7,299 research outputs found
User requirements for multimedia indexing and retrieval of unedited audio-visual footage - RUSHES
Multimedia analysis and reuse of raw un-edited audio visual content known as rushes is gaining acceptance by a large number of research labs and companies. A set of research projects are considering multimedia indexing, annotation, search and retrieval in the context of European funded research, but only the FP6 project RUSHES is focusing on automatic semantic annotation, indexing and retrieval of raw and un-edited audio-visual content. Even professional content creators and providers as well as home-users are dealing with this type of content and therefore novel technologies for semantic search and retrieval are required. As a first result of this project, the user requirements and possible user-scenarios are presented in this paper. These results lay down the foundation for the research and development of a multimedia search engine particularly dedicated to the specific needs of the users and the content
Management of incidentally detected heart murmurs in dogs and cats
A dog or a cat has an incidentally detected heart murmur if the murmur is an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient
Holonomic quantum computation in the presence of decoherence
We present a scheme to study non-abelian adiabatic holonomies for open
Markovian systems. As an application of our framework, we analyze the
robustness of holonomic quantum computation against decoherence. We pinpoint
the sources of error that must be corrected to achieve a geometric
implementation of quantum computation completely resilient to Markovian
decoherence.Comment: I. F-G. Now publishes under name I. Fuentes-Schuller Published
versio
Consequences of spontaneous reconnection at a two-dimensional non-force-free current layer
Magnetic neutral points, where the magnitude of the magnetic field vanishes
locally, are potential locations for energy conversion in the solar corona. The
fact that the magnetic field is identically zero at these points suggests that
for the study of current sheet formation and of any subsequent resistive
dissipation phase, a finite beta plasma should be considered, rather than
neglecting the plasma pressure as has often been the case in the past. The
rapid dissipation of a finite current layer in non-force-free equilibrium is
investigated numerically, after the sudden onset of an anomalous resistivity.
The aim of this study is to determine how the energy is redistributed during
the initial diffusion phase, and what is the nature of the outward transmission
of information and energy. The resistivity rapidly diffuses the current at the
null point. The presence of a plasma pressure allows the vast majority of the
free energy to be transferred into internal energy. Most of the converted
energy is used in direct heating of the surrounding plasma, and only about 3%
is converted into kinetic energy, causing a perturbation in the magnetic field
and the plasma which propagates away from the null at the local fast
magnetoacoustic speed. The propagating pulses show a complex structure due to
the highly non-uniform initial state. It is shown that this perturbation
carries no net current as it propagates away from the null. The fact that,
under the assumptions taken in this paper, most of the magnetic energy released
in the reconnection converts internal energy of the plasma, may be highly
important for the chromospheric and coronal heating problem
3_D modeling using TLS and GPR techniques to characterize above and below-ground wood distribution in pyroclastic deposits along the Blanco River (Chilean Patagonia)
To date, the study of in-stream wood in rivers has been focused mainly on quantifying wood pieces deposited above
the ground. However, in some particular river systems, the presence of buried dead wood can also represent an
important component of wood recruitment and budgeting dynamics. This is the case of the Blanco River (Southern
Chile) severely affected by the eruption of Chait\ue9n Volcano occurred between 2008 and 2009. The high pyroclastic
sediment deposition and transport affected the channel and the adjacent forest, burying wood logs and standing
trees. The aim of this contribution is to assess the presence and distribution of wood in two study areas (483 m2 and
1989 m2, respectively) located along the lower streambank of the Blanco River, and covered by thick pyroclastic
deposition up to 5 m. The study areas were surveyed using two different devices, a Terrestrial Laser Scanner (TLS)
and a Ground Penetrating Radar (GPR). The first was used to scan the above surface achieving a high point cloud
density ( 48 2000 points m-2) which allowed us to identify and measure the wood volume. The second, was used
to characterize the internal morphology of the volcanic deposits and to detect the presence and spatial distribution
of buried wood up to a depth of 4 m. Preliminary results have demonstrated differences in the numerousness and
volume of above wood between the two study areas. In the first one, there were 43 wood elements, 33 standing
trees and 10 logs, with a total volume of 2.96 m3 (109.47 m3 km-1), whereas the second one was characterized
by the presence of just 7 standing trees and 11 wood pieces, for a total amount of 0.77 m3 (7.73 m3 km-1). The
dimensions of the wood elements vary greatly according to the typology, standing trees show the higher median
values in diameter and length (0.15 m and 2.91 m, respectively), whereas the wood logs were smaller (0.06 m and
1.12 m, respectively). The low dimensions of deposited wood can be probably connected to their origin, suggesting
that these elements were generated by toppling and breaking of surrounding dead trees. Results obtained with the
GPR confirm the ability of this instrument to localize the presence and distribution of buried wood. From the 3-
D analysis it was possible to assess the spatial distribution and to estimate, as first approach, the volume of the
buried wood which represents approximately 0.04% of the entire volcanic deposit. Further analysis will focus on
additional GPR calibration with different wood sizes for a more accurate estimation of the volume. The knowledge
of the overall wood amount stored in a fluvial system that can be remobilized over time, represent an essential
factor to ensure better forest and river management actions
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