying units as infected or not. In this paper two-sided hypothesis testing and confidence intervals are derived based on the UMP(uniformly most powerful) unbiased test. The UMP unbiased approach is compared with Thompson's and Bhattacharyya et al.'s approaches by computing the length of confidence intervals and capture probabilities and shown to have a number of desirable properties. Unequal allocation one of advantages of the proposed approach is also mentioned.

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Deducing Coronary Artery Disease Anxiety through Musical Therapy and Providing Information (정보제공과 음악요법이 심혈관조영술 환자의 불안에 미치는 영향)

  • 강미숙;박경민;박청자
    • Journal of Korean Academy of Nursing
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    • v.30 no.2
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    • pp.380-390
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    • 2000
  • This study was performed to evaluate the effectiveness of music therapy as one of the psychiatric nursing intervention tools, with addtional information in relieving anxiety during the procedure. Data were collected through nonequivalent pre-and post tests from July 1, 1998 to September 30 1998 in 90 patients (test group A: 28 patients, test group B: 27 patients, control group: 33 patients) who were hospitalized in DongSan Medical Center in order to have cardiac catheterization. The Subjects were informed by educational videos, which were modified according to the sensory information of the 10 study patients. They were based on the informative booklet by Kim keum-soon (1989). The procedural information was also modified according to the hospital`s customs. Provided the music for patients suitable to their tastes, and measured their blood pressure, heart rate, the degree of anxiety using the Spielberger`s measurement device of anxiety, and behavioral response of Finesilver`s. The statistical significance was analyzed using chi-square test and ANOVA. The results of this study were as follows : Hypothesis 1 : There are significant differences in the degree of anxiety among test group A, Test group A was provided only information, Test group B was provided information and the control group was provided neither. Hypothesis 2 : There are significant differences in systolic blood pressure among test group A, test group B, and control group.: non-significant. Hypothesis 3 : There are significant differences in diastolic blood pressure among test group A, test group B, and control group.: significant(F=1.31, p=.27, interaction; F=3.80, p=.00). Hypothesis 4 : There are significant differences in heart rate among test group A, test group B, and control group.: non-significant. Hypothesis 5 : There are significant differences in behavioral responses among test group A, test group B, and control group.: significant(F=10.05, p=.00). Further validation study is required with other subjects and other settings.

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Some Nonparametric Tests for Change-points with Epidemic Alternatives

  • Kim, Kyung-Moo
    • Communications for Statistical Applications and Methods
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    • v.4 no.2
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    • pp.427-434
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    • 1997
  • The purpose of this paper is to discuss distribution-free tests of hypothesis that the random samples are identically distributed against the epidemic alternative. But most tests that have been considered are depended only on specific null distribution. Two nonparametric tests are considered and compared with a likelihood ratio test by the empirical powers.

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An Automatic Segmentation Method for Video Object Plane Generation (비디오 객체 생성을 위한 자동 영상 분할 방법)

  • 최재각;김문철;이명호;안치득;김성대
    • Journal of Broadcast Engineering
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    • v.2 no.2
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    • pp.146-155
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    • 1997
  • The new video coding standard Iv1PEG-4 is enabling content-based functionalities. It requires a prior decomposition of sequences into video object planes (VOP's) so that each VOP represents moving objets. This paper addresses an image segmentation method for separating moving objects from still background (non-moving area) in video sequences using a statistical hypothesis test. In the proposed method. three consecutive image frames are exploited and a hypothesis testing is performed by comparing two means from two consecutive difference images. which results in a T-test. This hypothesis test yields a change detection mask that indicates moving areas (foreground) and non-moving areas (background), Moreover. an effective method for extracting

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Hypothesis Testing: Means and Proportions (평균과 비율 비교)

  • Pak, Son-Il;Lee, Young-Won
    • Journal of Veterinary Clinics
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    • v.26 no.5
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    • pp.401-407
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    • 2009
  • In the previous article in this series we introduced the basic concepts for statistical analysis. The present review introduces hypothesis testing for continuous and categorical data for readers of the veterinary science literature. For the analysis of continuous data, we explained t-test to compare a single mean with a hypothesized value and the difference between two means from two independent samples or between two means arising from paired samples. When the data are categorical variables, the $x^2$ test for association and homogeneity, Fisher's exact test and Yates' continuity correction for small samples, and test for trend, in which at least one of the variables is ordinal is described, together with the worked examples. McNemar test for correlated proportions is also discussed. The topics covered may provide a basic understanding of different approaches for analyzing clinical data.

