42 research outputs found
Advances in Grid Computing
This book approaches the grid computing with a perspective on the latest achievements in the field, providing an insight into the current research trends and advances, and presenting a large range of innovative research papers. The topics covered in this book include resource and data management, grid architectures and development, and grid-enabled applications. New ideas employing heuristic methods from swarm intelligence or genetic algorithm and quantum encryption are considered in order to explain two main aspects of grid computing: resource management and data management. The book addresses also some aspects of grid computing that regard architecture and development, and includes a diverse range of applications for grid computing, including possible human grid computing system, simulation of the fusion reaction, ubiquitous healthcare service provisioning and complex water systems
Erreichen von Performance in Netzwerken-On-Chip für Echtzeitsysteme
In many new applications, such as in automatic driving, high performance requirements have reached safety critical real-time systems. Consequently, Networks-on-Chip (NoCs) must efficiently host new sets of highly dynamic workloads e.g., high resolution sensor fusion and data processing, autonomous decision’s making combined with machine learning.
The static platform management, as used in current safety critical systems, is no more sufficient to provide the needed level of service. A dynamic platform management could meet the challenge, but it usually suffers from a lack of predictability and the simplicity necessary for certification of safety and real-time properties. In this work, we propose a novel, global and dynamic arbitration for NoCs
with real-time QoS requirements. The mechanism decouples the admission control from arbitration in routers thereby simplifying a dynamic adaptation and real-time analysis. Consequently, the proposed solution allows the deployment of a sophisticated contract-based QoS provisioning without introducing complicated and hard to maintain schemes, known from the frequently applied static arbiters.
The presented work introduces an overlay network to synchronize transmissions using arbitration units called Resource Managers (RMs), which allows global and work-conserving scheduling. The description of resource allocation strategies is supplemented by protocol design and verification methodology bringing adaptive control to NoC communication in setups with different QoS requirements and traffic classes. For doing that, a formal worst-case timing analysis for the mechanism has been proposed which demonstrates that this solution not only exposes higher performance in simulation but, even more importantly, consistently reaches smaller formally guaranteed worst-case latencies than other strategies for realistic levels of system's utilization.
The approach is not limited to a specific network architecture or topology as the mechanism does not require modifications of routers and therefore can be used together with the majority of existing manycore systems. Indeed, the evaluation followed using the generic performance optimized router designs, as well as two systems-on-chip focused on real-time deployments. The results confirmed that the proposed approach proves to exhibit significantly higher average performance in simulation and execution.In vielen neuen sicherheitskritische Anwendungen, wie z.B. dem automatisierten
Fahren, werden große Anforderungen an die Leistung von Echtzeitsysteme gestellt.
Daher müssen Networks-on-Chip (NoCs) neue, hochdynamische Workloads
wie z.B. hochauflösende Sensorfusion und Datenverarbeitung oder autonome Entscheidungsfindung
kombiniert mit maschineller Lernen, effizient auf einem System unterbringen.
Die Steuerung der zugrunde liegenden NoC-Architektur, muss die Systemsicherheit vor Fehlern,
resultierend aus dem dynamischen Verhalten des Systems schützen und
gleichzeitig die geforderte Performance bereitstellen.
In dieser Arbeit schlagen wir eine neuartige, globale und dynamische Steuerung
für NoCs mit Echtzeit QoS Anforderungen vor. Das Schema entkoppelt die Zutrittskontrolle
von der Arbitrierung in Routern. Hierdurch wird eine dynamische Anpassung
ermöglicht und die Echtzeitanalyse vereinfacht. Der Einsatz einer ausgefeilten
vertragsbasierten Ressourcen-Zuweisung wird so ermöglicht, ohne komplexe und schwer wartbare Mechanismen, welche bereits aus dem statischen Plattformmanagement bekannt sind einzuführen.
Diese Arbeit stellt ein übergelagertes Netzwerk vor, welches Übertragungen mit
Hilfe von Arbitrierungseinheiten, den so genannten Resource Managern (RMs),
synchronisiert. Dieses überlagerte Netzwerk ermöglicht eine globale und lasterhaltende
Steuerung. Die Beschreibung verschiedener Ressourcenzuweisungstrategien
wird ergänzt durch ein Protokolldesign und Methoden zur Verifikation der
adaptiven NoC Steuerung mit unterschiedlichen QoS Anforderungen und Verkehrsklassen.
Hierfür wird eine formale Worst Case Timing Analyse präsentiert,
welche das vorgestellte Verfahren abbildet. Die Resultate bestätitgen, dass die präsentierte
Lösung nicht nur eine höhere Performance in der Simulation bietet, sondern
auch formal kleinere Worst-Case Latenzen für realistische Systemauslastungen
als andere Strategien garantiert.
