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Performance suffers under NFS Version 2 because the protocol requires servers to write data and file system metadata to stable storage (usually disk) synchronously, before replying successfully to a client WRITE request [Ousterhout90]. The performance problem with synchronous writes was recognized early. NFS Version 2 has an artifact of a proposed interface(More)
We present fast methods for filtering voltage measurements and performing optimal inference of the location and strength of synaptic connections in large dendritic trees. Given noisy, subsampled voltage observations we develop fast l 1-penalized regression methods for Kalman state-space models of the neuron voltage dynamics. The value of the l 1-penalty(More)
We investigate Bayesian methods for optimal decoding of noisy or incompletely-observed spike trains. Information about neural identity or temporal resolution may be lost during spike detection and sorting, or spike times measured near the soma may be corrupted with noise due to stochastic membrane channel effects in the axon. We focus on neural encoding(More)
We present a novel approach to fully dynamic management of physical disk blocks in Unix file systems. By adding a single system call, zero, to an existing file system, we permit applications to create holes, that is, regions of files to which no physical disk blocks are allocated, far more flexibly than previously possible. zero can create holes in the(More)