From heuristics-based to data-driven audio melody extraction

The identification of the melody from a music recording is a relatively easy task for humans, but very challenging for computational systems. This task is known as "audio melody extraction", more formally defined as the automatic estimation of the pitch sequence of the melody directly from the audio signal of a polyphonic music recording. This thesis investigates the benefits of exploiting knowledge automatically derived from data for audio melody extraction, by combining digital signal processing and machine learning methods. We extend the scope of melody extraction research by working with a varied dataset and multiple definitions of melody. We first present an overview of the state of the art, and perform an evaluation focused on a novel symphonic music dataset. We then propose melody extraction methods based on a source-filter model and pitch contour characterisation and evaluate them on a wide range of music genres. Finally, we explore novel timbre, tonal and spatial features for contour characterisation, and propose a method for estimating multiple melodic lines. The combination of supervised and unsupervised approaches leads to advancements on melody extraction and shows a promising path for future research and applications

Evidence for a 3 x 10^8 solar mass black hole in NGC 7052 from HST observations of the nuclear gas disk

We present an HST study of the nuclear region of the E4 radio galaxy NGC 7052, which has a nuclear disk of dust and gas. The WFPC2 was used to obtain B, V and I broad-band images and an H_alpha+[NII] narrow-band image. The FOS was used to obtain H_alpha+[NII] spectra along the major axis, using a 0.26 arcsec diameter circular aperture. The observed rotation velocity of the ionized gas is V = 155 +/- 17 km/s at r = 0.2 arcsec from the nucleus. The Gaussian dispersion of the emission lines increases from sigma = 70 km/s at r=1 arcsec, to sigma = 400 km/s on the nucleus. To interpret the gas kinematics we construct axisymmetric models in which the gas and dust reside in a disk in the equatorial plane of the stellar body. It is assumed that the gas moves on circular orbits, with an intrinsic velocity dispersion due to turbulence. The circular velocity is calculated from the combined gravitational potential of the stars and a possible nuclear black hole (BH). Models without a BH predict a rotation curve that is shallower than observed (V_pred = 92 km/s at r = 0.2 arcsec), and are ruled out at > 99% confidence. Models with a BH of 3.3^{+2.3}_{-1.3} x 10^8 solar masses provide an acceptable fit. NGC 7052 can be added to the list of active galaxies for which HST spectra of a nuclear gas disk provide evidence for the presence of a central BH. The BH masses inferred for M87, M84, NGC 6251, NGC 4261 and NGC 7052 span a range of a factor 10, with NGC 7052 falling on the low end. By contrast, the luminosities of these galaxies are identical to within 25%. Any relation between BH mass and luminosity, as suggested by independent arguments, must therefore have a scatter of at least a factor 10.Comment: 39 pages, LaTeX, with 16 PostScript figures. Submitted to the Astronomical Journal. Postscript version with higher resolution figures available from http://sol.stsci.edu/~marel/abstracts/abs_R22.htm

Incorporación de elementos traza en conchas de melanopsis durante el crecimiento : posibilidades de aplicación en paleoecología

