Ala~traet--Errors-in-variables problems are considered for the case of three variables, where the underlying relations among the noise-free variables are linear, and covariance information for the noisy variables is available. The static problem where the variables are complex (which can arise when narrowband filtering is used) is analysed in detail. Some results are also presented for the case...

Unintentional sleep and performance impairment due to extended wakefulness are often the cause of traffic and work accidents. Therefore, large-scale screening instruments assessing the ability to resist falling asleep during monotonous tasks are needed. The current widespread computer use in industrial and home settings offers the possibility to use software-based instruments as an alternative ...

Let Xλ1 , Xλ2 , . . . , Xλn be independent Weibull random variables with Xλi ∼ W (α,λi) where λi > 0, for i = 1, . . . , n. Let X n:n denote the lifetime of the parallel system formed from Xλ1 , Xλ2 , . . . , Xλn . We investigate the effect of the changes in the scale parameters (λ1, . . . , λn) on the magnitude of X λ n:n according to reverse hazard rate and likelihood ratio orderings.

We used National Performance Evaluation Survey data to estimate the prevalence and associated factors of edentulism among noninstitutionalized adults aged 35 years and older in Mexico. Statistically, the variables positively associated with edentulism were older age (odds ratio [OR]=1.08) and female gender (OR=1.79). Nonsmoking status (OR=0.70) and having a higher wealth index score (OR=0.72) w...

In many industrial manufacturing processes, the quality of products can depend on relative amount between two characteristics X and Y. Often, this calls for on-line monitoring ratio Z=X/Y as a characteristic itself by means control chart. A large number charts have been investigated in literature under assumption independent normal observations characteristics. practice, due to high frequency s...