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Palindrome recognition in real time by a multitape turing machine

Zvi Galil
1978 Journal of computer and system sciences (Print)  
Our Turing machines have several heads per tape. But by the well-known simulation of Fischer, et al., [7] , we can transform them into multitape Tm's with the same time behavior.  ...  Question a. Can we recognize palindromes on line in linear time ? Question b. Can we do it in real time ? Question c. Can we do string matching in real time ?  ...  which is called whenever an initial even palindrome is found. This obviously works in the case of a RAM. It works also in the case of a Turing machine.  ... 
doi:10.1016/0022-0000(78)90042-9 fatcat:cmm7zorivzctzcwxjiklhr2xgi

On the power of real-time turing machines under varying specifications [chapter]

Paul M. B. Vitányi
1980 Lecture Notes in Computer Science  
In particular it is shown that k+l heads are more powerful than k heads for real-time Turing machines.  ...  Differences in computing power between machines of unlike specifications emerge under the real-time restriction.  ...  KOSARAJU [1979] has claimed a proof that jump Turing machines can be simulated in real-time by multitape Turing machines at the cost of many tapes in the latter pro head in the former machine.  ... 
doi:10.1007/3-540-10003-2_106 fatcat:joacyoqkq5cetpglmdk2umu6fa

On the simulation of many storage heads by one

Paul M.B. Vitányi
1984 Theoretical Computer Science  
Each multitape Turing machine, of which the storage heads scan O(log n) distinct squares in each interval of n steps, for all n 2 I, can be real-time simulated by an oblivious one-head tape unit.  ...  Multitape Turing machines, on-line simulation by single head tape units, upper bounds, lower bounds, real-time simuiation by oblivious one-head tape unit, uniform logarithmic space, multicounter machines  ...  Cl Obviously, any real-time multitape Turing machine computation can be simulated on a uniform log n space Turing machine in exponential time.  ... 
doi:10.1016/0304-3975(84)90115-4 fatcat:vczyazzwubejnmkqop5d3cwkqe

Page 556 of Mathematical Reviews Vol. 58, Issue 1 [page]

1979 Mathematical Reviews  
on a multitape Turing machine and a recognition algorithm for P? on a two-way deterministic pushdown automaton. R. G. Buharaev (Kazan) Havel, Ivan M. Automata theory motivated by problem solving.  ...  They prove that P, (“palstar”) can be recognized on-line in linear time by an RAM. They also present a linear time on-line recognition algorithm for P?  ... 

Complexity, combinatorial group theory and the language of palutators

Carol Tretkoff
1988 Theoretical Computer Science  
Finally, in an attempt to find languages that have complexity which is greater than linear time, we discuss the language of palutators, where a palutator is defined as a generalization of a palindrome  ...  After a brief survey of the known results about group languages, we prove that many of the familiar classes of groups have word problems whose complexity is linear time.  ...  on a multitape Turing machine.  ... 
doi:10.1016/0304-3975(88)90134-x fatcat:zh5lspyb7zgbba7wp2n2zd2jqy

Palindrome recognition using a multidimensional tape

Therese Biedl, Jonathan F. Buss, Erik D. Demaine, Martin L. Demaine, Mohammadtaghi Hajiaghayi, Tomáš Vinař
2003 Theoretical Computer Science  
The problem of palindrome recognition using a Turing machine with one multidimensional tape is proved to require (n 2 =log n) time.  ...  A one-tape two-dimensional Turing machine can test whether a word of length n is a palindrome in time O(n 2 = log n).  ...  A multitape Turing machine can test for palindromes in real time [1] . We consider the case of one two-dimensional tape.  ... 
doi:10.1016/s0304-3975(03)00086-0 fatcat:co3wkn62mvghpbg3ogok4jzeii

Real-time language recognition by one-dimensional cellular automata

Alvy Ray Smith
1972 Journal of computer and system sciences (Print)  
The relationship of context-free languages to the languages recognized in real time by bounded cellular automata is detailed.  ...  The precise relationships of cellular automata to iterative automata and to Turing machines are established: In both cases, cellular automata are inherently faster.  ...  The quasirealtime languages are precisely the languages accepted in real time by nondeterministie on-line multitape Turing machines.  ... 
doi:10.1016/s0022-0000(72)80004-7 fatcat:tmzpp76o6ngvrhshla2a2lmltm

Fast on-line integer multiplication

Michael J. Fischer, Larry J. Stockmeyer
1974 Journal of computer and system sciences (Print)  
Other applications are to the on-line computation of products of polynomials, recognition of palindromes, and multiplication by a constant. *  ...  A Turing machine multiplies binary integers on-line if it receives its inputs, low-order digit first, and produces the jth digit of the product before reading in the (j+l)st digits of the two inputs.  ...  Paterson and A. Meyer for several helpful discussions.  ... 
doi:10.1016/s0022-0000(74)80047-4 fatcat:oxutieg7znajbfzrhd4qensfim

