5,533 research outputs found

    Dissimilarity Clustering by Hierarchical Multi-Level Refinement

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    We introduce in this paper a new way of optimizing the natural extension of the quantization error using in k-means clustering to dissimilarity data. The proposed method is based on hierarchical clustering analysis combined with multi-level heuristic refinement. The method is computationally efficient and achieves better quantization errors than theComment: 20-th European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN 2012), Bruges : Belgium (2012

    Managing Uncertainty: A Case for Probabilistic Grid Scheduling

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    The Grid technology is evolving into a global, service-orientated architecture, a universal platform for delivering future high demand computational services. Strong adoption of the Grid and the utility computing concept is leading to an increasing number of Grid installations running a wide range of applications of different size and complexity. In this paper we address the problem of elivering deadline/economy based scheduling in a heterogeneous application environment using statistical properties of job historical executions and its associated meta-data. This approach is motivated by a study of six-month computational load generated by Grid applications in a multi-purpose Grid cluster serving a community of twenty e-Science projects. The observed job statistics, resource utilisation and user behaviour is discussed in the context of management approaches and models most suitable for supporting a probabilistic and autonomous scheduling architecture

    Fronthaul-Constrained Cloud Radio Access Networks: Insights and Challenges

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    As a promising paradigm for fifth generation (5G) wireless communication systems, cloud radio access networks (C-RANs) have been shown to reduce both capital and operating expenditures, as well as to provide high spectral efficiency (SE) and energy efficiency (EE). The fronthaul in such networks, defined as the transmission link between a baseband unit (BBU) and a remote radio head (RRH), requires high capacity, but is often constrained. This article comprehensively surveys recent advances in fronthaul-constrained C-RANs, including system architectures and key techniques. In particular, key techniques for alleviating the impact of constrained fronthaul on SE/EE and quality of service for users, including compression and quantization, large-scale coordinated processing and clustering, and resource allocation optimization, are discussed. Open issues in terms of software-defined networking, network function virtualization, and partial centralization are also identified.Comment: 5 Figures, accepted by IEEE Wireless Communications. arXiv admin note: text overlap with arXiv:1407.3855 by other author

    Image data segmentation

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    Na začátku diplomové práce je čtenář seznámen s procesem zpracování obrazu a v navazující části jsou popsáný a vysvětleny dnes nejpoužívanější algoritmy pro segmentaci obrazu. Na základě watershed transform je vytvořen segmentační operátor pro volně šiřitelný program Rapid Miner a v dokumentu je popsáno, jak proces vývoje probíhal. V poslední části práce jsou prezentovány segmentované obrazy a popsána úskalí takto implementované watershed transform metody.A reader is acquaint with image segmentation process at the beginning of the master thesis and the most popular algorithms for image segmentation are explained and covered in the following part. Segmentation operator for Rapid Miner freeware program was created on basics of watershed transform; and in the paper was described process of development. In last section of the work segmented images are presented; and diculties of this watershed transform implementation are described.
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