A review on DISC 2005, the 19th International Symposium on Distributed Computing

DISC is an international symposium on the theory, design, analysis, implementation and application of distributed systems and networks. The well-known International Symposium on Distributed Computing is organized annually in cooperation with the European Association for Theoretical Computer Science (EATCS). This is a review on the 19th International Symposium on Distributed Computing, which took place in Kraków, Poland, on September 26--29, 2005. The proceedings of DISC 2005 are published by Springer, as volume 3724 of the Lecture Notes in Computer Science (LNCS) series. The conference website can be found at www.mimuw.edu.pl/~disc2005.Postprint (published version

Byzantine state machine replication for the masses

Tese de doutoramento, Informática (Ciência da Computação), Universidade de Lisboa, Faculdade de Ciências, 2018The state machine replication technique is a popular approach for building Byzantine fault-tolerant services. However, despite the widespread adoption of this paradigm for crash fault-tolerant systems, there are still few examples of this paradigm for real Byzantine fault-tolerant systems. Our view of this situation is that there is a lack of robust implementations of Byzantine fault-tolerant state machine replication middleware, and that the performance penalty is too high, specially for geo-replication. These hindrances are tightly coupled to the distributed protocols used for enforcing such resilience. This thesis has the objective of finding methodologies for enhancing robustness and performance of state machine replication systems. The first contribution is Mod-SMaRt, a modular protocol that preserves optimal latency in terms of the communications steps exchanged among processes. By being a modular protocol, it becomes simpler to validate and implement, thus resulting in greater robustness; by also preserving optimal message-exchanges among processes, the protocol is capable of delivering desirable performance. The second contribution is concerned with implementing Mod-SMaRt into BFTSMART, a reliable and high-performance codebase that was maintained and improved over the entire course of the PhD that offers multicore-awareness, reconfiguration support, and a flexible API. The third contribution presents WHEAT, a protocol derived from Mod-SMaRt that uses optimizations shown to be effective in reducing latency via a practical evaluation conducted in a geo distributed environment. We additionally conducted an evaluation of both BFT-SMART and WHEAT applied to a relational database middleware and an ordering service for a permissioned blockchain platform. These evaluations revealed encouraging results for both systems and validated our work conducted in the geo-distributed context.A técnica de replicação máquina de estados é um paradigma popular usado em vários sistemas distribuídos modernos. No entanto, apesar da adoção deste paradigma em sistemas reais tolerantes a faltas por paragem, ainda existem poucos exemplos de sistemas reais tolerantes a faltas bizantinas. Segundo a nossa experiência nesta área de investigação, isto deve-se ao fato de existirem poucas concretizações robustas para replicação máquina de estados tolerante a faltas bizantinas, assim como uma perda de desempenho demasiado elevada, especialmente em ambientes geo-replicados. A razão fundamental para a existência destes obstáculos vem dos protocolos distribuídos necessários para assegurar este tipo de resiliência. Esta tese tem como objetivo explorar metodologias para a robustez e eficiência da replicação máquina de estados. A primeira contribuição da tese é o algoritmo Mod-SMaRt, um protocolo modular que preserva latência ótima em termos de passos de comunicação executados pelos processos. Sendo um protocolo modular, torna-se mais simples de validar e concretizar, o que resulta em maior robustez; ao preservar troca de mensagens ótima entre processos, também é capaz de entregar um desempenho desejável. A segunda contribuição consiste em concretizar o protocolo Mod SMaRt na ferramenta BFT-SMART, uma biblioteca fiável de alto desempenho, mantida e melhorada ao longo de todo o período correspondente ao doutoramento, capaz de suportar arquiteturas multi-núcleo, reconfiguração do grupo de réplicas, e uma API de programação flexível. A terceira contribuição consiste em um protocolo derivado do Mod-SMaRt designado WHEAT, que usa otimizações que demostraram serem eficientes na redução da latência segundo uma avaliação prática em ambiente geo-replicado. Adicionalmente, foram também realizadas avaliações de ambos os protocolos quando aplicados num middleware para base de dados relacionais, e num serviço de ordenação para uma plataforma blockchain. Ambas as avaliações revelam resultados encorajadores para ambos os sistemas e validam o trabalho realizado em contexto geo-distribuído.Projeto IRCoC (PTDC/EEI-SCR/6970/2014); Comissão Europeia, FP7 (Seventh Framework Programme for Research and Technological Development), projetos FP7/2007-2013, ICT-25724