El objetivo del presente trabajo está encaminado al estudio de las variaciones de oligoelementos en la concha de un gasterópodo de agua dulce del género Melanopsis (U dufouri (FERUSSAC), con dos morfotipos) y si éstas tienen que ver, o no, con la fluctuación de una serie de parámetros ambientales. La importancia del trabajo radica en la posibilidad de la aplicación paleoecológica de sus resultados, ya que el género MelanopsÍs tiene un abundante registro fósil durante todo el Cenozoico. La incorporación de oligoelementos se efectúa a medida que la concha va creciendo por acreción; lo ideal sería que tal crecimiento fuera circadiano, ya que se podría seguir día a día, sobre la concha, la fluctuación de sus componentes químicos. Sin embargo, nuestro trabajo muestra que, para esta especie, ello no es así. La tasa de acreción, tanto si se mide en función de los incrementos segregados por unidad de tiempo como del espesor segregado durante un período fijo, es función del tamaño de la concha para la misma población. Una primera campaña, de un mes de duración, ha revelado que en aquellas conchas, cuya tasa de acreción coincide con el número de días, las composiciones químicas de cada línea de crecimiento no parecen tener una relación de carácter fijo con las variaciones diarias de los parámetros del medio. Parece haber unos organismos más sensibles que otros a tal variación. Ello, pues, probablemente sea atribuible a variabilidad genética en cuanto a la capacidad de filtrado de los distintos iones. Durante un período de siete meses, en que la variación más significativa corresponde a la temperatura, uno de los morfotipos presenta variaciones de composición química correlacionadas con las variaciones de los parámetros del medio, mientras que el otro no muestra tendencias claras al respecto. La posibilidad de ritmos circadianos de acreción en caparazones de invertebrados está en contradicción con los resultados obtenidos en este estudio. Sería interesante analizar casos dados como válidos desde las perspectivas que aquí se abren. Las posibilidades de aplicación paleoecológica son también bajas, al menos para el género aquí estudiado.The living freshwater gastropod Melanopsis dufouri (FERUSSAC) has two morphotypes. The study of chemical variation of trace-elements in this gastropod and its correlation with the environmental fluctuation are the aim of this paper. Due to the genus MelanopsÍs has an abundant fossil record during the Cenozoic, the results of the present work could be of paleoecological interest. Trace-elements are embodied in the shell during growth. The shell of U dufouri has accretionary growth. There are several examples cited on circadian accretionary growth in invertebrate shells. However, in the present case and as a first coclusion, the accretion rate depends on the size of the shell. In a short-time field study (l month) that has been carried out we are found sorne shells with circadian accretion. Chemical compositions of growth lines are generelly not related to dialy fluctuations of environmental parameters. There are gastropods of this species more sensitive to these parameter:> than others. This fact could be due to genetic variability. .In. a long-time field study (7 montbs) also carried out, the most significant environmental vanation observed concerns to temperature in this periodo The chemical composition of one of the two morphotypes is very sensitive to variations of environmental parameters. The other morphotype does not seem to be enough sensitive to environmental variation. The poss!ble circadian accr~tion rates in M dufoun' does not agree with many general results about acc!etio~ary gro~ of mvertebrate sheUs. It should be interesting analizing the reported cases oC Clrcadlan rates m sheUs under the assumptions oC too paper. Paleoecological applications of ow results are very difficult Cor Cossil species oC [email protected] [email protected]

Low-frequency radio observations of the MGRO J2019+37 Complex

We present here a preliminary account of the results of a wide-field mosaic obtained at 610 MHz (49 cm) with the Giant Metre-wave Radio Telescope (GMRT) in India covering the field of the unidentified TeV source MGRO J2019+37. A catalogue of all radio sources detected has been created including both compact and extended objects. Their observational properties are described and presented. We draw the attention to some peculiar objects inside the ˜1° uncertainty region of the TeV emission. The possible connection of these sources with the MILAGRO γ-ray emission will be assessed in future work.Fil: Sánchez Sutil, Juan R. . Universidad de Jaén; EspañaFil: Paredes, Josep M.. Universitat de Barcelona. Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos; EspañaFil: Moldón, J.. Universitat de Barcelona. Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos; EspañaFil: Zabalza, V.. Universitat de Barcelona. Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos; EspañaFil: Bordas, P.. Universitat de Barcelona. Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos; EspañaFil: Ribó, M.. Universitat de Barcelona. Departament d’Astronomia i Meteorologia and Institut de Ciències del Cosmos; EspañaFil: Martí, Josep. Universidad de Jaén; EspañaFil: Muñoz Arjonilla, Alvaro J.. Universidad de Jaén; EspañaFil: Luque Escamilla, Pedro L.. Universidad de Jaén; EspañaFil: Ishwara Chandra, C. H.. NCRA. TIFR; IndiaFil: Peracaula, Marta. Universidad de Girona; EspañaFil: Bosch Ramon, Valenti. Max Planck Institut Fur Kernphysik, Heidelberg; AlemaniaFil: Romero, Gustavo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto Argentino de Radioastronomia (i); Argentin