Genetic association tests when a nuisance parameter is not identifiable under no association

  • Kim, Wonkuk;Kim, Yeong-Hwa
    • Communications for Statistical Applications and Methods
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    • v.24 no.6
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    • pp.663-671
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    • 2017
  • Some genetic association tests include an unidentifiable nuisance parameter under the null hypothesis of no association. When the mode of inheritance (MOI) is not specified in a case-control design, the Cochran-Armitage (CA) trend test contains an unidentifiable nuisance parameter. The transmission disequilibrium test (TDT) in a family-based association study that includes the unaffected also contains an unidentifiable nuisance parameter. The hypothesis tests that include an unidentifiable nuisance parameter are typically performed by taking a supremum of the CA tests or TDT over reasonable values of the parameter. The p-values of the supremum test statistics cannot be obtained by a normal or chi-square distribution. A common method is to use a Davies's upper bound of the p-value instead of an exact asymptotic p-value. In this paper, we provide a unified sine-cosine process expression of the CA trend test that does not specify the MOI and the TDT that includes the unaffected. We also present a closed form expression of the exact asymptotic formulas to calculate the p-values of the supremum tests when the score function can be written as a linear form in an unidentifiable parameter. We illustrate how to use the derived formulas using a pharmacogenetics case-control dataset and an attention deficit hyperactivity disorder family-based example.

A Study on the History of Statistics in the Early Twentieth Century Focused on Statistical Tests and Psychology (20세기 전반기 통계학사에 대한 연구 : 통계적 검정과 심리학을 중심으로)

  • Jo, Jae Keun
    • Journal for History of Mathematics
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    • v.26 no.4
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    • pp.277-299
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    • 2013
  • It was not until the early twentieth century that statistics emerged as an independent academic discipline. The developments of statistical theory and methods would not have been possible without heated controversies among founding fathers. One of them, controversy on the statistical test between R. A. Fisher and J. Neyman, E. S. Pearson had been very fierce and long-lasting. On the other hand it was in the early twentieth century that psychologists began to utilize statistical test which was a hybrid of tests developed by Fisher and Neyman-Pearson. By considering the history of fields such as psychology, we can see distinctive characteristics specific to the history of statistics.

Double Unit Root Tests Based on Recursive Mean Adjustment and Symmetric Estimation

  • Shin, Dong-Wan;Lee, Jong-Hyup
    • Journal of the Korean Statistical Society
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    • v.30 no.2
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    • pp.281-290
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    • 2001
  • Symmetric estimation and recursive mean adjustment are considered to construct tests for the doble unit root hypothesis for both parametric and semiparametric time series models. It is shown that simultaneous application of symmetric estimation and recursive mean adjustment yields the most powerful test. Moreover, size property of the semiparametric test based on the simultaneous application is bet among all semiparametric tests.

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Heteroscedasticity of Random Effects in Crossover Design

  • Ahn, Chul-H.
    • Proceedings of the Korean Statistical Society Conference
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    • 2002.11a
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    • pp.79-83
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    • 2002
  • A phase III clinical trial of a new drug for neutropenia induced by chemotherapy is presented and consider adding random effects in crossover design which was used in the clinical study. The diagnostics for its heteroscedasticity based on score statistic is derived for detecting homoscedasticity of errors in crossover design. A small simulation study is peformed to investigate the finite sample behaviour of the test statistic which is known to have an asymptotic chi-square distribution under the null hypothesis.

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Test and Analysis for Comovement-Locomotive Hypothesis (동조화 현상의 견인차 가설 검정과 분석)

  • Kim, Tae-Ho
    • The Korean Journal of Applied Statistics
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    • v.24 no.2
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    • pp.239-251
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    • 2011
  • The need for statistical analysis to discern the existence and the type of international business comovement has increased as business and economic variations in one country is directly transmitted to business and financial market conditions in another without a long lag. This study performs the statistical tests for th locomotive hypothesis to understand the structural character of the long-run mechanism among Korea-US current and future business movements and the domestic stock market. The U.S. future business prospect, rather than the US current and the domestic current and future business conditions, appears to signi cantl a ect the domestic stock market movement.