895 research outputs found
Moduli of simple holomorphic pairs and effective divisors
In this note we identify two complex structures (one is given by algebraic
geometry, the other by gauge theory) on the set of isomorphism classes of
holomorphic bundles with section on a given compact complex manifold. In the
case of line bundles, these complex spaces are shown to be isomorphic to a
space of effective divisors on the manifold.Comment: 10 page
Stochastic equation of fragmentation and branching processes related to avalanches
We give a stochastic model for the fragmentation phase of a snow avalanche.
We construct a fragmentation-branching process related to the avalanches, on
the set of all fragmentation sizes introduced by J. Bertoin. A fractal property
of this process is emphasized. We also establish a specific stochastic equation
of fragmentation. It turns out that specific branching Markov processes on
finite configurations of particles with sizes bigger than a strictly positive
threshold are convenient for describing the continuous time evolution of the
number of the resulting fragments. The results are obtained by combining
analytic and probabilistic potential theoretical tools.Comment: 17 page
Flux Qubit Readout in the Persistent Current Basis at arbitrary Bias Points
Common flux qubit readout schemes are qubit dominated, meaning they measure
in the energy eigenbasis of the qubit. For various applications meausrements in
a basis different from the energy eigenbasis are required. Here we present an
indirect measurement protocol, which is detector dominated instead of qubit
dominated, yielding a projective measurements in the persistent current basis
for arbitrary bias points. We show that with our setup it is possible to
perform a quantum nondemolition measurement (QND) in the persistent current
basis at all flux bias points with fidelities reaching almost 100%.Comment: 5 pages, 3 figures + 5 pages Supplementa
Human Visual Perception and Retinal Diseases
Retinal diseases are causing alterations of
the visual perception leading sometimes to blindness. For this reason, early detection and diagnosis of retinal pathologies is very important. Using digital image processing
techniques, retinal images may be analyzed quickly and computer-assisted diagnosis systems may be developed in order to help the ophthalmologists to make a diagnosis.
In this paper we described shortly two computer-assisted systems for the detection of retinal landmarks (optic disc and vasculature) together with a brief introduction to the human visual system and to some alterations of the visual perception caused by retinal diseases
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