1,430 research outputs found
Semantic Indexing of Sport Program Sequences by Audio-Visual Analysis
Semantic indexing of sports videos is a subject of great interest to researchers working on multimedia content characterization. Sports programs appeal to large audiences and their efficient distribution over various networks should contribute to widespread usage of
multimedia services. In this paper, we propose a semantic indexing algorithm for soccer programs which uses both audio and visual
information for content characterization. The video signal is processed first by extracting low-level visual descriptors from the MPEG compressed bit-stream. The temporal evolution of these descriptors during a semantic event is supposed to be governed by a controlled Markov chain. This allows to determine a list of those video segments where a semantic event of interest is likely to be found, based on the maximum likelihood criterion. The audio information is then used to refine the results of the video classification procedure by ranking the candidate video segments in the list so that the segments associated to the event of interest appear in the very first positions of the ordered list. The proposed method is applied to goal detection. Experimental results show the effectiveness of the proposed cross-modal approach
A Markov Chain Model for Semantic Indexing of Sport Program Sequences
In this paper, we propose a semantic indexing algorithm based on the controlled Markov chain modeling framework. Controlled Markov chain models are used to describe the temporal evolution of low-level visual descriptors extracted from the MPEG compressed bit-stream. To reduce the number of false detections given by the proposed video-processing algorithm, we have considered also the audio signal. In particular we have evaluated the "loudeness" associated to each video segments identified by the analysis carried out on the video signal. The intensity of the "loudness" has then been used to order the selected video segments. In this way, the segments associated to interesting events appear in the very first positions of the ordered list, and the number of false detections can be greatly reduced. The proposed algorithm has been conceived for soccer game video sequences, and the simulation results have shown the effectiveness of the proposed algorithm
Effects of NSAIDs and paracetamol (acetaminophen) on protein kinase C epsilon translocation and on substance P synthesis and release in cultured sensory neurons.
Celecoxib, diclofenac, ibuprofen, and nimesulide are nonsteroidal anti-inflammatory drugs (NSAIDs) very commonly used for the treatment of moderate to mild pain, together with paracetamol (acetaminophen), a very widely used analgesic with a lesser anti-inflammatory effect. In the study reported here, we tested the efficacy of celecoxib, diclofenac, and ibuprofen on preprotachykinin mRNA synthesis, substance P (SP) release, prostaglandin E(2) (PGE(2)) release, and protein kinase C epsilon (PKC\u25b) translocation in rat cultured sensory neurons from dorsal root ganglia (DRGs). The efficacy of these NSAIDs was compared with the efficacy of paracetamol and nimesulide in in vitro models of hyperalgesia (investigated previously). While nimesulide and paracetamol, as in previous experiments, decreased the percentage of cultured DRG neurons showing translocation of PKC\u25b caused by 100 nM thrombin or 1 \u3bcM bradykinin in a dose-dependent manner, the other NSAIDs tested did not have a significant effect. The amount of SP released by peptidergic neurons and the expression level of preprotachykinin mRNA were assessed in basal conditions and after 70 minutes or 36 hours of stimulation with an inflammatory soup (IS) containing potassium chloride, thrombin, bradykinin, and endothelin-1. The release of SP at 70 minutes was inhibited only by nimesulide, while celecoxib and diclofenac were effective at 36 hours. The mRNA basal level of the SP precursor preprotachykinin expressed in DRG neurons was reduced only by nimesulide, while the increased levels expressed during treatment with the IS were significantly reduced by all drugs tested, with the exception of ibuprofen. All drugs were able to decrease basal and IS-stimulated PGE(2) release. Our study demonstrates novel mechanisms of action of commonly used NSAIDS
Avaliação do crescimento da microalga Chlorella vulgaris no tratamento de dejeto suíno sob diferentes condições de luminosidade.
