Search results for "SHAPE"
showing 10 items of 585 documents
A Unified Disk Scattering Model and Its Angle-of-Departure and Time-of-Arrival Statistics
2013
This paper proposes a novel probability density function (PDF) for the distribution of local scatterers inside a disk centered on the mobile station (MS). The new scattering model is introduced as the unified disk scattering model (UDSM), as it unifies a variety of typical circularly symmetric scattering models into one simple model. By adjusting a designated shape factor controlling the distribution of the scatterers, both the uniform circular and uniform ring scattering models can be obtained as special cases. Furthermore, the original Gaussian and uniform hollow-disk scattering models can be approximated with a high level of accuracy. In addition to these established scattering models, a…
One-dimensional quantum-spin—phonon solitons
1983
The quantum dynamics of a compressible harmonic chain of $N$ two-level atoms strongly interacting with the phonons of the lattice is investigated. Two types of mixed excitations are discussed which propagate through the lattice exhibiting solitonic properties. The first type of solitonlike excitation describes the motion of the wall separating two magnetoelastic domains. This transports less energy than the second type of solitonlike excitation which describes the motion of a single spin reversal in the chain. An explicit expression is obtained for the speed of these excitations as a function of an appropriate shape parameter $h$. These results are obtained by approximate self-consistent in…
Spectrum-shape method and the next-to-leading-order terms of the β-decay shape factor
2017
Effective values of the axial-vector coupling constant ${g}_{\mathrm{A}}$ have lately attracted much attention due to the prominent role of ${g}_{\mathrm{A}}$ in determining the half-lives of double $\ensuremath{\beta}$ decays, in particular their neutrinoless mode. The half-life method, i.e., comparing the calculated half-lives to the corresponding experimental ones, is the most widely used method to access the effective values of ${g}_{\mathrm{A}}$. The present paper investigates the possibilities offered by a complementary method: the spectrum-shape method (SSM). In the SSM, comparison of the shapes of the calculated and measured $\ensuremath{\beta}$ electron spectra of forbidden nonuniq…
Study of the far wing of the Balmer α line of hydrogen perturbed by collisions with protons
2002
The theory of the Balmer α line of atomic hydrogen perturbed by collisions with protons predicts quasi-molecular satellites in the line wing due to H-H+ collisions. Measurements of the spectrum of a laser-produced plasma confirm the existence of the strongest of these features.
Résolution parallèle appliquée à des grands systèmes linéaires creux pour le calcul de la matrice de souplesse d'une structure mécanique
2005
La resolution de systemes lineaires creux constitue une base essentielle pour le traitement numerique de nombreux problemes de calcul scientifique, notamment les problemes lies aux calculs des structures mecaniques. Ces systemes, qui apparaissent en particulier dans le cadre de la discretisation par elements ou volumes finis, et normalement sont de tres grande taille. Les couts operatoires et en memoire induits sont tels que le parallelisme est alors une technique incontournable pour resoudre ces tres grands systemes (qui peuvent atteindre dans certains cas plusieurs millions d'inconnues).
A complete X-ray spectral coverage of the 2010 May-June outbursts of Circinus X-1
2012
Circinus X-1 is a neutron-star-accreting X-ray binary in a wide (P$_{\rm orb}$ = 16.6 d), eccentric orbit. After two years of relatively low X-ray luminosity, in May 2010 Circinus X-1 went into outburst, reaching 0.4 Crab flux. This outburst lasted for about two orbital cycles and was followed by another shorter and fainter outburst in June. We focus here on the broadband X-ray spectral evolution of the source as it spans about three order of magnitudes in flux. We attempt to relate luminosity, spectral shape, local absorption, and orbital phase. We use multiple Rossi-XTE/PCA (3.0--25 keV) and Swift/XRT (1.0--9.0 keV) observations and a 20 ks long Chandra/HETGS observation (1.0--9.0 keV), t…
Long-range effects on the periodic deformable sine-Gordon chains
1999
The model of long-range interatomic interactions is found to reveal a number of new features, closely connected with the substrate potential shape parameter s. The phase trajectories, as well as an analytical analysis, provide information on a disintegration of solitons upon reaching some critical values of the lattice parameters. An implicit form for two classes of these topological solitons (kink) is calculated exactly.
VLBI Observations of FRI Radio Galaxies
1996
The Fanaroff-Riley type I radio galaxies (Fanaroff & Riley, 1974) presented in this paper belong to the complete sample of low-intermediate luminosity radio galaxies published in Giovannini, Feretti & Comoretto (1990). This sample includes radio galaxies with different morphologies on the arcsecond scale, such as compact sources, core-halos, FRIs and FRIIs.
VLBI Observations of Radio Galaxies
1994
We undertook a project of observation of a complete sample of radio galaxies with the VLBI technique, in order to test: a) current models on jet dynamics and b) the radio source unified schemes. A preliminary analysis based on the data obtained by us for 10 galaxies of our sample indicates that the parsec scale structure in low power radio galaxies (FR-I) and high power radio galaxies (FR-II) is essentially the same.
Lifetime measurements in 166Re : Collective versus magnetic rotation
2016
WOS: 000371740600004