No sublogarithmic-time approximation scheme for bipartite vertex cover

Polynomial Time Approximation Scheme for Connected Vertex Cover in Unit Disk Graph

Connected Vertex Cover Problem (CVC) is an NP -hard problem. The currently best known approximation algorithm for CVC has performance ration 2. This paper gives the first Polynomial Time Approximation Scheme for CVC in Unit Disk Graph.

Improved Approximation for Min-Sum Vertex Cover

The paper describes an approximation algorithm for the Min Sum Vertex Cover (MSVC) problem, achieving a constant approximation factor strictly smaller than 2, thus improving on the best currently known approximation algorithm for the problem. ∗Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot 76100, Israel. E-mail: [email protected]. †Depar...

Combinatorial approximation of maximum k-vertex cover in bipartite graphs within ratio~0.7

We propose a purely combinatorial algorithm for max k-vertex cover in bipartite graphs, achieving approximation ratio 0.7. The only combinatorial algorithms currently known until now for this problem are the natural greedy algorithm, that achieves ratio (e−1)/e = 0.632, and an easy 2/3-approximation algorithm presented in [4].

On approximation of max-vertex-cover

NFA reduction via hypergraph vertex cover approximation

In this thesis, we study the minimum vertex cover problem on the class of k-partite kuniform hypergraphs. This problem arises when reducing the size of nondeterministic finite automata (NFA) using preorders, as suggested by Champarnaud and Coulon. It has been shown that reducing NFAs using preorders is at least as hard as computing a minimal vertex cover on 3-partite 3-uniform hypergraphs, whic...