1,160 research outputs found
Spatial networks with wireless applications
Many networks have nodes located in physical space, with links more common
between closely spaced pairs of nodes. For example, the nodes could be wireless
devices and links communication channels in a wireless mesh network. We
describe recent work involving such networks, considering effects due to the
geometry (convex,non-convex, and fractal), node distribution,
distance-dependent link probability, mobility, directivity and interference.Comment: Review article- an amended version with a new title from the origina
Scale invariance in natural and artificial collective systems : a review
Self-organized collective coordinated behaviour is an impressive phenomenon, observed in a variety of natural and artificial systems, in which coherent global structures or dynamics emerge from local interactions between individual parts. If the degree of collective integration of a system does not depend on size, its level of robustness and adaptivity is typically increased and we refer to it as scale-invariant. In this review, we first identify three main types of self-organized scale-invariant systems: scale-invariant spatial structures, scale-invariant topologies and scale-invariant dynamics. We then provide examples of scale invariance from different domains in science, describe their origins and main features and discuss potential challenges and approaches for designing and engineering artificial systems with scale-invariant properties
The spatial structure of networks
We study networks that connect points in geographic space, such as
transportation networks and the Internet. We find that there are strong
signatures in these networks of topography and use patterns, giving the
networks shapes that are quite distinct from one another and from
non-geographic networks. We offer an explanation of these differences in terms
of the costs and benefits of transportation and communication, and give a
simple model based on the Monte Carlo optimization of these costs and benefits
that reproduces well the qualitative features of the networks studied.Comment: 5 pages, 3 figure
Spatially self-organized resilient networks by a distributed cooperative mechanism
The robustness of connectivity and the efficiency of paths are incompatible
in many real networks. We propose a self-organization mechanism for
incrementally generating onion-like networks with positive degree-degree
correlations whose robustness is nearly optimal. As a spatial extension of the
generation model based on cooperative copying and adding shortcut, we show that
the growing networks become more robust and efficient through enhancing the
onion-like topological structure on a space. The reasonable constraint for
locating nodes on the perimeter in typical surface growth as a self-propagation
does not affect these properties of the tolerance and the path length.
Moreover, the robustness can be recovered in the random growth damaged by
insistent sequential attacks even without any remedial measures.Comment: 34 pages, 12 figures, 2 table
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