The Heart of Everything in the Middle of Nowhere: The Role of Rural Identity in the Formation and Deployment of Political Attitudes in Pennsylvania

The world of American politics continues to infiltrate households across the United States as technological advancement extends the reach of breaking news and government action. With this expanding reach, communities all over the country are digesting and contemplating their place in national politics more fervently than ever. At the crux of this discussion is the backbone of political engagement and action—identity and its resulting political attitudes. For decades, partisanship has been a point of contention amongst American citizens. Cities across the nation showcase protests, demonstrations, town hall meetings, and more illustrating citizens’ care for their democratized input in government affairs. But what about those in the quieter parts of America? Until recently, rural America has been overlooked (and underseen) by the social and political sciences. This study illuminates the rural perspective on attitudes toward politics and peers as well as the role of rural identity in attitude formation. As a state with multiple kinds of rurality (suburbia, exurbia, rural farmland, small towns, and Appalachia), Pennsylvania proves worthy of its own analysis—particularly as it finds itself at the heart of political action as a battleground and swing state since the 2016 presidential election. Utilizing in-depth interviews from rural and small-town Pennsylvanians and observational data from the areas in which they live, this study explores rural Americans’ input on their individual contributions to government affairs as well as rural political attitudes and community needs/expectations from their elected officials— ultimately offering a renewed and under-considered perspective on rural identity and rural political attitudes

Negotiating ludic normativity in Facebook meme pages

Title: Negotiating ludic normativity in Facebook meme pages Author: Ondřej Procházka Affiliation: Department of Culture Studies, Tilburg School of Humanities and Digital Sciences This thesis explores the capacity of Internet memes to inflect social realities in the communities organized around them on social media, particularly Facebook. Memes are not mere playful ‘jokes’ or ‘parodies’ spreading virally on the Internet in countless variations, they are also powerful tools for political investment aimed to sway public attention and opinions. Memes have been increasingly documented as a vital component in the unprecedented spread and ‘normalization’ of hateful sentiments and ideologies characterized by ‘fake news’ and ‘post-truth’ politics appealing to emotions rather than ‘facts’ in the digital mainstream. Based on author’s more than five-year observation of communities around Countryball memes, this work argues that much of the socio-cultural and communicative dynamics involving memes can be understood in terms of ludic play. The object of the study – Countryballs memes – are simple meme-comics featuring ball-shaped creatures in colors denoting nation-states while satirically reinventing international ‘drama’ through the prism of socio-cultural and linguistic stereotypes. Having become a household name among memes, Countryballs offer communicative resources to playfully engage not only with wider socio-political issues, but also to with the linguistic, semiotic and ideological boundaries of our communicative norms shaped by the affordances of social media. The present work demonstrates how play can be used as a useful concept for understanding not only how matters of public attention are packed, framed and transmitted in the digital culture via (Countryball) memes, but more importantly how such matters are in fact interpreted by those who engage with them. More specifically, it shows how play enables alternative modes of expression and meaning making with different normative patterns and preferences which stand outside ‘standard’, ‘rational’ or ‘civil’ expectations. And it is precisely ludic play that fosters different types of communication and sociality which are often done ‘just for fun’, however serious or offensive their effects may be. To identify these effects and their implications in the contemporary digital age, the thesis employs a discourse-analytical methodology informed by current advances in digital ethnography and sociolinguistics. It focuses on negotiations among participants in memetic communities about what counts as ‘appropriate’, ‘acceptable’ or ‘correct’ in their socio-communicative behavior. Together in four case studies, the present work provides a comprehensive account of how participants articulate, police, break and re-construct ludic normativity in connection with recent socio-political issues and digital culture at large. This includes the role of memes in the newly emerging forms of communication, in the rise of populism and nationalism, algorithmic manipulation and exploitation, curating digital content and more. The concept of play is continually revisited throughout the discussion against the developments in the scholarship on Internet memes and their ludic genealogy. In doing so, the thesis also revisits some of the traditional concepts such as the notion of ‘community’ and ‘communicative competence’ to arrive at more precise accounts of the concrete processes of globalization and digitalization in our societies and their effects

