A testbed of difficult instances of the problem are created to evaluate the performance of the GA.
However, as we will show in this paper, some general purpose methods and the ideas on which they are built can provide guidance towards the efficient solution of difficult instances.
Family duty, for instance, is refracted through generations of difficult history and complicated identity: Stories about Japanese Americans tackle Pearl Harbor, the atomic legacy of World War II, and the internment of Americans of Japanese descent (which is, sigh, of continuing relevance).
Given this, any instance of Alawite silence is difficult to interpret; it may indicate a lack of support for the revolution, though, on the other hand, it may even signify defiance of the regime.
Graphs with high symmetry or regularity are the main source for experimentally hard instances of the notoriously difficult graph isomorphism problem.
Furthermore, the emerging consolidated model is compared to relevant algorithms from the literature for a set of difficult bidimensional instances from lattice protein models.
Instead of expanding in an unrelenting tone of shocked disapproval, the author could have offered a serious view on a number of difficult questions.For instance, if privatisation can increase the efficiency of the notoriously inefficient defence sector, how should the inherent political and security risks best be managed?
A predictive score that would assist the clinician in identifying difficult LMA placement was also developed, resulting in a model with low sensitivity but specificity of 98% and a negative likelihood ratio of 95.6% (for instance, excluding difficult LMA placement in male patients with neck circumference <44 cm).
Thus not explicitly addressing the pedagogical foundations of any instance of digital education makes it difficult to robustly question (let alone change) the ways in which the technology is being used to support learning.
Without such data we are unable to determine whether the LHTL exposures resulted in improved aerobic fitness in addition to the enhanced Hbmass observed, and thus scientific conclusions on the effectiveness of LHTL in this instance are difficult.
