Two-Party Direct-Sum Questions Through the Lens of Multiparty Communication Complexity

Direct-sum questions in (two-party) communication complexity ask whether two parties, Alice and Bob, can compute the value of a function f on l inputs (x_1,y_1),...,(x_l,y_l) more efficiently than by applying the best protocol for f, independently on each input (x_i,y_i). In spite of significant efforts to understand these questions (under various communication-complexity measures), the general question is still far from being well understood. In this paper, we offer a multiparty view of these questions: The direct-sum setting is just a two-player system with Alice having inputs x_1,...,x_l, Bob having inputs y_1,...,y_l and the desired output is f(x_1,y_1),...,f(x_l,y_l). The naive solution of solving the l problems independently, is modeled by a network with l (disconnected) pairs of players Alice i and Bob i, with inputs x_i,y_i respectively, and communication only within each pair. Then, we consider an intermediate ("star") model, where there is one Alice having l inputs x_1,...,x_l and l players Bob_1,...,Bob_l holding y_1,...,y_l, respectively (in fact, we consider few variants of this intermediate model, depending on whether communication between each Bob i and Alice is point-to-point or whether we allow broadcast). Our goal is to get a better understanding of the relation between the two extreme models (i.e., of the two-party direct-sum question). If, for instance, Alice and Bob can do better (for some complexity measure) than solving the l problems independently, we wish to understand what intermediate model already allows to do so (hereby understanding the "source" of such savings). If, on the other hand, we wish to prove that there is no better solution than solving the l problems independently, then our approach gives a way of breaking the task of proving such a statement into few (hopefully, easier) steps. We present several results of both types. Namely, for certain complexity measures, communication problems f and certain pairs of models, we can show gaps between the complexity of solving f on l instances in the two models in question; while, for certain other complexity measures and pairs of models, we can show that such gaps do not exist (for any communication problem f). For example, we prove that if only point-to-point communication is allowed in the intermediate "star" model, then significant savings are impossible in the public-coin randomized setting. On the other hand, in the private-coin randomized setting, if Alice is allowed to broadcast messages to all Bobs in the "star" network, then some savings are possible. While this approach does not lead yet to new results on the original two-party direct-sum question, we believe that our work gives new insights on the already-known direct-sum results, and may potentially lead to more such results in the future

Economic Theory, Divided Infringement and Enforcing Interactive Patents

High tech companies – especially in the emerging areas of the Internet of Things, wearable devices, and personalized medicine – have found it difficult to enforce their patents on interactive technologies. This is especially true when multiple parties combine to perform all of the steps of a claimed method. This problem is referred to as joint or divided infringement, and some commentators advocate that “interactive” patents susceptible to divided infringement should not be enforced. In contrast, this article argues that economic theory supports the enforcement of interactive patents. Previous papers have analyzed divided infringement problems from a doctrinal and policy perspective. This article is the first to analyze divided infringement from an economic perspective, using three prevalent economic theories of the patent system. Uniquely, all three prevalent economic theories of the patent system – (1) reward theory, (2) prospect theory, and (3) rent dissipation theory – support the enforcement of interactive patents. Reward theory is consistent with enforcing the rights of interactive patents so long as the patent system balances the social cost with the social benefit of interactive technologies. Prospect theory recommends enforcing interactive patents where it would promote an inventor’s ability to commercialize her invention free from direct competition. Finally, rent dissipation theory suggests enforcing interactive patents if it will effectively reduce the dissipation of patent rents. Viewing interactive patent enforcement through the lens of these economic theories reveals how doctrinal tests for divided infringement may align with the economic goals of the patent system. Although it is likely that the doctrinal test for divided infringement will continue to evolve, start-ups and disruptive, hi-tech companies who own interactive patents should find some guidance in the notion that the economic underpinnings of the patent system support enforcement of their interactive inventions

Achieving mutual engagement in ELT classroom interaction : a study of participation in the opening and closing practices of circle time

