structural steel sections are mainly used in beams and columns of building frames. iran national steel industrialgroup is among the oldest and largest producers of beams in iran. it has two beam production lines, namely line630 and line 650. in this study, the mechanical properties of manufactured beams in these production lines werecompared. based on the t-test results, the elongation is signi...

We introduce a bootstrap procedure to test the hypothesis Ho that K + 1 variances are homogeneous. The procedure uses a variance-based statistic, and is derived from a normal-theory test for equality of variances. The test equivalently expressed the hypothesis as Ho : η = (η1, . . . , ηK+1) = 0, where ηi’s are log contrasts of the population variances. A box-type acceptance region is constructe...

Results of a plasma cortisol suppression test have never been reported in a Black glaucoma population, although there have been reports of tests carried out on glaucomatous patients generally. The results have varied from marked suppression in glaucomatous patients (Becker, Podos, Assef, and Cooper, 1973; Rosenberg and Levene, 1974) to no suppression at all (Schwartz and Levene, 1972). Glaucoma...

In many applications, the underlying scientific question concerns whether the variances of k samples are equal. There are a substantial number of tests for this problem. Many of them rely on the assumption of normality and are not robust to its violation. In 1960 Professor Howard Levene proposed a new approach to this problem by applying the F -test to the absolute deviations of the observation...

The earlier work on thymonucleic acid by Levene and Mandell and by Levene and Jacobs2 led to the isolation of monophosphoric esters of pyrimidine nucleosides and diphosphoric esters of pyrimidine nucleosides. These observations were corroborated by Thannhauser and coworkers.3 In a recent publication Levene and London4 reported the isolation of a guanine nucleoside and the present paper contains...

A new graphical procedure for multiple comparisons of k standard deviations is provided. As a test for homogeneity of variances, the new procedure has similar type I and type II error properties as the Brown and Forsythe (1974) version of the Levene (1960) test, W50. The graphical display associated with the multiple comparisons test, however, provides a useful visual tool for screening samples...