Ch. 10 - Rethinking the Transgressive: A Call for “Pessimistic Activism” in Music Education

This essay asks the question: How are we to think of what Estelle Jorgensen has called “the transgressive” in music education today? My entry point to the question is the suggestion that the struggle against modes of music education that eulogize the status quo, against oppression and authoritarianism, against practices that exclude and intimidate students, has to take the form of “a struggle on two fronts” (Badiou). A struggle against imposed canonicities and obsolete approaches to music teaching but also a struggle against the emerging neoliberal appropriations of education, learning, and creativity. The chapter sketches a struggle-on-two-fronts perspective with regard to the following questions: (1) How are we to understand the call for being ‘open’ to students and their needs? What does it mean, today, to adopt a child-centric perspective in music education? (2) How should we think of the notion of “active” participation? (3) Should we simply accept an equation between informality and openness? The chapter concludes by arguing that, if an important task of education is to critically reconstruct, reinterpret, and re-examine “knowledge for the present and future,” as Estelle Jorgensen has put it, then our approach might need to take the form of a “pessimistic activism”. Invoking the Foucauldian notion of pessimistic activism, I wish to emphasize the need for persistent uncompromised working modes that foster experimentation and criticality on the basis of equality, in the knowledge that in the end, we can neither be sure that our efforts will lead to openness, nor that these efforts will not be cancelled and/or co-opted by the pervading neoliberal ethos

Bounding the inefficiency of compromise

Social networks on the Internet have seen an enormous growth recently and play a crucial role in different aspects of today's life. They have facilitated information dissemination in ways that have been beneficial for their users but they are often used strategically in order to spread information that only serves the objectives of particular users. These properties have inspired a revision of classical opinion formation models from sociology using game-theoretic notions and tools. We follow the same modeling approach, focusing on scenarios where the opinion expressed by each user is a compromise between her internal belief and the opinions of a small number of neighbors among her social acquaintances. We formulate simple games that capture this behavior and quantify the inefficiency of equilibria using the well-known notion of the price of anarchy. Our results indicate that compromise comes at a cost that strongly depends on the neighborhood size

Forgiving Debt in Financial Network Games

We consider financial networks, where nodes correspond to banks and directed labeled edges correspond to debt contracts between banks. Maximizing systemic liquidity, i.e., the total money flow, is a natural objective of any financial authority. In particular, the financial authority may offer bailout money to some bank(s) or forgive the debts of others in order to maximize liquidity, and we examine efficient ways to achieve this. We study the computational hardness of finding the optimal debt-removal and budget-constrained optimal bailout policy, respectively, and we investigate the approximation ratio provided by the greedy bailout policy compared to the optimal one. We also study financial systems from a game-theoretic standpoint. We observe that the removal of some incoming debt might be in the best interest of a bank. Assuming that a bank's well-being (i.e., utility) is aligned with the incoming payments they receive from the network, we define and analyze a game among banks who want to maximize their utility by strategically giving up some incoming payments. In addition, we extend the previous game by considering bailout payments. After formally defining the above games, we prove results about the existence and quality of pure Nash equilibria, as well as the computational complexity of finding such equilibria

Μελέτη σχηματισμού και κατανομής δευτερογενούς οργανικού αερολύματος στην ατμόσφαιρα

