58 research outputs found
Measuring the dimension of partially embedded networks
Scaling phenomena have been intensively studied during the past decade in the
context of complex networks. As part of these works, recently novel methods
have appeared to measure the dimension of abstract and spatially embedded
networks. In this paper we propose a new dimension measurement method for
networks, which does not require global knowledge on the embedding of the
nodes, instead it exploits link-wise information (link lengths, link delays or
other physical quantities). Our method can be regarded as a generalization of
the spectral dimension, that grasps the network's large-scale structure through
local observations made by a random walker while traversing the links. We apply
the presented method to synthetic and real-world networks, including road maps,
the Internet infrastructure and the Gowalla geosocial network. We analyze the
theoretically and empirically designated case when the length distribution of
the links has the form P(r) ~ 1/r. We show that while previous dimension
concepts are not applicable in this case, the new dimension measure still
exhibits scaling with two distinct scaling regimes. Our observations suggest
that the link length distribution is not sufficient in itself to entirely
control the dimensionality of complex networks, and we show that the proposed
measure provides information that complements other known measures
A Bayesian Approach to Identify Bitcoin Users
Bitcoin is a digital currency and electronic payment system operating over a
peer-to-peer network on the Internet. One of its most important properties is
the high level of anonymity it provides for its users. The users are identified
by their Bitcoin addresses, which are random strings in the public records of
transactions, the blockchain. When a user initiates a Bitcoin-transaction, his
Bitcoin client program relays messages to other clients through the Bitcoin
network. Monitoring the propagation of these messages and analyzing them
carefully reveal hidden relations. In this paper, we develop a mathematical
model using a probabilistic approach to link Bitcoin addresses and transactions
to the originator IP address. To utilize our model, we carried out experiments
by installing more than a hundred modified Bitcoin clients distributed in the
network to observe as many messages as possible. During a two month observation
period we were able to identify several thousand Bitcoin clients and bind their
transactions to geographical locations
On the network geography of the Internet
Abstract—The geographic layout of the physical Internet inherently determines important network properties and traffic characteristics. To give insight into the geography of the Internet, we examine the spatial properties of the topology and routing. To represent the network we conducted a geographically dispersed traceroute campaign, and embedded the extracted topology into the geographic space by applying a novel IP geolocalization service, called Spotter. In this paper we present the frequency analysis of link lengths, quantify path circuitousness and explore the symmetry of end-to-end Internet routes. I
Theory of chemical evolution of molecule compositions in the universe, in the Miller-Urey experiment and the mass distribution of interstellar and intergalactic molecules
A microsatellita-instabilitás kimutatásának jelentősége colorectalis carcinomában : Kezdeti tapasztalataink
Spectral correlations in systems undergoing a transition from periodicity to disorder
We study the spectral statistics for extended yet finite quasi 1-d systems
which undergo a transition from periodicity to disorder. In particular we
compute the spectral two-point form factor, and the resulting expression
depends on the degree of disorder. It interpolates smoothly between the two
extreme limits -- the approach to Poissonian statistics in the (weakly)
disordered case, and the universal expressions derived for the periodic case.
The theoretical results agree very well with the spectral statistics obtained
numerically for chains of chaotic billiards and graphs.Comment: 16 pages, Late
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