The function multiplying parameter β4 is a steep sigmoid (or Hill function) whose value is close to 1 when y is reasonably larger than 0.
Because the optical signal is inversed with respect to the neuronal activity, the sign in the model has been corrected by multiplying all parameters by −1 prior to creating the images [14], [17], [27], [28]; hence darker regions would be expected to have the highest rate of neuronal activity.
We modelled this effect in a phenomenologic way by multiplying toxicity parameters with a factor ≥ 1 at time of first application of chemotherapy.
The indirect effect is found by multiplying the parameters along each of the (directed) paths from X to Y that include M and summing them; here, this is (α xβ m + γ xα lβ m).
This was done simply by multiplying the parameter estimates (Beta) obtained from the GLM with the surface (S) under their respective predictor (S = BetaauditoryxSauditory + BetaactionxSaction). Brain activity across conditions were compared using this surface (for details please see [4]).
Percentage signal change within the ROI was calculated by multiplying the parameter estimate by the peak-to-peak height of the EV model, and dividing by the mean signal across the whole acquisition period (Mumford 2007).
Hazard ratios for each quartile of serum C1M was determined by multiplying the parameter estimate of the log-transformed C1M value derived from the multivariate Cox proportional-hazard analysis, with the range between the log-transformed means of serum C1M levels in each quartile, followed by a back-transformation to the original scale using the exponential function.
The system is allowed to contain unknown parameters multiplying output-dependent nonlinearities, and, also, unknown nonlinearities satisfying certain bounds.
The basic shortcoming of most of these models is the incapability to produce a stable path for the national income when realistic values for the different parameters (multiplier and accelerator parameters) are entered into the system of equations.
The basic shortcoming of the original model is: the incapability to produce a stable path for the national income when realistic values for the different parameters (multiplier and accelerator parameters) are entered into the system of equations.
