Issue Theoret. Informatics Appl. Volume 37, Number 2, April-June 2003 Page(s) 159 - 176 DOI 10.1051/ita:2003012

Theoret. Informatics Appl. 37, 159-176 (2003)
DOI: 10.1051/ita:2003012

The Communication Hierarchy of Time and Space Bounded Parallel Machines

Norbert Popély

Department of Computer Science, P. J. Safárik University, Jesenná 5, 04154 Kosice, Slovakia; popely@mail.com.

(Received June, 2001. Accepted August, 2003.)

Abstract
We describe the communicating alternating machines and their simulation. We show that, in the case of communicating alternating machines which are bounded, simultaneously, by polynomial time and logarithmic space, the use of three communication levels instead of two does not increase computational power of communicating alternating machines. This resolves an open problem [2] concerning the exact position of machines with three communication levels in the hierarchy.

Mathematics Subject Classification. 03D15

Key words: Computational complexity -- synchronized alternation.


© EDP Sciences 2003

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