Observations of cosmic rays in the outer heliosphere

Outward propagating cosmic ray modulation features seen in the outer heliosphere include Forbush decreases, the minimum of the 11 year cycle, and intervals of set recovery rate. The best theoretical model may not be the same for all these features. Some modulation features have been modified or have disappeared between Pioneer 11 and Pioneer 10 as if by the action of an interpalnetary low-pass filter. Azimuthal symmetry still applies, and the radial gradient for nucleons is greater than approximately 500 MeV nucleon is approximately 1 percent AU

Synthetic speech detection and audio steganography in VoIP scenarios

The distinction between synthetic and human voice uses the techniques of the current biometric voice recognition systems, which prevent that a person’s voice, no matter if with good or bad intentions, can be confused with someone else’s. Steganography gives the possibility to hide in a file without a particular value (usually audio, video or image files) a hidden message in such a way as to not rise suspicion to any external observer. This article suggests two methods, applicable in a VoIP hypothetical scenario, which allow us to distinguish a synthetic speech from a human voice, and to insert within the Comfort Noise a text message generated in the pauses of a voice conversation. The first method takes up the studies already carried out for the Modulation Features related to the temporal analysis of the speech signals, while the second one proposes a technique that derives from the Direct Sequence Spread Spectrum, which consists in distributing the signal energy to hide on a wider band transmission. Due to space limits, this paper is only an extended abstract. The full version will contain further details on our research

Music genre classification: a multilinear approach

In this paper, music genre classification is addressed in a multilinear perspective. Inspired by a model of auditory cortical processing, multiscale spectro-temporal modulation features are extracted. Such spectro-temporal modulation features have been successfully used in various content- based audio classification tasks recently, but not yet in music genre classification. Each recording is represented by a third-order feature tensor generated by the auditory model. Thus, the ensemble of recordings is represented by a fourth-order data tensor created by stacking the third-order feature tensors associated to the recordings. To handle large data tensors and derive compact feature vectors suitable for classification, three multilinear subspace techniques are examined, namely the Non-Negative Tensor Factorization (NTF), the High-Order Singular Value Decomposition (HOSVD), and the Multilinear Principal Component Analysis (MPCA). Classification is performed by a Support Vector Machine. Stratified cross-validation tests on the GTZAN dataset and the ISMIR 2004 Genre one demonstrate the advantages of NTF and HOSVD versus MPCA. The best accuracies obtained by the proposed multilinear approach is comparable with those achieved by state-of-the-art music genre classification algorithms

The Intensities of Cosmic Ray H and He Nuclei at ~250 MeV/nuc Measured by Voyagers 1 and 2 - Using these Intensities to Determine the Solar Modulation Parameter in the Inner Heliosphere and the Heliosheath Over a 40 Year Time Period

We have determined the solar modulation potential, phi, vs. time that is observed at Voyager 1 and 2 from measurements of the H and He nuclei intensities at a common energy of 250 MeVnuc. The H nuclei have a rigidity 0.7 GV, the He nuclei 1.4 GV. These measurements cover a 40 year time period, which includes almost 4 cycles of solar 11 year sunspot variations, throughout the inner heliosphere out to the HTS at distances of 95 AU and 85 AU, respectively at V1 and V2, and then beyond in the heliosheath. Inside the HTS the modulation potential vs. time curves at V1 and V2 show a very similar temporal structure to those observed at the Earth. During a later period of maximum solar modulation from 2000.0 to 2005.0 when V1 and V2 are in the outer heliosphere between 60-94 AU, the main temporal features of the modulation potential curves at all 3 locations match up with appropriate time delays at V1 and V2 if it is assumed that spatially coherent structures are moving outward past V1 and V2, with outward speeds of up to 700 Kms negative 1. After 2004.0 V1 and V2 are at latitudes of positive 35 and negative 30 respectively, placing lower limits on the latitude extent of these structures. Beyond the HTS in the heliosheath the modulation potential slowly decreases at both spacecraft with only a weak evidence of the unusual modulation minimum observed at the Earth in 2009, for example. A sudden decrease of the modulation potential 50 MV for both H and He nuclei occurs at V1 just before the heliopause crossing at about 122 AU. This decrease has not yet been observed at V2, which is now at 113 AU and still observing a modulation potential 60 MV.Comment: 28 pages, 9 Figure

The modulation features of the long-period cosmic ray variations in connection with the sign change of the general magnetic field of the Sun

On the basis of the model and experimental investigations, the spatial distribution of cosmic ray anisotropy for the different epochs of solar activity is studied. A solution is offered to the anisotropic diffusion equation with regard to the electromagnetic conditions for the periods of minimum and maximum solar activity and cosmic ray particle drift in a regular interplanetary magnetic field. It is shown that the long period changes amplitude and phase of the diurnal variations of cosmic rays is limited not only by convection and diffusion of particles but also by the drift effect before and after the sing change of the general magnetic field of the Sun. The calculated model is compared with the results obtained on the basis of an analysis of the experimental data from the neutron super monitor station, and it is shown that for the periods when the lines of magnetic force of the Sun come from the Northern Hemisphere the phase of the first harmonic diurnal variation is shifted forwards to an earlier time