• Title, Summary, Keyword: two-sample location test

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A Comparison of Distribution-free Two-sample Procedures Based on Placements or Ranks

  • Kim, Dong-Jae
    • Journal of the Korean Statistical Society
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    • v.23 no.1
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    • pp.135-149
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    • 1994
  • We discussed a comparison of distribution-free two-sample procedures based on placements or ranks. Iterative asymptotic distribution of both two-sample procedures is studies and small sample Monte Carlo simulation results are presented. Also, we proposed the Hodges-Lehmann type location estimator based on linear placement statistics.

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Two-sample Linear Rank Tests for Efficient Edge Detection in Noisy Images (잡음영상에서 효과적인 에지검출을 위한 이표본 선형 순위 검정법)

  • Lim Dong-Hoon
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4
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    • pp.9-15
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    • 2006
  • In this paper we propose Wilcoxon test, Median test and Van der Waerden test such as linear rank tests in two-sample location problem for detecting edges effectively in noisy images. These methods are based on detecting image intensity changes between two pixel neighborhoods using an edge-height model to perform effectively on noisy images. The neighborhood size used here is small and its shape is varied adaptively according to edge orientations. We compare and analysis the performance of these statistical edge detectors on both natural images and synthetic images with and without noise.

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Window Configurations Comparison Based on Statistical Edge Detection in Images (영상에서 윈도우 배치에 따른 통계적 에지검출 비교)

  • Lim, Dong-Hoon
    • Communications for Statistical Applications and Methods
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    • v.16 no.4
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    • pp.615-625
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    • 2009
  • In this paper we describe Wilcoxon test and T-test that are well-known in two-sample location problem for detecting edges under different window configurations. The choice of window configurations is an important factor in determining the performance and the expense of edge detectors. Our edge detectors are based on testing the mean values of local neighborhoods obtained under the edge model using an edge-height parameter. We compare three window configurations based on statistical tests in terms of qualitative measures with the edge maps and objective, quantitative measures as well as CPU time for detecting edge.

Asymptotic Relative Efficiency of t-test Following Transformations

  • Yeo, In-Kwon
    • Journal of the Korean Statistical Society
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    • v.26 no.4
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    • pp.467-476
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    • 1997
  • The two-sample t-test is not expected to be optimal when the two samples are not drawn from normal populations. According to Box and Cox (1964), the transformation is estimated to enhance the normality of the tranformed data. We investigate the asymptotic relative efficiency of the ordinary t-test versus t-test applied transformation introduced by Yeo and Johnson (1997) under Pitman local alternatives. The theoretical and simulation studies show that two-sample t-test using transformed date gives higher power than ordinary t-test for location-shift models.

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A Study on the Bi-Aspect Test for the Two-Sample Problem

  • Hong, Seung-Man;Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • v.19 no.1
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    • pp.129-134
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    • 2012
  • In this paper we review a bi-aspect nonparametric test for the two-sample problem under the location translation model and propose a new one to accommodate a more broad class of underlying distributions. Then we compare the performance of our proposed test with other existing ones by obtaining empirical powers through a simulation study. Then we discuss some interesting features related to the bi-aspect test with a comment on a possible expansion for the proposed test as concluding remarks.

k-Sample Rank Procedures for Ordered Location-Scale Alternatives

  • Park, Hee-Moon
    • Journal of the Korean Society for Quality Management
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    • v.22 no.2
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    • pp.166-176
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    • 1994
  • Some rank score tests are proposed for testing the equality of all sampling distribution functions against ordered location-scale alternatives in k-sample problem. Under the null hypothesis and a contiguous sequence of ordered location-scale alternatives, the asymptotic properties of the proposed test statistics are investigated. Also, the asymptotic local powers are compared with each others. The results show that the proposed tests based on the Hettmansperger-Norton type statistic are more powerful than others for the general ordered location-scale alternatives. However, the Shiraishi's tests based on the sum of two Bartholomew's rank analogue statistics are robust.

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Two-sample Tests for Edge Detection in Noisy Images (잡음영상에서 에지검출을 위한 이표본 검정법)

  • 임동훈;박은희
    • The Korean Journal of Applied Statistics
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    • v.14 no.1
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    • pp.149-160
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    • 2001
  • In this paper we employ two-sample location tests such as Wilcoxon test and T test for detecting edges in noisy images. For this, we compute a test statistic on pixel gray levels obtained using an edge-height parameter and compare it with a threshold determined by a significance level. Experimental results applied to sample images are given and performances of these tests in terms of the objective measure are compared.

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Testing Hypothesis for the Logistic Model with Estimated Parameters : Modified Tables of Cirticla Values for K-S Type Statistic

  • Hwang, Chung-Sun
    • Journal of the Korean Statistical Society
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    • v.13 no.1
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    • pp.48-56
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    • 1984
  • This paper considers one-sample and two-sample test for the logistic function by means of Kolmororov-Smirnov type statistics. The standard tables used for the Kolmogorov-Smirnov test are valid only when the function is completely specified; but they are not valid if the parameters of function are estimated from the sample. This note presents modified tables for the Kolmogorov-Sminov type staistic. These tables can be used to test the hypothesis that a sample comes from a logistic function when shape parameter $(\alpha)$ and location parameter $(\beta)$ must be estimated from the sample by the method of maximum likelihood. Monte Carlo method is employed to calculate the criticla values of the test. The tables of the critical values are provided.

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Weak Convergence of U-empirical Processes for Two Sample Case with Applications

  • Park, Hyo-Il;Na, Jong-Hwa
    • Journal of the Korean Statistical Society
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    • v.31 no.1
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    • pp.109-120
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    • 2002
  • In this paper, we show the weak convergence of U-empirical processes for two sample problem. We use the result to show the asymptotic normality for the generalized dodges-Lehmann estimates with the Bahadur representation for quantifies of U-empirical distributions. Also we consider the asymptotic normality for the test statistics in a simple way.

Fault Locator using GPS Time-synchronized Phasor for Transmission Line (송전선로의 동기페이저를 이용한 고장점 표정장치)

  • Lee, Kyung-Min;Park, Chul-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.1
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    • pp.47-52
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    • 2016
  • Fault location identification in the transmission line is an essential part of quick service restoration for maintaining a stable in power system. The application of digital schemes to protection IEDs has led to the development of digital fault locators. Normally, the impedance measurement had been used to for the location detection of transmission line faults. It is well known that the most accurate fault location scheme uses two-ended measurements. This paper deals with the complete design of a fault locator using GPS time-synchronized phasor for transmission line fault detection. The fault location algorithm uses the transmitted relaying signals from the two-ended terminal. The fault locator hardware consists of a Main Processor Unit, Analog Digital Processor Unit, Signal Interface Unit, and Power module. In this paper, sample real-time test cases using COMTRADE format of Omicron apparatus are included. We can see that the implemented fault locator identified all the test faults.