Equality Of Scale Parameters Research Articles

Analyzing treatment effects on Douglas-fir seedling survival with an extreme value regression model

First year survival patterns in a cohort of natural Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were assessed with an extreme value regression model. Extreme value distributions were fit to the data, assuming equal scale parameters among treatments but allowing location parameters to vary. The regression approach using indicator variables facilitated statistical comparison of survival curves among several habitats and treatments.

Bayes estimation of reliability in stress-strength model of Weibull distribution with equal scale parameters

The paper provides a Bayesian approach to inference about the reliability in a multicomponent stress-strength system. We consider Bayes' estimator of the system reliability from data consisting of a random sample from the stress distribution and one from the strength distribution when the two distributions are Weibull with equal and known scale parameters. The estimator of λ, ratio of two shape parameters, is also considered. The proposed estimators can be compared with the maximum likelihood estimators (mles). However, the comparison is carried out for single component stress-strength system and the Monte Carlo efficiencies are obtained. It is found that the proposed estimators are better than the corresponding mles.

Tests for Equality of Location & Scale Parameters of Exponential Distributions with Type-II Censoring

The likelihood ratio tests under various null hypotheses are derived for testing the equality of location and the equality of scale parameters of several exponential distributions. Since the closed form of the null distribution in most cases was intractable, an approximation is suggested in each case. The tests are relatively easy to apply and use only the F-tables which are readily available. A numerical example is discussed.

On a test of equality of scale parameters of several exponential distributions

In this paper, null distribution of the likelihood ratio criterion for testing the quality of scale parameters of p(p>2) two parameter exponential distributions for the case of equal sample sizes is obtained in a closed form for the first time. A short table of the critical values of the test statistic is also presented.

Use of a median test for a generalized Behrens-Fisher problem

A non-parametric test is proposed for testing differences of location in two independent samples without assuming equal scale parameters of the respective populations. The test is based on simultaneous application of two modified median tests, each using its sample median of the single samples.

Testing equality of several exponential distributions

AbstractRoy's union‐intersection principle is used to develop a test procedure to test the equality of scale parameters of several exponential distributions. Upper five and one percent values of the test statistic for two and three exponential distributions are tabulated and an illustrative simulated example is qiven.