The NP-complete problems are a sort of inner sanctum of computational difficulty; solve one and you've solved them all, not to mention all the lesser NP problems lurking in the rear.
Because of the computational difficulties experienced with the solution algorithm of nonlinear bi-level mixed integer programming with a large number of 0 1 variables, the discrete network design problem has been recognized as one of the most difficult yet challenging problems in transport.
Because of the computational difficulties in estimating large phylogenies, many computational biologists think that the only feasible strategy to estimating the Tree of Life will involve a divide-and-conquer approach where trees are estimated on subsets of taxa and a computational method is used to assemble a tree on the entire taxon set from these smaller trees.
T-optimum designs for model discrimination are notoriously difficult to find because of the computational difficulty involved in solving an optimization problem that involves two layers of optimization.
We emphasize that we exclude the case (eta=alpha) because of the computational difficulty and the fact that the integral int_{a}^{t} varphi^{-1}bigl(p s)^{-1} bigr),ds=int_{a}^{t} s^{-1}L bigl(s^{-eta }bigr)l_{p}(s)^{-frac{1}{alpha}},ds might be either convergent or divergent.
Finally, the analysis provides insights for understanding the sources of the computational difficulties associated with JTMS and ATMS.
However, because of the logistical and computational difficulties associated with simulating proximity, it was not possible in our study to assess this issue.
Application of these procedures to hexagonal polycrystals posed significant computational difficulties, because of the need to represent the texture in the hcp polycrystals in a much larger number of dimensions in the Fourier space compared with what was needed for the cubic polycrystals.
The security of this vault depends on the computational difficulties of solving polynomial reconstruction problem.
In the case of thermal equilibrium ((mathbf{J}_{n,K} = mathbf{J}_{p,K} = mathbf{0})), we can anticipate computational difficulties with the use of (4a) and (4b) because of exact cancellation of drift and diffusive current contributions.
