Real time recognition with cellular automata : a meaningful example
Recognizing when heuristics can approximate minimum vertex covers is complete for parallel access to NP
For both the edge deletion heuristic and the maximum-degree greedy heuristic, we study the problem of recognizing those graphs for which that heuristic can approximate the size of a minimum vertex cover within a constant factor of , where is a fixed rational number. Our main results are that these problems are complete for the class of problems solvable via parallel access to . To achieve these main results, we also show that the restriction of the vertex cover problem to those graphs for which...
Recognizing when heuristics can approximate minimum vertex covers is complete for parallel access to NP
For both the edge deletion heuristic and the maximum-degree greedy heuristic, we study the problem of recognizing those graphs for which that heuristic can approximate the size of a minimum vertex cover within a constant factor of r, where r is a fixed rational number. Our main results are that these problems are complete for the class of problems solvable via parallel access to NP. To achieve these main results, we also show that the restriction of the vertex cover problem to those...
Recursive classification of pseudo-random sequences
Reducibilities on tally and sparse sets
Relating automata-theoretic hierarchies to complexity-theoretic hierarchies
We show that some natural refinements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar refinements of the polynomial-time hierarchy. This extends a result of Burtschik and Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the Boolean hierarchy and the plus-hierarchy.
Relating Automata-theoretic Hierarchies to Complexity-theoretic Hierarchies
We show that some natural refinements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar refinements of the polynomial-time hierarchy. This extends a result of Burtschik and Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the Boolean hierarchy and the plus-hierarchy.
Relationships among , , and the determinant
Relativizations of the P = NP problem over the complex number field.
Restricted nondeterministic read-once branching programs and an exponential lower bound for integer multiplication
Branching programs are a well established computation model for Boolean functions, especially read-once branching programs have been studied intensively. In this paper the expressive power of nondeterministic read-once branching programs, more precisely the class of functions representable in polynomial size, is investigated. For that reason two restricted models of nondeterministic read-once branching programs are defined and a lower bound method is presented. Furthermore, the first exponential...
Restricted Nondeterministic Read-Once Branching Programs and an Exponential Lower Bound for Integer Multiplication
Branching programs are a well established computation model for Boolean functions, especially read-once branching programs have been studied intensively. In this paper the expressive power of nondeterministic read-once branching programs, more precisely the class of functions representable in polynomial size, is investigated. For that reason two restricted models of nondeterministic read-once branching programs are defined and a lower bound method is presented. Furthermore, the first exponential...
Reversals-space-parallelism tradeoffs for language recognition