In this paper the correspondence between safe Petri nets and event structures, due to Nielsen, Plotkin and Winskel, is extended to arbitrary nets without self-loops, under the collective token interpretation. To this end we propose a more general form of event structure, matching the expressive power of such nets. These new event structures and nets are connected by relating both notions with c...

Index Structures: We continue our discussion of useful geometric data structure for computer games. So far we have discussed data structures for representing meshes (and more generally, cell complexes), geometric graphs (such as the visibility graph, θ-graph), and spatial subdivisions (such as the Delaunay triangulation). Usually, when we think of data structures for 1-dimensional data (such as...

Treebanks are of two types according to their annotation schemata: phrase-structure Treebanks such as the English Penn Treebank [8] and dependency Treebanks such as the Czech dependency Treebank [6]. Long before Treebanks were developed and widely used for natural language processing, there had been much discussion of comparison between dependency grammars and context-free phrasestructure gramm...

DOD SBIR Phase II Company Name Title Quad Chart NTTC Taxonomy TEXAS RESEARCH INSTITUTE AUSTIN, INC. 9063 Bee Caves Road Austin, TX 78733-6201 Advanced Prognostic Health Management Technologies Using Integrated Detection Techniques with Physics of Failure Mode The proportion of fatigue life that is expended during fatigue crack nucleation is significant in the materials and loading typical of ai...

We show that quasi-Poisson structures can be identified with Dirac structures in suitable Courant algebroids. This provides a geometric way to construct Lie algebroids associated with quasi-Poisson spaces.

We define an abelian group, the conformal cobordism group of hyperbolic structures, which classifies the hyperbolic structures according to whether it bounds a (higher dimensional) conformally flat structure in a conformally invariant way. We then construct a homomorphism from this group to the circle group, using the eta invariant. The homomorphism can be highly nontrivial. It remains an inter...

Allochthonous masses are common structures in Zagros fold-thrust belt. They are generally considered as collapse structures formed by the influence of gravity and in rock units with competency contrast. However, large allochthonous masses mapped in Dowgonbadan area in Dezful Embayment near the Mountain Front Fault (MFF) of Zagros show characteristics different from the belt common collapse stru...