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We present the results of an experimental study on the jamming/flowing transition. A suspension of neutrally buoyant large particles flows in an horizontal rectangular duct, where an artificial restriction triggers jamming. We show that the avalanche distribution size is exponential, that is memoryless. We further demonstrate that the avalanche size diverges when the restriction size approaches a critical value and that this divergence is well described by a power law. The parameters (critical opening size and divergence velocity) are compared to literature values and show a strong similarity with others systems. Another result of this paper is the study of the influence of the particle morphology. We show that, for a moderate restriction size, the dead-zone formed right upstream of the restriction is larger for angular particles but, paradoxically, that the avalanche size is larger for polyhedra compared to spheres by at least one order of magnitude. [ABSTRACT FROM AUTHOR]

We present the design of DISco, a storage and communication middleware that enables distributed and task-centric autonomic control of networks. DISco allows multi-agent identification of anomalous situations (challenges) and assists coordinated remediation that will maintain service at an acceptable level, although degraded. The history of agents decisions, their context and outcomes is tracked as the situation evolves, and information is automatically gathered and organised to ease further human-assisted diagnosis. We then explore the feasibility of using state of the art peer-to-peer publish/subscribe and storage systems as building blocks for this service. The ability of those systems to support range queries and aggregation will be a key factor for their suitability to the task. [ABSTRACT FROM PUBLISHER]