Machines Equivalent To The Turing Machine Model
Turing equivalence
Many machines that might be thought to have more computational capability than a simple universal Turing machine can be shown to have no more power (Hopcroft and Ullman p. 159, cf Minsky). They might compute faster, perhaps, or use less memory, or their instruction set might be smaller, but they cannot compute more powerfully (i.e. more mathematical functions). (The Church-Turing thesis hypothesizes this to be true: that anything that can be “computed” can be computed by some Turing machine.)
The sequential-machine models
All of the following are called "sequential machine models" to distinguish them from "parallel machine models" (van Emde Boas (1990) p. 18).
Read more about this topic: Turing Machine Equivalents
Famous quotes containing the words machines, equivalent, machine and/or model:
“The machines that are first invented to perform any particular movement are always the most complex, and succeeding artists generally discover that, with fewer wheels, with fewer principles of motion, than had originally been employed, the same effects may be more easily produced. The first systems, in the same manner, are always the most complex.”
—Adam Smith (17231790)
“The notion that one will not survive a particular catastrophe is, in general terms, a comfort since it is equivalent to abolishing the catastrophe.”
—Iris Murdoch (b. 1919)
“The machine invades me all day.”
—Sharon Atkins, U.S. receptionist. As quoted in Working, book 2, by Studs Terkel (1973)
“The striking point about our model family is not simply the compete-compete, consume-consume style of life it urges us to follow.... The striking point, in the face of all the propaganda, is how few Americans actually live this way.”
—Louise Kapp Howe (b. 1934)