Although the joint estimation of the three parameters ρ,γ and λ is indeed a very difficult problem, and the method proposed here is unlikely to be optimal, we believe that we have taken an important step towards devising a robust, reliable method.
Finally, we point out that since the computation of practically useful Lyapunov functionals is a very difficult task, the fractional Lyapunov method has its own limitations and should be generalized and verified for more complicated linear and nonlinear problems.
This is a very difficult task since few body composition methods are applicable in this age group.
The analytical checking always represents a great challenge and is a very difficult step to overpass to validate the method.
Except for those parameters for which a consensus exists, the question of testing method harmonisation remains a very difficult issue.
This smart phone application provides an easy solution to collect, manage and process the data in the field which has been a very difficult task for field biologists using traditional methods.
A very difficult little man.
A very difficult opponent".
Although this requires further investigation, evaluating the impact of dialysis method on survival is very difficult, with the method adjusted for individual patients.
