The results achieved with IF suggest that IF can be beneficial when food is given during the activity period of the animal, as explained above.
The output of the CED operator is the square of the IF of one signal, IF can be derived directly via this detector by calculating its square root.
(1) IF-based features: As mentioned earlier, the IF can be estimated either as the peak of the TFD of the signal (Equation 8) f i n = f s 2 M arg max k ρ n, k (8) or the first order moment of the TFD (Equation 9).
The IF can be written as ω ̃ i ( t ) = d ϕ ̃ i ( t ) d t (35).
The measurement of IF can be achieved through manual blood sampling, the use of small counting systems such as beta microprobes, or by derivation from PET images.
It can be seen from Table 3 that no particular pattern in IF can be seen with the change in distances between the buildings.
Specific for sinusoidal FM, where a(t) remains a constant A, and q i (t) becomes a sinusoid, the IF can be further expressed as omega_{i}left tright) =omega_{c}+omega_{m}cos omega_{f}t+theta_{2}).
The IF can be estimated from the peak of the TFD for all time instants as shown below [[18], p. 429] f ^ ( t ) = arg max f ρ z ( t, f ), 0 ≤ t ≤ T (28).
The IF can be estimated using a peak detector in the T-F domain that selects the frequency with the maximum value in the T-F representation as a function of time.
In the case of the widely used tracer 18F-fluorodeoxyglucose (FDG), the time-activity curve of tracer uptake in a specific brain region, combined with the IF, can be used in a classical modeling approach to calculate the kinetic rate constants governing passage from one compartment to another, and to calculate the rate of glucose metabolism.
Finally, although the IF can be used as a rough indictor, it still has many limitations [ 14, 15].
