• Title/Summary/Keyword: Test Statistics

Search Result 6,443, Processing Time 0.029 seconds

Independence test of a continuous random variable and a discrete random variable

  • Yang, Jinyoung;Kim, Mijeong
    • Communications for Statistical Applications and Methods
    • /
    • v.27 no.3
    • /
    • pp.285-299
    • /
    • 2020
  • In many cases, we are interested in identifying independence between variables. For continuous random variables, correlation coefficients are often used to describe the relationship between variables; however, correlation does not imply independence. For finite discrete random variables, we can use the Pearson chi-square test to find independency. For the mixed type of continuous and discrete random variables, we do not have a general type of independent test. In this study, we develop a independence test of a continuous random variable and a discrete random variable without assuming a specific distribution using kernel density estimation. We provide some statistical criteria to test independence under some special settings and apply the proposed independence test to Pima Indian diabetes data. Through simulations, we calculate false positive rates and true positive rates to compare the proposed test and Kolmogorov-Smirnov test.

On Testing Fisher's Linear Discriminant Function When Covariance Matrices Are Unequal

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
    • /
    • v.22 no.2
    • /
    • pp.325-337
    • /
    • 1993
  • This paper propose two test statistics which enable us to proceed the variable selection in Fisher's linear discriminant function for the case of heterogeneous discrimination with equal training sample size. Simultaneous confidence intervals associated with the test are also given. These are exact and approximate results. The latter is based upon an approximation of a linear sum of Wishart distributions with unequal scale matrices. Using simulated sampling experiments, powers of the two tests have been tabulated, and power comparisons have been made between them.

  • PDF

Test for the Pareto Distribution Based on the Transformed Sample Lorenz Curve

  • Kang, Suk-Bok;Cho, Young-Suk
    • Proceedings of the Korean Statistical Society Conference
    • /
    • 2002.05a
    • /
    • pp.133-137
    • /
    • 2002
  • A powerful and easily computed goodness-of-fit test for Pareto distribution which does not depend on the unknown location and scale parameters is proposed based on the transformed sample Lorenz curve. We compare the power of the proposed test statistic with the other goodness-of-fit tests for Pareto distribution against various alternatives through Monte Carlo methods.

  • PDF

Goodness-of-Fit Test for the Pareto Distribution Based on the Transformed Sample Lorenz curve

  • Kang, Suk-Bok;Cho, Young-Suk
    • Journal of the Korean Data and Information Science Society
    • /
    • v.13 no.1
    • /
    • pp.113-119
    • /
    • 2002
  • A powerful and easily computed goodness-of-fit test for Pareto distribution which does not depend on the unknown location and scale parameters is proposed based on the transformed sample Lorenz curve. We compare the power of the proposed test statistic with the other goodness-of-fit tests for Pareto distribution against various alternatives through Monte Carlo methods.

  • PDF

A Note on the Chi-Square Test for Multivariate Normality Based on the Sample Mahalanobis Distances

  • Park, Cheolyong
    • Journal of the Korean Statistical Society
    • /
    • v.28 no.4
    • /
    • pp.479-488
    • /
    • 1999
  • Moore and Stubblebine(1981) suggested a chi-square test for multivariate normality based on cell counts calculated from the sample Mahalanobis distances. They derived the limiting distribution of the test statistic only when equiprobable cells are employed. Using conditional limit theorems, we derive the limiting distribution of the statistic as well as the asymptotic normality of the cell counts. These distributions are valid even when equiprobable cells are not employed. We finally apply this method to a real data set.

  • PDF

The Role of Artificial Observations in Testing for the Difference of Proportions in Misclassified Binary Data

  • Lee, Seung-Chun
    • The Korean Journal of Applied Statistics
    • /
    • v.25 no.3
    • /
    • pp.513-520
    • /
    • 2012
  • An Agresti-Coull type test is considered for the difference of binomial proportions in two doubly sampled data subject to false-positive error. The performance of the test is compared with the likelihood-based tests. It is shown that the Agresti-Coull test has many desirable properties in that it can approximate the nominal significance level with compatible power performance.

Cusum of squares test for discretely observed sample from multidimensional di usion processes

  • Na, Ok-Young;Ko, Bang-Won;Lee, Sang-Yeol
    • Journal of the Korean Data and Information Science Society
    • /
    • v.21 no.3
    • /
    • pp.547-554
    • /
    • 2010
  • In this paper, we extend the work by Lee et al. (2010) to multidimensional di usion processes. A test statistic analogous to the one-dimensional case is proposed to inves-tigate the joint stability of covariance matrix parameters and, under certain regularity conditions, is shown to have a limiting distribution of the sup of a multidimensional Brownian bridge. A simulation result is provided for illustration.

A Test For Trend Change in Failure Rate Using Censored Data

  • Kim, Jae-Joo;Jeong, Hai-Sung;Na, Myung-Hwan
    • Proceedings of the Korean Reliability Society Conference
    • /
    • 2000.11a
    • /
    • pp.365-371
    • /
    • 2000
  • The problem of trend change in the failure rate is great interest in the reliability and survival analysis. In this paper we develop a test statistic for testing whether or not the failure rate changes its trend using random censored data. The asymptotic normality of the test statistic is established. We discuss the efficiency values of loss due to censoring.

  • PDF

A Test For Trend Change in Failure Rate Using Censored Data

  • Kim, Jae Joo;Jeong, Hai Sung;Na, Myung Hwan
    • International Journal of Quality Innovation
    • /
    • v.1 no.1
    • /
    • pp.58-63
    • /
    • 2000
  • The problem of trend change in the failure rate is great interest in the reliability and survival analysis. In this paper we develop a test statistic for testing whether or not the failure rate changes its trend using random censored data. The asymptotic normality of the test statistic is established. The efficiency values of loss due to censoring are discussed.

  • PDF

Test for Parameter Changes in the AR(1) Process

  • Kim, Soo-Hwa;Cho, Sin-Sup;Park, Young J.
    • Journal of the Korean Statistical Society
    • /
    • v.26 no.3
    • /
    • pp.417-427
    • /
    • 1997
  • In this paper the parameter change problem in the stationary time series is considered. We propose a cumulative sum (CUSUM) of squares-type test statistic for detection of parameter changes in the AR(1) process. The proposed test statistic is based on the CUSIM of the squared observations and is shown to converge to a standard Brownian bridge. Simulations are performed to evaluate the performance of the proposed statistic and a real example is provided to illustrate the procedure.

  • PDF