Seeds: the social internet feed caching and dissemination architecture

Syndicated content in the Internet has been a huge success ever since the early days of RSS 0.9 and MyNetscape. Currently, it is the cornerstone of content push, ranging from podcasts to emerging Web 2.0 sites such as Friend-Feed and Plexus. Unfortunately, the simple technology that makes publication and subscription very simple and flexible, thus explaining in part its success, is also limiting its usefulness in more demanding applications. This paper proposes a novel distributed architecture for feed caching and dissemination. It leverages social networks as promoters of discovery and aggregation, and peer-to-peer protocols for content distribution, while providing an evolutionary upgrade path that does not disrupt current infrastructure or require changes to publishers’ or consumers’ habits

A topological proof of Eliaz's unified theorem of social choice theory (forthcoming in "Applied Mathematics and Computation")

Recently Eliaz(2004) has presented a unified framework to study (Arrovian) social welfare functions and non-binary social choice functions based on the concept of 'preference reversal'. He showed that social choice rules which satisfy the property of preference reversal and a variant of the Pareto principle are dictatorial. This result includes the Arrow impossibility theorem and the Gibbard-Satterthwaite theorem as its special cases. We present a concise proof of his theorem using elementary concepts of algebraic topology such as homomorphisms of homology groups of simplicial complexes induced by simplicial mappings.

Enabling Social Applications via Decentralized Social Data Management

An unprecedented information wealth produced by online social networks, further augmented by location/collocation data, is currently fragmented across different proprietary services. Combined, it can accurately represent the social world and enable novel socially-aware applications. We present Prometheus, a socially-aware peer-to-peer service that collects social information from multiple sources into a multigraph managed in a decentralized fashion on user-contributed nodes, and exposes it through an interface implementing non-trivial social inferences while complying with user-defined access policies. Simulations and experiments on PlanetLab with emulated application workloads show the system exhibits good end-to-end response time, low communication overhead and resilience to malicious attacks.Comment: 27 pages, single ACM column, 9 figures, accepted in Special Issue of Foundations of Social Computing, ACM Transactions on Internet Technolog

Non-bossy social classification

We consider the problem of how societies should be partitioned into classes if individuals express their views about who should be put with whom in the same class. A non-bossy social aggregator depends only on those cells of the individual partitions the society members classify themselves in. This fact allows us to concentrate on a corresponding 'opinion graph' for each profile of views. By means of natural sovereignty, liberalism, and equal treatment requirements, we characterize the non-bossy aggregators generating partitions in which the social classes are refinements of the weakly connected components of the opinion graph. --social aggregation,group identity,liberalism, non-bossiness

Information and Communication Flows through Community Multimedia Centers: Perspectives from Mozambican Communities.

Community multimedia centers (CMCs) are considered by initiating agencies as instruments able to inform, entertain and educate the population, as well as to offer them a voice into knowledge society and to public initiatives. This article presents a quali-quantitative content analysis of 230 interviews held with staff members, users of the venues, people of the community who listen to their radio component but do not use their telecenters, and community members not using CMCs. The sample includes 10 CMCs around Mozambique. The purpose of the study is to investigate the perception of local communities of inbound, outbound, and shared information and communication flows connected to CMCs. Results highlight how CMCs are perceived as inbound information enablers, mostly by means of their community radio component, and as means to share information and communication within the communities' boundaries. Yet, CMCs still do not appear to be widely recognized as participation means to a reality that transcends the communities' physical borders

A Unifying Impossibility Theorem

This paper considers social choice correspondences assigning a choice set to each non-empty subset of social alternatives. We impose three requirements on these correspondences: unanimity, independence of preferences over infeasible alternatives and choice consistency with respect to choices out of all possible alternatives. With more than three social alternatives and the universal preference domain, any social choice correspondence that satisfies our requirements is serially dictatorial. A number of known impossibility theorems — including Arrow’s Impossibility Theorem, the Muller-Satterthwaite Theorem and the impossibility theorem under strategic candidacy — follow as corollaries. Our new proof highlights the common logical underpinnings behind these theorems.