17,924 research outputs found

    A network-aware framework for energy-efficient data acquisition in wireless sensor networks

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    Wireless sensor networks enable users to monitor the physical world at an extremely high fidelity. In order to collect the data generated by these tiny-scale devices, the data management community has proposed the utilization of declarative data-acquisition frameworks. While these frameworks have facilitated the energy-efficient retrieval of data from the physical environment, they were agnostic of the underlying network topology and also did not support advanced query processing semantics. In this paper we present KSpot+, a distributed network-aware framework that optimizes network efficiency by combining three components: (i) the tree balancing module, which balances the workload of each sensor node by constructing efficient network topologies; (ii) the workload balancing module, which minimizes data reception inefficiencies by synchronizing the sensor network activity intervals; and (iii) the query processing module, which supports advanced query processing semantics. In order to validate the efficiency of our approach, we have developed a prototype implementation of KSpot+ in nesC and JAVA. In our experimental evaluation, we thoroughly assess the performance of KSpot+ using real datasets and show that KSpot+ provides significant energy reductions under a variety of conditions, thus significantly prolonging the longevity of a WSN

    Addressing the Challenges in Federating Edge Resources

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    This book chapter considers how Edge deployments can be brought to bear in a global context by federating them across multiple geographic regions to create a global Edge-based fabric that decentralizes data center computation. This is currently impractical, not only because of technical challenges, but is also shrouded by social, legal and geopolitical issues. In this chapter, we discuss two key challenges - networking and management in federating Edge deployments. Additionally, we consider resource and modeling challenges that will need to be addressed for a federated Edge.Comment: Book Chapter accepted to the Fog and Edge Computing: Principles and Paradigms; Editors Buyya, Sriram

    Renewables 2005: Global Status Report

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    The Global Status Report provides an assessment of several renewables technologies -- small hydro, modern biomass, wind, solar, geothermal, and biofuels -- that are now competing with conventional fuels in four distinct markets: power generation, hot water and space heating, transportation fuels, and rural (off-grid) energy supplies. The report finds that government support for renewable energy is growing rapidly. At least 48 countries now have some type of renewable energy promotion policy, including 14 developing countries. Most targets are for shares of electricity production, typically 5-30 percent, by the 2010-2012 timeframe. Mandates for blending biofuels into vehicle fuels have been enacted in at least 20 states and provinces worldwide as well as in three key countries -- Brazil, China and India. Government leadership provides the key to market success, according to the report. The market leaders in renewable energy in 2004 were Brazil in biofuels, China in solar hot water, Germany in solar electricity, and Spain in wind power. The Global Status Report fills a gap in the international energy reporting arena, which has tended to neglect the emerging renewable energy technologies. Regular updates will be produced in the future. The report was produced and published by the Worldwatch Institute and released today at the Beijing International Renewable Energy Conference 2005, sponsored by the Government of China. This Conference brings together government and private leaders from around the world, providing a forum for international leadership on renewable energy and connects the wide variety of stakeholders that came together at the International Conference for Renewable Energies in Bonn, Germany, in 2004. The creation of REN21 was sponsored by the German Federal Ministry for Economic Cooperation and Development and the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. Formally established in Copenhagen in June 2005, REN21 is now supported by a steering committee of 11 governments, 5 intergovernmental organizations, 5 non-governmental organizations, and several regional, local, and private organizations
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