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

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

An abstraction and refinement computational approach to safety verification of discrete time nonlinear systems

This paper addresses safety verification of nonlinear systems through invariant set computation. More precisely, our goal is verifying if the state of a given discrete time nonlinear system will keep evolving within a safe region, starting from a given set of initial conditions. To this purpose, we introduce a conformant PieceWise Affine (PWA) abstraction of the nonlinear system, which is instrumental to computing a conservative approximation of its maximal invariant set within the safe region. If the obtained set covers the set of initial conditions, safety is proven. Otherwise, subsequent refinements of the PWA abstraction are performed, either on the whole safe region or on some appropriate subset identified through a guided refinement approach and containing the set of initial conditions. Some numerical examples demonstrate the effectiveness of the approach

Raw and extruded pea (Pisum sativum), faba bean (Vicia faba var. minor) and lupin (Lupinus albus var. multitalia) as alternative protein sources in broiler diets

AbstractResearch on vegetable-based protein sources has grown as a result of the European Union ban on the inclusion of meat and bone meal in diets of agricultural livestock. This together with recent concern over genetically modified soybeans, the protein source of choice for monogastric diets, has sparked research into the identification of some alternative protein sources. The objective of this study was to evaluate the effect of raw or extruded pea (RP and EP), faba beans (RFb and EFb) or lupin (RL and EL) in partial substitution of soybean meal and other starch sources in broiler diets. A total of 462-d-old male Ross chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens/treatment). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The amount of alternative proteins used as fed basis and for 1-10 d-old and 11-42 d-old growing periods were: RP and EP: 350 g/kg for all diets; RFb..

Constraining blazar distances with combined Fermi and TeV data: an empirical approach

We discuss a method to constrain the distance of blazars with unknown redshift using combined observations in the GeV and TeV regimes. We assume that the VHE spectrum corrected for the absorption through the interaction with the Extragalactic Background Light can not be harder than the spectrum in the Fermi/LAT band. Starting from the observed VHE spectral data we derive the EBL-corrected spectra as a function of the redshift z and fit them with power laws to be compared with power law fits to the LAT data. We apply the method to all TeV blazars detected by LAT with known distance and derive an empirical law describing the relation between the upper limits and the true redshifts that can be used to estimate the distance of unknown redshift blazars. Using different EBL models leads to systematic changes in the derived upper limits. Finally, we use this relation to infer the distance of the unknown redshift blazar PKS 1424+240.Comment: 5 pages, 4 figures, accepted for publication in MNRAS, minor revisio