Seguidilles, fandangos i boleros a les sonates ibèriques per tecla dels compositors Domenico Scarlatti, José de Nebra i Antoni Soler

Aquest projecte neix amb la finalitat d’oferir una perspectiva sobre les sonates ibèriques de les dècades centrals del segle XVIII, i en concret dels cèlebres compositors Domenico Scarlatti, José de Nebra i Antoni Soler, centrada en alguns dels balls de major popularitat a l’època com són les seguidilles, els fandangos i els boleros. Algunes de les sonates ibèriques d’aquests compositors es corresponen amb molts dels paràmetres que condicionen aquests balls i com a conseqüència són sonates que poden ser ballades, tot i que desconeixem si a l’època s’interpretaven amb ballarins. Al voltant d’aquest tema se’ns formulen algunes preguntes referents al gènere i l’estil de les sonates o a la relació dels seus compositors amb els moviments culturals de la ciutat de Madrid que podien haver propiciat aquesta connexió.

ClubADSL: When your neighbors are your friends

ADSL is becoming the standard form of residential and small-business broadband Internet access due to, primarily, its low deployment cost. These ADSL residential lines are often deployed with 802.11 Access Points (AP) that providewireless connectivity. Given the density of ADSL deployment, it is often possible for a residential wireless client to be in range of several other APs, belonging to neighbors, with ADSL connectivity. While the ADSL technology has showed evident limits in terms of capacity (with speeds ranging 1-10 Mbps), the short-range wireless communication can guarantee a muchhigher capacity (up to 20 Mbps). Furthermore, the ADSL links in the neighborhood are generally under-utilized, since ADSL subscribers do not connect 100% of the time. Therefore, it is possible for a wireless client to simultaneously connect to several APs in range and effectively aggregate their available ADSL bandwidth.In this paper, we introduce ClubADSL, a wireless client that can simultaneously connect to several APs in range on different frequencies and aggregate both their downlink and uplink capacity. ClubADSL is a software that runs locally on the client-side, and it requires neither modification to the existing Internet infrastructure, nor any hardware/protocol upgradesto the 802.11 local area network. We show the feasibility of ClubADSL in seamlessly transmitting TCP traffic, and validate its implementation both in controlled scenarios and with current applications over real ADSL lines. In particular we show that a ClubADSL client can greatly benefit from the aggregated download bandwidth in the case of server-client applications such as video streaming, but can also take advantage of the increased upload bandwidth greatly reducing download times with incentive-based P2P applications such as BitTorrent.

Money, Fame and the Allocation of Talent: Brain Drain, the Matthew Effect and the Institution of Science

The earning structure in science is known to be flat relative to the one in the private sector, which could cause a brain drain toward the private sector. In this paper, we assume that agents value both money and fame and study the role of the institution of science in the allocation of talent between the science sector and the private sector. Following works on the Sociology of Science, we model the institution of science as a mechanism distributing fame (i.e. peer recognition). We show that since the intrinsic performance is less noisy signal of talent in the science sector than in the private sector, a good institution of science can mitigate the brain drain. We also find that providing extra monetary incentives through the market might undermine the incentives provided by the institution and thereby worsen the brain drain. Finally, we study the optimal balance between monetary and non-monetary incentives in science.

Experiments de Pávlov aplicats als peixos

Treball de recerca realitzat per un alumne d’ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l’any 2010. El motiu del treball ha estat aplicar els experiments de Pávlov realitzats amb gossos a una espècie diferent, Carassius sp, i verificar la idoneitat d'aplicar aquesta tècnica en l'espècie i estudiar així la capacitat d'apendre dels peixos.

Bundling and competition for slots: Sequential pricing

In this paper we study, as in Jeon-Menicucci (2009), competition between sellerswhen each of them sells a portfolio of distinct products to a buyer having limitedslots. This paper considers sequential pricing and complements our main paper (Jeon-Menicucci, 2009) that considers simultaneous pricing.First, Jeon-Menicucci (2009) find that under simultaneous individual pricing, equilibriumoften does not exist and hence the outcome is often inefficient. By contrast,equilibrium always exists under sequential individual pricing and we characterize it inthis paper. We find that each seller faces a trade-off between the number of slots heoccupies and surplus extraction per product, and there is no particular reason thatthis leads to an efficient allocation of slots.Second, Jeon-Menicucci (2009) find that when bundling is allowed, there alwaysexists an efficient equilibrium but inefficient equilibria can also exist due to purebundling (for physical products) or slotting contracts. Under sequential pricing,we find that all equilibria are efficient regardless of whether firms can use slottingcontracts, and both for digital goods and for physical goods. Therefore, sequentialpricing presents an even stronger case for laissez-faire in the matter of bundling thansimultaneous pricing.

