47 research outputs found
The typical cell in anisotropic tessellations
The typical cell is a key concept for stochastic-geometry based modeling in
communication networks, as it provides a rigorous framework for describing
properties of a serving zone associated with a component selected at random in
a large network. We consider a setting where network components are located on
a large street network. While earlier investigations were restricted to street
systems without preferred directions, in this paper we derive the distribution
of the typical cell in Manhattan-type systems characterized by a pattern of
horizontal and vertical streets. We explain how the mathematical description
can be turned into a simulation algorithm and provide numerical results
uncovering novel effects when compared to classical isotropic networks.Comment: 7 pages, 7 figure
Limit theorems for functionals on the facets of stationary random tessellations
We observe stationary random tessellations in
through a convex sampling window that expands unboundedly
and we determine the total -volume of those -dimensional manifold
processes which are induced on the -facets of () by their
intersections with the -facets of independent and identically
distributed motion-invariant tessellations generated within each cell
of . The cases of being either a Poisson hyperplane tessellation
or a random tessellation with weak dependences are treated separately. In both
cases, however, we obtain that all of the total volumes measured in are
approximately normally distributed when is sufficiently large. Structural
formulae for mean values and asymptotic variances are derived and explicit
numerical values are given for planar Poisson--Voronoi tessellations (PVTs) and
Poisson line tessellations (PLTs).Comment: Published at http://dx.doi.org/10.3150/07-BEJ6131 in the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm
Typical Geometry, Second-Order Properties and Central Limit Theory for Iteration Stable Tessellations
Since the seminal work of Mecke, Nagel and Weiss, the iteration stable (STIT)
tessellations have attracted considerable interest in stochastic geometry as a
natural and flexible yet analytically tractable model for hierarchical spatial
cell-splitting and crack-formation processes. The purpose of this paper is to
describe large scale asymptotic geometry of STIT tessellations in
and more generally that of non-stationary iteration infinitely
divisible tessellations. We study several aspects of the typical first-order
geometry of such tessellations resorting to martingale techniques as providing
a direct link between the typical characteristics of STIT tessellations and
those of suitable mixtures of Poisson hyperplane tessellations. Further, we
also consider second-order properties of STIT and iteration infinitely
divisible tessellations, such as the variance of the total surface area of cell
boundaries inside a convex observation window. Our techniques, relying on
martingale theory and tools from integral geometry, allow us to give explicit
and asymptotic formulae. Based on these results, we establish a functional
central limit theorem for the length/surface increment processes induced by
STIT tessellations. We conclude a central limit theorem for total edge
length/facet surface, with normal limit distribution in the planar case and
non-normal ones in all higher dimensions.Comment: 51 page
The typical cell in anisotropic tessellations
The typical cell is a key concept for stochastic-geometry based modeling in communication networks, as it provides a rigorous framework for describing properties of a serving zone associated with a component selected at random in a large network. We consider a setting where network components are located on a large street network. While earlier investigations were restricted to street systems without preferred directions, in this paper we derive the distribution of the typical cell in Manhattan-type systems characterized by a pattern of horizontal and vertical streets. We explain how the mathematical description can be turned into a simulation algorithm and provide numerical results uncovering novel effects when compared to classical isotropic networks
Fitting of stochastic telecommunication network models via distance measures and Monte–Carlo tests
LINE SEGMENTS WHICH ARE UNIONS OF TESSELLATION EDGES
Planar tessellation structures occur in material science, geology (in rock formations), physics (of foams, for example), biology (especially in epithelial studies) and in other sciences. Their mathematical and statistical study has many aspects to consider. In this paper, line-segments which are either a tessellation edge or a finite union of edges are studied. Our focus is on a sub-class of such line-segments – those we call M-segments – that are not contained in a longer union of edges. These encompass the so-called I-segments that have arisen in many recent tessellation models. We study the expected numbers of edges and cell-sides contained in these M-segments, and the prevalence of these entities. Many examples and figures, including some based on tessellation nesting and superposition, illustrate the theory. M-segments are much more prevalent when a tessellation is not side-to-side, so our paper has theoretical connections with the recent IAS paper by Cowan and Thäle (2014); that paper characterised non side-to-side tessellations