• Title/Summary/Keyword: null hypothesis

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Goodness-of-Fit Test Based on Smoothing Parameter Selection Criteria (평활(平滑) 모수(母數) 선택(選擇)에 기준(基準)한 적합도(適合度) 검정(檢定))

  • Kim, Jong-Tae
    • Journal of the Korean Data and Information Science Society
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    • v.4
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    • pp.137-146
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    • 1993
  • The Proposed goodness-of-fit test Statistic $\hat{\lambda}_{\alpha}$ derived from the test Statistc in Kim (1992) is itself a smoothing parameter which is selected to minimize an estimated MISE for a truncated series estimator, $d_{\hat{\lambda}{n}}$, of the comparison density function. Therefore, this test statistic leads immediately to a point estimate of the density function in the event that $H_{0}$ is ejected. The limiting distribution of $\hat{\lambda}_{\alpha}$ was obtained under the null hypothesis. It is also shown that this test is consistent against fixed alternatives.

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Test for Discontinuities in Nonparametric Regression

  • Park, Dong-Ryeon
    • Communications for Statistical Applications and Methods
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    • v.15 no.5
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    • pp.709-717
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    • 2008
  • The difference of two one-sided kernel estimators is usually used to detect the location of the discontinuity points of regression function. The large absolute value of the statistic imply discontinuity of regression function, so we may use the difference of two one-sided kernel estimators as the test statistic for testing null hypothesis of a smooth regression function. The problem is, however, we only know the asymptotic distribution of the test statistic under $H_0$ and we hardly expect the good performance of test if we rely solely on the asymptotic distribution for determining the critical points. In this paper, we show that if we adjust the bias of test statistic properly, the asymptotic rules hold for even small sample size situation.

A Study on Goodness of Fit Test in Accelerated Life Tests (가속수명시험에 대한 적합도 검정에 관한 연구)

  • Lee, Woo-Dong;Cho, Geon-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.7 no.1
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    • pp.37-46
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    • 1996
  • In this paper, we introduce the goodness of fit test procedure for lifetime distribution using step stress accelerated lifetime data. Using the nonpapametric estimate of acceleration factor, we prove the strong consistence of empirical distribution function under null hypothesis. The critical vailues of Kolmogorov-Smirnov, Anderson-Darling, Cramer-von Mises statistics are computed when the lifetime distibution is assumed to be exponential and Weibull. The power of test statistics are compared through Monte-Cairo simulation study.

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Application of Logit Model in Qualitative Dependent Variables (로짓모형을 이용한 질적 종속변수의 분석)

  • Lee, Kil-Soon;Yu, Wann
    • Journal of Families and Better Life
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    • v.10 no.1 s.19
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    • pp.131-138
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    • 1992
  • Regression analysis has become a standard statistical tool in the behavioral science. Because of its widespread popularity. regression has been often misused. Such is the case when the dependent variable is a qualitative measure rather than a continuous, interval measure. Regression estimates with a qualitative dependent variable does not meet the assumptions underlying regression. It can lead to serious errors in the standard statistical inference. Logit model is recommended as alternatives to the regression model for qualitative dependent variables. Researchers can employ this model to measure the relationship between independent variables and qualitative dependent variables without assuming that logit model was derived from probabilistic choice theory. Coefficients in logit model are typically estimated by the method of Maximum Likelihood Estimation in contrast to ordinary regression model which estimated by the method of Least Squares Estimation. Goodness of fit in logit model is based on the likelihood ratio statistics and the t-statistics is used for testing the null hypothesis.

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Test of Exponentiality in Step Stress Accelerated Life test Model based on Kullback­Leibler Information Function (쿨백­라이블러 정보함수 이용한 단계 스트레스 가속수명모형의 지수성 검정)

  • 박병구;윤상철
    • Journal of Korean Society for Quality Management
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    • v.31 no.4
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    • pp.194-202
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    • 2003
  • In this paper, we propose goodness of fit test statistics for exponentiality in accelerated life tests data based on Kullback­Leibler information functions. This acceleration model is assumed to be a tampered random variable model. The procedure is applicable when the exponential parameter using the data from accelerated life tests is or is not specified under null hypothesis. And we compare the power of the proposed test statistics with Kolmogorov­Smirnov, Cramer von Mises and Anderson­Darling statistics in the small sample.

