R is called commuting regular ring (resp. semigroup) if for each x,y $in$ R there exists a $in$ R such that xy = yxayx. In this paper, we introduce the concept of commuting $pi$-regular rings (resp. semigroups) and study various properties of them.

introduction commuting between urban centers and rural areas is a phenomenon that observed in all countries with different social and economic structure. commuting is a new phenomenon in move of population that emerged with metropolis development. this phenomenon is different with other population movement. because this move does not change in residential place, population work in other place. ...

the non commuting graph of a non-abelian finite group $g$ is defined as follows: its vertex set is $g-z(g)$ and two distinct vertices $x$ and $y$ are joined by an edge if and only if the commutator of $x$ and $y$ is not the identity. in this paper we prove some new results about this graph. in particular we will give a new proof of theorem 3.24 of [2]. we also prove that if $g_1$, $g_2$, ..., $...

In this paper we study various simplicial complexes associated to the commutative structure of a finite group G. We define NC(G) (resp. C(G)) as the complex associated to the poset of pairwise non-commuting (resp. commuting) sets of nontrivial elements in G. We observe that NC(G) has only one positive dimensional connected component, which we call BNC(G), and we prove that BNC(G) is simply conn...

We extend upper bounds on the quantum independence number and Shannon capacity of graphs to their counterparts in commuting operator model. introduce a von Neumann algebraic generalization fractional Haemers bound (over $\mathbb {C}$ ...

Let A be an algebra over a field K of characteristic zero, let δ1, . . . , δs ∈ DerK(A) be commuting locally nilpotent K-derivations such that δi(xj) = δij , the Kronecker delta, for some elements x1, . . . , xs ∈ A. A set of algebra generators for the algebra A := ∩i=1ker(δi) is found explicitly and a set of defining relations for the algebra A is described. Similarly, given a set σ1, . . . , ...

We introduce the notion of commuting regular Γsemiring and discuss some properties of commuting regular Γsemiring. We also obtain a necessary and sufficient condition for Γ-semiring to possess commuting regularity. Keywords—Commutative Γ-semiring, Idempotent Γ-semiring, Rectangular Γ-band, Commuting regular Γ-semiring, Clifford Γsemiring.

This paper focuses on regional variations in commuting trip lengths by calculating minimum (required) commuting distances, along with excess commuting rates. The study contributes to the excess commuting research framework from a regional perspective, both by stressing the specific characteristics of urban networks with overlapping commute areas, and by putting forward an alternative method for...

Let G be a finite non-abelian group and denote by Z(G) its center. The non-commuting graph of on transversal the center is whose vertices are non-central elements in two x y adjacent whenever xy=yx. In this work, we classify groups centeris double-toroidal or 1-planar.

OBJECTIVE Our aim was to review the effectiveness of physical activity promotion interventions in the worksite setting in Europe in order to identify those studies that had measured obesity-related outcomes and to evaluate how external validity of the findings had been assessed. METHODS We conducted a review of studies conducted in Europe, published up to December 2009. We assessed levels of ...