In [1,2,3], A. C. Baker and J.W. Baker studied the subspace Ma(S) of the convolution measure algebra M, (S) of a locally compact semigroup. H. Dzinotyiweyi in [5,7] considers an analogous measure space on a large class of C-distinguished topological semigroups containing all completely regular topological semigroups. In this paper, we extend the definitions to study the weighted semigroup ...

Expansive laminoplasty for ossification of the posterior longitudinal ligament (OPLL) has had favorable outcomes. Many modifications of expansive laminoplasty have been developed, including expansive laminoplasty with and without spinous process spacers (SPS). The purpose of this study was to determine whether surgical outcomes were similar between expansive laminoplasty surgeries with and with...

Semigroups whose congruences form a chain are often termed ∆-semigroups. The commutative ∆-semigroups were determined by Schein and by Tamura. A natural generalization of commutativity is permutativity: a semigroup is permutative if it satisfies a non-identity permutational identity. We completely determine the permutative ∆-semigroups. It turns out that there are only six noncommutative exampl...

We introduce the property of pre-expansivity for cellular automata (CA): it is the property of being expansive on asymptotic pairs of configurations (i.e. configurations that differ in only finitely many positions). Pre-expansivity therefore lies between expansivity and pre-injectivity, two important notions of CA theory. We show that there exist one-dimensional pre-expansive CAs which are not ...

In this paper theorems are proved which provide for lifting and projecting expansive homeomorphisms through pseudocovering mappings so that the lift or projection is also an expansive homeomorphism. Using these techniques it is shown that the compact orientable surface of genus 2 admits an expansive homeomorphism.

In this paper, we first introduce the new concept of completely semiprime fuzzy ideals of an ordered semigroup S, which is an extension of completely semiprime ideals of ordered semigroup S, and investigate some its related properties. Especially, we characterize an ordered semigroup that is a semilattice of simple ordered semigroups in terms of completely semiprime fuzzy ideals of ordered semi...

Methods Using herbarium records from the Oklahoma Vascular Plants Database from 1903 to 2004, we reconstructed the spatial and temporal collection history of two alien invasive taxa (Lonicera japonica and Tamarix spp.) and three native expansive species (Ambrosia psilostachya, Amphiachyris dracunculoides and Juniperus virginiana). To compare the overall collecting trend, groups of native non-ex...

We introduce the notion of Gröbner S-basis of an ideal of the free associative algebra K〈X〉 over a field K invariant under the action of a semigroup S of endomorphisms of the algebra. We calculate the Gröbner S-bases of the ideal corresponding to the universal enveloping algebra of the free nilpotent of class 2 Lie algebra and of the T-ideal generated by the polynomial identity [x, y, z] = 0, w...

We consider properties of second-order operatorsH = − ∑d i,j=1 ∂i cij ∂j on R with bounded real symmetric measurable coefficients. We assume that C = (cij) ≥ 0 almost everywhere, but allow for the possibility that C is singular. We associate with H a canonical self-adjoint viscosity operator H0 and examine properties of the viscosity semigroup S generated by H0. The semigroup extends to a posit...

Consider a semigroup action on a set. We derive conditions, in terms of the induced action of the semigroup on {0, 1}-valued probability charges, which ensure that all invariant probability charges are strongly continuous.