INDEPENDENCE TEST FOR BIVARIATE CENSORED DATA UNDER UNIVARIATE CENSORSHIP

  • Kim, Jin-Heum;Cai, Jian-Wen
    • Journal of the Korean Statistical Society
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    • v.32 no.2
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    • pp.163-174
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    • 2003
  • We propose a test for independence of bivariate censored data under univariate censorship. To do this, we first introduce a process defined by the difference between bivariate survival function estimator proposed by Lin and Ying (1993) and the product of the product-limit estimators (Kaplan and Meier, 1958) for the marginal survival functions, and derive its asymptotic properties under the null hypothesis of independence. We propose a Cramer-von Mises-type test procedure based on the process . We conduct simulation studies to investigate the finite-sample performance of the proposed test and illustrate the proposed test with a real example.

Analysis of counts in the one-way layout (일원배열 가산자료에서의 처리효과 비교)

  • 이선호
    • The Korean Journal of Applied Statistics
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    • v.10 no.1
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    • pp.105-119
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    • 1997
  • Barnwal and Paul(1988) derived the likelihood ratio statistic and $C(\alpha)$ statistic for testing the equality of the means of several groups of count data in the presence of a common dispersion parameter. These tests are generalized to be applicable without the restriction of a common dispersion parameter. And the assumed model of data is also extended from negative binomial to double exponential Poisson model. Monte Carlo simulations show the superiority of $C(\alpha)$ statistic based on the double exponential Poisson family which has a very simple form and requires estimates of the parameters only under the null hypothesis.

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Testing Exponentiality of Kullback-Leibler Information Function based on a Step Stress Accelerated Life Test

  • Park Byung Gu;Yoon Sang Chul
    • Proceedings of the Korean Statistical Society Conference
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    • 2000.11a
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    • pp.235-240
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    • 2000
  • In this paper a test of fit for exponentiality and we propose the estimator of Kullback-Leibler Information functions using the data from accelerated life tests. This acceleration model is assumed to be a tampered random variable model. The procedure is applicable when the exponential parameter based on the data from accelerated life tests is or is not specified under null hypothesis. Using Simulations, the power of the proposed test based on use condition of accelerated life test under alternatives is compared with that of other standard tests in the small sample.

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A Kolmogorov-Smirnov-Type Test for Independence of Bivariate Failure Time Data Under Independent Censoring

  • Kim, Jingeum
    • Journal of the Korean Statistical Society
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    • v.28 no.4
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    • pp.469-478
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    • 1999
  • We propose a Kolmogorov-Smirnov-type test for independence of paired failure times in the presence of independent censoring times. This independent censoring mechanism is often assumed in case-control studies. To do this end, we first introduce a process defined as the difference between the bivariate survival function estimator proposed by Wang and Wells (1997) and the product of the product-limit estimators (Kaplan and Meier (1958)) for the marginal survival functions. Then, we derive its asymptotic properties under the null hypothesis of independence. Finally, we assess the performance of the proposed test by simulations, and illustrate the proposed methodology with a dataset for remission times of 21 pairs of leukemia patients taken from Oakes(1982).

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Regional Traffic Accident Model of Elderly Drivers based on Urban Decline Index (도시쇠퇴 지표를 적용한 지역별 고령운전자 교통사고 영향 분석)

  • Park, Na Young;Park, Byung Ho
    • Journal of the Korean Society of Safety
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    • v.32 no.6
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    • pp.137-142
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    • 2017
  • This study deals with the relation between traffic accident and urban decline. The purpose of this study is to develop the regional accident models of elderly drivers. In order to develop the count data models, 2009-2015 traffic accident data from TAAS(traffic accident analysis system) and urban decline data from urban regeneration information system are collected. The main results are as follows. First, the null hypothesis that there is no difference in the accident number between elderly and non-elderly drivers is rejected. Second, 8 accident models which are all statistically significant have been developed. Finally, common variables between elderly and non-elderly are ratio of elderly people, elderly person living alone/1,000 persons and wholesale/retail employments/1,000 persons. This study could be expected to give many implications to making regional accident reduction policy.