3,897 research outputs found

    Aspects of practical implementations of PRAM algorithms

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    The PRAM is a shared memory model of parallel computation which abstracts away from inessential engineering details. It provides a very simple architecture independent model and provides a good programming environment. Theoreticians of the computer science community have proved that it is possible to emulate the theoretical PRAM model using current technology. Solutions have been found for effectively interconnecting processing elements, for routing data on these networks and for distributing the data among memory modules without hotspots. This thesis reviews this emulation and the possibilities it provides for large scale general purpose parallel computation. The emulation employs a bridging model which acts as an interface between the actual hardware and the PRAM model. We review the evidence that such a scheme can achieve scalable parallel performance and portable parallel software and that PRAM algorithms can be optimally implemented on such practical models. In the course of this review we presented the following new results: 1. Concerning parallel approximation algorithms, we describe an NC algorithm for findings an approximation to a minimum weight perfect matching in a complete weighted graph. The algorithm is conceptually very simple and it is also the first NC-approximation algorithm for the task with a sub-linear performance ratio. 2. Concerning graph embedding, we describe dense edge-disjoint embeddings of the complete binary tree with n leaves in the following n-node communication networks: the hypercube, the dc Bruijn and shuffle-exchange networks and the 2-dimcnsional mesh. In the embeddings the maximum distance from a leaf to the root of the tree is asymptotically optimally short. The embeddings facilitate efficient implementation of many PRAM algorithms on networks employing these graphs as interconnection networks. 3. Concerning bulk synchronous algorithmic, we describe scalable transportable algorithms for the following three commonly required types of computation; balanced tree computations. Fast Fourier Transforms and matrix multiplications

    ELAN development, keeping pace with communities' needs

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    ELAN is a versatile multimedia annotation tool that is being developed at the Max Planck Institute for Psycholinguistics. About a decade ago it emerged out of a number of corpus tools and utilities and it has been extended ever since. This paper focuses on the efforts made to ensure that the application keeps up with the growing needs of that era in linguistics and multimodality research; growing needs in terms of length and resolution of recordings, the number of recordings made and transcribed and the number of levels of annotation per transcription

    Improved Fair-Zone technique using Mobility Prediction in WSN

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    The self-organizational ability of ad-hoc Wireless Sensor Networks (WSNs) has led them to be the most popular choice in ubiquitous computing. Clustering sensor nodes organizing them hierarchically have proven to be an effective method to provide better data aggregation and scalability for the sensor network while conserving limited energy. It has some limitation in energy and mobility of nodes. In this paper we propose a mobility prediction technique which tries overcoming above mentioned problems and improves the life time of the network. The technique used here is Exponential Moving Average for online updates of nodal contact probability in cluster based network.Comment: 10 pages, 7 figures, Published in International Journal Of Advanced Smart Sensor Network Systems (IJASSN

    A weakly Stegall space that is not a Stegall space

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    A topological space X is said to belong to the class of Stegall (weakly Stegall) spaces if for every Baire (complete metric) space B and minimal usco φ : B2X, φ is single-valued at some point of B. In this paper we show that under some additional set-theoretic assumptions that are equiconsistent with the existence of a measurable cardinal there is a Banach space X whose dual, equipped with the weak topology, is in the class of weakly Stegall spaces but not in the class of Stegall spaces. This paper also contains an example of a compact space K such that K belongs to the class of weakly Stegall spaces but ( C(K), weak) does not

    The stability of external walls in panel construction

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    Graphoidal Tree d - Cover

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    Acharya and Sampathkumar defined a graphoidal cover as a partition of edges into internally disjoint (not necessarily open) paths. If we consider only open paths in the above definition then we call it as a graphoidal path cover

    Guest editors' introduction to special theme issue [of Studies in Learning, Evaluation, Innovation and Development]: Retention, recruitment and placement

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    Guest editors’ introduction to special theme issue [of Studies in Learning, Evaluation, Innovation and development]: Retention, recruitment and placement

    Decreasing attrition while increasing diversity: connections and contradictions in transforming marginalisation in an Australian contemporary university

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    This chapter uses the current focus on universities’ efforts to decrease student attrition as a lens to explore the connections and contradictions faced by those same universities as they increase diversity and aspire to transform marginalisation. The chapter draws on statistical data relating to Australian university students generally and to Central Queensland University (CQU) students specifically to illustrate some of the challenges and opportunities faced by universities as they bring their own institutional strategies into alignment at the macro level with government socioeconomic policy and at the micro level with the individual goals and aspirations of students and other stakeholders. Findings presented in the chapter support the argument that CQU specifically and the Australian higher education sector more broadly have contributed to maximising the educational outcomes, and hence to transforming the marginalisation, of some minority groups, such as students from non-English speaking backgrounds and some residents of regional communities. On the other hand, relatively high attrition rates remain the norm for other groups, such as Indigenous students, those from isolated areas and those from lower socioeconomic backgrounds, and for some groups not generally associated with minorities. For these groups, and for universities striving to increase their diversity by including such groups in their student cohorts, the groups’ marginalisation remains untransformed
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