Some Combinatorial Optimization Problems for Weak-Bisplit Graphs

Bisplit graphs

Some Combinatorial Problems on Halin Graphs

Let T be a tree with no degree 2 vertices and L(T) = {l1,. .. , lr}, r ≥ 2 denote the set of leaves in T. An Halin graph G is a graph obtained from T such that V (G) = V (T) and E(G) = E(T) ∪ {{li, li+1} | 1 ≤ i ≤ r − 1} ∪ {l1, lr}. In this paper, we investigate combinatorial problems such as, testing whether a given graph is Halin or not, chromatic bounds, an algorithm to color Halin graphs wi...

WEAK AND STRONG DUALITY THEOREMS FOR FUZZY CONIC OPTIMIZATION PROBLEMS

The objective of this paper is to deal with the fuzzy conic program- ming problems. The aim here is to derive weak and strong duality theorems for a general fuzzy conic programming. Toward this end, The convexity-like concept of fuzzy mappings is introduced and then a speci c ordering cone is established based on the parameterized representation of fuzzy numbers. Un- der this setting, duality t...

Differential Approximation Algorithms for Some Combinatorial Optimization Problems

We use a new approximation measure, the differential approximation ratio, to derive polynomial-time approximation algorithms for minimum set covering (for both weighted and unweighted cases), minimum graph coloring and bin-packing. We also propose differentialapproximation-ratio preserving reductions linking minimum coloring, minimum vertex covering by cliques, minimum edge covering by cliques ...

On some optimization problems for star-free graphs

It is shown that in star-free graphs the maximum independent set problem, the minimum dominating set problem and the minimum independent dominating set problem are approximable up to constant factor by any maximal independent set.