Sciweavers

CSR
2009
Springer
13 years 6 months ago
Approximability of the Maximum Solution Problem for Certain Families of Algebras
We study the approximability of the maximum solution problem. This problem is an optimisation variant of the constraint satisfaction problem and it captures a wide range of interes...
Peter Jonsson, Johan Thapper
CSR
2009
Springer
13 years 8 months ago
Characterizing the Existence of Optimal Proof Systems and Complete Sets for Promise Classes
In this paper we investigate the following two questions: Q1: Do there exist optimal proof systems for a given language L? Q2: Do there exist complete problems for a given promise ...
Olaf Beyersdorff, Zenon Sadowski
CSR
2009
Springer
13 years 9 months ago
The Reachability Problem over Infinite Graphs
Abstract. We survey classical and selected recent work on the reachability problem over finitely presented infinite graphs. The problem has a history of 100 years, and it is centra...
Wolfgang Thomas
CSR
2009
Springer
13 years 11 months ago
New Plain-Exponential Time Classes for Graph Homomorphism
A homomorphism from a graph G to a graph H (in this paper, both simple, undirected graphs) is a mapping f : V (G) → V (H) such that if uv ∈ E(G) then f(u)f(v) ∈ E(H). The pro...
Magnus Wahlström
CSR
2009
Springer
13 years 11 months ago
Depth Reduction for Circuits with a Single Layer of Modular Counting Gates
We consider the class of constant depth AND/OR circuits augmented with a layer of modular counting gates at the bottom layer, i.e AC0 ◦MODm circuits. We show that the following ...
Kristoffer Arnsfelt Hansen
CSR
2009
Springer
13 years 11 months ago
A Feebly Secure Trapdoor Function
Abstract. In 1992, A. Hiltgen [1] provided the first constructions of provably (slightly) secure cryptographic primitives, namely feebly one-way functions. These functions are pro...
Edward A. Hirsch, Sergey I. Nikolenko
CSR
2009
Springer
13 years 11 months ago
Variations on Muchnik's Conditional Complexity Theorem
Muchnik’s theorem about simple conditional descriptions states that for all strings a and b there exists a short program p transforming a to b that has the least possible length ...
Daniil Musatov, Andrei E. Romashchenko, Alexander ...