#Bigbirds never die: Understanding social dynamics of emergent hashtag

We examine the growth, survival, and context of 256 novel hashtags during the 2012 U.S. presidential debates. Our analysis reveals the trajectories of hashtag use fall into two distinct classes: “winners” that emerge more quickly and are sustained for longer periods of time than other “also-rans” hashtags. We propose a “conversational vibrancy” framework to capture dynamics of hashtags based on their topicality, interactivity, diversity, and prominence. Statistical analyses of the growth and persistence of hashtags reveal novel relationships between features of this framework and the relative success of hashtags. Specifically, retweets always contribute to faster hashtag adoption, replies extend the life of “winners” while having no effect on “also-rans.” This is the first study on the lifecycle of hashtag adoption and use in response to purely exogenous shocks. We draw on theories of uses and gratification, organizational ecology, and language evolution to discuss these findings and their implications for understanding social influence and collective action in social media more generally

Opinion dynamics: models, extensions and external effects

Recently, social phenomena have received a lot of attention not only from social scientists, but also from physicists, mathematicians and computer scientists, in the emerging interdisciplinary field of complex system science. Opinion dynamics is one of the processes studied, since opinions are the drivers of human behaviour, and play a crucial role in many global challenges that our complex world and societies are facing: global financial crises, global pandemics, growth of cities, urbanisation and migration patterns, and last but not least important, climate change and environmental sustainability and protection. Opinion formation is a complex process affected by the interplay of different elements, including the individual predisposition, the influence of positive and negative peer interaction (social networks playing a crucial role in this respect), the information each individual is exposed to, and many others. Several models inspired from those in use in physics have been developed to encompass many of these elements, and to allow for the identification of the mechanisms involved in the opinion formation process and the understanding of their role, with the practical aim of simulating opinion formation and spreading under various conditions. These modelling schemes range from binary simple models such as the voter model, to multi-dimensional continuous approaches. Here, we provide a review of recent methods, focusing on models employing both peer interaction and external information, and emphasising the role that less studied mechanisms, such as disagreement, has in driving the opinion dynamics. [...]Comment: 42 pages, 6 figure

Contributions to the Modelling of Auditory Hallucinations, Social robotics, and Multiagent Systems

165 p.The Thesis covers three diverse lines of work that have been tackled with the central endeavor of modeling and understanding the phenomena under consideration. Firstly, the Thesis works on the problem of finding brain connectivity biomarkers of auditory hallucinations, a rather frequent phenomena that can be related some pathologies, but which is also present in healthy population. We apply machine learning techniques to assess the significance of effective brain connections extracted by either dynamical causal modeling or Granger causality. Secondly, the Thesis deals with the usefulness of social robotics strorytelling as a therapeutic tools for children at risk of exclussion. The Thesis reports on the observations gathered in several therapeutic sessions carried out in Spain and Bulgaria, under the supervision of tutors and caregivers. Thirdly, the Thesis deals with the spatio-temporal dynamic modeling of social agents trying to explain the phenomena of opinion survival of the social minorities. The Thesis proposes a eco-social model endowed with spatial mobility of the agents. Such mobility and the spatial perception of the agents are found to be strong mechanisms explaining opinion propagation and survival

Migration systems, pioneers and the role of agency

The notion of a migration system is often invoked but it is rarely clearly defined or conceptualized. De Haas has recently provided a powerful critique of the current literature highlighting some important flaws that recur through it. In particular, migration systems tend to be identified as fully formed entities, and there is no theorization as to how they come into being. Moreover, there is no explanation of how they change in time, in particular how they come to decline. The inner workings – the mechanics – which drive such changes are not examined. Such critiques of migration systems relate to wider critiques of the concept of systems in the broader social science literature, where they are often presented as black boxes in which human agency is largely excluded. The challenge is how to theorize the mechanics by which the actions of people at one time contribute to the emergence of systemic linkages at a later time. This paper focuses on the genesis of migration systems and the notion of pioneer migration. It draws attention both to the role of particular individuals, the pioneers, and also the more general activity of pioneering which is undertaken by many migrants. By disentangling different aspects of agency, it is possible to develop hypotheses about how the emergence of migrations systems is related to the nature of the agency exercised by different pioneers or pioneering activities in different contexts.migration systems, agency, emergence, pioneer migrants, migrant networks, social capital

Transversality and Transition: Branching to New Regional Path Dependence

Since Paul David published his economic histories of path dependent innovation the subject has exerted fascination upon scholars of innovation, technological change and, latterly, regional scientists and economic geographers. This paper speaks to the third and fourth of these communities in the main, though it may have theoretical and empirical elements of interest to the first two as well. The paper begins with an overview of recent perspectives and critiques concerning the relevance of the path dependence concept to the understanding of regional economic development and its associated governance. It then goes on to discuss the contribution of evolutionary economic geography to thinking about ÔbranchingÕ from path dependence and the creation of new paths. Evidence for key generic spatial processes of path transition is provided before the main content of the paper concludes with new insights into the contributions of regional innovation policy to path evolution. Conclusions are then drawn.regional path dependence, branching, transition, transversality

