Frekansn

Frekansn is a term encountered in discussions of time-varying signals and dynamic systems to denote the local or instantaneous rate of repetitive events. Unlike a fixed, global frequency, frekansn is understood to vary with time and may be defined over short analysis windows or through the derivative of phase. The term is not part of formal metrology and its precise definition can vary by context.

Relationship to frequency and instantaneous frequency. In stationary signals, frekansn coincides with the conventional frequency. For non-stationary signals, frekansn describes the time-varying frequency component and is commonly estimated as the instantaneous frequency f_inst(t) = (1/2π) dφ(t)/dt, where φ(t) is the instantaneous phase of the analytic signal.

Measurement methods. Frekansn is often estimated using the analytic signal and Hilbert transform, or through time–frequency tools such as the short-time Fourier transform (STFT), reassigned spectrograms, and wavelet-based approaches. Each method trades time and frequency resolution and must contend with noise, window length, and signal nonlinearity.

Applications and relevance. Frekansn appears in contexts like speech and music processing for pitch tracking, vibration analysis, and biomedical signal analysis where rhythms or cycles vary over time. It provides a way to describe non-stationary phenomena that fixed-frequency models cannot capture.

See also: frequency; instantaneous frequency; time-frequency analysis; Hilbert transform; spectrogram; wavelet transform. Note: as a non-standard term, frekansn may be defined differently in different sources.