Replica Selection Research Articles

The data grid: Towards an architecture for the distributed management and analysis of large scientific datasets

In an increasing number of scientific disciplines, large data collections are emerging as important community resources. In this paper, we introduce design principles for a data management architecture called the data grid. We describe two basic services that we believe are fundamental to the design of a data grid, namely, storage systems and metadata management. Next, we explain how these services can be used to develop higher-level services for replica management and replica selection. We conclude by describing our initial implementation of data grid functionality.

A nearest neighbor algorithm for fast matched-field processing with a vertical line array

Selection of replica fields that are most like the data, i.e., the nearest neighbors (NNs) to the data, offers a way of reducing the computational search space in matched-field processing, thereby making larger physical search spaces or a larger number of frequencies practical. To enable selection of NNs a vector basis for the search space is required. The authors use the large eigenvectors of the covariance matrix for uncorrelated sources spread over the search region. This is not only a suitable vector basis of the search space, but also results in a dimensional reduction from the full set of eigenvectors, with a further computational saving. The replica vectors for the search region are partitioned by finding their projection on this vector basis. One can then select for matching only those replicas with similar squared projections on the vector basis. This selection process carries a modest cost in computing overhead, provided that the code, the partitioning, and the replica selection parameters are optimized. The detection performance and false alarm probability for the Bartlett beamformer, with and without selection of the replicas, were estimated from simulations of noisy data received on a vertical line array at practical time-bandwidth products. An order of magnitude speedup was obtained.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>