1,111 research outputs found
Seismicity of Algeria from 1365 to 2013: Maximum Observed Intensity Map (MOI2014)
Algeria is one of the most seismically active areas in the Medi- terranean basin. The available catalogs reported numerous de- structive earthquakes striking different regions, such as Algiers (1365, maximum observed intensity Io X; 1716, Io X; Ambraseys and Vogt, 1988), Oran (1790, Io X; Lopez Mari- nas and Salord, 1990), Djidjelli (1856, Io IX; Ambraseys, 1982), Orléansville (1854, Ms 6.7; Rothé, 1950), El Asnam (1980, Ms 7.3; Yielding et al., 1989), Constantine (1985, M s 5.9; Ousadou et al., 2013), Tipasa-Chenoua (1989, M s 6.0; Bounif et al., 2003), Mascara (1994, M s 6.0; Ayadi et al., 2002), and Zemmouri (2003, Mw 6.8; Harbi, Maouche, Ousadou, et al., 2007; Ayadi et al., 2008). This seismicity is related to the collision between the African and Eurasian plates and is lo- cated within the Tell Atlas of Algeria along the plate boundary zone. Two periods that are related to the installation of the Algerian seismic network are identified from the seismic cata- log of Algeria: the pre-1910 and post-1910 periods
Linear semigroups with coarsely dense orbits
Let be a finitely generated abelian semigroup of invertible linear
operators on a finite dimensional real or complex vector space . We show
that every coarsely dense orbit of is actually dense in . More
generally, if the orbit contains a coarsely dense subset of some open cone
in then the closure of the orbit contains the closure of . In the
complex case the orbit is then actually dense in . For the real case we give
precise information about the possible cases for the closure of the orbit.Comment: We added comments and remarks at various places. 14 page
Van der Waals induced polarization of molecules adsorbed on small metallic spheres : anisotropy and nonlocality effects
The calculation of Van der Waals induced polarization of molecules interacting with small metallic spheres is based on the spherical-tensor theory by using the response field susceptibility of the sphere. The first Euler angle appearing in the expression giving this polarization exhibits the anisotropy of the molecule. In order to illustrate the non locality and anisotropy effects as well as the importance of the metallic sphere curvature on the induced polarization magnitudes, we present numerical results for typical systems (HF, HCl) on (Ag, Al and Cu).The calculation of Van der Waals induced polarization of molecules interacting with small metallic spheres is based on the spherical-tensor theory by using the response field susceptibility of the sphere. The first Euler angle appearing in the expression giving this polarization exhibits the anisotropy of the molecule. In order to illustrate the non locality and anisotropy effects as well as the importance of the metallic sphere curvature on the induced polarization magnitudes, we present numerical results for typical systems (HF, HCl) on (Ag, Al and Cu)
Trigonometric Sutherland systems and their Ruijsenaars duals from symplectic reduction
Besides its usual interpretation as a system of indistinguishable
particles moving on the circle, the trigonometric Sutherland system can be
viewed alternatively as a system of distinguishable particles on the circle or
on the line, and these 3 physically distinct systems are in duality with
corresponding variants of the rational Ruijsenaars-Schneider system. We explain
that the 3 duality relations, first obtained by Ruijsenaars in 1995, arise
naturally from the Kazhdan-Kostant-Sternberg symplectic reductions of the
cotangent bundles of the group U(n) and its covering groups
and , respectively. This geometric interpretation
enhances our understanding of the duality relations and simplifies Ruijsenaars'
original direct arguments that led to their discovery.Comment: 34 pages, minor additions and corrections of typos in v
Temporal fluctuations of current surface density in a triangular lattice
In this paper, we examine the effect of the temporal fluctuation current correlation in the surface diffusion process in a triangular lattice, in the framework of the lattice gas model. Our calculations are per found in small circular surfaces equivalent to the probe areas in the scanning microscopy experiments. We have found that the correlation function, in the non- interacting case, follows the law Öp . In the presence of repulsive interactions between mobile particles, it behaves like Öp exp(8γp). We have also calculated the collective diffusion coefficient by the linear response theory and by the characteristic time method, which reflect clearly the order-disorder effect on the diffusion.In this paper, we examine the effect of the temporal fluctuation current correlation in the surface diffusion process in a triangular lattice, in the framework of the lattice gas model. Our calculations are per found in small circular surfaces equivalent to the probe areas in the scanning microscopy experiments. We have found that the correlation function, in the non- interacting case, follows the law Öp . In the presence of repulsive interactions between mobile particles, it behaves like Öp exp(8γp). We have also calculated the collective diffusion coefficient by the linear response theory and by the characteristic time method, which reflect clearly the order-disorder effect on the diffusion
Naturalistic Affective Expression Classification by a Multi-Stage Approach Based on Hidden Markov Models
In naturalistic behaviour, the affective states of a person
change at a rate much slower than the typical rate at which video or
audio is recorded (e.g. 25fps for video). Hence, there is a high probability
that consecutive recorded instants of expressions represent a same
affective content. In this paper, a multi-stage automatic affective expression
recognition system is proposed which uses Hidden Markov Models
(HMMs) to take into account this temporal relationship and finalize the
classification process. The hidden states of the HMMs are associated
with the levels of affective dimensions to convert the classification problem
into a best path finding problem in HMM. The system was tested on
the audio data of the Audio/Visual Emotion Challenge (AVEC) datasets
showing performance significantly above that of a one-stage classification
system that does not take into account the temporal relationship, as well
as above the baseline set provided by this Challenge. Due to the generality
of the approach, this system could be applied to other types of
affective modalities
Study of adatoms diffusion through current density fluctuation functions
In this work, we investigate the diffusion process by using a mean field lattice gas dynamical model. The temporal correlation function of the current density is calculated in a probe area of radius R. The latter is considered to test if the developed formulation can be applied to reproduce STM experiments. The obtained results concerning the effective diffusion coefficient exhibit clearly the order disorder transition effect translated by two minima appearing respectively at p=1/3 and p=2/3. The effect of the ordering phase at p=1/3 requires a threshold size more precisely, the minimum size system where, the ordering phase effect begins, to appear here is R=5.In this work, we investigate the diffusion process by using a mean field lattice gas dynamical model. The temporal correlation function of the current density is calculated in a probe area of radius R. The latter is considered to test if the developed formulation can be applied to reproduce STM experiments. The obtained results concerning the effective diffusion coefficient exhibit clearly the order disorder transition effect translated by two minima appearing respectively at p=1/3 and p=2/3. The effect of the ordering phase at p=1/3 requires a threshold size more precisely, the minimum size system where, the ordering phase effect begins, to appear here is R=5
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