Processament de música basat en el seu contingut

Projecte de recerca elaborat a partir d’una estada a la National University of Singapore Singapur, entre juliol i octubre del 2007. Donada l'explosió de la música a l'internet i la ràpida expansió de les col•leccions de música digital, un repte clau en l'àrea de la informació musical és el desenvolupament de sistemes de processament musical eficients i confiables. L'objectiu de la investigació proposada ha estat treballar en diferents aspectes de l'extracció, modelatge i processat del contingut musical. En particular, s’ha treballat en l'extracció, l'anàlisi i la manipulació de descriptors d'àudio de baix nivell, el modelatge de processos musicals, l'estudi i desenvolupament de tècniques d'aprenentatge automàtic per a processar àudio, i la identificació i extracció d'atributs musicals d'alt nivell. S’han revisat i millorat alguns components d'anàlisis d'àudio i revisat components per a l'extracció de descriptors inter-nota i intra-nota en enregistraments monofónics d'àudio. S’ha aplicat treball previ en Tempo a la formalització de diferents tasques musicals. Finalment, s’ha investigat el processat d'alt nivell de música basandonos en el seu contingut. Com exemple d'això, s’ha investigat com músics professionals expressen i comuniquen la seva interpretació del contingut musical i emocional de peces musicals, i hem usat aquesta informació per a identificar automàticament intèrprets. S’han estudiat les desviacions en paràmetres com to, temps, amplitud i timbre a nivell inter-nota i intra-nota.

The future of television : advertising, technology and the pursuit of audiences

La televisió està en crisi. Les noves tecnologies i els dispositius han fragmentat les audiències de televisió en segments més petits. En aquest informe, Marissa Gluck i Meritxell Roca Sales examinen l'explosió dels mitjans de comunicació que han impulsat aquesta fragmentació.

Recent human evolution has shaped geographical differences in susceptibility to disease

Background: Searching for associations between genetic variants and complex diseases has been a very active area of research for over two decades. More than 51,000 potential associations have been studied and published, a figure that keeps increasing, especially with the recent explosion of array-based Genome-Wide Association Studies. Even if the number of true associations described so far is high, many of the putative risk variants detected so far have failed to be consistently replicated and are widely considered false positives. Here, we focus on the world-wide patterns of replicability of published association studies.Results: We report three main findings. First, contrary to previous results, genes associated to complex diseases present lower degrees of genetic differentiation among human populations than average genome-wide levels. Second, also contrary to previous results, the differences in replicability of disease associated-loci between Europeans and East Asians are highly correlated with genetic differentiation between these populations. Finally, highly replicated genes present increased levels of high-frequency derived alleles in European and Asian populations when compared to African populations. Conclusions: Our findings highlight the heterogeneous nature of the genetic etiology of complex disease, confirm the importance of the recent evolutionary history of our species in current patterns of disease susceptibility and could cast doubts on the status as false positives of some associations that have failed to replicate across populations.

What do women do? World population growth and fertility patterns, 1960-2000

In this paper we attempt to describe the general picture reasons behind the world population explosion during the 20th century. In general we comment that if, according to some, at the end of the 20th century there were too many people, this was has a consequence of scientific innovation, circulation of information, and economic growth, leading to a dramatic improvement in life expectancies. Nevertheless, a crucial variable shaping differences in demographic growth is fertility. In this paper we identify as important exogenous variables affecting fertility female education levels, infant mortality, and racial identity and diversity. It is estimated that three additional years of schooling for mothers leads on average (at the world level ) to one child less per couple. Even if we can identify a worldwide trend towards convergence in demographic trends, the African case needs to be given more attention, not only because of its different demographic patterns, but also because this is the continent where the worldwide movement towards a higher quality of life has not yet been achieved for an important share of the world's population.

