Two-Tape Simulation of Multitape Turing Machines
Journal of the ACM (JACM)
Revised report on the algorithm language ALGOL 60
Communications of the ACM
Formal languages and their relation to automata
Formal languages and their relation to automata
The Vega Grid and Grid-Based Education
ICWL '02 Proceedings of the First International Conference on Advances in Web-Based Learning
ASIAN '02 Proceedings of the7th Asian Computing Science Conference on Advances in Computing Science: Internet Computing and Modeling, Grid Computing, Peer-to-Peer Computing, and Cluster
A Process Algebra for Reasoning About Quantum Security
Electronic Notes in Theoretical Computer Science (ENTCS)
The problem of space invariance for sequential machines
Information and Computation
A characterization of the power of vector machines
Journal of Computer and System Sciences
Nonexistence of program optimizers in several abstract settings
Journal of Computer and System Sciences
Computationally secure two-round authenticated message exchange
ASIACCS '10 Proceedings of the 5th ACM Symposium on Information, Computer and Communications Security
Basic notions in computational complexity
Algorithms and theory of computation handbook
Universality considerations in VLSI circuits
IEEE Transactions on Computers
Hierarchies of DLOGTIME-uniform circuits
MCU'04 Proceedings of the 4th international conference on Machines, Computations, and Universality
Survey: A survey of state vectors
Computer Science Review
Privacy-preserving matrix factorization
Proceedings of the 2013 ACM SIGSAC conference on Computer & communications security
Exact and efficient generation of geometric random variates and random graphs
ICALP'13 Proceedings of the 40th international conference on Automata, Languages, and Programming - Volume Part I
Processor--Time Tradeoffs under Bounded-Speed Message Propagation: Part I, Upper Bounds
Theory of Computing Systems
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The RAM, an abstract model for a random access computer, is introduced. A unique feature of the model is that the execution time of an instruction is defined in terms of l(n), a function of the size of the numbers manipulated by the instruction. This model has a fixed program, but it is shown that the computing speeds of this model and a stored-program model can differ by no more than a constant factor. It is proved that a T(n) time-bounded Turing machine can be simulated by an O(T(n).l(T(n))) timebounded RAM, and that a T(n) time-bounded RAM can be simulated by a Turing machine whose execution time is bounded by (T(n))^3 if l(n) is constant, or (T(n))^2 if l(n) is logarithmic. The main result states that if T"2(n) is a function such that there is a RAM that computes T"2(n) in time O(T"2(n)), and if T"1(n) is any function such that liminfn-~T"1(n)T"2(n)=0, then there is a set S that can be recognized by some RAM in time O(T"2(n)), but no RAM recognizes S in time O(T"1(n)). This is a sharper diagonal result than has been obtained for Turing machines. The proofs of most of the above results are constructive and are aided by the introduction of an ALGOL-like programming language for RMA's.