4,413 research outputs found
On Gauss-Bonnet Curvatures
The -th Gauss-Bonnet curvature is a generalization to higher dimensions
of the -dimensional Gauss-Bonnet integrand, it coincides with the usual
scalar curvature for . The Gauss-Bonnet curvatures are used in theoretical
physics to describe gravity in higher dimensional space times where they are
known as the Lagrangian of Lovelock gravity, Gauss-Bonnet Gravity and Lanczos
gravity. In this paper we present various aspects of these curvature invariants
and review their variational properties. In particular, we discuss natural
generalizations of the Yamabe problem, Einstein metrics and minimal
submanifolds.Comment: This is a contribution to the Proceedings of the 2007 Midwest
Geometry Conference in honor of Thomas P. Branson, published in SIGMA
(Symmetry, Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA
Disease control with quality compost in pot and field trials
Quality compost can have a positive effect on soil fertility and plant growth and health.
This positive effect is not only observable in the laboratory, but also by growers.
Phytopathological problems could be solved with the use of compost.
Durable success can only be obtained if a quality management is resolutely followed.
Further research is needed to optimize the quality management of compost production and
utilization. For example, very little is known about the long-term effect of the different composts on soil fertility and disease receptivity
Further studies on square-root boundaries for Bessel processes
We look at decompositions of perpetuities and apply that to the study of the
distributions of hitting times of Bessel processes of two types of square root
boundaries. These distributions are linked giving a new proof of some Mellin
transforms results obtained by David M. DeLong and M. Yor. Several random
factorizations and characterizations of the studied distributions are
established
An Ontology-Based Method for Semantic Integration of Business Components
Building new business information systems from reusable components is today
an approach widely adopted and used. Using this approach in analysis and design
phases presents a great interest and requires the use of a particular class of
components called Business Components (BC). Business Components are today
developed by several manufacturers and are available in many repositories.
However, reusing and integrating them in a new Information System requires
detection and resolution of semantic conflicts. Moreover, most of integration
and semantic conflict resolution systems rely on ontology alignment methods
based on domain ontology. This work is positioned at the intersection of two
research areas: Integration of reusable Business Components and alignment of
ontologies for semantic conflict resolution. Our contribution concerns both the
proposal of a BC integration solution based on ontologies alignment and a
method for enriching the domain ontology used as a support for alignment.Comment: IEEE New Technologies of Distributed Systems (NOTERE), 2011 11th
Annual International Conference; ISSN: 2162-1896 Print ISBN:
978-1-4577-0729-2 INSPEC Accession Number: 12122775 201
On exponential functionals, harmonic potential measures and undershoots of subordinators
We establish a link between the distribution of an exponential functional I
and the undershoots of a subordinator, which is given in terms of the
associated harmonic potential measure. This allows us to give a necessary and
sufficient condition in terms of the L\'evy measure for the exponential
functional to be multiplicative infinitely divisible. We then provide a formula
for the moment generating function of an exponential functional and the so
called remainder random variable associated to it. We provide a realization
of the remainder random variable as an infinite product involving
independent last position random variables of the subordinator. Some properties
of harmonic measures are obtained and some examples are provided.Comment: 24 page
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