143,490 research outputs found

    An unstructured-grid software system for solving complex aerodynamic problems

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    A coordinated effort has been underway over the past four years to elevate unstructured-grid methodology to a mature level. The goal of this endeavor is to provide a validated capability to non-expert users for performing rapid aerodynamic analysis and design of complex configurations. The Euler component of the system is well developed, and is impacting a broad spectrum of engineering needs with capabilities such as rapid grid generation and inviscid flow analysis, inverse design, interactive boundary layers, and propulsion effects. Progress is also being made in the more tenuous Navier-Stokes component of the system. A robust grid generator is under development for constructing quality thin-layer tetrahedral grids, along with a companion Navier-Stokes flow solver. This paper presents an overview of this effort, along with a perspective on the present and future status of the methodology

    Paving the road toward Smart Grids through large-scale advanced metering infrastructures

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    Upgrading current electricity grid to the so-called Smart Grid represents one of the major engineering challenges ever. Hence, the road toward the Smart Grid will be long and needs to be paved gradually, certainly driving the next wave of research and innovation in both the energy and the ICT (Information and Communications Technologies) sectors. Currently, the earliest stages of such a complex project are being undertaken and AMI (Advanced Metering Infrastructures) stand out as the first steps toward the Smart Grid. The Spanish R&D (Research and Development) demonstration project PRICE-GEN aims to be a flagship AMI project at both national and international level. It is focused on increasing the awareness of the status of the low voltage power distribution network through an optimal and interoperable communications architecture which provides detailed information on customers' consumption and generation. The project entails the deployment of over 200,000 smart meters in the area of Madrid, such a pilot scheme being also used as reference in other European R&D projects, such as the IGREENGrid (IntegratinG Renewables in the European Electricity Grid). This paper presents the communications architecture and technologies which are deployed in the field, analyzing how they fit some specific Smart Grid communications requirement. In addition, the paper describes in detail the pilot itself along with the services which are currently been delivered as well as with the foreseen ones. Finally, the main trends in AMI from the ICT perspective are also discussed.This work has been partly funded by the Spanish Ministry of Economy and Competitiveness through the INNPACTO Programme under the project PRICE-GEN (IPT-2011-1507-920000). The authors would like to thank the support and collaboration of all the partners of the PRICE-GEN consortium: Arteche, Centro de Investigación de Recursos y Consumos Energéticos, Current Iberia, Iberdrola Distribución, Universidad Carlos III de Madrid, Unión Fenosa Distribución, and ZIV Metering Solutions

    An analytic framework to assess organizational resilience

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    Background: Resilience Engineering is a paradigm for safety management that focuses on coping with complexity to achieve success, even considering several conflicting goals. Modern socio-technical systems have to be resilient to comply with the variability of everyday activities, the tight-coupled and underspecified nature of work and the nonlinear interactions among agents. At organizational level, resilience can be described as a combination of four cornerstones: monitoring, responding, learning and anticipating. Methods: Starting from these four categories, this paper aims at defining a semi-quantitative analytic framework to measure organizational resilience in complex socio-technical systems, combining the Resilience Analysis Grid (RAG) and the Analytic Hierarchy Process (AHP). Results: This paper presents an approach for defining resilience abilities of an organization, creating a structured domain-dependent framework to define a resilience profile at different levels of abstraction, to identify weaknesses and strengths of the system and thus potential actions to increase system’s adaptive capacity. An illustrative example in an anaesthesia department clarifies the outcomes of the approach. Conclusions: The outcome of the RAG, i.e. a weighted set of probing questions, can be used in different domains, as a support tool in a wider Safety-II oriented managerial action to bring safety management into the core business of the organization

    The OMII Software – Demonstrations and Comparisons between two different deployments for Client-Server Distributed Systems

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    This paper describes the key elements of the OMII software and the scenarios which OMII software can be deployed to achieve distributed computing in the UK e-Science Community, where two different deployments for Client-Server distributed systems are demonstrated. Scenarios and experiments for each deployment have been described, with its advantages and disadvantages compared and analyzed. We conclude that our first deployment is more relevant for system administrators or developers, and the second deployment is more suitable for users’ perspective which they can send and check job status for hundred job submissions

    Software Defined Networks based Smart Grid Communication: A Comprehensive Survey

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    The current power grid is no longer a feasible solution due to ever-increasing user demand of electricity, old infrastructure, and reliability issues and thus require transformation to a better grid a.k.a., smart grid (SG). The key features that distinguish SG from the conventional electrical power grid are its capability to perform two-way communication, demand side management, and real time pricing. Despite all these advantages that SG will bring, there are certain issues which are specific to SG communication system. For instance, network management of current SG systems is complex, time consuming, and done manually. Moreover, SG communication (SGC) system is built on different vendor specific devices and protocols. Therefore, the current SG systems are not protocol independent, thus leading to interoperability issue. Software defined network (SDN) has been proposed to monitor and manage the communication networks globally. This article serves as a comprehensive survey on SDN-based SGC. In this article, we first discuss taxonomy of advantages of SDNbased SGC.We then discuss SDN-based SGC architectures, along with case studies. Our article provides an in-depth discussion on routing schemes for SDN-based SGC. We also provide detailed survey of security and privacy schemes applied to SDN-based SGC. We furthermore present challenges, open issues, and future research directions related to SDN-based SGC.Comment: Accepte
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