Bundling electronic journals and competition among publishers

Site licensing of e-journals has been revolutionizing the way academicinformation is distributed. However, many librarians are concerned aboutthe possibility that publishers might abuse site licensing by practicingbundling. In this paper, we analyze the private and social incentives forthe publishers to use bundling in the context of STM electronic journalmarket. In the short run in which the number of journals is exogenouslygiven, we find a strong conflict between the two incentives: each publisherfinds bundling optimal and bundling increases the industry profit butreduces social welfare. However, in the long run we find that publishersmight have higher incentives to introduce new journals under bundlingthan without bundling and, in this case, bundling can reduce the industryprofit while increasing social welfare. Finally, we examine publishers incentive to provide links to the websites of the rival publishers underbundling and show that even asymmetric publishers have incentive tointerconnect.

Optimal second-degree price discrimination and arbitrage: On the role of asymetric information among buyers

The traditional theory of monopolistic screening tackles individualself-selection but does not address the possibility that buyers couldform a coalition to coordinate their purchases and to reallocate thegoods. In this paper, we design the optimal sale mechanism which takesinto account both individual and coalition incentive compatibilityfocusing on the role of asymmetric information among buyers. We showthat when a coalition of buyers is formed under asymmetric information,the monopolist can do as well as when there is no coalition. Although inthe optimal sale mechanism marginal rates of substitution are notequalized across buyers (hence there exists room for arbitrage), theyfail to realize the gains from arbitrage because of the transaction costsin coalition formation generated by asymmetric information.

Building an honest microfinance organization: Embezzlement and the optimality of rigid repayment schedules and joint liability

We consider the agency problem of a staff member managing microfinancing programs, who can abuse his discretion to embezzle borrowers' repayments. The fact that most borrowers of microfinancing programs are illiterate and live in rural areas where transportation costs are very high make staff's embezzlement particularly relevant as is documented by Mknelly and Kevane (2002). We study the trade-off between the optimal rigid lending contract and the optimal discretionary one and find that a rigid contract is optimal when the audit cost is larger than gains from insurance. Our analysis explains rigid repayment schedules used by the Grameen bank as an optimal response to the bank staff's agency problem. Joint liability reduces borrowers' burden of respecting the rigid repayment schedules by providing them with partial insurance. However, the same insurance can be provided byborrowers themselves under individual liability through a side-contract.

Money, fame and the allocation of talent: Brain drain and the institution of science

The earning structure in science is known to be flat relative to the one in theprivate sector, which could cause a brain drain toward the private sector. In thispaper, we assume that agents value both money and fame and study the role ofthe institution of science in the allocation of talent between the science sector andthe private sector. Following works on the Sociology of Science, we model theinstitution of science as a mechanism distributing fame (i.e. peer recognition). Weshow that since the intrinsic performance is less noisy signal of talent in the sciencesector than in the private sector, a good institution of science can mitigate thebrain drain. We also find that providing extra monetary incentives through themarket might undermine the incentives provided by the institution and therebyworsen the brain drain. Finally, we study the optimal balance between monetaryand non-monetary incentives in science.

Interconnection among academic journal platforms: Multilateral versus bilateral interconnection

Electronic academic journal websites provide new services of text and/or datamining and linking, indispensable for e¢ cient allocation of attention among abun-dant sources of scienti?c information. Fully realizing the bene?t of these servicesrequires interconnection among websites. Motivated by CrossRef, a multilateralcitation linking backbone, this paper performs a comparison between multilateralinterconnection through an open platform and bilateral interconnection, and ?ndsthat publishers are fully interconnected in the former regime while they can be par-tially interconnected in the latter regime for exclusion or di¤erentiation motives.Surprisingly, if partial interconnection arises for di¤erentiation motive, exclusion ofsmall publisher(s) occurs more often under multilateral interconnection. We also?nd that in the case of multilateral interconnection, a for-pro?t platform inducesless exclusion than an open platform. Various other extensions are analyzed.

