The Owner Concept for PRAMs
نویسنده
چکیده
We analyze the owner concept for PRAMs. In OROW-PRAMs each memory cell has one distinct processor that is the only one allowed to write into this memory cell and one distinct processor that is the only one allowed to read from it. By symmetric pointer doubling, a new proof technique for OROW-PRAMs, it is shown that list ranking can be done in O(log n) time by an OROWPRAM and that LOGSPACE OROW-TIME(log n). Then we prove that OROW-PRAMs are a fairly robust model and recognize the same class of languages when the model is modi ed in several ways and that all kinds of PRAMs intertwine with the NC -hierarchy without timeloss. Finally it is shown that EREWPRAMs can be simulated by OREW-PRAMs and ERCW-PRAMs by ORCW-PRAMs. This research was partially supported by the Deutsche Forschungsgemeinschaft, SFB 342, Teilprojekt A4 \Klassi kation und Parallelisierung durch Reduktionsanalyse" y E-mail: [email protected]
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