Results 301 to 310 of about 2,594,498 (363)
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Rheologica Acta, 1998
Oscillatory shear of polymeric liquids in the non-linear regime generates higher harmonic contributions in the shear stress response. These non-linear contributions are analyzed in Fourier space with respect to the different frequencies and intensities. Simulated and experimental Fourier rheology spectra for atactic poly(propylene) melts are shown.
Wilhelm, M., Maring, D., Spiess, H.
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Oscillatory shear of polymeric liquids in the non-linear regime generates higher harmonic contributions in the shear stress response. These non-linear contributions are analyzed in Fourier space with respect to the different frequencies and intensities. Simulated and experimental Fourier rheology spectra for atactic poly(propylene) melts are shown.
Wilhelm, M., Maring, D., Spiess, H.
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Compressive least-squares migration with on-the-fly Fourier transforms
Geophysics, 2019Least-squares reverse time migration is a powerful approach for true-amplitude seismic imaging of complex geologic structures, but the successful application of this method is currently hindered by its enormous computational cost, as well as its high ...
Philipp A. Witte +4 more
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Optics Letters, 1995
We propose a new method based on the differential absorption lidar technique for multipollutant detection. A broadband laser is sent into the atmosphere in a wavelength range in which several pollutants absorb. The backscattered light is analyzed by a Fourier-transform spectrometer with time resolution.
M, Douard +6 more
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We propose a new method based on the differential absorption lidar technique for multipollutant detection. A broadband laser is sent into the atmosphere in a wavelength range in which several pollutants absorb. The backscattered light is analyzed by a Fourier-transform spectrometer with time resolution.
M, Douard +6 more
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Seismological Research Letters, 2013
Online Material: Interactive numerical model of the Mader–Ott Harmonic Analyzer. For contemporary seismological observatory practice and seismic exploration work, the fast Fourier transform (FFT) has become such a common tool that we rarely think about single transforms. Often, we switch from time to frequency to time domain without even examining the
Hinzen, Klaus-G. +2 more
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Online Material: Interactive numerical model of the Mader–Ott Harmonic Analyzer. For contemporary seismological observatory practice and seismic exploration work, the fast Fourier transform (FFT) has become such a common tool that we rarely think about single transforms. Often, we switch from time to frequency to time domain without even examining the
Hinzen, Klaus-G. +2 more
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Growth and Integrability of Fourier Transforms on Euclidean Space
, 2013A fundamental theme in classical Fourier analysis relates smoothness properties of functions to the growth and/or integrability of their Fourier transform.
W. Bray
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Scientific American, 1989
To calculate a transform, just listen. The ear automatically performs the calculation, which the intellect can execute only after years of mathematical education. The ear formulates a transform by converting sound-the waves of pressure traveling through time and the atmosphere-into a spectrum, a description of the sound as a series of volumes at ...
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To calculate a transform, just listen. The ear automatically performs the calculation, which the intellect can execute only after years of mathematical education. The ear formulates a transform by converting sound-the waves of pressure traveling through time and the atmosphere-into a spectrum, a description of the sound as a series of volumes at ...
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2018
In the previous chapter, we observed a peculiar relation between the smoothness and the rapidity of vanishing at infinity of a function f, as well as its Fourier transform \(\hat {f}\). Based upon this observation, we introduce an important function space \(\mathfrak {S}\), which is invariant under the Fourier transforms. We then proceed to \(\mathfrak
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In the previous chapter, we observed a peculiar relation between the smoothness and the rapidity of vanishing at infinity of a function f, as well as its Fourier transform \(\hat {f}\). Based upon this observation, we introduce an important function space \(\mathfrak {S}\), which is invariant under the Fourier transforms. We then proceed to \(\mathfrak
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Fourier transform Raman spectroscopy
Mikrochimica Acta, 1986The basic experimental aspects of Fourier transform Raman Spectroscopy are reviewed with an emphasis on detector technology. The sensitivity is comparable to dispersive Raman Spectroscopy using visible lasers. The ease of spectral subtraction is demonstrated and examples are given showing the elimination of fluorescence.
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Diskrete Fourier-Transformation und Fast Fourier Transform
2017Handelt es sich bei der Zeitfunktion x = x(t) um eine analytisch nicht darstellbare Funktion, lasst sich die Fourier-Transformation nur numerisch bewerkstelligen. Voraussetzung ist, dass x(t) eine periodische Funktion ist (Abb. 33.1). Handelt es sich bei x(t) um eine aperiodische Funktion, gelingt nur eine Naherung, indem eine fiktive Periode T ...
Christian Petersen, Horst Werkle
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Fourier Transform, Short-Time Fourier Transform, and Wavelet Transform
2018This chapter presents information about the Fourier transform (FT), short-time Fourier transform (STFT), and wavelet transform. This chapter also covers use of this transform in speech signal processing.
Komal R. Borisagar +2 more
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