Chain-stretch relaxation from low-frequency Fourier transform rheology

Frequency modulation Fourier transform spectroscopy

A new method, FM-FTS, combining Frequency Modulation heterodyne laser spectroscopy and Fourier Transform Spectroscopy is presented. It provides simultaneous sensitive measurement of absorption and dispersion profiles with broadband spectral coverage capabilities. Experimental demonstration is made on the overtone spectrum of C2H2 in the 1.5 μm region. OCIS codes: 120.6200, 300.6300, 300.6380, 3...

From Fourier Transform to Wavelets

Low-frequency Fourier analysis of speech rhythm.

A method for studying speech rhythm is presented, using Fourier analysis of the amplitude envelope of bandpass-filtered speech. Rather than quantifying rhythm with time-domain measurements of interval durations, a frequency-domain representation is used--the rhythm spectrum. This paper describes the method in detail, and discusses approaches to characterizing rhythm with low-frequency spectral ...

Estimation of frequency offset using warped discrete-Fourier transform

In this paper, the problem of estimating a small frequency offset in a signal with a large carrier frequency is addressed. The warped discrete-Fourier transform (WDFT) [A. Makur, S.K. Mitra, IEEE Trans. Circuits Systems—I: Fundam. Theory Appl. 6 (9) (September 2001) 1086–1093] is used and the accuracy of estimation and computational complexity of this technique is compared with the conventional...

Iterated Fourier Transform Systems: A Method for Frequency Extrapolation

In this paper we introduce a fractal-based method over (complex-valued) Fourier transforms of functions with compact support X ⊂ . This method of “iterated Fourier transform systems” (IFTS) has a natural mathematical connection with the fractal-based method of “iterated function systems with greyscale maps” (IFSM) in the spatial domain [6,7]. A major motivation for our formulation is the proble...