Cognitive Computation sans Representation

The Computational Theory of Mind (CTM) holds that cognitive processes are essentially computational, and hence computation provides the scientific key to explaining mentality. The Representational Theory of Mind (RTM) holds that representational content is the key feature in distinguishing mental from non-mental systems. I argue that there is a deep incompatibility between these two theoretical frameworks, and that the acceptance of CTM provides strong grounds for rejecting RTM. The focal point of the incompatibility is the fact that representational content is extrinsic to formal procedures as such, and the intended interpretation of syntax makes no difference to the execution of an algorithm. So the unique 'content' postulated by RTM is superfluous to the formal procedures of CTM. And once these procedures are implemented in a physical mechanism, it is exclusively the causal properties of the physical mechanism that are responsible for all aspects of the system's behaviour. So once again, postulated content is rendered superfluous. To the extent that semantic content may appear to play a role in behaviour, it must be syntactically encoded within the system, and just as in a standard computational artefact, so too with the human mind/brain - it's pure syntax all the way down to the level of physical implementation. Hence 'content' is at most a convenient meta-level gloss, projected from the outside by human theorists, which itself can play no role in cognitive processing

Contributions to the Modelling of Auditory Hallucinations, Social robotics, and Multiagent Systems

165 p.The Thesis covers three diverse lines of work that have been tackled with the central endeavor of modeling and understanding the phenomena under consideration. Firstly, the Thesis works on the problem of finding brain connectivity biomarkers of auditory hallucinations, a rather frequent phenomena that can be related some pathologies, but which is also present in healthy population. We apply machine learning techniques to assess the significance of effective brain connections extracted by either dynamical causal modeling or Granger causality. Secondly, the Thesis deals with the usefulness of social robotics strorytelling as a therapeutic tools for children at risk of exclussion. The Thesis reports on the observations gathered in several therapeutic sessions carried out in Spain and Bulgaria, under the supervision of tutors and caregivers. Thirdly, the Thesis deals with the spatio-temporal dynamic modeling of social agents trying to explain the phenomena of opinion survival of the social minorities. The Thesis proposes a eco-social model endowed with spatial mobility of the agents. Such mobility and the spatial perception of the agents are found to be strong mechanisms explaining opinion propagation and survival

Firm relocation: state of the art and research prospects

This paper deals with firm relocation. Firm relocation is a particular form of locational adjustment of the firm and one of the possible ways to adjust to changes in markets, preferences of consumers, environmental regulations, technological progress etc. In section 2 we will treat the neo-classical, the behavioural, and the institutional approaches respectively. Next, a historical review of firm relocation research is presented, in section 3. It starts with the "classical studies" of the first post-war period, followed by a description of what can be called the golden era of firm relocation studies according to the large number of studies: the nineteen sixties and seventies. This section ends with an overview of firm relocation studies of the last decades of the previous century. In section 4 we present an example an empirical study that addresses relevant firm relocation for the present era by means of a statistical model estimated on data for individual firms of the Netherlands. We conclude the chapter with a discussion of why and how the firm relocation research frontier can be pushed forward and give suggestions for further research also in relation with policy.

The Provision of Security in an Age of Austerity: The Transformation of NATO, the Production of Trans-scalar Spaces of Intervention, and the Future of the West

This dissertation traces how NATO has evolved from a defensive alliance concerned with the collective defense of its members to a global security nexus engaged in preemptive crisis management interventions. In reaction to what I see as the limitations of traditional methodological approaches in the discipline of International Relations I develop an alternative research program that places the production of space and trans-scalar interactions at the heart of my analysis. I discuss how NATO reacted to the end of the Cold War and the emergence of a new geoeconomic order as neoliberalism spread across the planet and the United States became a global hegemon. Particular attention is paid to the effect of the 2007 Global Financial Crisis upon NATO. The new era of austerity, which followed, accelerated and deepened changes that had begun within NATO starting in the 1990s. NATO now sought to form partnerships with countries across the world and adopted a far broader understanding of security that saw it intervening far from its traditional European area of operations. The impact of austerity is also readily apparent in the two interventions NATO has carried out thus far in the 21st century in Afghanistan and Libya. NATO’s sustained peacekeeping operation in Afghanistan contrasts sharply with its aerial assault on Libya in 2011. I posit that the intervention in Libya can best be understood as a trans-scalar space of intervention, a concept I develop to analyze how and why NATO became embroiled in the country. I conclude the dissertation by examining Russia’s recent actions in Ukraine and hypothesize that they will lead to a renewed focus on collective defense within NATO