Classification of Triadic Chord Inversions Using Kohonen Self-organizing Maps

In this paper we discuss the application of the Kohonen Selforganizing Maps to the classification of triadic chords in inversions and root positions. Our motivation started in the validation of Schönberg´s hypotheses of the harmonic features of each chord inversion. We employed the Kohonen network, which has been generally known as an optimum pattern classification tool in several areas, including music, to verify that hypothesis. The outcomes of our experiment refuse the Schönberg´s assumption in two aspects: structural and perceptual/functional

Relativistic quantum dynamics of scalar bosons under a full vector Coulomb interaction

The relativistic quantum dynamics of scalar bosons in the background of a full vector coupling (minimal plus nonminimal vector couplings) is explored in the context of the Duffin-Kemmer-Petiau formalism. The Coulomb phase shift is determined for a general mixing of couplings and it is shown that the space component of the nonminimal coupling is a {\it sine qua non} condition for the exact closed-form scattering amplitude. It follows that the Rutherford cross section vanishes in the absence of the time component of the minimal coupling. Bound-state solutions obtained from the poles of the partial scattering amplitude show that the time component of the minimal coupling plays an essential role. The bound-state solutions depend on the nonminimal coupling and the spectrum consists of particles or antiparticles depending on the sign of the time component of the minimal coupling without chance for pair production even in the presence of strong couplings. It is also shown that an accidental degeneracy appears for a particular mixing of couplings.Comment: 8 pages, 1 table. arXiv admin note: text overlap with arXiv:1403.603

Built-in self test of high speed analog-to-digital converters

Signals found in nature need to be converted to the digital domain through analog-to-digital converters (ADCs) to be processed by digital means [1]. For applications in communication and measurement [2], [3], high conversion rates are required. With advances of the complementary metal oxide semiconductor (CMOS) technology, the conversion rates of CMOS ADCs are now well beyond the gigasamples per second (GS/s) range, but only moderate resolutions are required [4]. These ADCs need to be tested after fabrication and, if possible, during field operation. The test costs are a very significant fraction of their production cost [5]. This is mainly due to lengthy use of very expensive automated test equipment (ATE) to apply specific test stimuli to the devices under test (DUT) and to collect and analyze their responses.publishe

Modelos de distribuição de Zygodontomys brevicauda (Allen & Chapman, 1893) (Mammalia: Muridae) nas savanas de Roraima, norte do Brasil

The present study describes the distribution of Zygodontomys brevicauda (Rodentia, Sigmodontinae) relating the presence/absence of the species to a digital database on the vegetation of savannas of the northeastern State of Roraima , Brazil. The study area is situated in the Surumu River region, between 03o58’- 04o27’N and 60o13’-61o16’W, and is composed mainly of savanna formations. In a total effort of 9479 trap days, the trap success for Z. brevicauda was 0.57%. The probability of capture of the species was calculated for each trap station through logistic regression, using structural characteristics of each habitat. The association of capture probabilities with different habitat classes using a LANDSAT-TM satellite image allowed a spatial view of the potential distribution of the species considering the habitat mosaic of the region. The species is at least partially dependent on the savanna-forest boundary. The models show a high frequency of apparently unsuitable areas, especially of open and closed savannas, which might suggest that habitat occupancy is far from saturated. Zygodontomys brevicauda appears to be a colonizing species, and was shown to be associated particularly with the edges of the gallery forests. This habitat type may act as source habitats for open savannas.O presente estudo avalia a distribuição potencial de Zygodontomys brevicauda (Rodentia, Sigmodontinae) relacionando a presença/ausência da espécie através de uma base digital de dados sobre a vegetação das savanas do nordeste do Estado de Roraima, Brasil. A área de estudo situa-se na região do Alto e Médio Rio Surumu (3o58’-4o27’N; 60o13’-61o16’W) e é composta por várias formações, sendo mais extensas as de savana. Foram empregadas 9.479 armadilhas-dia e o sucesso de captura de Z. brevicauda foi de 0.57%. As probabilidades de captura da espécie foram calculadas para cada estação de captura através de regressões logísticas utilizando variáveis estruturais dos hábitats. As associações das probabilidades de captura com as diferentes classes de hábitats, reconhecidas via imagem de satélite LANDSAT-TM, permitiram avaliar a distribuição potencial da espécie no mosaico de hábitats da região. A espécie está parcialmente associada às áreas de contato savana-floresta. O modelo evidenciou alta freqüência de áreas potencialmente vagas, especialmente nas savanas arbóreas abertas e graminosas, sugerindo forte insaturação dos hábitats. Zygodontomys brevicauda é potencialmente uma espécie colonizadora dessas classes de hábitats, com as áreas de borda das matas de galeria atuando como hábitats-fonte para as savanas abertas

