An envelope is defined as the curve that is tangent to a given family of curves.
For FSK, the complex envelope is defined by: (19).
The mean value of the maxima and minima envelope is defined as (m_{1}).
The Gaussian envelope is defined by the standard deviation parallel to the wave, γ, and standard deviation perpendicular to the wave, η.
The Hilbert envelope is defined as the magnitude of the analytic signal, whose real part is the signal and the imaginary part is the Hilbert transform of the signal (which is the signal with its phase shifted by 90 degrees).
For each value of A, we calculated the average and standard deviation of M in a moving window of 5,000 pairs that were sorted in ascending order of A. Upper and lower envelopes were defined by the equation: μ ± Xσ, and positions outside the envelope recorded, as described previously [ 22, 23].
Nuclear envelope breakdown (NEB) was defined as the point when prophase chromatin lost a smooth, linear periphery, and the time of anaphase onset was defined to be the first frame where coordinated pole wards movement was observed [33].
An envelope of optimum parameters was defined from the bench scale study for this reagent.
The Gaussian contrast envelope of each Gabor was defined as <img src="http://journals.plos.org/plosone/article/asset?id=info?doi/10.1371/journal.pone.0000410.e001.PNG" class= inline-graphic"/>, where A is the peak contrast amplitude, r is the distance of (x,y) from the center of the Gaussian, σ is standard deviation, and M is the maximum radius.
In all patients who underwent 4D-CT scan, an internal target volume (ITV) was defined as the envelope of all GTVs in the different respiratory phases.
