• Title/Summary/Keyword: two one-sided tests

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Nonparametric test procedures the changepoint problem with multiple observations (다중자료를 갖는 변화시점 모형에서의 비모수적인 검정법)

  • 김경무
    • The Korean Journal of Applied Statistics
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    • v.4 no.1
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    • pp.33-45
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    • 1991
  • In the analysis of changepoint model the situation where single observation is taken at each time point has been considered. In an effort to extend this to the general situation, we may consider the changepoint model with more than one observation at each time point. These tests are developed without assuming any particular form for the underlying distribution, we propose the one-sided and two-sided nonparametric tests by extending the tests that have been considered in the changepoint model with single observation at each time point and obtain their asymptotic null distributions. We compare the empirical powers among the extended changepoint tests under one-sided or two-sided alternatives. We also compare the powers of the extended changepoint tests with those of the original test via the Monte Carlo simulation.

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Two Sequential Wilcoxon Tests for Scale Alternatives

  • Mishra, Prafulla-Chandra
    • Journal of the Korean Statistical Society
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    • v.30 no.4
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    • pp.679-691
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    • 2001
  • Two truncated sequential tests are developed for the two-sample scale problem based on the usual Wilcoxon rank-sum statistic for two different dispersion indices - absolute median deviations, when the medians of the two populations X and Y are equal or known and sums of squared mean deviations, when the medians are either unknown or unequal. The first test is briefly called SWAMD test and the second SWSMD test. For the SWAMD test, the percentile points for both the one-sided and two-sided alternatives, (equation omitted) have been found by Wiener approximation and their values computed for a range of values of a and N; analytical expression for the power function has been derived through Wiener process and its performance studied for various sequential designs for exponential distribution. This test has been illustrated by a numerical example. All the results of the SWAMD test, being directly applicable to the SWSMD test, are not dealt with separately Both the tests are compared and their suitable applications indicated.

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Effects of Plank Exercises with Resistance of One-Sided Hip Adduction on the Abdominal Muscle Thickness

  • Park, JaeCheol;Jeong, JinGyu
    • The Journal of Korean Physical Therapy
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    • v.31 no.2
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    • pp.82-87
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    • 2019
  • Purpose: The purpose of this study was to examine the effects of plank exercises with resistance of one-sided hip adduction on abdominal muscle thickness. Methods: Thirty subjects were divided into a group that underwent plank exercises with one-sided hip adduction resistance (n=15) and a group that underwent plank exercises only (n=15). Their changes in abdominal muscle thickness before the experiment (n=15) and three and six weeks after the experiment were analyzed using a two-way repeated analysis of variance at a statistical significance level of ${\alpha}=0.05$. When there was any interaction between the time of measurement and each group, post hoc t-tests were conducted at a statistical significance level of ${\alpha}=0.01$. Results: The results of the experiment showed statistically significant differences in the thickness of the rectus abdominis, internal oblique muscle, and transversus abdominis, depending on the time of measurement and the interaction between the time of measurement and each group (p<0.05). Statistically significant differences were observed in the thickness of the external oblique, depending on the time of measurement, the interaction between the time of measurement and each group, and variances between the groups (p<0.05). Conclusion: The results of this study indicated that plank exercises with resistance of one-sided adduction are effective for increasing abdominal muscle thickness. The study's overall findings will likely be used as basic data for lumbar stabilization exercises and rehabilitation treatment.

Some Distribution Free Tests for Exponential Distributions

  • Jeon, Jong Woo;Han, Suk Ki;Nam, Eun Woo
    • Journal of Korean Society for Quality Management
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    • v.14 no.1
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    • pp.39-46
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    • 1986
  • This paper considers two sided tests for exponential null distribution against NBUE or NWUE alternative in life testing. The main results concern the strong consistency of two proposed statistics, one being similar to Kolmogorov - Smirnov statistic, the other similar to Cramer-Von Mises statistic. Also obtained are the asymtotic null distribution and the exact Bahadur slope of the statistic similar to Kolmogorov-Smirnov.

