165 research outputs found

    Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

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    INE/AUTC 10.0

    High performance computing and communications: FY 1995 implementation plan

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    NetJobs: A new approach to network monitoring for the Grid using Grid jobs

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    With grid computing, the far-fl�ung and disparate IT resources act as a single "virtual datacenter". Grid computing interfaces heterogeneous IT resources so they are available when and where we need them. Grid allows us to provision applications and allocate capacity among research and business groups that are geographically and organizationally dispersed. Building a high availability Grid is hold as the next goal to achieve: protecting against computer failures and site failures to avoid downtime of resource and honor Service Level Agreements. Network monitoring has a key role in this challenge. This work is concerning the design and the prototypal implementation of a new approach to Network monitoring for the Grid based on the usage of Grid scheduled jobs. This work was carried out within the Network Support task (SA2) of the Enabling Grids for E-sciencE (EGEE) project. This thesis is organized as follows: Chapter 1: Grid Computing From the origins of Grid Computing to the latest projects. Conceptual framework and main features characterizing many kind of popular grids will be presented. Chapter 2: The EGEE and EGI projects This chapter describes the Enabling Grids for E-sciencE (EGEE) project and the European Grid Infrastructure (EGI). EGEE project (2004-2010) was the�flagship Grid infrastructure project of the EU. The third and last two-year phase of the project (started on 1 May 2008) was financed with a total budget of around 47 million euro, with a further estimated 50 million euro worth of computing resources contributed by the partners. A total manpower of 9,000 Person Months, of which over 4,500 Person Months has been contributed by the partners from their own funding sources. At its close, EGEE represented a worldwide infrastructure of approximately to 200,000 CPU cores, collaboratively hosted by more than 300 centres around the world. By the end of the project, around 13 million jobs were executed on the EGEE grid each month. The new organization, EGI.eu, has then been created to continue the coordination and evolution of the European Grid Infrastructure (EGI) based on EGEE Grid. Chapter3: gLite Middleware Chapter three gives an overview on the gLite Grid Middleware. gLite is the middleware stack for grid computing used by the EGEE and EGI projects with in a very large variety of scientifi�c domains. Born from the collaborative efforts of more than 80 people in 12 different academic and industrial research centers as part of the EGEE Project, gLite provides a complete set of services for building a production grid infrastructure. gLite provides a framework for building grid applications tapping into the power of distributed computing and storage resources across the Internet. The gLite services are currently adopted by more than 250 Computing Centres and used by more than 15000 researchers in Europe and around the world. Chapter 4: Network Activity in EGEE/EGI Grid infrastructures are distributed by nature, involving many sites, normally in different administrative domains. Individual sites are connected together by a network, which is therefore a critical part of the whole Grid infrastructure; without the network there is no Grid. Monitoring is a key component for the successful operation of any infrastructure, helping in the discovery and diagnosis of any problem which may arise. Network monitoring is able to contribute to the day-to-day operations of the Grid by helping to provide answers to specific questions from users and site administrators. This chapter will discuss all the effort lavished by EGEE and EGI in the Grid Network domain. Chapter 5: Grid Network Monitoring based on Grid Jobs Net Jobs is a prototype of a light weight solution for the Grid network monitoring. A job-based approach has been used in order to prove the feasibility of this non intrusive solution. It is currently configured to monitor eight production sites spread from Italy to France but this method could be applied to the vast majority of Grid sites. The prototype provides coherent RTT, MTU, number of hops and TCP achievable bandwidth tests

    LR&TS Annual Report 2005-2006

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    SNAP : A Software-Defined & Named-Data Oriented Publish-Subscribe Framework for Emerging Wireless Application Systems

