43 research outputs found

    InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services

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    Cloud computing providers have setup several data centers at different geographical locations over the Internet in order to optimally serve needs of their customers around the world. However, existing systems do not support mechanisms and policies for dynamically coordinating load distribution among different Cloud-based data centers in order to determine optimal location for hosting application services to achieve reasonable QoS levels. Further, the Cloud computing providers are unable to predict geographic distribution of users consuming their services, hence the load coordination must happen automatically, and distribution of services must change in response to changes in the load. To counter this problem, we advocate creation of federated Cloud computing environment (InterCloud) that facilitates just-in-time, opportunistic, and scalable provisioning of application services, consistently achieving QoS targets under variable workload, resource and network conditions. The overall goal is to create a computing environment that supports dynamic expansion or contraction of capabilities (VMs, services, storage, and database) for handling sudden variations in service demands. This paper presents vision, challenges, and architectural elements of InterCloud for utility-oriented federation of Cloud computing environments. The proposed InterCloud environment supports scaling of applications across multiple vendor clouds. We have validated our approach by conducting a set of rigorous performance evaluation study using the CloudSim toolkit. The results demonstrate that federated Cloud computing model has immense potential as it offers significant performance gains as regards to response time and cost saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape

    Cloudbus Toolkit for Market-Oriented Cloud Computing

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    This keynote paper: (1) presents the 21st century vision of computing and identifies various IT paradigms promising to deliver computing as a utility; (2) defines the architecture for creating market-oriented Clouds and computing atmosphere by leveraging technologies such as virtual machines; (3) provides thoughts on market-based resource management strategies that encompass both customer-driven service management and computational risk management to sustain SLA-oriented resource allocation; (4) presents the work carried out as part of our new Cloud Computing initiative, called Cloudbus: (i) Aneka, a Platform as a Service software system containing SDK (Software Development Kit) for construction of Cloud applications and deployment on private or public Clouds, in addition to supporting market-oriented resource management; (ii) internetworking of Clouds for dynamic creation of federated computing environments for scaling of elastic applications; (iii) creation of 3rd party Cloud brokering services for building content delivery networks and e-Science applications and their deployment on capabilities of IaaS providers such as Amazon along with Grid mashups; (iv) CloudSim supporting modelling and simulation of Clouds for performance studies; (v) Energy Efficient Resource Allocation Mechanisms and Techniques for creation and management of Green Clouds; and (vi) pathways for future research.Comment: 21 pages, 6 figures, 2 tables, Conference pape

    WS2 2D Semiconductor Down to Monolayers by Pulsed-Laser Deposition for Large-Scale Integration in Electronics and Spintronics Circuits

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    We report on the achievement of a large-scale tungsten disulfide (WS2) 2D semiconducting platform derived by pulsed-laser deposition (PLD) on both insulating substrates (SrTiO3), as required for in-plane semiconductor circuit definition, and ferromagnetic spin sources (Ni), as required for spintronics applications. We show thickness and phase control, with highly homogeneous wafer-scale monolayers observed under certain conditions, as demonstrated by X-ray photoelectron spectroscopy and Raman spectroscopy mappings. Interestingly, growth appears to be dependent on the substrate selection, with a dramatically increased growth rate on Ni substrates. We show that this 2D-semiconductor integration protocol preserves the interface integrity. Illustratively, the WS2/Ni electrode is shown to be resistant to oxidation (even after extended exposure to ambient conditions) and to present tunneling characteristics once integrated into a complete vertical device. Overall, these experiments show that the presented PLD approach used here for WS2 growth is versatile and has a strong potential to accelerate the integration and evaluation of large-scale 2D-semiconductor platforms in electronics and spintronics circuits

    AgentService: a framework to develop distributed multi-agent systems

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    Today software systems are complex, dynamic, distributed, and evolve over time. Multi-agent systems (MASs) are a powerful abstraction to model such systems. Agent programming frameworks support software engineers in transforming these abstractions into concrete distributed applications. Even though there is wide availability of tools for multi-agent development, only few of them constitute valid support from a software engineering point of view. AgentService provides a reliable, robust, and modular software infrastructure for MAS development. In this paper, we present the innovative features of the framework, including the agent model, the scheduling engine, and the run-time environment. These components are discussed in detail and compared with the solution adopted by other frameworks
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