Search results for "deterministic"
showing 10 items of 141 documents
Cost-Effective Congestion Management for Interconnection Networks Using Distributed Deterministic Routing
2010
The Interconnection networks are essential elements in current computing systems. For this reason, achieving the best network performance, even in congestion situations, has been a primary goal in recent years. In that sense, there exist several techniques focused on eliminating the main negative effect of congestion: the Head of Line (HOL) blocking. One of the most successful HOL blocking elimination techniques is RECN, which can be applied in source routing networks. FBICM follows the same approach as RECN, but it has been developed for distributed deterministic routing networks. Although FBICM effectively eliminates HOL blocking, it requires too much resources to be implemented. In this …
Representation of Autonomous Automata
2001
An autonomous automaton is a finite automaton with output in which the input alphabet has cardinality one when special reduced. We define the transition from automata to semigroups via a representation successful if given two incomparable automata (neither simulate the other), the semigroups representing the automata are distinct. We show that representation by the transition semigroup is not successful. We then consider a representation of automata by semigroups of partial transformations. We show that in general transition from automata to semigroups by this representation is not successful either. In fact, the only successful transition presented is the transiton to this semigroup of par…
The Many Faces of a Translation
2000
First-order translations have recently been characterized as the maps computed by aperiodic single-valued nondeterministic finite transducers (NFTs). It is shown here that this characterization lifts to "V-translations" and "V-single-valued-NFTs", where V is an arbitrary monoid pseudovariety. More strikingly, 2-way V-machines are introduced, and the following three models are shown exactly equivalent to Eilenberg's classical notion of a bimachine when V is a group variety or when V is the variety of aperiodic monoids: V-translations, V-single-valued-NFTs and 2-way V-transducers.
Quantum Finite One-Counter Automata
1999
In this paper the notion of quantum finite one-counter automata (QF1CA) is introduced. Introduction of the notion is similar to that of the 2-way quantum finite state automata in [1]. The well-formedness conditions for the automata are specified ensuring unitarity of evolution. A special kind of QF1CA, called simple, that satisfies the well-formedness conditions is introduced. That allows specify rules for constructing such automata more naturally and simpler than in general case. Possible models of language recognition by QF1CA are considered. The recognition of some languages by QF1CA is shown and compared with recognition by probabilistic counterparts.
A description based on languages of the final non-deterministic automaton
2014
The study of the behaviour of non-deterministic automata has traditionally focused on the languages which can be associated to the different states. Under this interpretation, the different branches that can be taken at every step are ignored. However, we can also take into account the different decisions which can be made at every state, that is, the branches that can be taken, and these decisions might change the possible future behaviour. In this case, the behaviour of the automata can be described with the help of the concept of bisimilarity. This is the kind of description that is usually obtained when the automata are regarded as labelled transition systems or coalgebras. Contrarily t…
Complexity of operations on cofinite languages
2010
International audience; We study the worst case complexity of regular operation on cofinite languages (i.e., languages whose complement is finite) and provide algorithms to compute efficiently the resulting minimal automata.
Real-Time Vector Automata
2013
We study the computational power of real-time finite automata that have been augmented with a vector of dimension k, and programmed to multiply this vector at each step by an appropriately selected k×k matrix. Only one entry of the vector can be tested for equality to 1 at any time. Classes of languages recognized by deterministic, nondeterministic, and "blind" versions of these machines are studied and compared with each other, and the associated classes for multicounter automata, automata with multiplication, and generalized finite automata.
On Finite Satisfiability of Two-Variable First-Order Logic with Equivalence Relations
2009
We show that every finitely satisfiable two-variable first-order formula with two equivalence relations has a model of size at most triply exponential with respect to its length. Thus the finite satisfiability problem for two-variable logic over the class of structures with two equivalence relations is decidable in nondeterministic triply exponential time. We also show that replacing one of the equivalence relations in the considered class of structures by a relation which is only required to be transitive leads to undecidability. This sharpens the earlier result that two-variable logic is undecidable over the class of structures with two transitive relations.
Active Learning of Recursive Functions by Ultrametric Algorithms
2014
We study active learning of classes of recursive functions by asking value queries about the target function f, where f is from the target class. That is, the query is a natural number x, and the answer to the query is f(x). The complexity measure in this paper is the worst-case number of queries asked. We prove that for some classes of recursive functions ultrametric active learning algorithms can achieve the learning goal by asking significantly fewer queries than deterministic, probabilistic, and even nondeterministic active learning algorithms. This is the first ever example of a problem where ultrametric algorithms have advantages over nondeterministic algorithms.
A Wideband One-Ring MIMO Channel Model Under Non-Isotropic Scattering Conditions
2008
In this paper, we present a wideband one-ring multiple-input multiple-output (MIMO) channel model for non-isotropic scattering environments. The model is designed in such a way that the delay power spectral density (PSD) of the resulting reference channel model is identical to a given delay PSD. Furthermore, we present an efficient deterministic channel simulation model obtained by using the principle of deterministic channel modeling. The statistical properties of both the reference model and the simulation model are also studied. Analytical expressions will be presented for the temporal autocorrelation function (ACF), the two-dimensional (2D) space cross-correlation function (CCF), and th…