6,935 research outputs found
Detecting highly overlapping community structure by greedy clique expansion
In complex networks it is common for each node to belong to several
communities, implying a highly overlapping community structure. Recent advances
in benchmarking indicate that existing community assignment algorithms that are
capable of detecting overlapping communities perform well only when the extent
of community overlap is kept to modest levels. To overcome this limitation, we
introduce a new community assignment algorithm called Greedy Clique Expansion
(GCE). The algorithm identifies distinct cliques as seeds and expands these
seeds by greedily optimizing a local fitness function. We perform extensive
benchmarks on synthetic data to demonstrate that GCE's good performance is
robust across diverse graph topologies. Significantly, GCE is the only
algorithm to perform well on these synthetic graphs, in which every node
belongs to multiple communities. Furthermore, when put to the task of
identifying functional modules in protein interaction data, and college dorm
assignments in Facebook friendship data, we find that GCE performs
competitively.Comment: 10 pages, 7 Figures. Implementation source and binaries available at
http://sites.google.com/site/greedycliqueexpansion
Mobilizing modernist magazines : Peter Sloterdijk and the Transatlantic review.
Many early examinations of “little magazines,” or avant-garde modernist publications, tend to focus on the biographical narratives of their editors or center their discussion on early versions of canonical works in order to develop a greater understanding of the body of work itself. Works like Bernard Poli’s Ford Madox Ford and the Transatlantic Review follow this biographical model, and while well researched and informative, Poli\u27s study strictly focuses on the role Ford played in the publication; in doing so, it limits what can be said about the review’s project to the local editorial level. This thesis, by contrast, seeks to extend modernist studies and the examination of modernist magazines into the field of post-human studies. By looking at magazines like the review as tools of bio-power and examining them in relation to massive communicative systems, this thesis develops a foundation to explore this moment of radical technological, informational, and cultural expansion using language developed by New German Media theorists such as Peter Sloterdijk and Vilém Flusser
Tunable Assembly of Gold Nanorods in Polymer Solutions to Generate Controlled Nanostructured Materials
Gold nanorods grafted with short chain polymers are assembled into controlled
open structures using polymer-induced depletion interactions and structurally
characterized using small angle x-ray scattering. When the nanorod diameter is
smaller than the radius of gyration of the depletant polymer, the depletion
interaction depends solely on the correlation length of the polymer solution
and not directly on the polymer molecular weight. As the polymer concentration
increases, the stronger depletion interactions increasingly compress the
grafted chains and push the gold nanorods closer together. By contrast, other
structural characteristics such as the number of nearest neighbors and fractal
dimension exhibit a non-monotonic dependence on polymer concentration. These
parameters are maximal at intermediate concentrations, which are attributed to
a crossover from reaction-limited to diffusion-limited aggregation. The control
over structural properties of anisotropic nanoscale building blocks
demonstrated here will be beneficial to designing and producing materials
\emph{in situ} with specific direction-dependent nanoscale properties and
provides a crucial route for advances in additive manufacturing
Seeding for pervasively overlapping communities
In some social and biological networks, the majority of nodes belong to
multiple communities. It has recently been shown that a number of the
algorithms that are designed to detect overlapping communities do not perform
well in such highly overlapping settings. Here, we consider one class of these
algorithms, those which optimize a local fitness measure, typically by using a
greedy heuristic to expand a seed into a community. We perform synthetic
benchmarks which indicate that an appropriate seeding strategy becomes
increasingly important as the extent of community overlap increases. We find
that distinct cliques provide the best seeds. We find further support for this
seeding strategy with benchmarks on a Facebook network and the yeast
interactome.Comment: 8 Page
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