IPhD ThesisMost studies investigating classroom participation seek an answer for enquiries to such issues as whether students receive adequate opportunities to access interaction and, if so, in what capacity and in what roles. Recently, Conversation Analytic (CA) studies have contributed to the existing body of knowledge on classroom participation by addressing the question of how teachers and students organise such participation in L2 classrooms. However, most of these studies have approached participation in contexts where participation rights are established by the teacher and met by students. In contrast, this study is concerned more with the organisation of participation in EFL classrooms where such conditions do not apply. That is, in the context of this study, teachers need to perform additional interactional practices to encourage participation. The analyses in this study focus on the opening and closing practices of one recurring teacher-led activity in the data—Circle Time (CT). The data come from audiovisual recordings of teacher-student cohort interaction occurring in ‘Fundamental English Listening-Speaking’ (FELS) classes at a Thai university. To examine the organisation of participation, a collection of 30 examples of CT openings and 24 examples of CT closings were made and CA methodology was used in the analysis. CA procedures, including the organisation of sequence, of multimodalities, and of topic, were employed as analytic tools to explicate the classroom participation that participants jointly construct through their verbal behaviour and embodied actions. The findings demonstrate that dedicated openings are the norm for CT openings, and are formed from two action sequences: 1) locating topic for participation, and 2) establishing topic-as-action. The former manifests a clear framework of participation while the latter enhances the participants’ readiness to participate more actively. Regarding CT closings, a typical form of CT closing, termed here dedicated closings, comprise three sequences of action: 1) disengaging from interaction with individual students, 2) gradually bonding contributions and simultaneously connecting participants into one association, and 3) moving out of CT talk. Furthermore, a microanalysis of opening and closing actions illustrates that teachers employ a variety of extra interactional resources, including embodied conducts, turn-design and various techniques of topic development. ii These various types of interactional work are used to establish and maintain multiparty interaction and generate dynamic participation roles among the participants. By participating in CT dedicated opening and closing, students are observed to have more and more opportunities to establish mutual attention, negotiate mutual understanding, and, above all, develop interpersonal relations, or so-called rapport. These three components are evidently oriented to by experienced EFL teachers to achieve mutual engagement of students involved in teacher-led classroom interaction. The main contribution of the study is an enhanced understanding of how participation ‘gets done’ in a CT context where bidding for turns is normally not present. In addition, by using a micro-analytic approach, the study demonstrates how embodied mutual engagement is accomplished in ELT classroom interaction.Department of Foreign Languages, Faculty of Humanities, Kasetsart University, for granting me a partial scholarshi

Ethnonational affective polarization as a mediator of pro-national media on political misperception in Montenegro

Recognizing the potential threat of political misperception to democracy and democracy processes, scholars have extensively studied the causes and effects of this phenomenon. It is well documented that partisan and social media play a role in the spreading of political misperceptions in part through their contribution to affective polarization. However, most previous research on political misperceptions has focused on divisions along partisan lines and partisanship as group identity (Iyengar et al., 2019). The extent to which affective polarization is associated with hostility directed at the opposition, partisans could be more inclined to accept opponents' unsupported or poorly reasoned criticisms. Other identities such as nationality, ethnicity, and religion have not received much scholarly attention in the context of political misperceptions and partisan media. Furthermore, scholars have tended to focus on western democracies, and the majority of scientific conclusions are based on the two-party system, while fewer studies focus on the complex multiparty systems of underdeveloped countries, with turbulent and complex political relationships underlined with layers of other divisions are deficit. Having that in mind, this thesis will focus on a historically and strategically important yet unconsolidated democratic country in South-East Europe -- Montenegro, with a multiparty system and internal divisions along ethnonational lines. Montenegro is a NATO member county, on a path to become the next member state of the European Union with a turbulent and complex relationship with Russia. Thus, it is an important and interesting case study. Furthermore, to understand the underlying mechanisms linking media exposure and increased dissemination of political misperceptions, it is important to understand the role of group identity salience. Garrett et al. (2019) argues that the more individuals rely on partisan outlets, the greater their dislike of the out-group vis-a-vis the in-group, which unconsciously triggers affective reactions associated with the subject of a false claim. Thus, Garrett et al. (2019) find that affective polarization is an important mediator linking partisan media exposure and misperceptions. This thesis argues that the pro-national media will be associated with a higher level of ethnonational affective polarization and that pro-national and social media will increase political misperceptions. Additionally, I argue that pro-national media will have an indirect effect on misperceptions through affective polarization such that pro-national media will increase affective polarization and subsequently increase misperceptions. These hypotheses were tested with a large and nationally representative probability sample of the population of Montenegro conducted in consultation with the author. Results confirmed the above expectations. However, for social media contributing to a higher level of political misperception, results were reversed than expected, social media was actually associated with fewer political misperceptions.Includes bibliographical references

