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As an entry for the 2009 Gordon Bell price/performance prize, we present the results of two different hierarchical <i>N</i>-body simulations on a cluster of 256 graphics processing units (GPUs). Unlike many previous <i>N</i>-body simulations on GPUs that scale as <i>O</i>(<i>N</i><sup>2</sup>), the present method calculates the <i>O</i>(<i>N</i> log(More)
To distinguish axons from Schwann cell processes in the denervated (Büngner's bands) and reinnervated peripheral nerves, the nearest-neighbor distance of intermediate filaments (NND) was measured in axons and Schwann cells from denervated and subsequent regenerating peripheral nerves. It was revealed that the NND was much larger in regenerating axons (41.9(More)
Fast multipole methods have O(N) complexity, are compute bound, and require very little synchronization, which makes them a favorable algorithm on next-generation super-computers. Their most common application is to accelerate N-body problems, but they can also be used to solve boundary integral equations. When the particle distribution is irregular and the(More)
We have developed a parallel algorithm for radial basis function (rbf) interpolation that exhibits O(N) complexity, requires O(N) storage, and scales excellently up to a thousand processes. The algorithm uses a gmres iterative solver with a restricted additive Schwarz method (rasm) as a preconditioner and a fast matrix-vector algorithm. Previous fast rbf(More)
Extracting maximum performance of multi-core architectures is a difficult task primarily due to bandwidth limitations of the memory subsystem and its complex hierarchy. In this work, we study the implications of fork-join and data-driven execution models on this type of architecture at the level of task parallelism. For this purpose, we use a highly(More)
Nerve segments approximately 7 mm long were excised from the predegenerated sciatic nerves of mice, and treated 5 times by repetitive freezing and thawing to kill the Schwann cells. Such treated nerve segments were grafted into the original places so as to be in contact with the proximal stumps. The animals were sacrificed 1, 2, 3, 5, 7 and 10 days after(More)
We present teraflop-scale calculations of biomolecular electrostatics enabled by the combination of algorithmic and hardware acceleration. The algorithmic acceleration is achieved with the fast multipole method (fmm) in conjunction with a boundary element method (bem) formulation of the continuum electrostatic model, as well as the bibee approximation to(More)
The dermal melanocytes in the lesions of nevus of Ito and Mongolian spot were shown to possess the extracellular sheath composed of both fine filaments and granules (2-5 nm in diameter). In the case of nevus of Ito, the granular component appeared to predominate in the shealth, which measured up to 3 micrometers in width and was estimated to cover about 97%(More)