2,603 research outputs found
Kiri Michele Vincenzo Giacinto Malacarnele
No full textAmoretti, Carlo, 1741-1816, itaalia õpetlane, Biblioteca Ambrosiana raamatukoguhoidjaMalacarne, Michele Vincenzo Giacinto, 1744-1816, itaalia meedik, anatoomia- ja kirurgiaprofesso
Modeling and Simulation of Network-on-Chip Systems with DEVS and DEUS
No full textNetworks on-chip (NoCs) provide enhanced performance, scalability, modularity, and design productivity as compared with previous communication architectures for VLSI systems on-chip (SoCs), such as buses and dedicated signal wires. Since the NoC design space is very large and high dimensional, evaluation methodologies rely heavily on analytical modeling and simulation. Unfortunately, there is no standard modeling framework. In this paper we illustrate how to design and evaluate NoCs by integrating the Discrete Event System Specification (DEVS) modeling framework and the simulation environment called DEUS. The advantage of such an approach is that both DEVS and DEUS support modularity—the former being a sound and complete modeling framework and the latter being an open, general-purpose platform, characterized by a steep learning curve and the possibility to simulate any system at any level of detail
The Peer-to-Peer Paradigm Applied to Hydrogen Energy Distribution
No full textThe shift from centralized power plants to fully distributed generation, storage and provision of energy may be the greatest innovation of next decades. To succeed, it must be supported by the completion of the decarbonization process, using hydrogen as main energy carrier. The envisioned new energy economy (hydrogen economy) promises to eliminate global warming, pollution and dependency on oil reserves. Among the many issues that still have to be solved, in this paper we focus on the ICT aspect. Distributed energy production and sharing requires efficient distributed software architectures. To this purpose, the peer-to-peer paradigm is highly suitable for the realization of robust and scalable systems
Towards fully autonomic peer-to-peer systems
No full textAbstractLarge-scale distributed applications are becoming more and more demanding in terms of efficiency and flexibility of the technological infrastructure, for which traditional solutions based on the client/server paradigm are not suitable. The peer-to-peer paradigm provides an appealing solution to this problem, allowing to deploy robust networks of collectors, providers and consumers of resources. One step beyond, in an autonomic computing vision, the structure of each peer, or at least its configuration, may be dynamically adjusted by an adaptive plan which determines successive re-configurations in response to the environment, and turns the P2P network in a complex adaptive system (CAS). We analyze a Grid Computing architecture whose resource sharing mechanisms are based on this framework
Towards a Peer-to-Peer Hydrogen Economy Framework
No full textThe research community is seeking for novel technological/business models to speed up the decarbonization process, i.e. a decreasing relative reliance on carbon. The completion of decarbonization ultimately depends on the production and use of pure hydrogen as energy carrier. With respect to electricity, which is currently the most relevant and clean energy carrier, hydrogen has a fundamental advantage that it can be stored efficiently. In this research context, we propose a Peer-to-Peer Hydrogen Economy Framework based on decentralized production, storage and trading of energy. We apply the peer-to-peer paradigm for designing a virtual network, where peer software entities implement distributed algorithms for the localization of remote energy providers. The proposed approach has many advantages, both technical (availability, robustness, scalability) and socio-economic (shared responsibilities and improved competition)
A Computational Field Framework for Collaborative Task Execution in Volunteer Clouds
No full textThe increasing diffusion of cloud technologies is opening new opportunities for distributed and collaborative computing. Volunteer clouds are a prominent example, where participants join and leave the platform and collaborate by sharing their computational resources. The high dynamism and unpredictability of such scenarios call for decentralized self-* approaches to guarantee QoS. We present a simulation framework for collaborative task execution in volunteer clouds and propose one concrete instance based on Ant Colony Optimization, which is validated through a set of simulation experiments based on Google workload data
A Design Framework for Ultra-Large-Scale Autonomic Systems
No full textThe origins of ultra-large-scale (ULS) systems derive from social problems that are getting more and more complex, such as climatic monitoring, transportation, citizens protection and security. These factors imply a continuous increase of information systems that evolve towards ultra-dimension systems, requiring digital communication networks that allow for communication between people, between objects, and objects and people. The aim of this paper is to present novel approaches for the engineering of highly adaptive ULS systems, with the focus on computer-supported evolution, adaptable structure, emergent behaviors as well as advanced monitoring and control techniques. We illustrate the Networked Autonomic Machine (NAM), a framework for the characterization of the elements of self-*, highly dynamic ULS systems. Moreover, we recall the Adaptive Evolutionary Framework (AEF), for the implementation of distributed evolutionary strategies. Finally, we describe an example scenario of large peer-to-peer network under targeted attacks, showing the benefits of the NAM-AEF design
A Modeling Framework for Unstructured Supernode Networks
No full textEvery peer-to-peer system is based on an overlay scheme, which defines how peers are connected, how messages are propagated among nodes to share resources and information, and what security mechanisms are adopted. In this letter, we propose a modeling framework for unstructured 2-layered overlay schemes, also known as Unstructured Supernode Networks (USNs). Moreover, we present an application of the proposed methodology, i.e. search cost analysis
Review of Elements of Parallel Computing
No full textAs the title clearly states, this book is about parallel computing. Modern computers are no longer characterized by a single, fully sequential CPU. Instead, they have one or more multicore/manycore processors. The purpose of such parallel architectures is to enable the simultaneous execution of instructions, in order to achieve faster computations. In high performance computing, clusters of parallel processors are used to achieve PFLOPS performance, which is necessary for scientific and Big Data applications.
Mastering parallel computing means having deep knowledge of parallel architectures, parallel programming models, parallel algorithms, parallel design patterns, and performance analysis and optimization techniques. The design of parallel programs requires a lot of creativity, because there is no universal recipe that allows one to achieve the best possible efficiency for any problem.
The book presents the fundamental concepts of parallel computing from the point of view of the algorithmic and implementation patterns. The idea is that, while the hardware keeps changing, the same principles of parallel computing are reused. The book surveys some key algorithmic structures and programming models, together with an abstract representation of the underlying hardware. Parallel programming patterns are purposely not illustrated using the formal design patterns approach, to keep an informal and friendly presentation that is suited to novices
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