Coverage is one of the main research interests in wireless sensor networks (WSN), it is used to determine the quality of service (QoS) of the networks. Therefore this paper aims to review the common strategies use in solving coverage problem in WSN. The strategies studied are used during deployment phase where the coverage is calculated based on the placement of the sensors on the region of int...

Mathematical physics problems are often formulated using differential oprators of vector analysis invariant operators of first order, namely, divergence, gradient and rotor operators. In approximate solution of such problems it is natural to employ similar operator formulations for grid problems, too. The VAGO (Vector Analysis Grid Operators) method is based on such a methodology. In this paper...

The linear shallow water equations on the sphere are discretized on a quasi-uniform, geodesic, icosahedral Voronoi-Delaunay grid with a C-grid variable arrangement and semi-implicit time discretization. A finite volume discretization is employed for the continuity equation in conservation law form, using as control volumes either the hexagonal/pentagonal or the dual triangular cells. A geostrop...

An algorithm for the generation of nonuniform, locally-orthogonal staggered unstructured grids on spheroidal geometries is described. This technique is designed to generate high-quality staggered Voronoi/Delaunay dual meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather predication. Using a re...

In this paper we present a new interface for geometry description. This interface is based on four intersection routines. It allows to use geometry description without explicit boundary description, for example using characteristic functions and boolean operations. This seams to be useful especially for time dependent geometries. We show how to create and change this geometry description, and h...

In this paper we apply spatial database and structure to render the paleo-relief of the Borod Basin. The boreholes data are stored in a spatial database. For the effective surface rendering we use local-Shepard interpolation with variable radius, based on a spatial grid and Delaunay triangulation. The generated pictures are more realistic compared to picture generated by mean of other methods. ...

The Self-Organizing Map (SOM) is a vector quantization method which places prototype vectors on a regular low-dimensional grid in an ordered fashion. A new method to obtain piecewise linear models of dynamic processes is presented. The operating regimes of the local linear models are obtained by the Delaunay tessellation of the codebook of the SOM. The proposed technique is demonstrated by mean...

We introduce a novel method for the generation of fully adaptive streak surfaces in time-varying flow fields based on particle advection and adaptive mesh refinement. Moving least squares approximation plays an important role in multiple stages of the proposed algorithm, which adaptively refines the surface based on curvature approximation and circumradius properties of the underlying Delaunay ...

This paper addresses the problem of computing visual hulls from image contours. We propose a new hybrid approach which overcomes the precision-complexity trade-off inherent to voxel based approaches by taking advantage of surface based approaches. To this aim, we introduce a space discretization which does not rely on a regular grid, where most cells are ineffective, but rather on an irregular ...