Recreating the South Sea bubble: Lessons from an experiment in financial history

Major bubble episodes are rare events. In this paper, we examine what factors might cause some asset price bubbles to become very large. We recreate, in a laboratory setting, some of the specific institutional features investors in the South Sea Company faced in 1720. Several factors have been proposed as potentially contributing to one of the greatest periods of asset overvaluation in history: an intricate debt-for-equity swap, deferred payment for these shares, and the possibility of default on the deferred payments. We consider which aspect might have had the most impact in creating the South Sea bubble. The results of the experiment suggest that the company?s attempt to exchange its shares for government debt was the single biggest contributor to the stock price explosion, because of the manner in which the swap affected fundamental value. Issuing new shares with only partial payments required, in conjunction with the debt-equity swap, also had a significant effect on the size of the bubble. Limited contract enforcement, on the other hand, does not appear to have contributed significantly.

Rockfall induced seismic signals: case study in Montserrat, Catalonia

After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. Seismic measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, seismic techniques could provide important information on rockfall size and location of impacts. On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the seismic data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain) carried out in order to purge a slope. Two 3 component seismic stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. Seismic signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10¿4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the release zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the seismic records and seismic energy estimation were performed. The results are as follows: 1 ¿ A rockfall event generates seismic signals with specific characteristics in the time domain; 2 ¿ the seismic signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact). This feature could be used for detection purposes; 3 ¿ particle motion plot analysis shows that the procedure to locate the rock impact using two stations is feasible; 4 ¿ The feasibility and validity of seismic methods for the detection of rockfall events, their localization and size determination are comfirmed.

Matching stages of heavy-ion collision models

Heavy-ion reactions and other collective dynamical processes are frequently described by different theoretical approaches for the different stages of the process, like initial equilibration stage, intermediate locally equilibrated fluid dynamical stage, and final freeze-out stage. For the last stage, the best known is the Cooper-Frye description used to generate the phase space distribution of emitted, noninteracting particles from a fluid dynamical expansion or explosion, assuming a final ideal gas distribution, or (less frequently) an out-of-equilibrium distribution. In this work we do not want to replace the Cooper-Frye description, but rather clarify the ways of using it and how to choose the parameters of the distribution and, eventually, how to choose the form of the phase space distribution used in the Cooper-Frye formula. Moreover, the Cooper-Frye formula is used in connection with the freeze-out problem, while the discussion of transition between different stages of the collision is applicable to other transitions also. More recently, hadronization and molecular dynamics models have been matched to the end of a fluid dynamical stage to describe hadronization and freeze-out. The stages of the model description can be matched to each other on space-time hypersurfaces (just like through the frequently used freeze-out hypersurface). This work presents a generalized description of how to match the stages of the description of a reaction to each other, extending the methodology used at freeze-out, in simple covariant form which is easily applicable in its simplest version for most applications.

L'avaluació, tria i eliminació de fons fotogràfics digitals. Estudi de cas del fons del fotògraf Efren Montoya a l'Arxiu Històric de Sabadell

Durant la última dècada hem viscut l’explosió de la fotografia digital. Les possibilitats de captar imatges s’ha multiplicat de manera gairebé infinita sense implicar costos afegits pel fotògraf. Això ens obliga a replantejar-nos la necessitat d’establir uns criteris ben definits per avaluar, triar i eliminar les fotografies que ingressen als nostres arxius. El treball que es presenta aquí té com a objectiu establir uns protocols per tal de poder aplicar aquests procediments al nous fons que passin a formar part del nostre patrimoni documental. Finalment, s’ha dut a terme l’experiència d’entregar al productor d’un fons part de la seva documentació per tal que ell l’avalués i després comparar els resultats amb l’avaluació duta a terme des de l’arxiu. Paraules clau: avaluació, tria, eliminació, fotografia born-digital, ingrés, metadades, arxiu digital, formats de preservació

Hacia la arquitectura de la información 3.0: pasado, presente y futuro

La arquitectura de la información (IA), aunque presente en cierta manera desde hace más de 50 años, ha tomado especial relevancia con la llegada de la Web y el aumento de la cantidad de información a nuestro alcance. La disciplina cuenta ya con unos pilares claros, que se fundamentan en los contenidos gestionados pero sobre todo en los usuarios, sin olvidar su contexto. También se identifica una serie de componentes a combinar a la hora de elaborar una IA y una metodología básica. Pero la cantidad de información a nuestro alcance no para de crecer, así que se continúa innovando en nuevas formas de organización, buscadores más eficaces o tecnologías de web semántica que permiten a los ordenadores encargarse de la parte menos creativa de enfrentarse a esa avalancha de información.

