Sentence examples for model very difficult from inspiring English sources

In 1916, Arnold Sommerfeld added elliptical orbits to the Bohr model to explain the extra emission lines, but this made the model very difficult to use, and it still couldn't explain more complex atoms.

Interaction terms have not been included in the model as given the large numbers of patients all interaction terms are found to be significant and make interpretation of the model very difficult.

Differences in implementation, assumptions, and evaluations have made comparison of these models very difficult.

However, the results show that this variable has no effect on the reporting process, making identification of the parameters of the count data models very difficult.

On other hand, the complexity of natural systems and the number of processes that successively contribute to rainfall runoff phenomena make modeling very difficult, so the performance of these models is highly dependent on the quality and quantity of the input data.

It makes calculation of the likelihood in the setting of state-space models very difficult.

This makes fitting of models very difficult.

Based on our knowledge, designing the stereo-vision model is very difficult and we only find two models in [17], because the mechanisms of stereo vision still pose several research challenges, such as how to build then apply the model for the stereoscopic vision mechanism.

Indeed, the complexity of a model including both covariate by covariate interactions and time by covariate interactions, especially when covariates have several modalities, such as in our example (primary nephropathies), makes the model interpretation very difficult.

Generally, because of high level of uncertainties, some authors believe that a precise quantitatively prediction of such a complex problem with a conventional computational model seems very difficult and unlikely, and they may even accept a model that can predict with twofold difference for practical purposes (Nilson et al. 1985).

Implementation of the model of Xing et al. [ 7] showed that controlling the error rate through the hyperparameters of their model was very difficult.