The contraction model of Field and Colgate for proto-galaxies, first proposed to describe the observed properties of quasars, is generalized and used to investigate the evolution of galaxies. The LEDA data base for elliptical, spiral, compact and diffuse galaxies is employed and it is shown that the above model is consistent with observational evidences regarding their dynamical evolution, star...

This article aims to review the representations of exceptional mosaic found in vicinity Kornmarkt Trier, which, since its discovery, has been subject different interpretations.Undoubtedly, unique character and inexplicable, at least appearance, conjugation two main scenes, with various inscriptions, large concave octagons that stand out geometric scheme field, is, a scene perhaps sleight hand a...

Software Architecture deals with the description, analysis and reuse of the structure of software systems. Several notations and languages for architectural specification have been recently proposed. However, some important aspects of composition, extension, and reuse deserve further research. These include language aspects, such as refinement of components and architectures, and also validatio...

Over the past decades, two major software libraries that support a wide range of geometric computing have been developed: Leda, the Library of Efficient Data Types and Algorithms, and Cgal, the Computational Geometry Algorithms Library. We start with an introduction of common aspects of both libraries and major differences. We continue with sections that describe each library in detail. Both li...