Η παρούσα διδακτορική διατριβή έχει ως θέμα τη μελέτη σχηματισμού και κατανομής του δευτερογενούς οργανικού αερολύματος στην ατμόσφαιρα. Σε αυτό το πλαίσιο, πραγματοποιήθηκε η μελέτη διαφόρων δεικτών-SOA και σχετικών πολικών οργανικών ενώσεων, σε αιωρούμενα σωματίδια σε περιοχές της Ελλάδας και της Κύπρου με διαφορετικά χαρακτηριστικά. Για τη μελέτη αυτή αναπτύχθηκε και επικυρώθηκε μέθοδος τριπλής παραγωγοποίησης για τον προσδιορισμό πολικών οργανικών ενώσεων με την τεχνική της αέριας χρωματογραφίας συζευγμένη με φασματομετρία μαζών, ενώ συντέθηκαν και αναπτύχθηκε μέθοδος προσδιορισμού οργανοθειικών ενώσεων μέσω υγρής χρωματογραφίας συζευγμένης με τετραπολικό φασματόμετρο μαζών με αναλυτή «χρόνου πτήσης». Η μελέτη των ενώσεων SOA σε ΑΣ10 και ΑΣ2,5 σε αστική περιοχή και περιοχή υποβάθρου της Κύπρου, έδειξε τη συσσώρευση της πλειοψηφίας των ενώσεων στα ΑΣ2,5, όμως κατά τη θερμή περίοδο, ενώσεις με αυξημένη πτητικότητα παρουσίασαν υψηλότερες συγκεντρώσεις στα ΑΣ10. Μετεωρολογικές παράμετροι, όπως η ένταση της ηλιακής ακτινοβολίας όσο και η σχετική υγρασία της ατμόσφαιρας έδειξαν να επηρεάζουν σημαντικά το σχηματισμό SOA. Επίσης, τόσο το Ο3 όσο και τα επίπεδα ΝΟx συσχετίσθηκαν σημαντικά με τις διαφορετικές ομάδες SOA, δείχνοντας την επίδρασή τους στον σχηματισμό αυτών. Μεταξύ των δύο περιοχών παρατηρήθηκαν σημαντικές διαφορές ως προς το σχετικό προφίλ των δεικτών-BSOA αλλά και των δικαρβοξυλικών οξέων, που αποδίδεται στα αυξημένα επίπεδα NOx καθώς και στις έντονες εκπομπές της καύσης βιομάζας στην αστική περιοχή. Η μελέτη της κατανομής των δεικτών SOA στα ΑΣ με βάση το μέγεθος κατά τη διάρκεια της μέρας και της νύχτας σε ημιαστική περιοχή της Αθήνας έδειξε τη συσσώρευση της πλειοψηφίας των ενώσεων σε σωματίδια διαμέτρου <1,0 μm, με την αύξηση του ποσοστού υγρασίας των σωματιδίων κατά τη διάρκεια της νύχτας καθώς και με τη συμπύκνωση ενώσεων της αέριας φάσης εξαιτίας των υψηλών τιμών σχετικής υγρασίας να έχουν σημαντικό ρόλο στην κατανομή των ενώσεων. Επίσης, η καύση πλαστικών και βιομάζας, όπως φάνηκε σε αστική/βιομηχανική περιοχή της Αττικής, φάνηκε να ενισχύει σημαντικά τον σχηματισμό των SOA, ενώ παρατηρήθηκαν και υψηλότερα επίπεδα ανθρωπογενών SOA. Τέλος, μελετήθηκε η εποχιακή διακύμανση οργανοθειικών ενώσεων σε ΑΣ2,5 στην Αθήνα και την Πάτρα, με τα προϊόντα του ισοπρενίου να κυριαρχούν και στις δύο περιοχές.In this thesis we study the formation and distribution of secondary organic aerosols in the atmosphere. In this light, particle-bound SOA tracers and related polar organic compounds were studied in areas of Greece and Cyprus with different characteristics. For this purpose, a 3-step derivatization method was developed for the determination of polar organic compounds with gas chromatography coupled with mass spectrometry. In addition, organosulfates standards were synthesized and a method has been developed for their determination in PM using liquid chromatography coupled with quadrupole time of flight mass spectrometry. The study of SOA compounds bound to PM10 and PM2.5 particles, in an urban and a background area of Cyprus, revealed the accumulation of the majority of the compounds at PM2.5. However, during the warm period, compounds with higher volatility presented higher concentration in PM10. Meteorological conditions, such as solar radiation and relative humidity, appeared to significantly affect SOA formation. Moreover, both O3 and NOx levels were significantly correlated with different SOA groups, indicating possible influence to their formation. Among the two areas, noteworthy differences have been observed regarding the relative profile of BSOA tracers and dicarboxylic acids, which were attributed to the higher NOx levels as well as to the intense biomass burning emissions in the urban area. The study of the distribution of SOA markers in different PM sizes during daytime and nighttime, in a suburban area of Athens, showed the accumulation of the most of the compounds in particles with a diameter <1.0 μm. Particle hygroscopic growth during nighttime, as well as the condensation of gas phase compounds under higher nighttime humid conditions played a pivotal role of the compounds’ particle size distribution. In addition, in an urban/industrial site of Attica, higher levels of anthropogenic SOA markers were observed, with the practices of biomass and plastic enriched waste burning appeared to enhance SOA formation. Finally, the seasonal trends of organosulfates bound to PM2.5 were studied in urban areas of Athens and Patra, with those derived from isoprene’s reactions being the dominant compounds at both studied sites