Fast on-line integer multiplication

Michael J. Fischer, Larry J. Stockmeyer
1973 Proceedings of the fifth annual ACM symposium on Theory of computing - STOC '73  
Other applications are to the on-line computation of products of polynomials, recognition of palindromes, and multiplication by a constant. *  ...  A Turing machine multiplies binary integers on-line if it receives its inputs, low-order digit first, and produces the jth digit of the product before reading in the (j+l)st digits of the two inputs.  ...  Paterson and A. Meyer for several helpful discussions.  ... 
doi:10.1145/800125.804037 dblp:conf/stoc/FischerS73 fatcat:sxmusx6utfhqzpbjleihrrd7la

An overview of computational complexity

Stephen A. Cook
1983 Communications of the ACM  
The important notion of complexity measure defined by the computation time on multitape Turing machines was introduced, and hierarchy theorems were proved.  ...  This is the second Turing Award lecture on Computational Complexity, The first was given by Michael Rabin in 1976.1 In reading Rabin's excellent article [62] now, one of the things that strikes me is how  ...  A little later Rabin's result was amplified in detail for time on multitape Turing machines by Hartmanis and Stearns [37] , and for space by Stearns, Hartmanis, and Lewis [78] .  ... 
doi:10.1145/358141.358144 fatcat:47ylh6ac7va7ngt53t22fxsyzq

One-way bounded cellular automata

Charles R. Dyer
1980 Information and Control  
Real-time aeceptors are presented for many of the languages that have been shown to he accepted by conventional two-way acceptors, including several classes of context-free languages.  ...  This paper studies a restriction of one-dimensional bounded cellular automata in which information is allowed to move only in one direction.  ...  There is a context-free language, not accepted in real time by any deterministic on-line multitape Turing acceptor, which is a real-time OCA language. Proof.  ... 
doi:10.1016/s0019-9958(80)90164-3 fatcat:m5qjdqpmgrcmrd4f3b2t5grxae

The computational power of parsing expression grammars [article]

Bruno Loff, Nelma Moreira, Rogério Reis
2020 arXiv   pre-print
) and has |y| > |x|. (*) PEGs are strongly non real-time for Turing machines.  ...  There exists a language with a PEG, such that neither it nor its reverse can be recognised by any multi-tape online Turing machine which is allowed to do only o(n/log n) steps after reading each input  ...  This work is partially funded by the ERDF through the COM-  ... 
arXiv:1902.08272v2 fatcat:zvva3yz3i5ckpgcwjtmliml3tq

One-way multihead writing finite automata

I. Hal Sudborough
1976 Information and Control  
Since it also takes 0(n) head reversals for the recognition of {xxlx c{0, 1}*} by a single tape nondeterministic Turing machine, the result follows. [] Since L is recognized by a deterministic one-way  ...  Vollmar (1970) showed that the language L = {uv2u, uv2v ] u ~ {0, 1}*, v ~ {a, b}*} is not recognized by any deterministic real-time buffer automaton.  ...  ACKNOWLEDGMENTS The author acknowledges the stimulating guidance of Professor Neil Jones in directing his dissertation, and the assistance of A.  ... 
doi:10.1016/s0019-9958(76)90426-5 fatcat:cbvmwsnkg5eevat4tgfmlxp4hi

On the simulation of many storage heads by a single one [chapter]

Paul M. B. Vitányi
Automata, Languages and Programming  
Each multitape machine can be on-line simulated by a one-head tape unit in square time [HU] , and also by a two-tape Turing machine in time* 0 (n log n) [HS] .  ...  If we can simulate each multitape Turing machine by a one-head tape unit in time T(n) then we can also simulate each multitape Turing machine by an oblivious one-head tape unit in time T(n).  ... 
doi:10.1007/bfb0036948 dblp:conf/icalp/Vitanyi83 fatcat:6wexkef6tvf2vmtycyu7wphoay

Computation in Cellular Automata: A Selected Review [chapter]

Melanie Mitchell
2005 Non-Standard Computation  
This work has been supported by the Santa Fe Institute and by grants from the National Science Foundation (IRI-9320200), the Department of Energy (DE-FG03-94ER25231), and the Defense Advanced Projects  ...  The first in the series was a two-dimensional cellular automaton M s that simulates a given Turing machine M in "real time"-that is, there is a one-to-one correspondence between the time steps of M s and  ...  He compared the language-recognition capability of such CAs with certain other parallel architectures (e.g., "bounded iterative automata" and multitape Turing machines), and proved a number of results  ... 
doi:10.1002/3527602968.ch4 fatcat:6elcgxgiy5bjrencagl6uay2hq
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