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    The evolution of Cyber-Physical Systems (CPSs) has given rise to an emergent class of CPSs defined by ad-hoc wireless connectivity, mobility, and resource constraints in computation, memory, communications, and battery power. These systems are expected to fulfill essential roles in critical infrastructure sectors. Vehicular Ad-Hoc Network (VANET) and a swarm of Unmanned Aerial Vehicles (UAV swarm) are examples of such systems. The significant utility of these systems, coupled with their economic viability, is a crucial indicator of their anticipated growth in the future. Typically, the tasks assigned to these systems have strict Quality-of-Service (QoS) requirements and require sensing, perception, and analysis of a substantial amount of data. To fulfill these QoS requirements, the system requires network connectivity, data dissemination, and data analysis methods that can operate well within a system\u27s limitations. Traditional Internet protocols and methods for network connectivity and data dissemination are typically designed for well-engineering cyber systems and do not comprehensively support this new breed of emerging systems. The imminent growth of these CPSs presents an opportunity to develop broadly applicable methods that can meet the stated system requirements for a diverse range of systems and integrate these systems with the Internet. These methods could potentially be standardized to achieve interoperability among various systems of the future. This work presents a solution that can fulfill the communication and data dissemination requirements of a broad class of emergent CPSs. The two main contributions of this work are the Application System (APPSYS) system abstraction, and a complementary communications framework called the Software-Defined NAmed-data enabled Publish-Subscribe (SNAP) communication framework. An APPSYS is a new breed of Internet application representing the mobile and resource-constrained CPSs supporting data-intensive and QoS-sensitive safety-critical tasks, referred to as the APPSYS\u27s mission. The functioning of the APPSYS is closely aligned with the needs of the mission. The standard APPSYS architecture is distributed and partitions the system into multiple clusters where each cluster is a hierarchical sub-network. The SNAP communication framework within the APPSYS utilized principles of Information-Centric Networking (ICN) through the publish-subscribe communication paradigm. It further extends the role of brokers within the publish-subscribe paradigm to create a distributed software-defined control plane. The SNAP framework leverages the APPSYS design characteristics to provide flexible and robust communication and dynamic and distributed control-plane decision-making that successfully allows the APPSYS to meet the communication requirements of data-oriented and QoS-sensitive missions. In this work, we present the design, implementation, and performance evaluation of an APPSYS through an exemplar UAV swarm APPSYS. We evaluate the benefits offered by the APPSYS design and the SNAP communication framework in meeting the dynamically changed requirements of a data-intensive and QoS-sensitive Coordinated Search and Tracking (CSAT) mission operating in a UAV swarm APPSYS on the battlefield. Results from the performance evaluation demonstrate that the UAV swarm APPSYS successfully monitors and mitigates network impairment impacting a mission\u27s QoS to support the mission\u27s QoS requirements

    A decomposition approach for the Frequency Assignment Problem

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    The Frequency Assignment Problem (FAP) is an important optimization problem that arises in operational cellular wireless networks. Solution techniques based on meta-heuristic algorithms have been shown to be successful for some test problems but they have not been usually demonstrated on large scale problems that occur in practice. This thesis applies a problem decomposition approach in order to solve FAP in stances with standard meta-heuristics. Three different formulations of the problem are considered in order of difficulty: Minimum Span (MS-FAP), Fixed Spectrum (MS-FAP), and Minimum Interference FAP (MI-FAP). We propose a decomposed assignment technique which aims to divide the initial problem into a number of subproblems and then solves them either independently or in sequence respecting the constraints between them. Finally, partial subproblem solutions are recomposed into a solution of the original problem. Standard implementations of meta-heuristics may require considerable run times to produce good quality results whenever a problem is very large or complex. Our results, obtained by applying the decomposed approach to a Simulated Annealing and a Genetic Algorithm with two different assignment representations (direct and order-based), show that the decomposed assignment approach proposed can improve their outcomes, both in terms of solution quality and runtime. A number of partitioning methods are presented and compared for each FAP, such as clique detection partitioning based on sequential orderings and novel applications of existing graph partitioning and clustering methods adapted for this problem

    National Science Foundation Advisory Committee for Cyberinfrastructure Task Force on Campus Bridging Final Report

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    The mission of the National Science Foundation (NSF) Advisory Committee on Cyberinfrastructure (ACCI) is to advise the NSF as a whole on matters related to vision and strategy regarding cyberinfrastructure (CI). In early 2009 the ACCI charged six task forces with making recommendations to the NSF in strategic areas of cyberinfrastructure: Campus Bridging; Cyberlearning and Workforce Development; Data and Visualization; Grand Challenges; High Performance Computing (HPC); and Software for Science and Engineering. Each task force was asked to offer advice on the basis of which the NSF would modify existing programs and create new programs. This document is the final, overall report of the Task Force on Campus Bridging.National Science Foundatio
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