Human Rights Treaty Commitment and Compliance: A Machine Learning-based Causal Inference Approach

Why do states ratify international human rights treaties? How much do human rights treaties influence state behaviors directly and indirectly? Why are some human rights treaty monitoring procedures more effective than others? What are the most predictively and causally important factors that can reduce and prevent state repression and human rights violations? This dissertation provide answers to these keys causal questions in political science research, using a novel approach that combines machine learning and the structural causal model framework. The four research questions are arranged in a chronological order that refects the causal process relating to international human rights treaties, going from (a) the causal determinants of treaty ratification to (b) the causal mechanisms of human rights treaties to (c) the causal effects of human rights treaty monitoring procedures to (d) other factors that causally influence human rights violations. Chapter 1 identifies the research traditions within which this dissertation is located, offers an overview of the methodological advances that enable this research, specifies the research questions, and previews the findings. Chapters 2, 3, 4, and 5 present in chronological order four empirical studies that answer these four research questions. Finally, Chapter 6 summarizes the substantive findings, suggests some other research questions that could be similarly investigated, and recaps the methodological approach and the contributions of the dissertation

FinBook: literary content as digital commodity

This short essay explains the significance of the FinBook intervention, and invites the reader to participate. We have associated each chapter within this book with a financial robot (FinBot), and created a market whereby book content will be traded with financial securities. As human labour increasingly consists of unstable and uncertain work practices and as algorithms replace people on the virtual trading floors of the worlds markets, we see members of society taking advantage of FinBots to invest and make extra funds. Bots of all kinds are making financial decisions for us, searching online on our behalf to help us invest, to consume products and services. Our contribution to this compilation is to turn the collection of chapters in this book into a dynamic investment portfolio, and thereby play out what might happen to the process of buying and consuming literature in the not-so-distant future. By attaching identities (through QR codes) to each chapter, we create a market in which the chapter can ‘perform’. Our FinBots will trade based on features extracted from the authors’ words in this book: the political, ethical and cultural values embedded in the work, and the extent to which the FinBots share authors’ concerns; and the performance of chapters amongst those human and non-human actors that make up the market, and readership. In short, the FinBook model turns our work and the work of our co-authors into an investment portfolio, mediated by the market and the attention of readers. By creating a digital economy specifically around the content of online texts, our chapter and the FinBook platform aims to challenge the reader to consider how their personal values align them with individual articles, and how these become contested as they perform different value judgements about the financial performance of each chapter and the book as a whole. At the same time, by introducing ‘autonomous’ trading bots, we also explore the different ‘network’ affordances that differ between paper based books that’s scarcity is developed through analogue form, and digital forms of books whose uniqueness is reached through encryption. We thereby speak to wider questions about the conditions of an aggressive market in which algorithms subject cultural and intellectual items – books – to economic parameters, and the increasing ubiquity of data bots as actors in our social, political, economic and cultural lives. We understand that our marketization of literature may be an uncomfortable juxtaposition against the conventionally-imagined way a book is created, enjoyed and shared: it is intended to be

Network Poetics: Studies in Early Modern Literary Collaboration

Literature scholars often consider the seventeenth century to be the period in which the role of the individual author as we know it today was consolidated, strengthened, or even invented. Scholars of collaboration, most notably Jeffrey Masten in his book Textual Intercourse, tend to treat the phenomenon of joint literary work as limited to coauthorship and either to specific genres (usually drama) or specific periods in time (usually 1590 to 1620). In this model, collaborative environments give way to authorial ones, particularly in Restoration England as the position of the professional author was strengthened by changes in publishing practices. However scholars of book history from Donald McKenzie to Harold Love to Lisa Jardine have shown that exchange, association, and relationality were the rule rather than the exception throughout the period. I extend these principles outside print and manuscript practices as I show that the many social communities an author engages with affect the creative work that they produce, and I make a case that the techniques of network analysis provide an important perspective on the collectivity of literary production. In so doing I argue that early modern literary production is driven by sets of relationships which give character to literary works, and I discuss social relations and modes of collaboration that have identifiable and distinct effects on literary forms in different genres and historical periods