Der vorgestellte Ansatz ist nicht auf eine bestimmte Netzwerkarchitektur oder
Topologie beschränkt, da der Mechanismus keine Änderungen an den unterliegenden
Routern erfordert und kann daher zusammen mit bestehenden Manycore-Systemen
eingesetzt werden. Die Evaluierung erfolgte auf Basis eines leistungsoptimierten
Router-Designs sowie zwei auf Echtzeit-Anwendungen fokusierten Platformen.
Die Ergebnisse bestätigten, dass der vorgeschlagene Ansatz im Durchschnitt
eine deutlich höhere Leistung in der Simulation und Ausführung liefert
Embedded dynamic programming networks for networks-on-chip
PhD ThesisRelentless technology downscaling and recent technological advancements
in three dimensional integrated circuit (3D-IC) provide a promising
prospect to realize heterogeneous system-on-chip (SoC) and homogeneous
chip multiprocessor (CMP) based on the networks-onchip
(NoCs) paradigm with augmented scalability, modularity and
performance. In many cases in such systems, scheduling and managing
communication resources are the major design and implementation
challenges instead of the computing resources. Past research
efforts were mainly focused on complex design-time or simple heuristic
run-time approaches to deal with the on-chip network resource
management with only local or partial information about the network.
This could yield poor communication resource utilizations and amortize
the benefits of the emerging technologies and design methods.
Thus, the provision for efficient run-time resource management in
large-scale on-chip systems becomes critical. This thesis proposes a
design methodology for a novel run-time resource management infrastructure
that can be realized efficiently using a distributed architecture,
which closely couples with the distributed NoC infrastructure. The
proposed infrastructure exploits the global information and status
of the network to optimize and manage the on-chip communication
resources at run-time.
There are four major contributions in this thesis. First, it presents a
novel deadlock detection method that utilizes run-time transitive closure
(TC) computation to discover the existence of deadlock-equivalence
sets, which imply loops of requests in NoCs. This detection scheme,
TC-network, guarantees the discovery of all true-deadlocks without
false alarms in contrast to state-of-the-art approximation and heuristic
approaches. Second, it investigates the advantages of implementing
future on-chip systems using three dimensional (3D) integration and
presents the design, fabrication and testing results of a TC-network
implemented in a fully stacked three-layer 3D architecture using a
through-silicon via (TSV) complementary metal-oxide semiconductor
(CMOS) technology. Testing results demonstrate the effectiveness
of such a TC-network for deadlock detection with minimal computational
delay in a large-scale network. Third, it introduces an adaptive
strategy to effectively diffuse heat throughout the three dimensional
network-on-chip (3D-NoC) geometry. This strategy employs a dynamic
programming technique to select and optimize the direction of data
manoeuvre in NoC. It leads to a tool, which is based on the accurate
HotSpot thermal model and SystemC cycle accurate model, to simulate
the thermal system and evaluate the proposed approach. Fourth, it
presents a new dynamic programming-based run-time thermal management
(DPRTM) system, including reactive and proactive schemes, to
effectively diffuse heat throughout NoC-based CMPs by routing packets
through the coolest paths, when the temperature does not exceed
chip’s thermal limit. When the thermal limit is exceeded, throttling is
employed to mitigate heat in the chip and DPRTM changes its course
to avoid throttled paths and to minimize the impact of throttling on
chip performance.
This thesis enables a new avenue to explore a novel run-time resource
management infrastructure for NoCs, in which new methodologies
and concepts are proposed to enhance the on-chip networks for
future large-scale 3D integration.Iraqi Ministry of Higher Education and Scientific Research (MOHESR)
Design and Evaluation of a Traffic Safety System based on Vehicular Networks for the Next Generation of Intelligent Vehicles
La integración de las tecnologÃas de las telecomunicaciones en el sector del automóvil permitirá a los vehÃculos intercambiar información mediante Redes Vehiculares, ofreciendo numerosas posibilidades. Esta tesis se centra en la mejora de la seguridad vial y la reducción de la siniestralidad mediante Sistemas Inteligentes de Transporte (ITS). El primer paso consiste en obtener una difusión eficiente de los mensajes de advertencia sobre situaciones potencialmente peligrosas. Hemos desarrollado un marco para simular el intercambio de mensajes entre vehÃculos, utilizado para proponer esquemas eficientes de difusión. También demostramos que la disposición de las calles tiene gran influencia sobre la eficiencia del proceso. Nuestros algoritmos de difusión son parte de una arquitectura más amplia (e-NOTIFY) capaz de detectar accidentes de tráfico e informar a los servicios de emergencia. El desarrollo y evaluación de un prototipo demostró la viabilidad del sistema y cómo podrÃa ayudar a reducir el número de vÃctimas en carretera