Efficient generation of photonic entanglement and multiparty quantum communication

Entangled photons are at the heart of experimental quantum physics. They were used for the first fundamental tests of quantum theory, and became a basic building block for many novel quantum protocols, such as quantum cryptography, dense coding or teleportation. Therefore, the efficient generation of entangled photons, as well as their distribution and accurate analysis are of paramount importance, particularly with regard to the practicability of many applications of quantum communication. This thesis deals largely with the problem of efficient generation of photonic entanglement with the principal aim of developing a bright source of polarization-entangled photon pairs, which meets the requirements for reliable and economic operation of quantum communication prototypes and demonstrators. Our approach uses a correlated photon-pair emission in nonlinear process of spontaneous parametric down-conversion pumped by light coming from a compact and cheap blue laser diode. Two alternative source configurations are examined within the thesis. The first makes use of a well established concept of degenerate non-collinear emission from a single type-II nonlinear crystal and the second relies on a novel method where the emissions from two adjacent type-I phase-matched nonlinear crystals operated in collinear non-degenerate regime are coherently overlapped. The latter approach showed to be more effective, yielding a total detected rate of almost 10^6 pairs/s at >98 % quantum interference visibility of polarization correlations. This performance, together with the almost free of alignment operation of the system, suggest that it is an especially promising candidate for many future practical applications, including quantum cryptography, detector calibration or use in undergraduate lab courses. The second issue addressed within the thesis is the simplification and practical implementation of quantum-assisted solutions to multiparty communication tasks. While the recent rapid progress in the development of bright entangled photon-pair sources has been followed with ample experimental reports on two-party quantum communication tasks, the practical implementations of tasks for more than two parties have been held back, so far. This is mainly due to the requirement of multiparty entangled states, which are very difficult to be produced with current methods and moreover suffer from a high noise. We show that entanglement is not the only non-classical resource endowing the quantum multiparty information processing its power. Instead, only the sequential communication and transformation of a single qubit can be sufficient to accomplish certain tasks. This we prove for two distinct communication tasks, secret sharing and communication complexity. Whereas the goal of the first is to split a cryptographic key among several parties in a way that its reconstruction requires their collaboration, the latter aims at reducing the amount of communication during distributed computational tasks. Importantly, our qubit-assisted solutions to the problems are feasible with state-of-the-art technology. This we clearly demonstrate in the laboratory implementation for 6 and 5 parties, respectively, which is to the best of our knowledge the highest number of actively performing parties in a quantum protocol ever implemented. Thus, by successfully solving and implementing a cryptographic task as well as a task originating in computer science, we clearly illustrate the potential to introduce multiparty communication problems into real life.Verschränkte Photonen sind von zentralem Interesse im Bereich experimenteller Quantenphysik. Sie wurden für die ersten fundamentalen Tests der Quantentheorie verwendet und bilden die Grundlage bei der Realisierung vieler neuer Kommunikationsprotokolle die auf quantenmechanischen Effekten basieren, wie zum Beispiel Quantenkryptographie, "dense coding" oder Teleportation. Die effiziente Erzeugung verschränkter Photonen sowie deren genaue Analyse ist folglich von großer Bedeutung, insbesondere im Hinblick auf die Umsetzbarkeit der vielen Quantenkommunikationsanwendungen. Die vorliegende Arbeit behandelt im Wesentlichen das Problem der effizienten Erzeugung von Photon Verschränkung. Das Hauptaugenmerk liegt dabei auf der Entwicklung einer Quelle verschränkter Photonen, die den Anforderungen für einen zuverlässigen und wirtschaftlichen Betrieb in Beispielanwendungen der Quantenkommunikation genügt. Unser Ansatz verwendet die Emission korrelierter Photonen Paare im Prozess der spontanen parametrischen Fluoreszenz. Der Prozess wird mit Licht einer handlichen und billigen blauen Laserdiode gepumpt. Es werden zwei alternative Aufbauten für die Quelle betrachtet. Der erste verwendet das altbewährte Konzept der entarteten nicht-kollinearen Emission in einem einzelnen nichtlinearen Kristall vom Typ II. Der zweite Ansatz basiert auf einer neuen Methode in der die Emission zweier aneinaderliegender, phasenangepasster Kristalle vom Typ I kohärent überlagert wird. Die Phasenanpassung erfolgt dabei im kollinearen nicht-entarteten Zustand. Mit einer Rate von 10^6 Paaren in der Sekunde bei einem Interferenzkontrast der Polarisationskorrelationen von >98 % erwies sich die neue Methode als wesentlich effizienter. Diese Leistungsfähigkeit, in Verbindung mit einem nahezu justagefreien Betrieb, lässt dieses System vielversprechend für zukünftige praktische Anwendungen, wie Quantenkryptographie, Detektorkalibrierung oder Praktikumsversuche für Studenten erscheinen. Ein weiteres Thema das im Rahmen dieser Arbeit behandelt wird ist die Vereinfachung und Implementierung kommunikationstheoretischer Problemlösungen unter Zuhilfenahme quantenmechanischer Effekte. Während der rasante Fortschritt der letzten Jahre bei der Entwicklung von Quellen zur Erzeugung verschränkter Photonenpaare zu einer großen Anzahl von Veröffentlichungen auf dem Gebiet der Zwei-Parteien-Quantenkommunikation geführt hat, hielt sich die Zahl der Implementierungen von Protokollen mit mehr als zwei Parteien in Grenzen. Dies liegt hauptsächlich daran, dass die benötigten Mehr-Teilchen verschränkten Zustände mit dem heutigen Stand der Technik schwer zu produzieren sind und darüber hinaus hohes Rauschen aufweisen. Wir zeigen, dass Verschränkung nicht die einzige Ressource ist, die Mehrparteien-Quanten-Informationsverarbeitung ihre Stärke verleiht. Im Gegenteil, die sequentielle Kommunikation und Transformation eines einzelnen Qubits kann bereits ausreichend für die Lösung bestimmter Probleme sein. Dies zeigen wir anhand zweier verschiedener informationstheoretischer Problemstellungen, dem "secret sharing" und der Kommunikationskomplexität. Die erste befasst sich mit der Aufteilung eines kryptographischen Schlüssels auf mehrere Parteien in einer Weise, die für dessen Rekonstruktion die Zusammenarbeit aller Parteien erfordert. Die zweite zielt auf die Reduzierung der Kommunikation beim Lösen distributiver Berechnungen ab. Bemerkenswerterweise ist das hier verwendete qubit-basierte Lösungsverfahren mit dem heutigen Stand der Technik umsetzbar, was wir durch dessen Realisierung im Labor für 6 bzw. 5 Personen zeigen. Nach unserem Wissen ist dies die höchste Anzahl an aktiv agierenden Teilnehmern in einem Quantenkommunikationsprotokoll die je implementiert wurde. Die erfolgreiche Lösung und Implementierung von Problemstellungen aus den Bereichen der Kryptographie und der Informatik bringt somit Mehrparteien Quantenkommunikation einen Schritt näher an kommerzielle Anwendungen heran

