25,094 research outputs found
A Fractional Calculus of Variations for Multiple Integrals with Application to Vibrating String
We introduce a fractional theory of the calculus of variations for multiple
integrals. Our approach uses the recent notions of Riemann-Liouville fractional
derivatives and integrals in the sense of Jumarie. Main results provide
fractional versions of the theorems of Green and Gauss, fractional
Euler-Lagrange equations, and fractional natural boundary conditions. As an
application we discuss the fractional equation of motion of a vibrating string.Comment: Accepted for publication in the Journal of Mathematical Physics
(14/January/2010
Anderson localization on the Falicov-Kimball model with Coulomb disorder
The role of Coulomb disorder is analysed in the Anderson-Falicov-Kimball
model. Phase diagrams of correlated and disordered electron systems are
calculated within dynamical mean-field theory applied to the Bethe lattice, in
which metal-insulator transitions led by structural and Coulomb disorders and
correlation can be identified. Metallic, Mott insulator, and Anderson insulator
phases, as well as the crossover between them are studied in this perspective.
We show that Coulomb disorder has a relevant role in the phase-transition
behavior as the system is led towards the insulator regime
Interoperability and Standards: The Way for Innovative Design in Networked Working Environments
Organised by: Cranfield UniversityIn today’s networked economy, strategic business partnerships and outsourcing has become the dominant
paradigm where companies focus on core competencies and skills, as creative design, manufacturing, or
selling. However, achieving seamless interoperability is an ongoing challenge these networks are facing,
due to their distributed and heterogeneous nature. Part of the solution relies on adoption of standards for
design and product data representation, but for sectors predominantly characterized by SMEs, such as the
furniture sector, implementations need to be tailored to reduce costs. This paper recommends a set of best
practices for the fast adoption of the ISO funStep standard modules and presents a framework that enables
the usage of visualization data as a way to reduce costs in manufacturing and electronic catalogue design.Mori Seiki – The Machine Tool Compan
Dependence of Dust Obscuration on Star Formation Rates in Galaxies
Many investigations of star formation rates (SFRs) in galaxies have explored
details of dust obscuration, with a number of recent analyses suggesting that
obscuration appears to increase in systems with high rates of star formation.
To date these analyses have been primarily based on nearby (z < 0.03) or UV
selected samples. Using 1.4 GHz imaging and optical spectroscopic data from the
Phoenix Deep Survey, the SFR-dependent obscuration is explored. The use of a
radio selected sample shows that previous studies exploring SFR-dependent
obscurations have been biased against obscured galaxies. The observed relation
between obscuration and SFR is found to be unsuitable to be used as an
obscuration measure for individual galaxies. Nevertheless, it is shown to be
successful as a first order correction for large samples of galaxies where no
other measure of obscuration is available, out to intermediate redshifts (z ~
0.8).Comment: 9 pages (including 5 encapsulated postscript figures), aastex, uses
emulateapj5.sty. Accepted for publication in Ap
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