The restoration techniques are usually oriented toward modeling the type of degradation in order to infer the inverse process for recovering the given image. This approach usually involves the option for a criterion to numerically evaluate the quality of the resulted image and consequently the...

Let[Sigma]be an unknown covariance matrix. Perturbation (in)equalities are derived for various scale-invariant functionals of[Sigma]such as correlations (including partial, multiple and canonical correlations) or angles between eigenspaces. These results show that a particular confidence set...

Children are seldom accounted for in household behavioural models. They are usually assumed to have neither the capacity nor the power to influence the household decision process. The literature on collective models has so far incorporated children through the "caring preferences" of their...

This paper considers tests in an instrumental variables (IVs) regression model with IVs that may be weak. Tests that have near-optimal asymptotic power properties with Gaussian errors for weak and strong IVs have been determined in Andrews, Moreira, and Stock (2006a). In this paper, we seek...

We consider a semiparametric competing risk model given by k independent survival times. The paper offers an asymptotic treatment of tests for the semiparametric null hypothesis of equality of the underlying risks. It turns out that modified rank tests are asymptotically efficient for certain...

Gene expression data from microarray experiments have been studied using several statistical models. Significance Analysis of Microarrays (SAM), for example, has proved to be useful in analyzing microarray data. In the spirit of the SAM procedures, we develop permutation based rank-tests for...