68,113 research outputs found

    HoPP: Robust and Resilient Publish-Subscribe for an Information-Centric Internet of Things

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    This paper revisits NDN deployment in the IoT with a special focus on the interaction of sensors and actuators. Such scenarios require high responsiveness and limited control state at the constrained nodes. We argue that the NDN request-response pattern which prevents data push is vital for IoT networks. We contribute HoP-and-Pull (HoPP), a robust publish-subscribe scheme for typical IoT scenarios that targets IoT networks consisting of hundreds of resource constrained devices at intermittent connectivity. Our approach limits the FIB tables to a minimum and naturally supports mobility, temporary network partitioning, data aggregation and near real-time reactivity. We experimentally evaluate the protocol in a real-world deployment using the IoT-Lab testbed with varying numbers of constrained devices, each wirelessly interconnected via IEEE 802.15.4 LowPANs. Implementations are built on CCN-lite with RIOT and support experiments using various single- and multi-hop scenarios

    On Constructing Persistent Identifiers with Persistent Resolution Targets

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    Persistent Identifiers (PID) are the foundation referencing digital assets in scientific publications, books, and digital repositories. In its realization, PIDs contain metadata and resolving targets in form of URLs that point to data sets located on the network. In contrast to PIDs, the target URLs are typically changing over time; thus, PIDs need continuous maintenance -- an effort that is increasing tremendously with the advancement of e-Science and the advent of the Internet-of-Things (IoT). Nowadays, billions of sensors and data sets are subject of PID assignment. This paper presents a new approach of embedding location independent targets into PIDs that allows the creation of maintenance-free PIDs using content-centric network technology and overlay networks. For proving the validity of the presented approach, the Handle PID System is used in conjunction with Magnet Link access information encoding, state-of-the-art decentralized data distribution with BitTorrent, and Named Data Networking (NDN) as location-independent data access technology for networks. Contrasting existing approaches, no green-field implementation of PID or major modifications of the Handle System is required to enable location-independent data dissemination with maintenance-free PIDs.Comment: Published IEEE paper of the FedCSIS 2016 (SoFAST-WS'16) conference, 11.-14. September 2016, Gdansk, Poland. Also available online: http://ieeexplore.ieee.org/document/7733372

    Age 5 cognitive development in England

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    Children’s development in the early years has been shown to be related to their success in later life in a range of areas including education, employment and crime. Determining why some children do better than others in the early years is a key issue for policy and is crucial in attempts to reduce inequalities. This research examines differences in early child development by examining the factors associated with the cognitive ability of children up to age 5 using cognitive assessments administered as part of the Millennium Cohort Study (MCS) and teacher reports of child ability. The results show that younger children, those with low birth weight, lower parental education, lower income and living in social housing is related both to lower achievement, on average. and the probability of being at the bottom of the distribution of cognitive scores at age 5

    Cognitive control: componential or emergent?

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    The past twenty-five years have witnessed an increasing awareness of the importance of cognitive control in the regulation of complex behavior. It now sits alongside attention, memory, language and thinking as a distinct domain within cognitive psychology. At the same time it permeates each of these sibling domains. This paper reviews recent work on cognitive control in an attempt to provide a context for the fundamental question addressed within this Topic: is cognitive control to be understood as resulting from the interaction of multiple distinct control processes or are the phenomena of cognitive control emergent

    Efficient Batch Update of Unique Identifiers in a Distributed Hash Table for Resources in a Mobile Host

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    Resources in a distributed system can be identified using identifiers based on random numbers. When using a distributed hash table to resolve such identifiers to network locations, the straightforward approach is to store the network location directly in the hash table entry associated with an identifier. When a mobile host contains a large number of resources, this requires that all of the associated hash table entries must be updated when its network address changes. We propose an alternative approach where we store a host identifier in the entry associated with a resource identifier and the actual network address of the host in a separate host entry. This can drastically reduce the time required for updating the distributed hash table when a mobile host changes its network address. We also investigate under which circumstances our approach should or should not be used. We evaluate and confirm the usefulness of our approach with experiments run on top of OpenDHT.Comment: To be presented at the 2010 International Workshop on Cloud Computing, Applications and Technologie

    Developing Materials for Deliberative Forums

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    When citizens deliberate together about important issues, they can reach decisions and take action together on problems that confront them. Deliberation does not require a certain kind of guide, or framework, or language, or facilitator, but, because it can be difficult to face such choices, supporting materials can make it easier. Many community groups, national organizations, and others, including the National Issues Forums (NIF), develop materials meant to help groups deliberate together over difficult public issues. Through its research, the Kettering Foundation has learned about the kinds of materials that can spark this public work. This document explores the important elements involved in going from an initial topic to having a complete issue guide suitable to use in the kinds of deliberative forums that are the hallmark of the NIF
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