Manual para buenos directivos de PYMES que quieren innovar: Empresas 2.0

Estamos viviendo desde la entrada al siglo XXI una explosión acelerada de las tecnologías, de las TIC’s, las redes sociales en internet, etc. que están modificando enormemente los hábitos de consumo y los principios de la sociedad. A todo ello, hay que añadir la situación de crisis económica general que existe en el mundo, y que afecta enormemente a las empresas y al tejido empresarial de un país. En este entorno, las compañías deben basar sus estrategias en estar cerca del cliente y ser capaces de visualizar necesidades no cubiertas. Sobre todo, las empresas deben transformarse para crear organizaciones humanizadas capaces de generar innovación y adaptarse rápidamente a los nuevos entornos que van surgiendo. Para poder hacer frente a esta nueva situación las empresas deben poner en valor el talento de todas las personas que forman parte de la organización. El activo más importante y escaso, para poder desarrollar estrategias triunfadoras. El trabajo pretende resumir la situación actual para las empresas, recoger todas las ideas y nuevas tendencias que existen en cuanto a la gestión del talento, la organización del trabajo y la creación de estructuras que permitan innovar. A lo largo del trabajo se van desarrollando las diferentes herramientas, sistemas y disciplinas que están a disposición de las empresas para crear un entorno que favorezca la innovación, como camino para mantenerse en el mercado global.

LS 5039: A runaway microquasar ejected from the galactic plane

We have compiled optical and radio astrometric data of the microquasar LS 5039 and derived its proper motion. This, together with the distance and radial velocity of the system, allows us to state that this source is escaping from its own regional standard of rest, with a total systemic velocity of about 150 km/s and a component perpendicular to the galactic plane larger than 100 km/s. This is probably the result of an acceleration obtained during the supernova event that created the compact object in this binary system. We have computed the trajectory of LS 5039 in the past, and searched for OB associations and supernova remnants in its path. In particular, we have studied the possible association between LS 5039 and the supernova remnant G016.8-01.1, which, despite our efforts, remains dubious. We have also discovered and studied an HI cavity in the ISM, which could have been created by the stellar wind of LS 5039 or by the progenitor of the compact object in the system. Finally, in the symmetric supernova explosion scenario, we estimate that at least 17 solar masses were lost in order to produce the high eccentricity observed. Such a mass loss could also explain the observed runaway velocity of the microquasar.

Control and femtosecond time-resolved imaging of torsion in a chiral molecule

We study how the combination of long and short laser pulses can be used to induce torsion in an axially chiral biphenyl derivative (3,5-difluoro-3 ,5 -dibromo-4 -cyanobiphenyl). A long, with respect to the molecular rotational periods, elliptically polarized laser pulse produces 3D alignment of the molecules, and a linearly polarized short pulse initiates torsion about the stereogenic axis. The torsional motion is monitored in real-time by measuring the dihedral angle using femtosecond time-resolved Coulomb explosion imaging. Within the first 4 picoseconds (ps), torsion occurs with a period of 1.25 ps and an amplitude of 3◦ in excellent agreement with theoretical calculations. At larger times, the quantum states of the molecules describing the torsional motion dephase and an almost isotropic distribution of the dihedral angle is measured.We demonstrate an original application of covariance analysis of two-dimensional ion images to reveal strong correlations between specific ejected ionic fragments from Coulomb explosion. This technique strengthens our interpretation of the experimental data