Network Propaganda

"Is social media destroying democracy? Are Russian propaganda or ""Fake news"" entrepreneurs on Facebook undermining our sense of a shared reality? A conventional wisdom has emerged since the election of Donald Trump in 2016 that new technologies and their manipulation by foreign actors played a decisive role in his victory and are responsible for the sense of a ""post-truth"" moment in which disinformation and propaganda thrives. Network Propaganda challenges that received wisdom through the most comprehensive study yet published on media coverage of American presidential politics from the start of the election cycle in April 2015 to the one year anniversary of the Trump presidency. Analysing millions of news stories together with Twitter and Facebook shares, broadcast television and YouTube, the book provides a comprehensive overview of the architecture of contemporary American political communications. Through data analysis and detailed qualitative case studies of coverage of immigration, Clinton scandals, and the Trump Russia investigation, the book finds that the right-wing media ecosystem operates fundamentally differently than the rest of the media environment. The authors argue that longstanding institutional, political, and cultural patterns in American politics interacted with technological change since the 1970s to create a propaganda feedback loop in American conservative media. This dynamic has marginalized centre-right media and politicians, radicalized the right wing ecosystem, and rendered it susceptible to propaganda efforts, foreign and domestic. For readers outside the United States, the book offers a new perspective and methods for diagnosing the sources of, and potential solutions for, the perceived global crisis of democratic politics.

Why incumbents survive : authoritarian dominance and regime persistence in Russia

Defence date: 20 September 2018Examining Board: Hanspeter Kriesi, European University Institute (Supervisor); Vladimir Gelman, European University at Saint Petersburg; Anton Hemerijck, European University Institute; John Ora Reuter, University of Wisconsin, MilwaukeeWhy do incumbents in electoral authoritarian regimes retain power? This study seeks to answer this fundamental question by linking electoral fraud and sincere voting for the incumbent with incumbent’s distributive politics and, accordingly, by looking at the puzzle of authoritarian survival from two perspectives. An elite-oriented incumbent’s strategy suggests that, unlike democracies, where distributive politics is primarily targeted at voters, authoritarian incumbents inevitably have to deliver benefits to political elites in order to secure their loyalty, which is eventually converted into electoral fraud, repression of the opposition forces, persecution of the media, refraining from challenging the incumbent, and other authoritarian policy outcomes. A mass-oriented incumbent’s strategy implies that, if electoral competition is not meaningless, authoritarian incumbents also have to deliver benefits to the general public in order to secure genuine mass support, which eventually results in sincere voting for the incumbent. This argument is tested on cross-regional data from Russia as a prominent case of persistent electoral authoritarianism. The analysis begins with a poorly studied but an immanent element of any kind of authoritarianism – electoral fraud perpetrated by political elites and their local agents. Having developed a novel measure of electoral fraud forensics based on quintile regression, I demonstrate that electoral fraud in the Russian 2000–2012 presidential elections played a typical role for electoral authoritarianism: it was neither outcome-changing as it occurs in closed authoritarian regimes nor intrinsically sporadic as in electoral democracies, but it was widespread and hardly avoidable by the incumbent. The study then dwells on examination of the federal transfers to regional budgets as a type of public and formally legal yet politically motivated distribution. Not only were the central transfers allocated to the regions according to the principle of electoral allegiance to the federal incumbent presidents, but it also appears that, as authoritarian regime was consolidating over time, the larger amount of transfer funds was allocated to the bureaucracy (as part of the regime’s elite clientele) in order to secure its loyalty. The loyalty of regional elites, in its turn, was eventually converted into distinct authoritarian policy outcomes, including electoral fraud and persecution of the media. This resulted in a general bias of the electoral playing field and, thereby, contributed to sustaining the authoritarian equilibrium. By contrast, the analysis finds no evidence that the politicized transfers influenced sincere voting for the incumbent. These mixed findings indicate that popular support under electoral authoritarianism is still puzzling and calls for further examination, whereas securing loyalty of political elites via delivering them clientelist benefits is crucial for regime survival in personalist electoral dictatorships