It has been recently acknowledged [4, 6, 9] that the use of double bases representations of scalars n, that is an expression of the form n = ∑ e,s,t(−1) AB can speed up significantly scalar multiplication on those elliptic curves where multiplication by one base (say B) is fast. This is the case in particular of Koblitz curves and supersingular curves, where scalar multiplication can now be ach...

We present an efficient and robust algorithm for computing continuous visibility for twoor three-dimensional shapes whose boundaries are NURBS curves or surfaces by lifting the problem into a higher dimensional parameter space. This higher dimensional formulation enables solving for the visible regions over all view directions in the domain simultaneously, therefore providing a reliable and fas...

This paper proposes a method to improve the shortest path problem on a NURBS (Non-uniform rational basis spline) surfaces. It comes from an application of the theory in classic differential geometry on surfaces and can improve the distance problem not only on surfaces but in the Euclidean 3-space R . Keywords—shortest paths, geodesic-like method, NURBS surfaces.

We present a novel approach for 3D reconstruction based on a set of images taken from a static scene. Our solution is inspired by the spatiotemporal analysis of video sequences. The method is based on a best fitting scheme for spatiotemporal curves, that allows us to compute 3D world coordinates of points within the scene. As opposed to a large number of current methods, our technique deals wit...

Abstract. In this paper we present a new approach which integrates the T-Surfaces model and isosurface generation methods in a general framework for surface reconstruction in 3D medical images. T-Surfaces is a deformable model based on a triangulation of the image domain, a discrete surface model and an image threshold. Two types of isosurface generation methods are considered: the continuation...

Huff curves are well known for efficient arithmetics to their group law. In this paper, we propose two deterministic encodings from Fq to generalized Huff curves. When q ≡ 3 (mod 4), the first deterministic encoding based on Skalpa’s equality saves three field squarings and five multiplications compared with birational equivalence composed with Ulas’ encoding. It costs three multiplications les...

Travelling wave solutions to the vortex lament ow generated by elastica produce surfaces in R 3 that carry mutually orthogonal foliations by geodesics and by helices. These surfaces are classiied in the special cases where the helices are all congruent or are all generated by a single screw motion. The rst case yields a new characterization for the BB acklund transformation for constant torsion...

We show that every irreducible, simply connected curve on a toric affine surface X over C is an orbit closure of a Gm-action on X . It follows that up to the action of the automorphism group Aut(X) there are only finitely many non-equivalent embeddings of the affine line A in X . A similar description is given for simply connected curves in the quotients of the affine plane by small finite line...

Digitalization of agriculture bring controllable industrial production and computer-aided design ideas into agriculture, NURBS curves and surfaces is described freedom of widely popular technology, CAD systems are widely used. Method can be easily applied to generate curves, surfaces with NURBS. In this paper, we have developed model of cotton organs using NURBS surface, present a introduction ...

In this work, a new discretization scheme of the gyrokinetic quasi-neutrality equation is proposed. It is based on Isogeometric Analysis; the IGA which relies on NURBS functions, seems to accommodate arbitrary coordinates and the use of complicated computation domains. Moreover, arbitrary high order degree of basis functions can be used. Here, this approach is successfully tested on elliptic pr...