217 research outputs found
On a clique covering problem of orlin
AbstractLet T2n be the complement of a perfect matching in the complete graph on 2n vertices, and cc(T2n) be the minimum number of complete subgraphs necessary to cover all the edges of T2n Orlin posed the problem of determining the asymptotic behaviour of cc(T2n). We show that cc(T2n)=min{k:nâ©œ(kâ1âk2â)} for all n>1, (which implies that limnââcc(T 2n)/log2n=1). This is done by applying a Sperner-type theorem on set families due to BollobĂĄs and Schönheim
On complexity of optimized crossover for binary representations
We consider the computational complexity of producing the best possible
offspring in a crossover, given two solutions of the parents. The crossover
operators are studied on the class of Boolean linear programming problems,
where the Boolean vector of variables is used as the solution representation.
By means of efficient reductions of the optimized gene transmitting crossover
problems (OGTC) we show the polynomial solvability of the OGTC for the maximum
weight set packing problem, the minimum weight set partition problem and for
one of the versions of the simple plant location problem. We study a connection
between the OGTC for linear Boolean programming problem and the maximum weight
independent set problem on 2-colorable hypergraph and prove the NP-hardness of
several special cases of the OGTC problem in Boolean linear programming.Comment: Dagstuhl Seminar 06061 "Theory of Evolutionary Algorithms", 200
Mod/Resc Parsimony Inference
We address in this paper a new computational biology problem that aims at
understanding a mechanism that could potentially be used to genetically
manipulate natural insect populations infected by inherited, intra-cellular
parasitic bacteria. In this problem, that we denote by \textsc{Mod/Resc
Parsimony Inference}, we are given a boolean matrix and the goal is to find two
other boolean matrices with a minimum number of columns such that an
appropriately defined operation on these matrices gives back the input. We show
that this is formally equivalent to the \textsc{Bipartite Biclique Edge Cover}
problem and derive some complexity results for our problem using this
equivalence. We provide a new, fixed-parameter tractability approach for
solving both that slightly improves upon a previously published algorithm for
the \textsc{Bipartite Biclique Edge Cover}. Finally, we present experimental
results where we applied some of our techniques to a real-life data set.Comment: 11 pages, 3 figure
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