Unspliced long non-coding RNAs are an important, rapidly evolving, component of mammalian transcriptomes.
Pulse trains are composed of a series of pulses that are separated by an IPI, a rapidly evolving component of song that is important for female choice [ 3, 4, 10, 20].
3) Calculating the presence 'probability' of the rapidly evolving components .
Calculating the presence 'probability' of the rapidly evolving components.
The threshold value δ is used to determine whether the rapidly evolving components are present in one channel.
The presence 'probability' of the rapidly evolving components is obtained as, p m, j = 1, if R m, j > δ 0, if R m, j ≤ δ (7).
Dependent on the presence 'probability' of the rapidly evolving components in each channel, the time smoothing factor is adaptively adjusted to estimate the 'steady-state' audio spectrum at the current frame.
The 'steady-state' smoothing factor α d (m,j) is dynamically adjusted according to the presence 'probability' of the rapidly evolving components p′(m,j) and is updated as, α d m, j = α + 1 − α p ' m, j (10).
By using the hard threshold method, R m,j) can be exploited to determine whether the rapidly evolving components are present in the j th channel at the m th frame.
Through asymmetric filtering, the resulting S slow (m,j) approaches the lower envelope of the smoothed energy spectrum S m,j) to describe the slowly evolving components of the audio spectrum in the j th channel, and the rapidly evolving components are presented by S m,j) − S slow (m,j).
Through recursive averaging, the presence 'probability' of the rapidly evolving components p′(m,j) which are continuously evolved over frames can be further given as, p ' m, j = α p p ' m − 1, j + 1 − α p p m, j (8).
