A pomonoid S is a monoid equipped with a partial order that is compatible with the binary operation. In the same way that M -acts over a monoid M correspond to the representation of M by transformations of sets, S-posets correspond to the representation of a pomonoid S by order preserving transformations of posets. Following standard terminology from the theories of R-modules over a unital ring...

We prove that any cycle Cn, n ≥ 4, with list assignment L, has a k -fold list coloring from the given lists if (i) each list contains at least 2k colors and (ii) Cn and L satisfy Hall’s condition for k -fold list colorings. Further, 2k in (i) cannot be replaced by 2k − 1 if either n is odd, or n is even and n ≥ k + 2. In other words, if n ≥ 4, the k -fold Hall number of a cycle Cn satifies h (C...

We derive the Brown-Henneaux’s commutation relation and central charge in the framework of the path integral. If we use the leading part of the asymptotic symmetry to derive the Ward-Takahashi identity, we can see the central charge arises from the fact that the boundary condition of the path integral is not invariant under the transformation.

Polarity changes in converted-wave images constructed by elastic reverse-time migration causes destructive interference after stacking over the experiments of a seismic survey. We derive a simple imaging condition for converted waves imaging designed to correct the image polarity and reveal the conversion strength from one wave mode to another. Our imaging condition exploits pure Pand S-modes o...

DeTemple, D.W.. M.J. Dineen, J.M. Robertson and K.L. McAvaney, theory of partition graphs, Discrete Mathematics 113 (1993) 255-258. examples in the A partition graph is an intersection graph for a collection of subsets of a universal set S with the property that every maximal independent set of vertices corresponds to a partition of S. Two questions which arose in the study of partition graphs ...

This study aimed to verify the effect of visual afference (eyes open – EO vs. eyes closed – EC) on inphase (IP) and anti-phase (AP) homolateral inter-limb coordination performance in relation to age. Forty individuals (12 youths, age=12±1 years; 16 young adults, age=24±3 years; 12 older adults, age=59±11 years) performed IP and AP synchronized (80, 120, and 180 bpm) hand and foot flexions and e...

The problem of delay-dependent condition for a new class of Takagi-Sugeno (T-S) fuzzy Lurie control systems with time-delay and time-variant uncertainties is investigated in this paper, which is different from existing ones. We use T-S fuzzy models to describe Lurie system in the form of a weighted sum of some simple linear subsystems, and a new delay-dependent absolute stability criterion for ...

Using causal diagrams and an axiomatization of causality, we examined the well-known claim that conditioning on confounders (“adjustment” for confounders) is sufficient to remove confounding bias. We show that this advice is poorly stated and is incomplete. To remove confounding bias, it is necessary to condition on three types of variables, none of which is a confounder. Conditioning on one of...