Scalar radiation from a radially infalling source into a Schwarzschild black hole in the framework of quantum field theory

We investigate the radiation to infinity of massless scalar field from a source falling radially towards a Schwarzschild black hole using the framework of quantum field theory at tree level. In the case where the source falls from infinity, the monopole radiation is dominant for low initial velocities but higher multipoles become dominant at high initial velocities. It is found that, as in the electromagnetic and gravitational cases, at high initial velocities the energy spectrum for each multipole with $l \geq 1$ is approximately constant up to the fundamental quasinormal frequency and then drops to zero. We also investigate the case where the source falls from rest at a finite distance from the black hole. We find that the monopole and dipole contributions are dominant in this case. We point out that this case needs to be distinguished carefully from the unphysical process where the source abruptly appears at rest and starts falling, which would result in radiation of an infinite amount of energy. We also investigate the radiation of massless scalar field to the horizon of the black hole, finding some features similar to the gravitational case

Using Modified Bessel Functions for Analysis of Nonlinear Effects in a MOS Transistor Operating in Moderate Inversion

This work was supported in part by the NSERC, Canada, in part by the Portuguese Foundation for Science and Technology under Project PESTOEEEI/UI0066/2015 and foRESTER Project PCIF/SSI/0102/2017, and in part by the Academy of Finland.This paper describes analysis of nonlinear effects in a MOS transistor operating in moderate inversion and saturation. The dependence of the drain current on the gate-source and drain-source voltages is described using a modified version of the 'reconciliation' model developed by Y. Tsividis. In the new model, the current components, which correspond to the terms depending exponentially on normalized gate-source or drain-source modulating sinusoidal voltages, are presented using modified Bessel functions. This approach allows one to find the first, second, and third harmonics of the drain current caused by the gate-source or drain-source voltage sinusoidal modulation and find also the intermodulation terms produced by these two modulating voltages. The results are applied to set the requirements to the gate-source and drain-source bias voltages in design of low-distortion and/or low-voltage amplifiers. It is shown that the realization of the stage with the zero value of third-order harmonic requires extremely tight tolerances for the threshold voltage. The suppression of intermodulation terms requires increased drain-source voltage. These recommendations are confirmed by simulations.authorsversionpublishe

Approximate Distributions of the Residual Self-Interference Power in Multi-tap Full-Duplex Systems

In this letter, we investigate closed-form distributions to approximate the power of the residual Self-Interference (SI) due to: 1) uncanceled signals transmitted over multiple delay-taps, and 2) the presence of radio frequency and transceiver impairments, of an In-Band Full-duplex (IBFDX) wireless system. Starting with the distribution of the residual SI power for a single tap, we extend the analysis for multiple taps comparing two different solutions. The first one is based on the Welch-Satterthwaite (W-S) approximation, while the second is a moment-based approximation to an α-μ distribution. When compared to empirical results obtained by simulation, our work shows that the distribution of the residual SI power can be accurately represented by the W-S approximation when the uncertainty level of the fading in the different taps is low. However, for higher levels of uncertainty we show that the α-μ moment-based approximation is more accurate. A comparison between simulated and numerical results show the effectiveness of the proposed model.authorsversionpublishe