179 research outputs found
A software system for pathological voice acoustic analysis
International audienceA software system for pathological voice analysis using only the resources of a personal computer with a sound card is proposed. The system is written on the basis of specific methods and algorithms for pathological voice analysis and allows evaluation of: 1) Pitch period (To); 2) Degree of unvoiceness; 3) Pitch perturbation and amplitude perturbation quotients; 4) Dissimilarity of surfaces of the pitch pulses; 5) Ratio aperiodic/periodic components in cepstra; 6) Ratio {energy in the cepstral pitch pulse}-to-{total cepstral energy}; 7) Harmonics-to-noise ratio; 8) Degree of hoarseness; 9) Ratio low-to-high frequency energies; 10) Glottal Closing Quotient. The voices of 400 persons were analyzed - 100 (50 females/50 males) normal speakers and 300 (100 females/200 males) patients. The statistical analysis shows very significant changes in PPQ, DH, DPP, DUV, APR, HNR and PECM, and significant changes in APQ and CQ
Immersed nano-sized Al dispersoids in an Al matrix; effects on the structural and mechanical properties by Molecular Dynamics simulations
We used molecular dynamics simulations based on a potential model in analogy
to the Tight Binding scheme in the Second Moment Approximation to simulate the
effects of aluminum icosahedral grains (dispersoids) on the structure and the
mechanical properties of an aluminum matrix. First we validated our model by
calculating several thermodynamic properties referring to the bulk Al case and
we found good agreement with available experimental and theoretical data.
Afterwards, we simulated Al systems containing Al clusters of various sizes. We
found that the structure of the Al matrix is affected by the presence of the
dispersoids resulting in well ordered domains of different symmetries that were
identified using suitable Voronoi analysis. In addition, we found that the
increase of the grain size has negative effect on the mechanical properties of
the nanocomposite as manifested by the lowering of the calculated bulk moduli.
The obtained results are in line with available experimental data.Comment: 15 pages, 8 figures. Submitted to J. Phys: Condens. Matte
Photonuclear Reactions of Three-Nucleon Systems
We discuss the available data for the differential and the total cross
section for the photodisintegration of He and H and the corresponding
inverse reactions below MeV by comparing with our calculations
using realistic interactions. The theoretical results agree within the
errorbars with the data for the total cross sections. Excellent agreement is
achieved for the angular distribution in case of He, whereas for H a
discrepancy between theory and experiment is found.Comment: 11 pages (twocolumn), 12 postscript figures included, uses psfig,
RevTe
Non-chiral current algebras for deformed supergroup WZW models
We study deformed WZW models on supergroups with vanishing Killing form. The
deformation is generated by the isotropic current-current perturbation which is
exactly marginal under these assumptions. It breaks half of the global
isometries of the original supergroup. The current corresponding to the
remaining symmetry is conserved but its components are neither holomorphic nor
anti-holomorphic. We obtain the exact two- and three-point functions of this
current and a four-point function in the first two leading orders of a 1/k
expansion but to all orders in the deformation parameter. We further study the
operator product algebra of the currents, the equal time commutators and the
quantum equations of motion. The form of the equations of motion suggests the
existence of non-local charges which generate a Yangian. Possible applications
to string theory on Anti-de Sitter spaces and to condensed matter problems are
briefly discussed.Comment: 43 pages, Latex, one eps figure; v.2: minor corrections, a reference
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LIDAR observation of PSCs in the arctic and antarctic
Polar Stratospheric Clouds and aerosols are here reported which do not clearly corresponding to present interpretations. They were monitored in the Antarctic and in the Arctic from 1989 to 1995 and therefore refer both to the pre-Pinatubo, the Pinatubo and after Pinatubo period. Such cases comprehend non depolarizing PSCs and warm depolarizing aerosols. Non Depolarizing PSCs have been observed over Dumont d'Urville, Antarctica during the POLE experiment (1989-today) and over Sodankyla during SESAME. For the case of Sodankyla particle size evaluation for non depolarizing PSCs were carried out with interesting results. An index of refraction has been used for Mie calculations which may well correspond to the one expected for a diluted ternary solution of H2O/H2SO4/HNO3PublishedFirenze, Italy1.8. Osservazioni di geofisica ambientaleope
Symmetry enhancements via 5d instantons, qW-algebrae and (1, 0) superconformal index
We explore N=(1,0) superconformal six-dimensional theories arising from M5 branes probing a transverse Ak singularity. Upon circle compactification to 5 dimensions, we describe this system with a dual pq-web of five-branes and propose the spectrum of basic five-dimensional instanton operators driving global symmetry enhancement. For a single M5 brane, we find that the exact partition function of the 5d quiver gauge theory matches the 6d (1, 0) index, which we compute by letter counting. We finally show that S-duality of the pq-web implies new relations among vertex correlators of qW-algebrae
Fusion rules and boundary conditions in the c=0 triplet model
The logarithmic triplet model W_2,3 at c=0 is studied. In particular, we
determine the fusion rules of the irreducible representations from first
principles, and show that there exists a finite set of representations,
including all irreducible representations, that closes under fusion. With the
help of these results we then investigate the possible boundary conditions of
the W_2,3 theory. Unlike the familiar Cardy case where there is a consistent
boundary condition for every representation of the chiral algebra, we find that
for W_2,3 only a subset of representations gives rise to consistent boundary
conditions. These then have boundary spectra with non-degenerate two-point
correlators.Comment: 50 pages; v2: changed formulation in section 1.2.1 and corrected
typos, version to appear in J. Phys.
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