Unfortunately, manual curation of metabolic reactions becomes impractical in surveys of many metabolic networks.
However, this would become impractical in the structured case, and a more efficient way to find the MLE is with an EM algorithm, where, at each iteration, we update the estimate of s using the value that maximizes the expected log-likelihood under the posterior distribution on the hidden variables f t, conditional on the previous estimate of s.
When numbers in double-precision floating-point format are written into a BDML file, storing the entire values may become impractical in terms of file size and file operations.
Obviously, this becomes impractical for a large number of samples.
ODEs or PDEs mathematically represent signal transduction by introducing many parameters in the model, which becomes impractical for extremely large networks due to the increasing difficulty in parameter estimation [ 1].
While all parameters can be manually adjusted, this becomes impractical as the number of compartments N in the model increases, since the total number of parameters is 4×N.
It should be noted that such a verbal clarification becomes impractical when too many rating scales (e.g., 10-point format) are involved because the level of agreement becomes too fine to be easily expressed in words [36].
Hunt acknowleded that at some scale, data storage becomes impractical, adding that he meant "forever being in quotes" when he said the agency wants to keep data "forever".
Consequently, the tuning of an optimal ML-MPP by exhaustive search within a prescribed frequency band becomes impractical.
Like most NP-Complete problems, what is easy for a few small objects becomes impractical for larger more numerous objects.
