Sciweavers

STACS
2001
Springer
13 years 7 months ago
New Bounds on the OBDD-Size of Integer Multiplication via Universal Hashing
Abstract. Ordered binary decision diagrams (OBDDs) nowadays belong to the most common representation types for Boolean functions. Although they allow important operations such as s...
Philipp Woelfel
STACS
2001
Springer
13 years 7 months ago
A Logical Approach to Decidability of Hierarchies of Regular Star-Free Languages
We propose a new, logical, approach to the decidability problem for the Straubing and Brzozowski hierarchies based on the preservation theorems from model theory, on a theorem of ...
Victor L. Selivanov
STACS
2001
Springer
13 years 7 months ago
Semantical Principles in the Modal Logic of Coalgebras
Coalgebras for a functor on the category of sets subsume many formulations of the notion of transition system, including labelled transition systems, Kripke models, Kripke frames a...
Dirk Pattinson
STACS
2001
Springer
13 years 7 months ago
Approximation Algorithms for the Bottleneck Stretch Factor Problem
The stretch factor of a Euclidean graph is the maximum ratio of the distance in the graph between any two points and their Euclidean distance. Given a set S of n points in Rd, we ...
Giri Narasimhan, Michiel H. M. Smid
STACS
2001
Springer
13 years 7 months ago
Myhill-Nerode Relations on Automatic Systems and the Completeness of Kleene Algebra
It is well known that finite square matrices over a Kleene algebra again form a Kleene algebra. This is also true for infinite matrices under suitable restrictions. One can use t...
Dexter Kozen
STACS
2001
Springer
13 years 7 months ago
A Toolkit for First Order Extensions of Monadic Games
In 1974 R. Fagin proved that properties of structures which are in NP are exactly the same as those expressible by existential second order sentences, that is sentences of the form...
David Janin, Jerzy Marcinkowski
STACS
2001
Springer
13 years 7 months ago
Small PCPs with Low Query Complexity
Most known constructions of probabilistically checkable proofs (PCPs) either blow up the proof size by a large polynomial, or have a high (though constant) query complexity. In thi...
Prahladh Harsha, Madhu Sudan
STACS
2001
Springer
13 years 7 months ago
Generalized Langton's Ant: Dynamical Behavior and Complexity
Langton’s ant is a simple discrete dynamical system, with a surprisingly complex behavior. We study its extension to general planar graphs. First we give some relations between c...
Anahí Gajardo, Eric Goles Ch., André...
STACS
2001
Springer
13 years 7 months ago
Gathering of Asynchronous Oblivious Robots with Limited Visibility
Abstract. We consider a collection of robots which are identical (anonymous), have limited visibility of the environment, and no memory of the past (oblivious); furthermore, they a...
Paola Flocchini, Giuseppe Prencipe, Nicola Santoro...
STACS
2001
Springer
13 years 7 months ago
Randomness, Computability, and Density
We study effectively given positive reals (more specifically, computably enumerable reals) under a measure of relative randomness introduced by Solovay [32] and studied by Calud...
Rodney G. Downey, Denis R. Hirschfeldt, Andr&eacut...