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275,222
A model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies
 Bull. Seism. Soc. Am
, 1984
"... At high frequencies f the spectrum of Swave accelerations is characterized by a trend of exponential decay, e~". In our study, the spectral decay parameter shows little variation at a single station for multiple earthquakes at the same distances, but it increases gradually as the epicentral d ..."
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Cited by 144 (6 self)
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At high frequencies f the spectrum of Swave accelerations is characterized by a trend of exponential decay, e~". In our study, the spectral decay parameter shows little variation at a single station for multiple earthquakes at the same distances, but it increases gradually as the epicentral
Hierarchical properties of AE amplitude spectrum of rock fracture
"... The principal point in the hierarchical description of a system is the possibility of selecting discrete subsystems in it which are called levels, or ranks of the system [1]. A certain set of properties and parameters which permits one to consider the given subsystem separately enough is meant by r ..."
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The principal point in the hierarchical description of a system is the possibility of selecting discrete subsystems in it which are called levels, or ranks of the system [1]. A certain set of properties and parameters which permits one to consider the given subsystem separately enough is meant by rank. The independence of ranks is not absolute; there is an interaction between them that is asymmetric. This manifests the fact that a change of a parameter at an upper rank j may lead to a significant change of a state at lower ranks jn (n = 1, 2...), while the effect of lower ranks on upper ones is much less. The asymmetric character of the dependence between the ranks results in their certain ordering, which makes this system hierarchic. Let us note two important properties of nature multilevel systems. The division of a given system into ranks is ambiguous and depends on the way of description and analysis aims. There is always overlapping between ranks. Beginning from studies [2] which were the base of the notions on rocks as discrete multilevel environments, the studies of corresponding properties of a material and processes originating at its deforming have been rapidly developed. At present, there
Bottomup saliency detection model based on amplitude spectrum
 in Proc. Int. Conf. MultiMedia Modeling
, 2011
"... Abstract—With the wide applications of saliency information in visual signal processing, many saliency detection methods have been proposed. However, some key characteristics of the human visual system (HVS) are still neglected in building these saliency detection models. In this paper, we propose a ..."
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Cited by 6 (2 self)
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a new saliency detection model based on the human visual sensitivity and the amplitude spectrum of quaternion Fourier transform (QFT). We use the amplitude spectrum of QFT to represent the color, intensity, and orientation distributions for image patches. The saliency value for each image patch
KodairaSpencer theory of gravity and exact results for quantum string amplitudes
 Commun. Math. Phys
, 1994
"... We develop techniques to compute higher loop string amplitudes for twisted N = 2 theories with ĉ = 3 (i.e. the critical case). An important ingredient is the discovery of an anomaly at every genus in decoupling of BRST trivial states, captured to all orders by a master anomaly equation. In a particu ..."
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Cited by 545 (60 self)
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We develop techniques to compute higher loop string amplitudes for twisted N = 2 theories with ĉ = 3 (i.e. the critical case). An important ingredient is the discovery of an anomaly at every genus in decoupling of BRST trivial states, captured to all orders by a master anomaly equation. In a
SOME METHODS TO IMPROVE THE EVALUATION OF AMPLITUDE SPECTRUM GIVEN BY FFT
, 2007
"... FFT gives satisfactory evaluation of amplitude spectrum only when the frequency of the fundamental is an integer (or very close to integer) multiple of frequency resolution. Usually we do not know precisely the frequency of the power converters feeding machines in electric drives. This is why we can ..."
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FFT gives satisfactory evaluation of amplitude spectrum only when the frequency of the fundamental is an integer (or very close to integer) multiple of frequency resolution. Usually we do not know precisely the frequency of the power converters feeding machines in electric drives. This is why we
The Application Research of Amplitude Spectrum in the Coating Layer Thickness Detection
"... Abstract—The caoting layer of each industry structure detected by ultrasonic testing is one commonly used thickness detection technique. This article proposed a method which used the extreme value of resonant amplitude spectrum to extract the thickness feature value, it can solve the feature value e ..."
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Abstract—The caoting layer of each industry structure detected by ultrasonic testing is one commonly used thickness detection technique. This article proposed a method which used the extreme value of resonant amplitude spectrum to extract the thickness feature value, it can solve the feature value
Spectrum estimation and harmonic analysis
, 1982
"... AbstmctIn the choice of an eduutor for the spectnrm of a ation ..."
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Cited by 438 (3 self)
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AbstmctIn the choice of an eduutor for the spectnrm of a ation
A ROOTMEANSQUARE REDUCTION OF A GENERIC VARIABLEAMPLITUDE SPECTRUM TO A CONSTANT
"... A rootmeansquare reduction of a generic variableamplitude spectrum to a constantamplitude equivalent for aluminum 7075T651 ..."
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A rootmeansquare reduction of a generic variableamplitude spectrum to a constantamplitude equivalent for aluminum 7075T651
Image denoising using a scale mixture of Gaussians in the wavelet domain
 IEEE TRANS IMAGE PROCESSING
, 2003
"... We describe a method for removing noise from digital images, based on a statistical model of the coefficients of an overcomplete multiscale oriented basis. Neighborhoods of coefficients at adjacent positions and scales are modeled as the product of two independent random variables: a Gaussian vecto ..."
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Cited by 514 (17 self)
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vector and a hidden positive scalar multiplier. The latter modulates the local variance of the coefficients in the neighborhood, and is thus able to account for the empirically observed correlation between the coefficient amplitudes. Under this model, the Bayesian least squares estimate of each
A Practical Guide to Wavelet Analysis
, 1998
"... A practical stepbystep guide to wavelet analysis is given, with examples taken from time series of the El Nio Southern Oscillation (ENSO). The guide includes a comparison to the windowed Fourier transform, the choice of an appropriate wavelet basis function, edge effects due to finitelength t ..."
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Cited by 833 (3 self)
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intervals. It is shown that smoothing in time or scale can be used to increase the confidence of the wavelet spectrum. Empirical formulas are given for the effect of smoothing on significance levels and confidence intervals. Extensions to wavelet analysis such as filtering, the power Hovmller, cross
Results 1  10
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275,222