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JACM
2000

Parallel RAMs with owned global memory and deterministic context-free language recognition

13 years 11 months ago
Parallel RAMs with owned global memory and deterministic context-free language recognition
We identify and study a natural and frequently occurring subclass of Concurrent Read, Exclusive Write Parallel Random Access Machines (CREW-PRAMs). Called Concurrent Read, Owner Write, or CROW-PRAMs, these are machines in which each global memory location is assigned a unique "owner" processor, which is the only processor allowed to write into it. Considering the difficulties that would be involved in physically realizing a full CREW-PRAM model, it is interesting to observe that in fact, most known CREW-PRAM algorithms satisfy the CROW restriction or can be easily modified to do so. This paper makes three main contributions. First, we formally define the CROW-PRAM model and demonstrate its stability under several definitional changes. Second, we precisely characterize the power of the CROW-PRAM by showing that the class of languages recognizable by it in time O(log n) (and implicitly with a polynomial number of processors) is exactly the class LOGDCFL of languages log space r...
Patrick W. Dymond, Walter L. Ruzzo
Added 18 Dec 2010
Updated 18 Dec 2010
Type Journal
Year 2000
Where JACM
Authors Patrick W. Dymond, Walter L. Ruzzo
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