To identify the current state-of-the-art, and to better understand the heuristic components that prove most effective for several classes of heuristic algorithms applied to the TSP, the 8th DIMACS Implementation Challenge on the Traveling Salesman Problem [3] was recently organized by Johnson, McGeogh, Glover and Rego [3]. In this talk we describe findings from this Implementation Challenge as ...

We present and use a sequence similarity metric to solve sets of similar problems with case injected genetic algorithms. Rather than starting anew on each problem, we periodically inject a genetic algorithm's population with appropriate intermediate solutions to similar, previously solved problems. Using simple syntactic similarity measures, our experimental results from optimizing a series of ...

Using a contingent valuation survey, people’s willingness to pay for a given risk reduction is found to be much larger when traveling by air compared to by taxi. Follow-up questions revealed that an important reason for this discrepancy is that many experience a higher mental suffering from flying, and that they are willing to pay to reduce this suffering. It was also consistently found that pe...

Several works indicate the relationship between well-solved combinatorial optimization problems and the core non-emptiness of cooperative games associated with them. In this paper, we consider the core of symmetric traveling salesman games and relate it with well-solved cases of traveling salesman problems. We show that the core of a traveling salesman game in which the distance matrix is a sym...

This paper is concerned with the following two-species LotkaVolterra competition-diffusion system in the three-dimensional spatial space { ∂ ∂t u1(x, t) = ∆u1(x, t) + u1(x, t) [1− u1(x, t)− k1u2(x, t)] , ∂ ∂t u2(x, t) = d∆u2(x, t) + ru2(x, t) [1− u2(x, t)− k2u1(x, t)] , where x ∈ R3 and t > 0. For the bistable case, namely k1, k2 > 1, it is well known that the system admits a one-dimensional mo...