We propose a simple algorithm for lattice point counting in rational polygons. A rational polygon is one whose vertices have rational coordinates. The algorithm decomposes a given polygon into right trapezoids and counts the number of lattice points in the right trapezoids. Each right trapezoid can be dissected into a rectangle and a right-angled triangle in the obvious way. The number of latti...

We hypothesized that a simulator designed to train surgical novices angled laparoscopic navigation would show an improvement in subjects' performance, a high test re-test reliability and high internal validity as measured by standardized coefficient alpha. It was also predicted that simulator performance would be strongly related to objectively assess perceptual and visuospatial ability. EndoTo...

We prove that every RAAG (Right Angled Artin Group) embeds in the group of Hamiltonian symplectomorphisms of every symplectic manifold.

In this paper, a connection between rewriting systems and embedding of monoids in groups is found. We show that if a group with a positive presentation has a complete rewriting system R that satisfies the condition that each rule in R with positive left-hand side has a positive right-hand side, then the monoid presented by the subset of positive rules from R embeds in the group. As an example, ...

Let Γ be a graph. The (unlabelled) configuration space UCnΓ of n points on Γ is the space of n-element subsets of Γ. The n-strand braid group of Γ, denoted BnΓ, is the fundamental group of UCnΓ. We use the methods and results of [10] to get a partial description of the cohomology rings H∗(BnT ), where T is a tree. Our results are then used to prove that BnT is a right-angled Artin group if and ...

We characterize convex cocompact subgroups of mapping class groups that arise as subgroups of specially embedded right-angled Artin groups. That is, if the right-angled Artin group G < Mod(S) satisfies certain conditions that imply G is quasi-isometrically embedded in Mod(S), then a purely pseudo-Anosov subgroup H < G is convex cocompact in Mod(S) if and only if it is combinatorially quasiconve...

We show that right-angled Coxeter groups are relatively hyperbolic in the sense defined by Farb, relative to a natural collection of rank-2 parabolic subgroups.