Financial network games

We study financial systems from a game-theoretic standpoint. A financial system is represented by a network, where nodes cor- respond to firms, and directed labeled edges correspond to debt contracts between them. The existence of cycles in the network indicates that a payment of a firm to one of its lenders might result to some incoming payment. So, if a firm cannot fully repay its debt, then the exact (partial) payments it makes to each of its creditors can affect the cash inflow back to itself. We naturally assume that the firms are interested in their financial well-being (utility) which is aligned with the amount of incoming payments they receive from the network. This defines a game among the firms, that can be seen as utility-maximizing agents who can strategize over their payments. We are the first to study financial network games that arise under a natural set of payment strategies called priority-proportional payments. We investigate both the existence and the (in)efficiency of equilibrium strategies, under different assumptions on how the firms’ utility is defined, on the types of debt contracts allowed between the firms, and on the presence of other financial features that commonly arise in practice. Surprisingly, even if all firms’ strategies are fixed, the existence of a unique payment profile is not guaranteed. So, we also investigate the existence and computation of valid payment profiles for fixed payment strategies

On Discrete Truthful Heterogeneous Two-Facility Location

We revisit the discrete heterogeneous two-facility location problem, in which there is a set of agents that occupy nodes of a line graph, and have private approval preferences over two facilities. When the facilities are located at some nodes of the line, each agent derives a cost that is equal to her total dis- tance from the facilities she approves. The goal is to decide where to locate the two facilities, so as to (a) incentivize the agents to truthfully report their preferences, and (b) achieve a good approximation of the minimum total (social) cost or the maximum cost among all agents. For both objectives, we de- sign deterministic strategyproof mechanisms with approximation ratios that significantly outperform the state-of-the-art, and complement these results with (almost) tight lower bounds

On Interim Envy-Free Allocation Lotteries

With very few exceptions, recent research in fair division has mostly focused on deterministic allocations. Deviating from this trend, we study the fairness notion of interim envy-freeness (iEF) for lotteries over allocations, which serves as a sweet spot between the too stringent notion of ex-post envy-freeness and the very weak notion of ex-ante envy-freeness. iEF is a natural generalization of envy-freeness to random allocations in the sense that a deterministic envy-free allocation is iEF (when viewed as a degenerate lottery). It is also certainly meaningful as it allows for a richer solution space, which includes solutions that are provably better than envy-freeness according to several criteria. Our analysis relates iEF to other fairness notions as well, and reveals tradeoffs between iEF and efficiency. Even though several of our results apply to general fair division problems, we are particularly interested in instances with equal numbers of agents and items where allocations are perfect matchings of the items to the agents. Envy-freeness can be trivially decided and (when it can be achieved, it) implies full efficiency in this setting. Although computing iEF allocations in matching allocation instances is considerably more challenging, we show how to compute them in polynomial time, while also maximizing several efficiency objectives. Our algorithms use the ellipsoid method for linear programming and efficient solutions to a novel variant of the bipartite matching problem as a separation oracle. We also study the extension of interim envy-freeness notion when payments to or from the agents are allowed. We present a series of results on two optimization problems, including a generalization of the classical rent division problem to random allocations using interim envy-freeness as the solution concept