Leonard F. Wisniewski

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We give asymptotically equal lower and upper bounds for the number of parallel 1/0 operations required to perform BMMC permutations (defined by a characteristic matrix that is nonsingular over GF(2)) on parallel disk systems. Under the Vitter-Shriver parallel-disk model with N records, D disks, block size B, and M records of RAM, we show a universal lower(More)
We present the design and implementation of a parallel out-of-core sorting algorithm, which is based on Leighton's columnsort algorithm. We show how to relax some of the steps of the original columnsort algorithm to permit a faster out-of-core implementation. Our algorithm requires only 4 passes over the data, and a 3-pass implementation is possible.(More)
Research computing in the social sciences requires access to statistical software and quantitative tools that perform embarrassingly parallel computation at moderate scale, large memory to fit entire data sets, and secure storage for potentially confidential data. The Research Computing Environment (RCE) was designed as a three-tier system to satisfy these(More)
The fast cosine transform algorithms introduced in [ST91, Ste92] require fewer operations than any other known general algorithm. Similar to related fast transform algorithms (e.g., the FFT), these algorithms permute the data before, during, or after the computation of the transform. The choice of this permutation may be an important consideration in(More)
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