Showing papers by "Juris Hartmanis published in 1970"
TL;DR: The essence of various proofs of undecidability are abstracted and wide classes of properties and general conditions on families of languages such that these proofs of Undecidable hold are found.
48 citations
TL;DR: It is shown that there exist arbitrarily complex functions with optimal RASP programs whose running time cannot be improved by any multiplicative constant and these optimal programs cannot be fixed procedures, and the difference in computation speed between fixed procedures and self-modifying programs.
Abstract: In this paper we explore the computational complexity measure defined by running times of programs on random access stored program machines, RASP''S. The purpose of this work is to study more realistic complexity measures and to provide a setting and some techniques to explore different computer organizations. The more interesting results of this paper are obtained by an argument about the size of the computed functions. For example, we show (without using diagonalization) that there exist arbitrarily complex functions with optimal RASP programs whose running time cannot be improved by any multiplicative constant. We show, furthermore, that these optimal programs cannot be fixed prodecures and self-modifying programs. The same technique is used to compare computation speed of machines with and without built in multiplication. We conclude the paper with a look at machines with associative memory and distributed logic machines.
42 citations