72 research outputs found
Memetic Multilevel Hypergraph Partitioning
Hypergraph partitioning has a wide range of important applications such as
VLSI design or scientific computing. With focus on solution quality, we develop
the first multilevel memetic algorithm to tackle the problem. Key components of
our contribution are new effective multilevel recombination and mutation
operations that provide a large amount of diversity. We perform a wide range of
experiments on a benchmark set containing instances from application areas such
VLSI, SAT solving, social networks, and scientific computing. Compared to the
state-of-the-art hypergraph partitioning tools hMetis, PaToH, and KaHyPar, our
new algorithm computes the best result on almost all instances
A one-dimensional Vlasov-Maxwell equilibrium for the force-free Harris sheet
In this paper the first non-linear force-free Vlasov-Maxwell equilibrium is
presented. One component of the equilibrium magnetic field has the same spatial
structure as the Harris sheet, but whereas the Harris sheet is kept in force
balance by pressure gradients, in the force-free solution presented here force
balance is maintained by magnetic shear. Magnetic pressure, plasma pressure and
plasma density are constant. The method used to find the equilibrium is based
on the analogy of the one-dimensional Vlasov-Maxwell equilibrium problem to the
motion of a pseudo-particle in a two-dimensional conservative potential. This
potential is equivalent to one of the diagonal components of the plasma
pressure tensor. After finding the appropriate functional form for this
pressure tensor component, the corresponding distribution functions can be
found using a Fourier transform method. The force-free solution can be
generalized to a complete family of equilibria that describe the transition
between the purely pressure-balanced Harris sheet to the force-free Harris
sheet.Comment: 10 pages, 2 figures, submitted to PRL, revised versio
'I never felt like she was just doing it for the money': Disabled men's intimate (gendered) realities of purchasing sexual pleasure and intimacy
Scholarly enquiry into the interrelationships of disability and commercial sex remains seriously under-represented within disability and sexuality research. This article, however, draws upon the sexual stories of heterosexual disabled men in order to explore their embodied realities of purchasing of sex, pleasure and intimacy from non-disabled female sex workers. A thematic analysis of these sexual stories revealed multiple and complex motivations for, and experiences of, purchasing of sex, pleasure and intimacy; a purchase ultimately shaped by men’s social and political positioning as disabled and, as with the motivations and experiences of heterosexual non-disabled men, by discourses of hegemonic masculinity and heteronormative sexuality. Given the dearth of research in this area, a number of questions are identified which make important contributions to transdisciplinary knowledges of disabled sexualities, commercial sex work and disabled sexual citizenship
Introducing Automated Reasoning in Network Management
This paper proposes the adoption of Artificial Intelligence
techniques in the field of network management and monitoring.
In order to allow automated reasoning on networking
topics, we constructed an accurate ontological model
capable of fitting as more as possible networking concepts.
The thoroughly representation of the domain knowledge is
used by a Logical Reasoner, which is an expert system capable
of performing management tasks typically executed
by human experts. The Logical Reasoner is integrated in
a distributed multi-agent architecture for network management,
which exploits the dynamic reasoning capabilities of
the Situation Calculus formalism to provide a powerful system
capable of performing high-level management tasks in
order to deal with network fault situations. The system exploits
programmable network technology to make possible
the deployment of code which implements teleo-reactive
agents, distributed across the whole network. The information
related to network events, generated by programmable
sensors deployed on the network devices, is collected by
the logical entity where it is merged with general domain
knowledge, with a view to identifying the root causes of
faults, and to decide on reparative actions
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