Discovery of very high energy gamma-rays from the flat spectrum radio quasar 3C 279 with the MAGIC telescope
3C 279 is one of the best studied flat spectrum radio quasars located at a
comparatively large redshift of z = 0.536. Observations in the very high energy
band of such distant sources were impossible until recently due to the expected
steep energy spectrum and the strong gamma-ray attenuation by the extragalactic
background light photon field, which conspire to make the source visible only
with a low energy threshold. Here the detection of a significant gamma-ray
signal from 3C 279 at very high energies (E > 75 GeV) during a flare in early
2006 is reported. Implications of its energy spectrum on the current
understanding of the extragalactic background light and very high energy
gamma-ray emission mechanism models are discussed.Comment: 4 pages, 6 figures, submitted to proceedings of "4th Heidelberg
International Symposium on High Energy Gamma-Ray Astronomy 2008
Using muon rings for the optical throughput calibration of the SST-1M prototype for the Cherenkov Telescope Array
Imaging Atmospheric Cherenkov Telescopes (IACTs) are ground-based instruments
devoted to the study of very high energy gamma-rays coming from space. The
detection technique consists of observing images created by the Cherenkov light
emitted when gamma rays, or more generally cosmic rays, propagate through the
atmosphere. While in the case of protons or gamma-rays the images present a
filled and more or less elongated shape, energetic muons penetrating the
atmosphere are visualised as characteristic circular rings or arcs. A
relatively simple analysis of the ring images allows the reconstruction of all
the relevant parameters of the detected muons, such as the energy, the impact
parameter, and the incoming direction, with the final aim to use them to
calibrate the total optical throughput of the given IACT telescope. We present
the results of preliminary studies on the use of images created by muons as
optical throughput calibrators of the single mirror small size telescope
prototype SST-1M proposed for the Cherenkov Telescope Array.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Software design for the control system for Small-Size Telescopes with single-mirror of the Cherenkov Telescope Array
The Small-Size Telescope with single-mirror (SST-1M) is a 4 m Davies-Cotton
telescope and is among the proposed telescope designs for the Cherenkov
Telescope Array (CTA). It is conceived to provide the high-energy ( few TeV)
coverage. The SST-1M contains proven technology for the telescope structure and
innovative electronics and photosensors for the camera. Its design is meant to
be simple, low-budget and easy-to-build industrially.
Each device subsystem of an SST-1M telescope is made visible to CTA through a
dedicated industrial standard server. The software is being developed in
collaboration with the CTA Medium-Size Telescopes to ensure compatibility and
uniformity of the array control. Early operations of the SST-1M prototype will
be performed with a subset of the CTA central array control system based on the
Alma Common Software (ACS). The triggered event data are time stamped,
formatted and finally transmitted to the CTA data acquisition.
The software system developed to control the devices of an SST-1M telescope
is described, as well as the interface between the telescope abstraction to the
CTA central control and the data acquisition system.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
DigiCam - Fully Digital Compact Read-out and Trigger Electronics for the SST-1M Telescope proposed for the Cherenkov Telescope Array
The SST-1M is one of three prototype small-sized telescope designs proposed
for the Cherenkov Telescope Array, and is built by a consortium of Polish and
Swiss institutions. The SST-1M will operate with DigiCam - an innovative,
compact camera with fully digital read-out and trigger electronics. A high
level of integration will be achieved by massively deploying state-of-the-art
multi-gigabit transmission channels, beginning from the ADC flash converters,
through the internal data and trigger signals transmission over backplanes and
cables, to the camera's server link. Such an approach makes it possible to
design the camera to fit the size and weight requirements of the SST-1M
exactly, and provide low power consumption, high reliability and long lifetime.
The structure of the digital electronics will be presented, along with main
physical building blocks and the internal architecture of FPGA functional
subsystems.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope
We report the detection of a new source of very high energy (VHE, E_gamma >=
100GeV) gamma-ray emission located close to the Galactic Plane, MAGIC
J0616+225, which is spatially coincident with SNR IC443. The observations were
carried out with the MAGIC telescope in the periods December 2005 - January
2006 and December 2006 - January 2007. Here we present results from this
source, leading to a VHE gamma-ray signal with a statistical significance of
5.7 sigma in the 2006/7 data and a measured differential gamma-ray flux
consistent with a power law, described as dN_gamma/(dA dt dE) = (1.0 +/-
0.2)*10^(-11)(E/0.4 TeV)^(-3.1 +/- 0.3) cm^(-2)s^(-1)TeV^(-1). We briefly
discuss the observational technique used and the procedure implemented for the
data analysis. The results are put in the perspective of the multiwavelength
emission and the molecular environment found in the region of IC443.Comment: Accepted by ApJ Letter
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