1,211 research outputs found

    Energy challenges for ICT

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    The energy consumption from the expanding use of information and communications technology (ICT) is unsustainable with present drivers, and it will impact heavily on the future climate change. However, ICT devices have the potential to contribute signi - cantly to the reduction of CO2 emission and enhance resource e ciency in other sectors, e.g., transportation (through intelligent transportation and advanced driver assistance systems and self-driving vehicles), heating (through smart building control), and manu- facturing (through digital automation based on smart autonomous sensors). To address the energy sustainability of ICT and capture the full potential of ICT in resource e - ciency, a multidisciplinary ICT-energy community needs to be brought together cover- ing devices, microarchitectures, ultra large-scale integration (ULSI), high-performance computing (HPC), energy harvesting, energy storage, system design, embedded sys- tems, e cient electronics, static analysis, and computation. In this chapter, we introduce challenges and opportunities in this emerging eld and a common framework to strive towards energy-sustainable ICT

    On delay stable communications in asynchronous networks

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    This dissertation defines a frame forwarding technique offering a fixed delay to a subclass of traffic in closed industrial control networks. In these networks bandwidth is dedicated to periodic traffic supporting tight inter-process control and control loop communication. Ideally periodic traffic arrival will have minimal delay-jitter with constant realized delays. This simplifies the implementation of connected control devices. Furthermore networks are simplified with asynchronous node and switch operation. Switch designs are simplified as there is no dependence on adjacent switch clock operation. Correct network function only relies on switches directly traversed by each flow and is not dependent on complex clock synchronization mechanisms. Existing packet scheduling schemes that attempt to minimize delay-jitter, suffer from either requiring inter-switch clock coordination (i.e. RCSP-DJ), or maintain a fixed priority so that the highest priority flows must contend without regard to past frame arrival treatment (i.e. RCSP-RJ). In this dissertation the FlexTDMA protocol is defined which supports closed network communication. FlexTDMA will be enhanced to accommodate real-world networking conditions (FlexTDMA+) and will be enhanced to support simultaneous multicast (FlexTDMA++). The FlexTDMA scheduling algorithm delivers frame data on each flow nearly at the maximal delay bound with minimal delay-jitter in an asynchronous network. Industrial control switching network systems will benefit from FlexTDMA when the complexity of system level synchronization is unacceptable, but the component switches must operate independently. FlexTDMA does not require synchronous network clock coordination and preserves the data content of frames. FlexTDMA+ includes three improvements: baseline preemption, partial baselining and baseline deadline density control, which are used to support real-world conditions of node periodic on-off transmission, clock drift, frame loss and bandwidth load. FlexTDMA++ supports simultaneous multicast under real-world conditions of switch failures, node periodic on-off transmission, clock drift, frame loss and bandwidth load

    A Broker based Web Service Allocation Mechanism

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    Los servicios web son considerados por la industria y la investigación de facto por proporcionar funcionalidad de forma distribuida que sea usable en entornos heterogéneos. En pocas palabras, los servicios web son funcionalidad empaquetada que se basa en un conjunto de estándares que facilitan la definición de los métodos de los servicios web, sus números y formatos de entrada, así como sus números y formatos de salida. En combinación con la replicación, los servicios web pueden proporcionar soluciones de optimización del rendimiento a un número ilimitado de aplicaciones de negocio de la vida real. Sin embargo, cuando se habla de replicación es necesario plantearse cómo asignar o elegir las réplicas para proporcionar el mejor rendimiento posible. Esta tesis está dedicada a responder a esta pregunta. La tesis se titula "Un mecanismo de asignación de servicios web basado en Broker" donde un paradigma de ejecución (Proteus) es presentado, y varios algoritmos de asignación son también presentados, examinados y analizados para mostrar el óptimo. La tesis se centra en el componente broker del paradigma de ejecución. Este componente tiene embebido el algoritmo de asignación. Por otra parte, la tesis se centra en el Algoritmo de menor tiempo de servicio (LRT), el cual funciona asignando las réplicas del servicio web que proporcionan un tiempo de respuesta más rápido. La tesis ofrece todo el trabajo de fondo necesario, así como toda la investigación relacionada. Contiene una parte simulada, así como una descripción de un sistema de la vida real (Proteus). Contiene también una sección dedicada a analizar los resultados de los registros de ejecución y analizar las diferentes variaciones de los entornos (homogéneos y heterogéneos), el número de replicas y el nivel de paralelismo. Los registros son examinados y las conclusiones expuestas.Alwagait, EAK. (2011). A Broker based Web Service Allocation Mechanism [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/12500Palanci

    Design of automated system for management of arrival traffic

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    The design of an automated air traffic control system based on a hierarchy of advisory tools for controllers is described. Compatibility of the tools with the human controller, a key objective of the design, is achieved by a judicious selection of tasks to be automated and careful attention to the design of the controller system interface. The design comprises three interconnected subsystems referred to as the Traffic Management Advisor, the Descent Advisor, and the Final Approach Spacing Tool. Each of these subsystems provides a collection of tools for specific controller positions and tasks. The design of two of these tools, the Descent Advisor, which provides automation tools for managing descent traffic, and the Traffic Management Advisor, which generates optimum landing schedules is focused on. The algorithms, automation modes, and graphical interfaces incorporated in the design are described

    RAS Modeling of a Large InfiniBand Switch System

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    Assessment of cockpit interface concepts for data link retrofit

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    The problem is examined of retrofitting older generation aircraft with data link capability. The approach taken analyzes requirements for the cockpit interface, based on review of prior research and opinions obtained from subject matter experts. With this background, essential functions and constraints for a retrofit installation are defined. After an assessment of the technology available to meet the functions and constraints, candidate design concepts are developed. The most promising design concept is described in detail. Finally, needs for further research and development are identified

    Third International Symposium on Space Mission Operations and Ground Data Systems, part 1

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    Under the theme of 'Opportunities in Ground Data Systems for High Efficiency Operations of Space Missions,' the SpaceOps '94 symposium included presentations of more than 150 technical papers spanning five topic areas: Mission Management, Operations, Data Management, System Development, and Systems Engineering. The papers focus on improvements in the efficiency, effectiveness, productivity, and quality of data acquisition, ground systems, and mission operations. New technology, techniques, methods, and human systems are discussed. Accomplishments are also reported in the application of information systems to improve data retrieval, reporting, and archiving; the management of human factors; the use of telescience and teleoperations; and the design and implementation of logistics support for mission operations
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