8,682 research outputs found
Some Issues on Ontology Integration
The word integration has been used with different
meanings in the ontology field. This article
aims at clarifying the meaning of the word âintegrationâ
and presenting some of the relevant work
done in integration. We identify three meanings of
ontology âintegrationâ: when building a new ontology
reusing (by assembling, extending, specializing
or adapting) other ontologies already available;
when building an ontology by merging several
ontologies into a single one that unifies all of
them; when building an application using one or
more ontologies. We discuss the different meanings
of âintegrationâ, identify the main characteristics
of the three different processes and proposethree words to distinguish among those meanings:integration, merge and use
On equivariant mirror symmetry for local P^2
We solve the problem of equivariant mirror symmetry for O(-3)->P^2 for the
(three) cases of one independent equivariant parameter. This gives a
decomposition of mirror symmetry for local P^2 into that of three subspaces,
each of which may be considered independently. Finally, we give a new
interpretation of mirror symmetry for O(k)+O(-2-k)->P^1.Comment: 26 pages, 4 figures. v2: minor correction in section
Scattering theory of discrete (pseudo) Laplacians on a Weyl chamber
To a crystallographic root system we associate a system of multivariate
orthogonal polynomials diagonalizing an integrable system of discrete pseudo
Laplacians on the Weyl chamber. We develop the time-dependent scattering theory
for these discrete pseudo Laplacians and determine the corresponding wave
operators and scattering operators in closed form. As an application, we
describe the scattering behavior of certain hyperbolic Ruijsenaars-Schneider
type lattice Calogero-Moser models associated with the Macdonald polynomials.Comment: 31 pages, LaTe
Multiscale Representations for Manifold-Valued Data
We describe multiscale representations for data observed on equispaced grids and taking values in manifolds such as the sphere , the special orthogonal group , the positive definite matrices , and the Grassmann manifolds . The representations are based on the deployment of Deslauriers--Dubuc and average-interpolating pyramids "in the tangent plane" of such manifolds, using the and maps of those manifolds. The representations provide "wavelet coefficients" which can be thresholded, quantized, and scaled in much the same way as traditional wavelet coefficients. Tasks such as compression, noise removal, contrast enhancement, and stochastic simulation are facilitated by this representation. The approach applies to general manifolds but is particularly suited to the manifolds we consider, i.e., Riemannian symmetric spaces, such as , , , where the and maps are effectively computable. Applications to manifold-valued data sources of a geometric nature (motion, orientation, diffusion) seem particularly immediate. A software toolbox, SymmLab, can reproduce the results discussed in this paper
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