Bundling and competition for slots: On the portfolio effects of bundling

We consider competition among sellers when each of them sells a portfolio ofdistinct products to a buyer having limited slots. We study how bundling affectscompetition for slots. Under independent pricing, equilibrium often does not existand hence the outcome is often inefficient. When bundling is allowed, each sellerhas an incentive to bundle his products and an efficient equilibrium always exists.Furthermore, in the case of digital goods, all equilibria are efficient if slotting contracts are prohibited. We also identify portfolio effects of bundling and analyze theconsequences on horizontal mergers. Finally, we derive clear-cut policy implications.

Mobile Communication 2012 : Experiències i recerques sobre comunicació mòbil

La comunicació mòbil és un dels temes de més actualitat en diferents fòrums, des de diferents perspectives. Espanya juga un paper important per les dinàmiques i l’evolució del seu mercat. En aquest sentit, el nostre país ofereix un interès específic per l'amplitud del seu parc de dispositius 3G (el segon d'Europa, després d'Itàlia) i per la intensitat del desenvolupament de xarxes socials mòbils, a més de per la creixent implicació d'empreses en la producció i distribució de continguts mòbils. Com va passar amb Internet, es tracta d’un procés d'innovació pel qual els formats de contingut, les pràctiques de consum i els models de negoci característics de la televisió i la xarxa, per exemple, s'adapten, primer, al nou mitjà, per a després desenvolupar formes i models específics que aprofiten les potencialitats de personalització, geolocalització i conectivitat ubiqua.

Spectral properties of the Laplacian of multiplex networks.

One of the more challenging tasks in the understanding of dynamical properties of models on top of complex networks is to capture the precise role of multiplex topologies. In a recent paper, Gómez et al. [ Phys. Rev. Lett. 110 028701 (2013)], some of the authors proposed a framework for the study of diffusion processes in such networks. Here, we extend the previous framework to deal with general configurations in several layers of networks and analyze the behavior of the spectrum of the Laplacian of the full multiplex. We derive an interesting decoupling of the problem that allow us to unravel the role played by the interconnections of the multiplex in the dynamical processes on top of them. Capitalizing on this decoupling we perform an asymptotic analysis that allow us to derive analytical expressions for the full spectrum of eigenvalues. This spectrum is used to gain insight into physical phenomena on top of multiplex, specifically, diffusion processes and synchronizability.

Emergence of assortative mixing between clusters of cultured neurons

The analysis of the activity of neuronal cultures is considered to be a good proxy of the functional connectivity of in vivo neuronal tissues. Thus, the functional complex network inferred from activity patterns is a promising way to unravel the interplay between structure and functionality of neuronal systems. Here, we monitor the spontaneous self-sustained dynamics in neuronal cultures formed by interconnected aggregates of neurons (clusters). Dynamics is characterized by the fast activation of groups of clusters in sequences termed bursts. The analysis of the time delays between clusters' activations within the bursts allows the reconstruction of the directed functional connectivity of the network. We propose a method to statistically infer this connectivity and analyze the resulting properties of the associated complex networks. Surprisingly enough, in contrast to what has been reported for many biological networks, the clustered neuronal cultures present assortative mixing connectivity values, meaning that there is a preference for clusters to link to other clusters that share similar functional connectivity, as well as a rich-club core, which shapes a"connectivity backbone" in the network. These results point out that the grouping of neurons and the assortative connectivity between clusters are intrinsic survival mechanisms of the culture.

Mobile Communication 2012 : Experiències i recerques sobre comunicació mòbil

La comunicació mòbil és un dels temes de més actualitat en diferents fòrums, des de diferents perspectives. Espanya juga un paper important per les dinàmiques i l’evolució del seu mercat. En aquest sentit, el nostre país ofereix un interès específic per l'amplitud del seu parc de dispositius 3G (el segon d'Europa, després d'Itàlia) i per la intensitat del desenvolupament de xarxes socials mòbils, a més de per la creixent implicació d'empreses en la producció i distribució de continguts mòbils. Com va passar amb Internet, es tracta d’un procés d'innovació pel qual els formats de contingut, les pràctiques de consum i els models de negoci característics de la televisió i la xarxa, per exemple, s'adapten, primer, al nou mitjà, per a després desenvolupar formes i models específics que aprofiten les potencialitats de personalització, geolocalització i conectivitat ubiqua.