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We present a simple algorithm for emulating an N processor CRCW PRAM on an N node butterfly. Each step of the PRAM is emulated in time O(log N) with high probability, using FIFO queues of size O(1) at each node. The only use of randomization is in selecting a hash function to distribute the shared address space of the PRAM onto the nodes of the butterfly.(More)
This paper presents a general paradigm for the design of packet routing algorithms for fixed-connection networks. Its basis is a ran-domized on-line algorithm for scheduling any set of N packets whose paths have congestion c on any bounded-degree leveled network with depth L in O(c + L + log N) steps, using constant-size queues. In this paradigm, the design(More)
We show lower bounds of (E V Sort(V)) for the I/O-complexity of graph theoretic problems like connected components , biconnected components, and minimum spanning trees, where E and V are the number of edges and vertices in the input graph, respectively. We also present a determin-istic O(E V Sort(V) max(1; log log V BD E)) algorithm for the problem of graph(More)
We explore two ways of incorporating parallelism into priority queues. The rst is to speed up the execution of individual priority operations so that they can be performed one operation per time step, unlike sequential implementations which require O(log N) time steps per operation for an N element heap. We give an optimal parallel implementation that uses(More)
We present a variation to the well studied SVD based image compression technique. Our variation can be viewed as a preprocessing step in which the input image is permuted as per a fixed, data independent permutation, after which it is fed to the standard SVD algorithm. Likewise, our de-compression algorithm can be viewed as the standard SVD algorithm(More)
Shared memory multiprocessors are considered among the easiest parallel computers to program. However building shared memory machines with thousands of processors has proved difficult because of the inevitably long memory latencies. Much previous research has focused on cache coherency techniques, but it remains unclear if caches can obtain sufficiently(More)