11. The Siegert equation relates the second-order autocorrelation function with the first-order autocorrelation function as follows: 12. The maximum of the autocorrelation function of \ scriptstyle s _ { c'} is reached at 0. 13. As the autocorrelation function and the power spectra form a Fourier pair, complementary sequences also have complementary spectra. 14. These fluctuations are traditionally described by the two dimensional autocorrelation function , or by the corresponding Fourier power spectrum. 15. A stationary random process does have an autocorrelation function and hence a spectral density according to the Wiener Khinchin theorem. 16. Specifically, for an AR ( 1 ) process, the sample autocorrelation function should have an exponentially decreasing appearance. 17. We do this by placing the 95 % confidence interval for the sample autocorrelation function on the sample autocorrelation plot. 18. This way, x ( t ) is a cyclostationary signal with period T _ 0 and cyclic autocorrelation function : 19. The degree of voicing is determined by the value of the normalized autocorrelation function at a shift of one pitch period. 20. Through analysis of the resultant exponential autocorrelation function , average particle size can be calculated as well as a polydispersity index.
