Background: RNA molecules play many important regulatory, catalytic and structural <span style="font-variant: normal; font-style: norma...

in this paper we study the existence of commuting regular elements, verifying the notion left (right) commuting regular elements and its properties in the groupoid g(n) . also we show that g(n) contains commuting regular subsemigroup and give a necessary and sucient condition for the groupoid g(n) to be commuting regular.

We give lower bounds on the largest singular value of arbitrary matrices, some of which are asymptotically tight for almost all matrices. To study when these bounds are exact, we introduce several combinatorial concepts. In particular, we introduce regular, pseudo-regular, and almost regular matrices. Nonnegative, symmetric, almost regular matrices were studied earlier by Ho¤man, Wolfe, and Ho¤...

using the mixed solvents, (water +ethanol + propanol), the solubility of cdf2 was determined byevaporating method at 25° c. the results showed that the sollbility, s, of cdf2 decreases bydecreasing the dielectric constant of the mixed solvent .once the solubility of cdf2 was determined,the concentration solubility product, ksp(c)=4s3, was calculated .furthermore ,by estimating the meanactivity ...

in this paper we introduce the concept of generalized baer-invariant of a pair of groups with respect to two varieties ? and ? of groups. we give some inequalities for the generalized baer-invariant of a pair of finite groups, when ? is considered to be the schur-baer variety. further, we present a sufficient condition under which the order of the generalized baer-invariant of a pair of finite ...

We present a compressed data structure to store free trajectories of moving objects (ships over the sea, for example) allowing spatio-temporal queries. Our method, GraCT, uses a k-tree to store the absolute positions of all objects at regular time intervals (snapshots), whereas the positions between snapshots are represented as logs of relative movements compressed with Re-Pair. Our experimenta...

Necessary and sufficient conditions for the existence of at least a full-column rank solution to the matrix equation AV 1⁄4 EVJ is obtained when the matrix pair ðA;EÞ is regular. Furthermore, a simple representation of the all full-column rank solutions to the matrix equation is derived if it has such solutions. An example illustrates the proposed approach. 2003 Elsevier Inc. All rights reserved.

Let us introduce n pairs of random variables (Xi, Yi)i=1,...,n that we suppose drawn from the pair (X,Y ), valued in F × IR, where F is a semi-metric space. Let d denotes the semi-metric. Assume that there exists a regular version of the conditional probability of Y given X , which is absolutely continuous with respect to Lebesgue measure on IR and has bounded density. Assume that for a corresp...

Two new fixed polarity linear Kronecker transforms executed over GF(3) are introduced in this article. Both transforms are based on recursive equations using Kronecker products what allows to obtain simple corresponding fast transforms and very regular butterfly diagrams. The computational costs to calculate the new pair of transforms and their experimental comparison with ternary Reed-Muller t...