• 제목/요약/키워드: signed-rank test

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Investigation of Terminology Coverage in Radiology Reporting Templates and Free-text Reports

  • Hong, Yi;Zhang, Jin
    • International Journal of Knowledge Content Development & Technology
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    • 제5권1호
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    • pp.5-14
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    • 2015
  • The Radiological Society of North America (RSNA) is improving reporting practices by developing an online library of clear and consistent report templates. To compare term occurrences in free-text radiology reports and RSNA reporting templates, the Wilcoxon signed-rank test method was applied to investigate how much of the content of conventional narrative reports is covered by the terms included in the RSNA reporting templates. The results show that the RSNA reporting templates cover most terms that appear in actual radiology reports. The Wilcoxon test may be helpful in evaluatingexisting templates and guiding the enhancement of reporting templates.

A Wilcoxon signed-rank test for random walk hypothesis based on slopes (기울기를 이용한 랜덤워크 윌콕슨 부호순위검정)

  • Kim, Tae Yoon;Park, Cheolyong;Kim, Seul Gee;Kim, Min Seok;Lee, Woo Jung;Kwon, Yunji
    • Journal of the Korean Data and Information Science Society
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    • 제25권6호
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    • pp.1499-1506
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    • 2014
  • Random walk is used for describing random phenomenon in various areas but tests for random walk developed so far are known to suffer from size distortion and low power. Kim et al. (2014) proposed a sign test for unit root (${\rho}=1$) hypothesis based on slopes. This article proposes a Wilcoxon signed rank test based on slopes for unit root hypothesis, and compares it with the augmented Dickey-Fuller test and the sign test by a simulation study. Our results confirm that the nonparametric tests are better than ADF test for small samples like n = 30. The results also show that the sign test is better than the Wilcoxon signed rank test and that for 0 < ${\rho}$ < 1 (-1 < ${\rho}$ < 0), the nonparametric tests suffer from power loss (improvement) as normal error changes to double exponential error.

Short-term Variation in Species Composition of Surf-zone Fishes at Daechon Beach, the Yellow Sea of Korea (대천 해빈 쇄파대어류 종조성의 단기 변화)

  • Lee, Tae-Won
    • Korean Journal of Ichthyology
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    • 제13권1호
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    • pp.32-39
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    • 2001
  • Surf-zone fishes in Daechon Beach, situated at the mouth of Cheonsu Bay, Korea, were collected by a beach seine during the spring and neap tides in August 1999. Short-term variation in species composition was analyzed based on tidal range, tidal level, and time of day. Of 24 species identified, juvenile pelagic fishes predominated in the number of individuals captured. Wilcoxon signed-rank test revealed that the number of individuals was significantly higher during the spring tide than during the neap tide. During the spring tide the fishes were more abundant at the low level than at the high level, while during the neap tide there was no significant difference. The mean density of pelagic fishes did not show significant differences between high and low tides. Demersal fishes were caught mainly in the water below the low level of the neap tide.

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The Impact of Abdominal Muscle Strengthening Exercises, Back Muscle Stretching and Multi-Training on the Lumbar Flexibility of 20s Adults (복부근력강화운동, 배부근 스트레칭 및 복합운동이 20대 성인의 허리 유연성에 미치는 영향)

  • Hong, Ki-Hoon;An, Ji-Hye;Yoo, Sun-Wook;Yun, Hyun-Joo;Lee, Chun-Yeop;Kim, Hee-Jung
    • The Journal of Korean society of community based occupational therapy
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    • 제3권2호
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    • pp.57-65
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    • 2013
  • Objective : The purpose of this study was to identify the effect and difference of abdominal muscle strengthening exercise, back muscle stretching and multi-training on the lumbar flexibility of 20s adults. Method : The abdominal muscle strengthening exercise, back muscle stretching and multi-training were conducted 9 times targeting 21 subjects who attended K University from 2013 May 29 to June 14. Sit and Reach Tests were conducted 2 times(before and after exercise program) for flexibility test and measured data were processed with SPSS program WIN 12.0K. By the Wilcoxon signed rank test, the effectiveness of exercises are verified. By the Kruskal-Wallis test and Mann-Whitney test, the difference of effectiveness among the exercise groups are verified. Result : The results of this study were summerized below 1. Before and after exercise, in abdominal muscle strengthening exercise group, back muscle stretching group and multi-training group are showed statistically significant differences(p<.05), 2. There were statistically significant difference in the improvement of the flexibility between each group(p>.05). Conclusion : These data suggests that all of the 3 exercise programs are brought positive influences on the improvement of flexibility, and abdominal muscle strengthening exercises and flexibility multi-training are effective on the flexibility more than, back muscle stretching in 20s adults.

