Using fuzzy filters in the sense of P. Eklund and W. Gähler [2], it turns out that fuzzy preuniform convergence spaces introduced in [11] form a strong topological universe in which fuzzy topological spaces as well as fuzzy (quasi) uniform spaces can be studied. Thus, better tools such as the existence of natural function spaces, the existence of one-point extensions (and consequently, the here...

Ever since the first hybrid fuzzy rough set model was proposed in the early 1990’s, many researchers have focused on the definition of the lower and upper approximation of a fuzzy set by means of a fuzzy relation. In this paper, we review those proposals which generalize the logical connectives and quantifiers present in the rough set approximations by means of corresponding fuzzy logic operati...

binayak et al in [1] proved a fixed point of generalized kannan type-mappings in generalized menger spaces. in this paper we extend gen- eralized kannan-type mappings in generalized fuzzy metric spaces. then we prove a fixed point theorem of this kind of mapping in generalized fuzzy metric spaces. finally we present an example of our main result.

in this paper, we give some new definitions of m-fuzzy metric spaces and we prove a common fixed point theorem for six mappings under the condition of weakly compatible mappings in complete m-fuzzy metric spaces.

in 1997, fang proposed the concept of boundedness of $l$-fuzzy setsin $l$-topological vector spaces. since then, this concept has beenwidely accepted and adopted in the literature. in this paper,several characterizations of bounded $l$-fuzzy sets in$l$-topological vector spaces are obtained and some properties ofbounded $l$-fuzzy sets are investigated.

In this paper, we define the concept of almost generalized (S, T )− contractive condition, and prove some common fixed point results for four mappings satisfying almost generalized (S, T )− contractive condition in partially ordered fuzzy metric spaces.

We study the approximation properties of a harmonic function u ∈ H1−k(Ω), k > 0, on a relatively compact subset A of Ω, using the Generalized Finite Element Method (GFEM). If Ω = O, for a smooth, bounded domain O, we obtain that the GFEM–approximation uS ∈ S of u satisfies ‖u−uS‖H1(A) ≤ Ch‖u‖H1−k(O), where h is the typical size of the “elements” defining the GFEM–space S and γ ≥ 0 is such that ...

In this work we prove optimal W s,p-approximation estimates (with p P r1,`8s) for elliptic projectors on local polynomial spaces. The proof hinges on the classical Dupont– Scott approximation theory together with two novel abstract lemmas: An approximation result for bounded projectors, and an Lp-boundedness result for L2-orthogonal projectors on polynomial subspaces. The W s,p-approximation re...

Constructive proofs and several generalizations of approximation results of J. H. Bramble and S. R. Hubert are presented. Using an averaged Taylor series, we represent a function as a polynomial plus a remainder. The remainder can be manipulated in many ways to give different types of bounds. Approximation of functions in fractional order Sobolev spaces is treated as well as the usual integer o...