Fast Discrete Consensus Based on Gossip for Makespan Minimization in Networked Systems

In this paper we propose a novel algorithm to solve the discrete consensus problem, i.e., the problem of distributing evenly a set of tokens of arbitrary weight among the nodes of a networked system. Tokens are tasks to be executed by the nodes and the proposed distributed algorithm minimizes monotonically the makespan of the assigned tasks. The algorithm is based on gossip-like asynchronous local interactions between the nodes. The convergence time of the proposed algorithm is superior with respect to the state of the art of discrete and quantized consensus by at least a factor O(n) in both theoretical and empirical comparisons

Global Migration, Local Communities and the Absent State: Resentment and Resignation on the Italian Island of Lampedusa

This article draws on the case of the Italian island of Lampedusa to explore how global migration nurtures populist discourses at the local community level. Lampedusa, a key transitory site for migrants crossing the Mediterranean Sea to reach Europe, revealed strong concerns about the neglect of local public services and the mismanagement of migration. These concerns fed a deep sense of resentment that the islanders addressed toward the Italian state, resonating with the experiences of other communities around the world and reifing populist ideas. Based on interviews and ethnographic fieldwork, and disseminated by a film documentary, the article reveals how apparently similar global populist experiences disclose different local worries and long-term historical processes. In doing so, it unfolds the socially situated nature of Lampedusa’s populist resentment and so it contributes to a more thorough understanding of the relation between local communities and the national state as it is being reflected through debates on migration

Imagined mobilities and the materiality of migration: the search for 'anchored lives' in post-recession Europe

The dichotomy between mobility and migration became a disputed conceptual distinction during the expansion of European Free Movement between the 1990s and early 2000s. Then, mobility literature sought to open a new chapter in the study of contemporary human lives by theorising them as ‘liquid' and suggesting movement as their universalising feature. Intra-European migrants have been increasingly characterised by their ‘mobility spirit' and therefore as legally unconstrained, driven by individualised behaviours and engaged in temporary cross-border movements. Set in the backdrop of post-recession intra-European migration, this paper explores how migrants’ mobility spirit is being negotiated with the need to anchor their lives to stable relationships and to the attainment of financial security. It draws on interviews conducted with Italian young adults in London and shows how imagined projects of temporary mobility materialize into longer-term migration experiences where the search for anchored rather than liquid lives becomes more prominent. Henceforth, the analysis challenges the typified profile of EU movers by pointing at their quest for social and financial stability and by exposing their personal vulnerabilities while making the theoretical distinction between migration and mobility less relevant

'Being modern and modest': South Asian young British Muslims negotiating multiple influences on their identity

With the rise of multiculturalism in Britain the visibility of religion, in particularly Islam, has increased. A growing religious diversity has created new contexts and affected young people’s identity and transitions to adulthood. This article applies and extends Bourdieu’s theory of habitus and social fields to a new area: the study of how South Asian young Muslims living in England negotiate between the Muslim and British aspects of their identity. The set of individual dispositions (habitus), which originates in the family field under the influence of South Asian cultures and Islam, changes when it comes into contact with non-Islamic fields. As with the concept of habitus, identity involves reconciling individual dispositions and structural conditions. Based on qualitative insights emerging from 25 semi-structured interviews with young South Asian Muslims, the article presents different strategies of identity negotiations exemplifying the constant and complex interplay between individual agency and the social world

The use of film documentary in social science research: audio-visual accounts of the ‘migration crisis’ from the Italian island of Lampedusa

The importance of visual evidence – and particularly films and videos – has become more prominent with the fast pace of technological development that has made filming more easily accessible. Since the early 20th century, films have been used as a data collection method in social science research, but less attention has been given to their potential for research dissemination. It is well documented that visual representations are powerful means to broadcast public discourses. The Arab Spring in 2011 and the increasing movement of people across the Mediterranean Sea are a case in point. Images and videos of people trying to reach Europe have contributed to the construction of what is often referred to as the ‘Mediterranean migration crisis’. In this article, we explore the process of making a film documentary about the people in the Italian island of Lampedusa, a key transitory site for migrants, and how they deal with the challenges of this ‘crisis’ while trying to respond to the local struggles of their isolated community. Drawing on the analysis of ‘audio-visual accounts’ – as the filmed verbal elaborations that broadcast themes emerging from social science research – we reflect on the potential and drawbacks of film documentaries for both knowledge production and research dissemination

'A fish out of water?' The therapeutic narratives of class change

Young people from working class backgrounds remained mostly excluded from the widening educational participation which characterised postwar Britain. Based on 20 semi-structured interviews which were part of a wider study about ‘Social Participation and Identity’ (2008–2009), this article explores the unusual learning trajectories of a group of working class adults born in 1958, who participated in higher education (HE) in a context where most people from the same socio-economic backgrounds did not. Drawing on Bourdieu’s social theory, the findings suggest that different types of retrospective accounts were mobilised to reconcile working class habitus of origin and the perceived habitus as adults. Most research on working class and higher education focuses on the experiences of youth. By contrast, the use of retrospective accounts of adults has enabled the study to capture the implications that the educational trajectories have later in life. The authors consider these accounts a part of wider narratives that they define ‘therapeutic’. Therapeutic narratives were employed to come to terms with the ambivalence produced by social mobility. Therefore, respondents were negotiating the sense of exclusion attached to class change, and the acknowledgement of the opportunities associated with a working class habitus accessing new social fields viaeducation

Dynamic Resilient Containment Control in Multirobot Systems

In this article, we study the dynamic resilient containment control problem for continuous-time multirobot systems (MRSs), i.e., the problem of designing a local interaction protocol that drives a set of robots, namely the followers, toward a region delimited by the positions of another set of robots, namely the leaders, under the presence of adversarial robots in the network. In our setting, all robots are anonymous, i.e., they do not recognize the identity or class of other robots. We consider as adversarial all those robots that intentionally or accidentally try to disrupt the objective of the MRS, e.g., robots that are being hijacked by a cyber–physical attack or have experienced a fault. Under specific topological conditions defined by the notion of (r,s)-robustness, our control strategy is proven to be successful in driving the followers toward the target region, namely a hypercube, in finite time. It is also proven that the followers cannot escape the moving containment area despite the persistent influence of anonymous adversarial robots. Numerical results with a team of 44 robots are provided to corroborate the theoretical findings

Dynamic max-consensus with local self-tuning

This work describes a novel control protocol for multi-agent systems to solve the dynamic max-consensus problem. In this problem, each agent has access to an external timevarying scalar signal and has the objective to estimate and track the maximum among all these signals by exploiting only local communications. The main strength of the proposed protocol is that it is able to self-tune its internal parameters in order to achieve an arbitrary small steady-state error without significantly affecting the convergence time. We employ the proposed protocol in the context of distributed graph parameter estimations, such as size, diameter, and radius, and provide simulations in the scenario of open multi-agent systems. Copyright (C) 2022 The Authors

Robust reconstruction of the discrete state for a class of nonlinear uncertain switched systems

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