4,752 research outputs found

    IP-based NGNs and Interconnection: The Debate in Europe

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    Historically, interconnection in the world of the Internet has been approached significantly differently from interconnection in the fixed Public Switched Telephone Network (PSTN) and the mobile Public Land Mobile Network (PLMN). As fixed and mobile networks evolve to Next Generation Networks (NGNs) based on the Internet Protocol (IP), it becomes increasingly necessary to merge these perspectives in order to achieve a unified and integrated approach to network interconnection. There is a rich history of economic analysis of IP-based and of conventional switched networks that began to converge early in this decade. In 2008, this issue is coming to a boil, as regulators seek to provide regulatory certainty for the build-out of NGNs, even in the face of substantial uncertainties, and even though practical experience with NGNs is still in a very preliminary state. What can we learn from the historical evolution of the theory of interconnection for Internet, NGN, PSTN and PLMN? What issues are "in play" today? What is the appropriate destination in the long term? What nearer term measures are appropriate?interconnection, NGN, Internet Protocol (IP), bill and keep, Calling Party's Network Pays (CPNP), peering, transit.

    Subcube embeddability and fault tolerance of augmented hypercubes

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    Hypercube networks have received much attention from both parallel processing and communications areas over the years since they offer a rich interconnection structure with high bandwidth, logarithmic diameter, and high degree of fault tolerance. They are easily partitionable and exhibit a high degree of fault tolerance. Fault-tolerance in hypercube and hypercube-based networks received the attention of several researchers in recent years; The primary idea of this study is to address and analyze the reliability issues in hypercube networks. It is well known that the hypercube can be augmented with one dimension to replace any of the existing dimensions should any dimension fail. In this research, it is shown that it is possible to add i dimensions to the standard hypercube, Qn to tolerate (i - 1) dimension failures, where 0 \u3c i ≤ n. An augmented hypercube, Qn +(n) with n additional dimensions is introduced and compared with two other hypercube networks with the same amount of redundancy. Reliability analysis for the three hypercube networks is done using the combinatorial and Markov modeling. The MTTF values are calculated and compared for all three networks. Comparison between similar size hypercube networks show that the augmented hypercube is more robust than the standard hypercube; As a related problem, we also look at the subcube embeddability. Subcube embeddability of the hypercube can be enhanced by introducing an additional dimension. A set of new dimensions, characterized by the Hamming distance between the pairs of nodes it connects, is introduced using a measure defined as the magnitude of a dimension. An enumeration of subcubes of various sizes is presented for a dimension parameterized by its magnitude. It is shown that the maximum number of subcubes for a Qn can only be attained when the magnitude of dimension is n - 1 or n. It is further shown that the latter two dimensions can optimally increase the number of subcubes among all possible choices

    Software metrics: Software quality metrics for distributed systems

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    Software quality metrics was extended to cover distributed computer systems. Emphasis is placed on studying embedded computer systems and on viewing them within a system life cycle. The hierarchy of quality factors, criteria, and metrics was maintained. New software quality factors were added, including survivability, expandability, and evolvability

    Sense of Place in the Anthropocene: A students-teaching-students course

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    Contemporary environmental education is tasked with the acknowledgement of the Anthropocene - an informal but ubiquitous term for the current geological epoch which arose from anthropogenic changes to the Earth system - and its accompanying socio-ecological implications. Sense of Place can be a hybridized tool of personal agency and global awareness for this task. Through the creation, execution and reflection of a 14-student students-teaching-students (STS) course at the University of Vermont in the Spring of 2019, Giannina Gaspero-Beckstrom and Ella Mighell aimed to facilitate a peer-to-peer learning environment that addressed sense of place, social justice and community engagement. The students-teaching-students framework is an alternative educational approach that supports the values and practices of the University of Vermont’s Environmental Program, as well as an intentional breakdown of the hierarchical knowledge paradigm. Using alternative pedagogies (predominately critical and place-based), we attempted to facilitate meaningful learning through creative expression, experiential education, community dialogue and personal reflection. Our intention with this was to encourage awareness and action

    A Brief Library & Internet Glossary

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    Useful terms for a research project

    Mixed mode education: implications for library user services

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    The Faculty of Information Technology at QUT does not formally carry out distance education for any of its courses. However, it has pursued a number of initiatives that have made it possible for students to carry out an increasing proportion of their coursework off-site. These initiatives include computer-managed learning, World Wide Web and CDROM delivery of administrative and educational materials, and most recently the development of an integrated learning environment (ILE) for electronic delivery. These developments have been complemented and supported by the QUT Library by means of different avenues of access to CDROMs, a regional electronic document delivery service (REDD), and an electronic reserve (E-Reserve) service. Issues associated with the operation and evaluation of such facilities are described, and future library role in educational delivery are discussed