The Middle East Quartet of Mediators: Understanding Multiparty Mediation in the Middle East Peace Process

This dissertation seeks to answer the question: Under what conditions does multiparty mediation fail to move conflicting parties toward a comprehensive peace agreement? The object of study is the Middle East Quartet of Mediators from its formation in 2002 to the Annapolis Conference in November, 2007. Although some progress was made during this period, no formal peace agreement was reached and therefore, the ultimate objective of the Quartet was not attained. The study seeks both to deepen our theoretical understanding of multiparty mediation as well as identify specific leverage points that could lead toward resolution of the conflict in Palestine and Israel. The methodology employed is a qualitative investigation of the multiparty mediation efforts of the Quartet. It is based on an investigation of Quartet statements as well as a series of interviews of key Quartet participants and academic experts on the contemporary Israeli-Palestinian peace process. The ultimate aim is to make future mediation efforts more successful

Beyond Dyads: Decision support for online multiparty negotiation, coalition formation and negotiation outcomes

Ph.DDOCTOR OF PHILOSOPH

What type of Europe?

How much and why do political parties emphasize Europe in election campaigns? The literature is increasingly focusing on two aspects of party issue competition: position and salience. However, recent studies on salience tend to ignore the fact that Europe is a compound political issue. This article contributes to the debate by highlighting the crucial difference between constitutive and policy-related European issues. Using data from the Euromanifestos Project for 14 EU member states for the period 1979–2009, we first show that Europe is much more salient in European Parliament elections than previously assumed. Second, EU issue salience depends on party position and party system polarization over European integration. However, different explanations come into play once we bring in the polity-vs.-policy distinction. This has important implications for our understanding of party competition on European integration