Regular map is an algebraic concept to describe most symmetric tilings of closed surfaces of arbitrary genus. All regular maps resp. symmetric tilings of surfaces up to genus 302 are algebraically known in the form of symmetry groups acting on their universal covering spaces. But still little is known about geometric realizations, i.e. finding most symmetric embeddings of closed surfaces and a ...

In this paper, we introduce the formalism of duration-constrained regular expressions to model real-time and hybrid systems, which is an extension of regular expressions with duration constraints. It is equivalent in expressive power to a class of linear hybrid automata called loop-closed automata in which any variable tested in a loop is reset or tested to exact values in the same loop. Based ...

This paper presents SUCRE, a new software tool for coreference resolution and its feature engineering. It is able to separately do noun, pronoun and full coreference resolution. SUCRE introduces a new approach to the feature engineering of coreference resolution based on a relational database model and a regular feature definition language. SUCRE successfully participated in SemEval-2010 Task 1...

We consider some questions about formal languages that arise when inverses of letters, words and languages are defined. The reduced representation of a language over the free monoid is its unique equivalent representation in the free group. We show that the class of regular languages is closed under taking the reduced representation, while the class of context-free languages is not. We also giv...

We consider C Hamiltonian functions on compact 4-dimensional symplectic manifolds to study elliptic dynamics of the Hamiltonian flow, namely the so-called Newhouse dichotomy. We show that for any open set U intersecting a far from Anosov regular energy surface, there is a nearby Hamiltonian having an elliptic closed orbit through U . Moreover, this implies that for far from Anosov regular energ...

A language L is closed if L = L. We consider an operation on closed languages, L , that is an inverse to Kleene closure. It is known that if L is closed and regular, then L −∗ is also regular. We show that the analogous result fails to hold for the contextfree languages. Along the way we find a new relationship between the unbordered words and the prime palstars of Knuth, Morris, and Pratt. We ...

r is called commuting regular ring (resp. semigroup) if for each x,y $in$ r thereexists 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.

A regular operator T on a Hilbert C *-module is defined just like a closed operator on a Hilbert space, with the extra condition that the range of (I + T * T) is dense. Semiregular operators are a slightly larger class of operators that may not have this property. It is shown that, like in the case of regular operators, one can, without any loss in generality, restrict oneself to semiregular op...

In this paper, the concepts of LωH-sets and LωH-closed spaces are proposed in Lω-spaces by means of (αω)−-remote neighborhood family. The characterizations of LωH-sets and LωH-closed spaces are systematically discussed. Some important properties of LωH-closed spaces, such as the LωH-closed spaces is ω-regular closed hereditary, arbitrarily multiplicative and preserving invariance under almost (...

The concept of γ-semi-regular-open sets and γ-sclosed spaces have been introduced and explored in [6]. In this paper, we continue studying the properties and characterizations of γ-semi-regular open sets and γ-s-closed spaces.