Abstract. Geometric predicates are used in many GIS algorithms, such as the construction of Delaunay Triangulations for Triangulated Irregular Networks (TIN) or geospatial predicates. With floating-point arithmetic, these computations can incur roundoff errors that may lead to incorrect results and inconsistencies, causing fail. This issue has been addressed using a combination exact arithmetic...

Comme le laisse entendre la célèbre formule de Lawrence Lessig selon laquelle « code est loi », informatique qu’exécutent les ordinateurs produit des effets régulation sociale. Or, ce lui-même encadré par tout un ensemble standards techniques qui forment une sorte du dont rédaction porteuse nombreux enjeux techno-politiques débattus dans arènes spécialisées. Cet article propose pistes méthodolo...

For a given linear compressor, the geometric configuration of the PTR (pulse tube refrigerator) affects the dynamic behavior of the linear compressor as well as the cooling performance of the PTR. The geometric configuration of each component precisely determines the flow impedance which contains the flow resistance, the inertance effect, and the compliance effect. In this paper, several simula...

This paper describes a simple pushbroom camera model for Earth observation satellites and proposes a new algorithm to refine the orientation parameters of a camera from a set of ground control points. The relative importance of the various orientation parameters is analyzed. On the last generation of high resolution satellites such as Pléiades and WorldView, the attitude angles are shown to be ...

Delphi is a new geometry-guided predictive compression scheme for squeezing the connectivity of a triangluar mesh. The mesh is traversed using the Edgebreaker state machine. Instead of creating the Edgebreaker clers sequence both compression and decompression perform the same geometric prediction of the location of the unknown vertex of the next triangle during the mesh traversal. Based on this...

Solving a system of polynomial equations is a ubiquitous problem in the applications of mathematics. Until recently, it has been hopeless to find explicit solutions to such systems, and mathematics has instead developed deep and powerful theories about the solutions to polynomial equations. Enumerative Geometry is concerned with counting the number of solutions when the polynomials come from a ...