In this paper we analyze some of the main properties of a double base number system, using bases 2 and 3; in particular we emphasize the sparseness of the representation. A simple geometric interpretation allows an efficient implementation of the basic arithmetic operations and we introduce an index calculus for logarithmic-like arithmetic with considerable hardware reductions in look-up table ...

This paper presents 3D-EPUG-OVERLAY, an exact and parallel algorithm for computing the intersection of 3D triangulated meshes, a problem with applications in several fields such as GIS and CAD. 3D-EPUG-OVERLAY presents several innovations: it employs exact arithmetic and, thus, the computations are completely exact, which avoids topological impossibilities that are often created by floating poi...

As we indicated in our paper [9], the standard arithmetic Chow groups introduced by Gillet-Soulé [3] are rather restricted to consider arithmetic analogues of geometric problems. In this note, we would like to propose a suitable extension of the arithmetic Chow group of codimension one, in which the Hodge index theorem still holds as in papers [1], [7] and [14]. Let X → Spec(Z) be a regular ari...

As we indicated in our paper [10], the standard arithmetic Chow groups introduced by Gillet-Soulé [4] are rather restricted to consider arithmetic analogues of geometric problems. In this note, we would like to propose a suitable extension of the arithmetic Chow group of codimension one, in which the Hodge index theorem still holds as in papers [2], [8] and [15]. Let X → Spec(Z) be a regular ar...

particulate matters commonly found dispersed in the atmosphere are composed of a large variety of substances. dustfall is the usual index of particles in the size range greater than 10 m. two semi automated so2 sampling units were installed in tehran university campus (from 21 january 1973 to 22 dec. 1974) and gheitarieh area (from 23 august to 23 oct. 1974) hydrogen peroxide method was used fo...

We construct and describe moduli spaces of Azumaya algebras on a smooth projective surface. These spaces are the algebro-geometric version of the spaces of principal PGL n -bundles and they also have strong connections to arithmetic. A geometric approach to the problem leads one to study moduli spaces of twisted sheaves. We show that these spaces are very similar to the moduli spaces of semi-st...

We show for the rst time how to reduce the cost of performing speciic geometric constructions by using rounded arithmetic instead of exact arithmetic. Exploiting a property of oating point arithmetic called monotonicity, a new technique, double precision geometry, can replace exact arithmetic with rounded arithmetic in any eecient algorithm for computing the set of intersections of a set of lin...

In this paper we analyze some of the main properties of a double base number system, using bases 2 and 3; in particular we emphasize the sparseness of the representation. A simple geometric interpretation allows an efficient implementation of the basic arithmetic operations and we introduce an index calculus for logarithmic-like arithmetic with considerable hardware reductions in look-up table ...