Search results for "edge"

A framework for sign language sentence recognition by common sense context

2007

This correspondence proposes a complete framework for sign language recognition that integrates a commonsense engine in order to deal with sentence recognition. The proposed system is based on a multilevel architecture that allows modeling and managing of the knowledge of the recognition process in a simple and robust way. The final abstraction level of this architecture introduces the semantic context and the analysis of the correctness of a sentence given in a sequence of recognized signs. Experimentations are presented using a set of signs from the Italian sign language (LIS) for domotic applications. The implemented system maintains a high recognition rate when the set of signs grows, c…

Implicit and explicit syntactic knowledge and reading in pre-adolescents

1999

This aim of this paper is to analyse the links between syntactic awareness and reading, in its recoding and comprehension aspects, in pre-adolescent readers. The study, conducted with 83 sixth grade pupils, examined the relation between (1) seven syntactic and morpho-syntactic tasks (repetition, judgment, correction, localization, explanation, replication and identification) and (2) several indicators of recoding and comprehension in reading. Regression analyses revealed differential contributions as a function of syntactic task, type of agrammaticality, and the aspect of reading tested, after we had controlled for the influence of reasoning, memory, and linguistic competences. Contribution…

Growth and Spatial Dependence in Europe

2009

The convergence of European regions has been largely discussed in the empirical literature during the last decade. Two observations are often emphasized. First, the convergence rate among European regions appears to be very slow (Barro and Sala-i-Martins 1991, 1995; Armstrong 1995, Sala-i-Martin 1996a,b). Second, the tools used in the regional science literature show that the geographical distribution of European per capita GDP is highly clustered and characterized by global and local autocorrelation (Armstrong 1995; Ertur et al. 2007; Lopez-Bazo et al. 1999; Le Gallo and Ertur 2003 with a UE15 regional database and Ertur and Koch 2006, with a UE27 enlarged regional database). Many other st…

Non-Markovian dynamics from band edge effects and static disorder

2017

It was recently shown [S. Lorenzo et al., Sci. Rep. 7, 42729 (2017)] that the presence of static disorder in a bosonic bath - whose normal modes thus become all Anderson-localised - leads to non-Markovianity in the emission of an atom weakly coupled to it (a process which in absence of disorder is fully Markovian). Here, we extend the above analysis beyond the weak-coupling regime for a finite-band bath so as to account for band edge effects. We study the interplay of these with static disorder in the emergence of non-Markovian behaviour in terms of a suitable non-Markovianity measure.

Excitonic absorption and Urbach's tail in bismuth sulfide single crystals

1988

The absorption coefficient of bismuth sulfide single crystals has been measured through more than four orders of magnitude and in the range of energies from 1.25 to 1.70 eV. A detailed study as a function of temperature has been carried out from 29 to 300 K. An Urbach tail for low values of absorption has been found. This tail and its temperature evolution fit the expression for ionic materials. An excitonic region appears at low temperature and the shape of the exciton peak is Gaussian, which corresponds to a strong exciton-phonon coupling. The exciton binding energy is estimated (28±3 meV) and then the energy gap at 29 K is obtained (Eg=1.523±0.003 eV). The fundamental electronic transiti…

In-service and pre-service physics teacher education and pedagogical content knowledge construction

2010

Ab-Initio Studies of Electronic and Spectroscopic Properties of MgO, ZnO and CdO

2008

We present ab-initio calculations of excited-state properties within single-particle and two-particle approaches in comparison with corresponding experimental results. For the theoretical treatment of the electronic structure, we compute eigenvalues and eigenfunctions by using a spatially nonlocal exchange-correlation potential. From this starting point, quasiparticle energies within the fully frequency-dependent G(0)W(0) approximation are obtained. By solving the Bethe-Salpeter equation, we evaluate optical properties, including the electron-hole attraction and the local-field effects. The results are compared with experimental spectra from soft X-ray emission, as well as from X-ray photoe…

Disappearance of Hard X-Ray Emission in the Last BeppoSAX Observation of the Z Source GX 349+2

2003

We report on the results from two BeppoSAX observations of the Z source GX 349+2 performed in February 2001 and covering the broad energy range 0.12-200 keV. The light curve obtained from these observations shows a large flaring activity, the count rate varying from ~130 to ~260 counts/s, indicating that the source was in the flaring branch during these observations. The average spectrum is well described by a soft blackbody and a Comptonized component. To well fit the energy spectrum three gaussian lines are needed at 1.2 keV, 2.6 keV, and 6.7 keV with corresponding equivalent widths of 13 eV, 10 eV, and 39 eV, probably associated to L-shell emission of Fe XXIV, Ly-alpha S XVI, and Fe XXV,…

A Hard Tail in the X‐Ray Broadband Spectrum of Circinus X‐1 at the Periastron: A Peculiar Z Source

2001

We report on the spectral analysis of the peculiar source Cir X-1 observed by the BeppoSAX satellite when the X-ray source was near the periastron. A flare lasting ~6 × 103 s is present at the beginning of the observation. The luminosity during the persistent emission is 1 × 1038 ergs s-1, while during the flare it is 2 × 1038 ergs s-1. We produced broadband (0.1-100 keV) energy spectra during the flare and the persistent emission. At low energies the continuum is well fitted by a model consisting of Comptonization of soft photons, with a temperature of ~0.4 keV, by electrons at a temperature of ~1 keV. After the flare, a power-law component with photon index ~3 is dominant at energies high…

Spectral Evolution of Circinus X-1 along Its Orbit

2001

We report on the spectral analysis of Circinus X-1 observed by the ASCA satellite in March 1998 along one orbital period. The luminosity of the source (in the 0.1-100 keV band) ranges from $2.5 \times 10^{38}$ erg s$^{-1}$ at the periastron (orbital phase 0.01) to $1.5 \times 10^{38}$ erg s$^{-1}$ at orbital phase 0.3. From the spectral analysis and the lightcurve we argue that Cir X-1 shows three states along the orbital evolution. The first state is at the orbital phase interval 0.97-0.3: the luminosity becames super-Eddington and a strong flaring activity is present. In this state a shock could form in the inner region of the system due to the super-Eddington accretion rate, producing an…