• 제목/요약/키워드: Null distribution

검색결과 172건 처리시간 0.025초

Some Distribution Free Tests for Exponential Distributions

  • Jeon, Jong Woo;Han, Suk Ki;Nam, Eun Woo
    • 품질경영학회지
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    • 제14권1호
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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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MUSIC Null-Spectrum의 평균과 분산 (The Mean and Variance of the MUSIC Null-Spectrum)

  • 최진호;윤진선;김형명;송익호;박성일
    • 한국통신학회논문지
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    • 제17권2호
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    • pp.114-120
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    • 1992
  • 이 논문에서는 MUSIC null-spectrum의 점근 분포를 유도하여, 이로부터 MUSIC null-spectrum의 정확한 점근 분산을 얻었다. 또한 이 결과에서 정규표준편차의 표현식을 얻어, 정규표준편차가 수신기와 신호원수를 따라 바뀜을 보였다.

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Goodness-of-fit tests for randomly censored Weibull distributions with estimated parameters

  • Kim, Namhyun
    • Communications for Statistical Applications and Methods
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    • 제24권5호
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    • pp.519-531
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    • 2017
  • We consider goodness-of-fit test statistics for Weibull distributions when data are randomly censored and the parameters are unknown. Koziol and Green (Biometrika, 63, 465-474, 1976) proposed the $Cram\acute{e}r$-von Mises statistic's randomly censored version for a simple hypothesis based on the Kaplan-Meier product limit of the distribution function. We apply their idea to the other statistics based on the empirical distribution function such as the Kolmogorov-Smirnov and Liao and Shimokawa (Journal of Statistical Computation and Simulation, 64, 23-48, 1999) statistics. The latter is a hybrid of the Kolmogorov-Smirnov, $Cram\acute{e}r$-von Mises, and Anderson-Darling statistics. These statistics as well as the Koziol-Green statistic are considered as test statistics for randomly censored Weibull distributions with estimated parameters. The null distributions depend on the estimation method since the test statistics are not distribution free when the parameters are estimated. Maximum likelihood estimation and the graphical plotting method with the least squares are considered for parameter estimation. A simulation study enables the Liao-Shimokawa statistic to show a relatively high power in many alternatives; however, the null distribution heavily depends on the parameter estimation. Meanwhile, the Koziol-Green statistic provides moderate power and the null distribution does not significantly change upon the parameter estimation.

A Study on Goodness-of-fit Test for Density with Unknown Parameters

  • Hang, Changkon;Lee, Minyoung
    • Communications for Statistical Applications and Methods
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    • 제8권2호
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    • pp.483-497
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    • 2001
  • When one fits a parametric density function to a data set, it is usually advisable to test the goodness of the postulated model. In this paper we study the nonparametric tests for testing the null hypothesis against general alternatives, when the null hypothesis specifies the density function up to unknown parameters. We modify the test statistic which was proposed by the first author and his colleagues. Asymptotic distribution of the modified statistic is derived and its performance is compared with some other tests through simulation.

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GSTM1 and GSTT1 Allele Frequencies among Various Indian and non-Indian Ethnic Groups

  • Senthilkumar, K.P.;Thirumurugan, R.
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권12호
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    • pp.6263-6267
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    • 2012
  • Background: Glutathione-S-transferase (GST) is an important phase II xenobiotic compound metabolizing enzyme family, involved in tolerance to a particular drug or susceptibility to a diseasec. This study focused the GSTM1 and T1 null allele frequency in the Gujarat population with a comparison across other Inter- and Intra-Indian ethnic groups to predict variation in the possible susceptible status. Methods: DNA was isolated by a salting out method and GSTM1 and T1 homozygous null genotypes were detected by multiplex polymerase chain reaction in 504 unrelated individuals. The genotype distribution of null alleles was compared with Indian and non Indian ethnics reported earlier in the literature using Fisher's test. Results: The frequencies of the homozygous null genotypes of GSTM1 and GSTT1 were 20% (95%CI 16.7-23.9) and 35.5% (95%CI 31.4-39.9) respectively. GSTM1 null frequency did not deviate from most other Indian ethnic groups but differed from the majority of those of non Indian ethnicity studied. The frequency of homozygous null type of GSTT1 was significantly higher and deviated from all Indian groups and a few of non Indian ethnicity. Conclusions: Gujarat ethnicity, possibly the most susceptible for GSTT1 dependent drug disposition and diseases regarding effects of pollution. Further, the results have implications for GSTT1 dependent drugs used for treatment, a serious problem which needs to be solved by physicians and clinical researchers.

A NEW UDB-MRL TEST WITH UNKNOWN CHANCE POINT

  • Na, Myung-Hwan
    • 품질경영학회지
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    • 제30권3호
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    • pp.195-202
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    • 2002
  • The problem of trend change in the mean residual life is great Interest in the reliability and survival analysis. In this paper, a new test statistic for testing whether or not the mean residual life changes its trend Is developed. It is assumed that neither the change point nor the proportion at which the trend change occurs is known. The asymptotic null distribution of test statistic is established and asymptotic critical values of the asymptotic null distribution is obtained. Monte Carlo simulation is used to compare the proposed test with previously known tests.

ASYMPTPTIC DISTRIBUTION OF LIKELINOOD RATIO STATISTIC FOR TESTING MULTISAMPLE SPHERICITY

  • Gupta, A.K.;Nagar, D.K.;Jain, Kalpana
    • Journal of the Korean Statistical Society
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    • 제21권1호
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    • pp.14-26
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    • 1992
  • In this paper, asymptotic expansions of the distribution of the likelihood ratio statistic for testing multisample sphericity have been derived in the null and nonnull cases when the alternatives are close to the null hypothesis. These expansions are obtained in the form of series of data distributions.

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The Nonparametric Test for Detecting Main Effects for Three-Way ANOVA Models

  • Park, Young-Hun
    • Journal of the Korean Statistical Society
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    • 제25권3호
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    • pp.419-432
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    • 1996
  • When interactions are not present in a three-way layout, the lim-iting null distribution of the F statistic for testing main effects when applied to the rank-score transformed data is the same as the limiting null distribution of the usual F statistic when applied to the normal data. The simulation results exhibit that the rank transform test is robust with respect to significance level and powerful for testing main effects in a three-way factorial experiment.

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A NEW UDB-MRL TEST FOR WITH UNKNOWN

  • Na, Myung-Hwan
    • 품질경영학회지
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    • 제30권4호
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    • pp.78-85
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    • 2002
  • The problem of trend change in the mean residual life is great interest in the reliability and survival analysis. In this paper, a new test statistic for testing whether or not the mean residual life changes its trend is developed. It is assumed that neither the change point nor the proportion at which the trend change occurs is known. The asymptotic null distribution of test statistic is established and asymptotic critical values of the asymptotic null distribution is obtained. Monte Carlo simulation is used to compare the proposed test with previously known tests.

AESA 레이더 최대탐지거리의 통계적 접근 (Statistical Approach for AESA Radar Maximum Detection Range)

  • 탁대석;신경수
    • 시스템엔지니어링학술지
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    • 제15권1호
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    • pp.43-50
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    • 2019
  • Statistical hypothesis tests are important for quantifying answers to questions about samples of data. The Step Process of Statistical Hypothesis Testing; state the null hypothesis, State the alternate hypothesis, State the alpha level, Find the z-score associated with alpha level, Find the test statistic using this formula, If the calculated t distribution value from the data is larger than the t distribution value of alpha level, then you are in the Rejection region and you can reject the Null Hypothesis with ($1-{\alpha}$) level of confidence.