Sentence examples for rather difficult problems from inspiring English sources

Experience has shown [25 27] that an appropriate combination of FFs and UFs frequently allows the solution of rather difficult problems.

Finding exact geometric properties characterizing sets with optimal admissible meshes appears to be a rather difficult problem.

Detecting the presence of resonant SMS waves in a plasma of high dissipation level is a rather difficult problem.

Faced with so many discrete choice models, how to choose an appropriate one to simulate travel behavior is still a rather difficult problem.

Thus Russell has set himself a rather difficult problem, since it is not at all clear that there can be any true propositions that are not, in some sense, propositions about what is, has been or will be.

Because the ray direction does not coincide with the normal to wavefront and the index of crystal changes with the direction of propagation, the design of crystal components is a rather difficult problem.

Multiphase flow and displacement can pose a rather difficult problem, both because the underlying physics is complex, and also because standard laboratory investigation reveals little about the mechanisms that control micro-scale processes.

However, unless the cover model is a complete statistical descriptor of the empirical source, such optimized schemes may, paradoxically, end up being more detectable if the warden designs the detector 'outside of the model'[6, 7], which brings us back to the main and rather difficult problem - modeling the source.

One group adopted a practical approach to this rather difficult problem.

Generally, it is a rather difficult problem to choose the most appropriate value for the threshold (see Figure S1.4 and Table S1.2 in the Electronic Supplementary Material S1).

It is a rather difficult philosophical problem to discuss the (possible, non-technical) nature of such "truth degrees" or "truth values".