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One-step Sample Size Determination for 2×2 Bioequivalence Study (2×2 생물학적 동등성 시험 적정 피험자 수의 간단한 계산 방법)

  • Lee, Young-Joo;Yi, Hong-Jae;Kim, Han-Gyul;Oh, Ju-Hee;Shin, Yong-Jun;Kim, Young-Gi;Kim, Sang-Nyun
    • Journal of Pharmaceutical Investigation
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    • v.39 no.3
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    • pp.217-219
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    • 2009
  • There are several approaches to calculate a sample size for bioequivalence test. Among these approaches, sample sizes determination based on Schuirmann's two one-sided tests procedures has been used most popularly in case of 2${\times}$2 bioequivalence study. Here we proposed simple sample size table for conventional 2${\times}$2 bioequivalence test based on Schuirmann's two one-sided tests in accordance with Korean Guidelines for Bioequivalence Test. This table will allow researchers with a little statistical background to calculate the sample size for bioequivalence with easy process.

Improved Mid P-value Method for Statistical Inference in Three-Way Contingency Tables

  • Donguk Kim
    • Communications for Statistical Applications and Methods
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    • v.5 no.3
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    • pp.905-926
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    • 1998
  • We propose a modified mid P-value method to reduce the conservativeness for the inference of conditional associations in three-way contingency tables. This improves the ordinary mfd P-value method. For $2{\times} 2${\times} K$ tables, we propose confidence intervals for an assumed common odds ratio based on inverting two separate one-sided tests using the modified mid P-value. Also, an alternative and usually even better ways of constructing intervals, based on Inverting a two-sided test, are presented. The actual probability of coverage of a 100($1-\alpha$)% confidence interval is centered about the nominal level, but the modified mid P-value approach gives actual coverage probability even closer to the nominal level than the ordinary mid P-value approach.

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On Sample Size Determination of Bioequivalence Trials

  • Park, Sang-Gue
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.365-373
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    • 2007
  • Sample size determination plays an important role in designing a bioequivalence trial. Formulae of sample sizes based on Schuirmann's two one-sided tests procedures are given for bioequivalence studies with the $2{\times}2$ crossover design and two-sample parallel design. A practical discussion for the relationship among these formulae is given.

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Spatial Point-pattern Analysis of a Population of Lodgepole Pine

  • Chhin, Sophan;Huang, Shongming
    • Journal of Forest and Environmental Science
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    • v.34 no.6
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    • pp.419-428
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    • 2018
  • Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.

Nonparametric Test Procedures for Change Point Problems in Scale Parameter

  • Cho, Wan-Hyun;Lee, Jae-Chang
    • Journal of the Korean Statistical Society
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    • v.19 no.2
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    • pp.128-138
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    • 1990
  • In this paper we study the properties of nonparametric tests for testing the null hypothesis of no changes against one sided and two sideds alternatives in scale parameter at unknown point. We first propose two types of nonparametric tests based on linear rank statistics and rank-like statistics, respectively. For these statistics, we drive the asymptotic distributions under the null and contiguous alternatives. The main theoreticla tools used for derivation are the stochastic process representation of the test staistic and the Brownian bridge approximation. We evaluate the Pitman efficiencies of the test for the contiguous alternatives, and also compute empirical power by Monte Carlo simulation.

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Comparison of Two Dependent Agreements Using Test of Marginal Homogeneity (주변동질성검정법을 이용한 종속된 두 일치도의 비교)

  • Oh, Myong-Sik
    • Communications for Statistical Applications and Methods
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    • v.15 no.4
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    • pp.605-614
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    • 2008
  • Oh (2008) has proposed the one-sided likelihood ratio test of the equality of two agreement measures. However the use of this test may be limited since the computations of test statistic and critical value are not easy. We propose a test for comparing two dependent agreements using some well known tests for marginal homogeneity, for instance, Bhapkar test, Stuart-Maxwell test. Data obtained from 2008 world figure skating championship ladies single is analyzed for illustration purposes.