Multi-Document summarization strictly needs distinguishing the similarity between sentences & paragraphs of texts because repeated sentences shouldn’t exist in final summary so in order to applying this anti-redundancy we need a mechanism that can determining semantic similarities between sentences and expressions and paragraphs and finally between texts. In this paper it’s used a fuzzy approac...

In this paper, we consider the problem of solving systems of fuzzy relation equations in a space with fuzzy preorder. Two types of these systems with different compositions are considered. New solvability criteria are proposed for systems of both types. The new criteria are weaker than all the known ones that are based on the assumption that fuzzy sets on the left-hand side of a system establis...

In this paper we study subsystems, reverse subsystems and double subsystems of a fuzzy transition system. We characterize them in terms of fuzzy relation inequalities and equations, as eigen fuzzy sets of the fuzzy quasi-order Qδ and the fuzzy equivalence Eδ generated by fuzzy transition relations, and as linear combinations of aftersets and foresets of Qδ and equivalence classes of Eδ. We also...

Fuzzy sets theory has several applications in biomedicine. The dissimilarity of fuzzy sets is used for this purpose. In this paper, we present the generalized equation of the dissimilarity of fuzzy sets. This relation is based on the set theoretic point of view. The parameter of this generalized equation and also its relation to a recently introduced metric defined in fuzzy hypercube are discus...

We study graded properties (α–properties) of fuzzy relations, which are parameterized versions of fuzzy relation properties defined by L.A. Zadeh. Namely, we take into account fuzzy relations which are: α–reflexive, α– irreflexive, α–symmetric, α–antisymmetric, α–asymmetric, α–connected, α–transitive, where α ∈ [0, 1]. We also pay our attention to the composed versions of these basic properties...

Multi–granulation is an improvement of the classical rough set theory since it uses a family of binary relations instead of of a single indiscernibility relation for the constructing of approximation. In this paper, the multi–granulation rough set approach is further generalized into fuzzy environment. A family of fuzzy T–similarity relations are used to define the optimistic and pessimistic fu...

We redefine a fuzzy congruence, discuss some properties of the fuzzy congruences, find the fuzzy congruence generated by a fuzzy relation on a semigroup, and give some lattice theoretic properties of the fuzzy congruences on semigroups.

The $L$-fuzzy approximation operator associated with an $L$-fuzzy approximation space $(X,R)$ turns out to be a saturated $L$-fuzzy closure (interior) operator on a set $X$ precisely when the relation $R$ is reflexive and transitive. We investigate the relations between $L$-fuzzy approximation spaces and $L$-(fuzzy) topological spaces.

Using the belongs to relation (∈) and quasi-coincidence with relation (q) between fuzzy points and fuzzy sets, the concept of (α, β)fuzzy subalgebras where α, β are any two of {∈, q, ∈ ∨ q, ∈∧ q} with α 6=∈∧ q was introduced, and related properties were investigated in [3]. As a continuation of the paper [3], in this paper, the notion of a fuzzy subalgebra with thresholds is introduced, and its...