In this paper we obtain some bounds for outer connected domination numbers and global outer connected domination numbers of graphs.

In the paper [6], we introduced Gram matrices for the signed partition algebras, the algebra of Z₂-relations and the partition algebras. (s₁, s₂, r₁, r₂, p₁, p₂)-Stirling numbers of the second kind are also introduced and ...

In this paper,we introduce the notion of δ-Hopfian modules. We give some properties of these modules and provide a characterization of semisimple rings in terms of δ-Hopfian modules by proving that a ring R is semisimple ...

We give a lower bound on multiplicative orders of certain elements in defined by Conway towers of finite fields of characteristic 2 and also formulate a condition under that these elements are primitive.

A graph G is called a graphoidal graph if there exists a graph H and a graphoidal cover ψ of H such that G ≅ Ω (H, ψ ). Then the graph G is said to be self-graphoidal if it is isomorphic to one of its graphoidal graphs. ...

Let G be a group, S = {Sᵢ, i ∊ I} a non empty family of (not necessarily distinct) subgroups of infinite index in G and M a Z₂G-module. In [4] the authors defined a homological invariant E*(G, S,M), which is “dual” to the ...

A subgroup H of a finite group G is said to be Hall normally embedded in G if there is a normal subgroup N of G such that H is a Hall subgroup of N. A Schmidt group is a non-nilpotent finite group whose all proper subgroups ...

For any two positive integers m, n, we denote the graph Km,n ⊙ K₁ by G. Ma Ke-Jie proposed a conjecture [9] that pendant edge extension of a complete bipartite graph is a k-graceful graph for k > 2. In this paper we prove ...

Lie algebras are exactly the anticommutative Leibniz algebras. In this article, we conduct a brief analysis of the approach to Leibniz algebras which based on the concept of the anti-center (Lie-center) and antinilpotency ...

Let R ⊆ S be a ring extension, and let A be an R-submodule of S. The saturation of A (in S) by τ is set A[τ] = {x ∈ S : tx ∈ A for some t ∈ τ}, where τ is a multiplicative subset of R. We study properties of saturations ...