Gossip Algorithms for Distributed Signal Processing

Gossip algorithms are attractive for in-network processing in sensor networks because they do not require any specialized routing, there is no bottleneck or single point of failure, and they are robust to unreliable wireless network conditions. Recently, there has been a surge of activity in the computer science, control, signal processing, and information theory communities, developing faster and more robust gossip algorithms and deriving theoretical performance guarantees. This article presents an overview of recent work in the area. We describe convergence rate results, which are related to the number of transmitted messages and thus the amount of energy consumed in the network for gossiping. We discuss issues related to gossiping over wireless links, including the effects of quantization and noise, and we illustrate the use of gossip algorithms for canonical signal processing tasks including distributed estimation, source localization, and compression.Comment: Submitted to Proceedings of the IEEE, 29 page

Visibility, Gossip and Intimate Neighbourly Knowledges (Findings paper no. 7)

Findings papers associated with ESRC-funded research project, 'Social Geographies of Rural Mental Health' (R000 23 8453)

British Asian families and the use of child and adolescent mental health services: a qualitative study of a hard to reach group

We explored attitudes to and experiences of Child and Adolescent Mental Health Services (CAMHS) among families of South Asian origin who are underrepresented as service-users in an area of a Scottish city with a high concentration of people of South Asian origin. Six community focus groups were conducted, followed by semi-structured interviews with families who had used CAMHS and with CAMHS professionals involved in those families’ cases. Lastly, parents of children who had problems usually referred to CAMHS but who had not used the service were interviewed. Qualitative analysis of transcripts and notes was undertaken using thematic and logical methods. Participants consisted of 35 adults who identified themselves as Asian and had children; 7 parents and/or the young service users him-herself; 7 health care professionals involved in the young person's care plus 5 carers of 6 young people who had not been referred to CAMHS, despite having suitable problems. Focus groups identified the stigma of mental illness and the fear of gossip as strong disincentives to use CAMHS. Families who had been in contact with CAMHS sought to minimise the stigma they suffered by emphasising that mental illness was not madness and could be cured. Families whose children had complex emotional and behavioural problems said that discrimination by health, education and social care professionals exacerbated their child's difficulties. Families of children with severe and enduring mental illness described tolerating culturally inappropriate services. Fear of gossip about children's ‘madness’ constituted a major barrier to service use for Asian families in this city. Given the widespread nature of the concern over the stigma of children's mental illness, it should be considered in designing culturally competent services for children's mental health

Gossip at Work: Unsanctioned Evaluative Talk in Formal School Meetings

This article uses a form of linguistic ethnography to analyze videotaped recordings of gossip that took place during formal school meetings. By comparing this gossip data against existing models of gossip based on data collected in informal settings, we identify eleven new response classes, including four forms of indirectness that operate to cloak gossip under ambiguity, and seven forms of avoidance that change the trajectory of gossip. In doing so, this article makes three larger contributions. First, it opens a new front in research on organizational politics by providing an empirically grounded, conceptually rich vocabulary for analyzing gossip in formal contexts. Second, it contributes to knowledge about social interactions in organizations. By examining gossip talk embedded within a work context, this project highlights the nexus between structure, agency, and interaction. Third, it contributes to understandings of gossip in general. By examining gossip in a context previously unexamined, this project provides analytical leverage for theorizing conditions under which gossip is likely and when it will take various forms

Style over Substance?: Fashion, Spectacle and Narrative in Contemporary US Television

Previous scholarship on fashion and film has debated the aesthetic role played by onscreen costume. Yet there has been little exploration of fashion and its use in television. Existing work on fashion in onscreen media has approached the debate from a textual perspective, and such work has been informed by the longstanding assumption that fashion acts primarily as ‘spectacle’, disrupting the economy of narrative flow. This article seeks to challenge this assumption by arguing that previous work is limited by the wider conceptual and methodological problems of purely textual approaches. Using CW’s Gossip Girl as a case study, the author suggests that a mixed method approach to the study of costume (using both textual analysis and reception studies) provides a more productive foundation upon which to begin to examine the function of onscreen fashion in contemporary US television. Such an approach may have particular importance in understanding how costume in ‘fashion-forward’ television can be best understood if one steps beyond the text to explore the sense-making of viewers, the intentions of costume designers and the relationship between viewers, the shows and the wider fashion market

Global Computation in a Poorly Connected World: Fast Rumor Spreading with No Dependence on Conductance

In this paper, we study the question of how efficiently a collection of interconnected nodes can perform a global computation in the widely studied GOSSIP model of communication. In this model, nodes do not know the global topology of the network, and they may only initiate contact with a single neighbor in each round. This model contrasts with the much less restrictive LOCAL model, where a node may simultaneously communicate with all of its neighbors in a single round. A basic question in this setting is how many rounds of communication are required for the information dissemination problem, in which each node has some piece of information and is required to collect all others. In this paper, we give an algorithm that solves the information dissemination problem in at most $O(D+\text{polylog}{(n)})$ rounds in a network of diameter $D$, withno dependence on the conductance. This is at most an additive polylogarithmic factor from the trivial lower bound of $D$, which applies even in the LOCAL model. In fact, we prove that something stronger is true: any algorithm that requires $T$ rounds in the LOCAL model can be simulated in $O(T +\mathrm{polylog}(n))$ rounds in the GOSSIP model. We thus prove that these two models of distributed computation are essentially equivalent