We use nonstandard topology and the g-topology to characterize normal, almost-normal, regular, almost-regular, semiregular spaces. The cluster [resp. 0-cluster] set relation is used to characterize regular, almostregular [resp. strongly-regular] spaces. The Whyburn [resp. Dickman] filter bases are characterized and it is shown that the cluster [resp. f-cluster] set relation restricted to the do...

By identifying functions whose difference has zero norm, he proved that {^£{R), || ||) is actually a Banach space. The space had been studied by many authors in the theory of almost periodic functions and generalized harmonic analysis (e.g., Besicovitch [4], Bohr and Folner [6], Bertrandias [3] and Lau and Lee [10]). In [10], it was shown that the transformation defined in (1.1) can be extended...

R. Devi, A. Selvakumar and M. Parimala, αψ-closed sets in Topological spaces (Submitted). Y. Kucuk, On some characterizations of δ-continuous multifunctions, Demonstratio Math., Vol 28(3)(1995), 587-595. P. E. Long and L. L. Herrington, The τθ topology and faintly continuous functions, Kyungpook Math. J., 22(1982), 7-14. T. Noiri and V. Popa, Almost weakly continuous multifunctions, Demon-strat...

the main purpose of this paper is to define a new regular matrix by using fibonacci numbers and to investigate its matrix domain in the classical sequence spaces $ell _{p},ell _{infty },c$ and $c_{0}$, where $1leq p

A nongraphic matroid M is said to be almost-graphic if, for all elements e, either M\e or M/e is graphic. We determine completely the class of almost-graphic matroids, thereby answering a question posed by Oxley in his book “Matroid Theory.” A nonregular matroid is said to be almost-regular if, for all elements e, either M\e or M/e is regular. An element e for which both M\e and M/e are regular...

We investigate the relations of almost isometric embedding and of almost isometry between metric spaces. These relations have several appealing features. For example, all isomorphism types of countable dense subsets of R form exactly one almost-isometry class, and similarly with countable dense subsets of Uryson’s universal separable metric space U. We investigate geometric, set-theoretic and m...

In this paper, a new kind of sets called regular μ-generalized closed (briefly rμg-closed) sets are introduced and studied in a topological space. Some of their properties are investigated. Finally, some characterizations of almost μ-regular, almost μ-normal and mildly μ-normal spaces have been given.

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¤...