We present some experimental results illustrating the fact that on highly ill–conditioned Hermitian matrices the relative accuracy of computed small eigenvalues by QR eigenreduction may drastically depend on the initial permutation of the rows and columns. Mostly there was an “accurate” permutation, but there does not seem to be an easy method to get at it. For banded matrices, like those from ...

By slightly reframing the concept of covariance adjustment in randomized experiments, a method of exact permutation inference is derived that is entirely free of distributional assumptions and uses the random assignment of treatments as the “reasoned basis for inference.” This method of exact permutation inference may be used with many forms of covariance adjustment, including robust regression...

Permutation decoding is a technique, introduced in [3] by MacWilliams, that strongly depends on the existence of special subsets, called PD-sets, of the permutation automorphism group PAut(C) of a linear code C. In [2], it is shown how to find s-PD-sets of minimum size s + 1 for partial permutation decoding for the binary simplex code Sm of length 2 − 1, for all m ≥ 4 and 1 < s ≤ ⌊ 2−m−1 m ⌋ . ...

The least significant bit (LSB) embedding method is one of the most commonly used techniques; it targets the LSB's of the host image to hide the data. This paper deals with three main steganography challenges (i.e. capacity, imperceptibility, and security). This is achieved by hybrid data hiding scheme incorporates LSB technique with a key-permutation method. The paper also proposes an optimal ...

Contemporary genetic association studies may test hundreds of thousands of genetic variants for association, often with multiple binary and continuous traits or under more than one model of inheritance. Many of these association tests may be correlated with one another because of linkage disequilibrium between nearby markers and correlation between traits and models. Permutation tests and simul...

We present an algorithm for the all pairs shortest distance problem on permutation graphs. Given a permutation model for the graph on n vertices, after O(n) preprocessing the algorithm will deliver answers to distance queries in O(1) time. In the EREW PRAM model, preprocessing can be accomplished in O(log n) time with O(n) work. Where the distance between query vertices is k, a path can be deli...

In a previous work [12], we proposed a method for generating permutations in lexicographic order. In this study, we extend it to generate multiset permutations. A multiset is a collection of items that are not necessarily distinct. The guideline of the extension is to skip, as soon as possible, those partially-formed permutations that are less than or equal to the latest generated eligible perm...

Permutation and multipermutation codes in the Ulam metric have been suggested for use in non-volatile memory storage systems such as flash memory devices. In this paper we introduce a new method to calculate permutation sphere sizes in the Ulam metric using Young Tableaux and prove the non-existence of non-trivial perfect permutation codes in the Ulam metric. We then extend the study to multipe...

the geometric morphometrics method was applied to study the morphological differences in 95 specimens of kura barbel (barbus lacerta, heckel 1834) collected from three riverine ecosystems of the sefidrud basin, viz. taleghan, totkabon and kloraz rivers.  for this purpose, the left sides of the specimens were photographed. then, 14 landmark-points were defined and digitized on 2d pictures using ...

By assigning a permutation polytope to a group we produce new interesting polytopes. For the effective use of this construction method it is desirable to understand which groups are leading to affine equivalent polytopes. Therefore, the notion of effective equivalence has been introduced [BHNP09]. In this note we clarify the notion of effective equivalence and characterize geometrically the eff...