scispace - formally typeset
Journal ArticleDOI

Elimination graphs

Reads0
Chats0
TLDR
It turns out that if the authors take <i>P</i> as a graph with maximum independent set size no greater than <i*k</i>, then this definition gives a natural generalization of both chordal graphs and (<i-k + 1)-claw-free graphs.
Abstract
In this article we study graphs with inductive neighborhood properties. Let P be a graph property, a graph G = (V, E) with n vertices is said to have an inductive neighborhood property with respect to P if there is an ordering of vertices v1, …, vn such that the property P holds on the induced subgraph G[N(vi)∩ Vi], where N(vi) is the neighborhood of vi and Vi = {vi, …, vn}. It turns out that if we take P as a graph with maximum independent set size no greater than k, then this definition gives a natural generalization of both chordal graphs and (k + 1)-claw-free graphs. We refer to such graphs as inductive k-independent graphs. We study properties of such families of graphs, and we show that several natural classes of graphs are inductive k-independent for small k. In particular, any intersection graph of translates of a convex object in a two dimensional plane is an inductive 3-independent graph; furthermore, any planar graph is an inductive 3-independent graph. For any fixed constant k, we develop simple, polynomial time approximation algorithms for inductive k-independent graphs with respect to several well-studied NP-complete problems. Our generalized formulation unifies and extends several previously known results.

read more

Citations
More filters
Journal ArticleDOI

Network Design under General Wireless Interference

TL;DR: This work introduces the problem of finding a spanning tree along with a partition of the tree edges into the fewest number of feasible sets, where constraints on the edges define feasibility, and gives a simple algorithm that attains inductive independence of the conflict graph.
Journal ArticleDOI

Hardness and approximation for L-EPG and B1-EPG graphs

TL;DR: This work shows that fully-subdivided graphs are ⌞ -EPG graphs, and later uses this result in order to show that the following problems are APX-hard on ⌾ -E PG graphs: Minimum Vertex Cover, Maximum Independent Set , and Maximum Weighted Independent Set, and also that Minimum Dominating Set is NP-complete on⌞-EPG graph.
Posted Content

The clique problem on inductive $k$-independent graphs

TL;DR: An algorithm computing a maximum clique for this class of graphs in time O(1.2127^{k}(n-k+1)$, thus improving previous best results and proving some structural properties for inductive $k-independent graphs.
Posted Content

Algorithms for Intersection Graphs of Multiple Intervals and Pseudo Disks

TL;DR: For the minimum weight dominating set problem, a simple $O(t \log t)$ approximation is given for Multiple-Interval Graphs, improving on the previously known bound of $t^2$ and it is shown that it is NP-hard to obtain an $o(t)$-approximation in this case.
Journal ArticleDOI

Efficient assembly consensus algorithms for divergent contig sets

TL;DR: In this paper, a consensus approach is proposed that takes the best parts of several contigs datasets produced by different methods, and combines them into a better assembly, which can be viewed as an optimization problem where the aim is to find an alignment of two fragmented strings that maximizes an arbitrary scoring function between matched characters.
References
More filters
Journal ArticleDOI

The ellipsoid method and its consequences in combinatorial optimization

TL;DR: The method yields polynomial algorithms for vertex packing in perfect graphs, for the matching and matroid intersection problems, for optimum covering of directed cuts of a digraph, and for the minimum value of a submodular set function.
Book ChapterDOI

Paths, Trees, and Flowers

TL;DR: A graph G is a set of elements called vertices and a finite set of edges called edges such that each edge meets exactly two vertices, called the end-points of the edge as mentioned in this paper.
Book

Graph Coloring Problems

TL;DR: In this article, the Conjectures of Hadwiger and Hajos are used to define graph types, such as planar graph, graph on higher surfaces, and critical graph.
Journal ArticleDOI

Approximation algorithms for NP-complete problems on planar graphs

TL;DR: A general technique that can be used to obtain approximation algorithms for various NP-complete problems on planar graphs, which includes maximum independent set, maximum tile salvage, partition into triangles, maximum H-matching, minimum vertex cover, minimum dominating set, and minimum edge dominating set.
Journal ArticleDOI

Matroids and the greedy algorithm

TL;DR: Linear-algebra rank is the solution to an especially tractable optimization problem which are linear programs relative to certain derived polyhedra.