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Computer Programs for Nonparametric Tests (비모수적(非母數的) 통계(統計) 프로그램의 개발(開發))

  • Bae, Do-Seon;Jang, Jung-Sun;Kim, Sang-Bok
    • Journal of Korean Institute of Industrial Engineers
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    • 제12권2호
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    • pp.101-108
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    • 1986
  • Computer programs for IBM PC/XT/AT or compatibles, are presented for running 9 nonparametric tests. They include sign test, Wilcoxon signed rank test, Mann-Whitney Wilcoxon test, Kruskal-Wallis test, Kolmogorov-Smirnov one sample and two sample tests, Kendall and Spearman rank correlation coefficient tests, and Chi square test for contingency table. Each program is written with BASIC language and is combined into a statistical package, 'NONPARA'. It is easily accessible through the menu programs. The alogorithms on which each test is based, are also explained and 3 examples are given.

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Comparative Statistic Module (CSM) for Significant Gene Selection

  • Kim, Young-Jin;Kim, Hyo-Mi;Kim, Sang-Bae;Park, Chan;Kimm, Kuchan;Koh, InSong
    • Genomics & Informatics
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    • 제2권4호
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    • pp.180-183
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    • 2004
  • Comparative Statistic Module(CSM) provides more reliable list of significant genes to genomics researchers by offering the commonly selected genes and a method of choice by calculating the rank of each statistical test based on the average ranking of common genes across the five statistical methods, i.e. t-test, Kruskal-Wallis (Wilcoxon signed rank) test, SAM, two sample multiple test, and Empirical Bayesian test. This statistical analysis module is implemented in Perl, and R languages.

On a Distribution-Free Test for Parallelism of Regression Lines Against Ordered Alternatives

  • Song, Moon Sup;Huh, Moon Yul;Kang, Hee Jeong
    • Journal of Korean Society for Quality Management
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    • 제15권2호
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    • pp.50-54
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    • 1987
  • A distribution-free rank test for parallelism of regression lines against ordered alternatives is considered. The proposed test statistic is based on the Kepner-Robinson's transformation. The null distribution of the proposed statistic is the same as that of the Wilcoxon signed rank statistic. But, the proposed procedure can be applied only to four or fewer regression lines. The results of a small-sample Monte Carlo study show that the proposed test is comparable with the parametric test in heavy tailed distributions.

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Statistical evaluation of the monotonic models for FRP confined concrete prisms

  • Hosseinpour, Farid;Abdelnaby, Adel E.
    • Advances in concrete construction
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    • 제3권3호
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    • pp.161-185
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    • 2015
  • FRP confining is a widely used method for seismic retrofitting of concrete columns. Several studies investigated the stress-strain behavior of FRP confined concrete prisms with square and rectangular sections both experimentally and analytically. In some studies, the monotonic stress-strain behavior of confined concrete was investigated and compressive strength models were developed. To study the reliability of these models, thorough statistical tests are required. This paper aims to investigate the reliability of the presented models using statistical tests including t-test, wilcoxon rank sum test, wilcoxon signed rank test and sign test with a level of significance of 5%. Wilk Shapiro test was also employed to evaluate the normality of the data distribution. The results were compared for different cross section and confinement types. To see the accuracy of the models when there were no significant differences between the results, the coefficient of confidence was used.

A Note on the Median Control Chart

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • 제20권2호
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    • pp.107-113
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    • 2013
  • This study reviews several well-known control charts for the location parameter with a discussion of the relationship between the maintenance of the control chart and a series of hypotheses testing. As a by-product, we then propose a new median control chart with the sign test statistic. We also modify the nonparametric control charts to easily understand the relation. Then we illustrate the construction of several median control charts with the industrial data and compare the efficiency among several control charts. Finally, we discuss some interesting features for the median control charts as concluding remarks.

Estimation of slope , βusing the Sequential Slope in Simple Linear Regression Model

  • Choi, Yong;Kim, Dongjae
    • Communications for Statistical Applications and Methods
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    • 제10권2호
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    • pp.257-266
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    • 2003
  • Distribution-free estimation methods are proposed for slope, $\beta$ in the simple linear regression model. In this paper, we suggest the point estimators using the sequential slope based on sign test and Wilcoxon signed rank test. Also confidence intervals are presented for each estimation methods. Monte Carlo simulation study is carried out to compare the efficiency of these methods with least square method and Theil´s method. Some properties for the proposed methods are discussed.