    A bibliography on parallel and vector numerical algorithms

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    This is a bibliography of numerical methods. It also includes a number of other references on machine architecture, programming language, and other topics of interest to scientific computing. Certain conference proceedings and anthologies which have been published in book form are listed also

    Reasoning & Querying – State of the Art

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    Various query languages for Web and Semantic Web data, both for practical use and as an area of research in the scientific community, have emerged in recent years. At the same time, the broad adoption of the internet where keyword search is used in many applications, e.g. search engines, has familiarized casual users with using keyword queries to retrieve information on the internet. Unlike this easy-to-use querying, traditional query languages require knowledge of the language itself as well as of the data to be queried. Keyword-based query languages for XML and RDF bridge the gap between the two, aiming at enabling simple querying of semi-structured data, which is relevant e.g. in the context of the emerging Semantic Web. This article presents an overview of the field of keyword querying for XML and RDF

    MPSoCBench : um framework para avaliação de ferramentas e metodologias para sistemas multiprocessados em chip

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    Orientador: Rodolfo Jardim de AzevedoTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Recentes metodologias e ferramentas de projetos de sistemas multiprocessados em chip (MPSoC) aumentam a produtividade por meio da utilização de plataformas baseadas em simuladores, antes de definir os últimos detalhes da arquitetura. No entanto, a simulação só é eficiente quando utiliza ferramentas de modelagem que suportem a descrição do comportamento do sistema em um elevado nível de abstração. A escassez de plataformas virtuais de MPSoCs que integrem hardware e software escaláveis nos motivou a desenvolver o MPSoCBench, que consiste de um conjunto escalável de MPSoCs incluindo quatro modelos de processadores (PowerPC, MIPS, SPARC e ARM), organizado em plataformas com 1, 2, 4, 8, 16, 32 e 64 núcleos, cross-compiladores, IPs, interconexões, 17 aplicações paralelas e estimativa de consumo de energia para os principais componentes (processadores, roteadores, memória principal e caches). Uma importante demanda em projetos MPSoC é atender às restrições de consumo de energia o mais cedo possível. Considerando que o desempenho do processador está diretamente relacionado ao consumo, há um crescente interesse em explorar o trade-off entre consumo de energia e desempenho, tendo em conta o domínio da aplicação alvo. Técnicas de escalabilidade dinâmica de freqüência e voltagem fundamentam-se em gerenciar o nível de tensão e frequência da CPU, permitindo que o sistema alcance apenas o desempenho suficiente para processar a carga de trabalho, reduzindo, consequentemente, o consumo de energia. Para explorar a eficiência energética e desempenho, foram adicionados recursos ao MPSoCBench, visando explorar escalabilidade dinâmica de voltaegem e frequência (DVFS) e foram validados três mecanismos com base na estimativa dinâmica de energia e taxa de uso de CPUAbstract: Recent design methodologies and tools aim at enhancing the design productivity by providing a software development platform before the definition of the final Multiprocessor System on Chip (MPSoC) architecture details. However, simulation can only be efficiently performed when using a modeling and simulation engine that supports system behavior description at a high abstraction level. The lack of MPSoC virtual platform prototyping integrating both scalable hardware and software in order to create and evaluate new methodologies and tools motivated us to develop the MPSoCBench, a scalable set of MPSoCs including four different ISAs (PowerPC, MIPS, SPARC, and ARM) organized in platforms with 1, 2, 4, 8, 16, 32, and 64 cores, cross-compilers, IPs, interconnections, 17 parallel version of software from well-known benchmarks, and power consumption estimation for main components (processors, routers, memory, and caches). An important demand in MPSoC designs is the addressing of energy consumption constraints as early as possible. Whereas processor performance comes with a high power cost, there is an increasing interest in exploring the trade-off between power and performance, taking into account the target application domain. Dynamic Voltage and Frequency Scaling techniques adaptively scale the voltage and frequency levels of the CPU allowing it to reach just enough performance to process the system workload while meeting throughput constraints, and thereby, reducing the energy consumption. To explore this wide design space for energy efficiency and performance, both for hardware and software components, we provided MPSoCBench features to explore dynamic voltage and frequency scalability (DVFS) and evaluated three mechanisms based on energy estimation and CPU usage rateDoutoradoCiência da ComputaçãoDoutora em Ciência da Computaçã
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