scispace - formally typeset
Search or ask a question
Author

J.K. Hammond

Bio: J.K. Hammond is an academic researcher from University of Southampton. The author has contributed to research in topics: Covariance & Linear filter. The author has an hindex of 15, co-authored 43 publications receiving 1131 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the bispectrum and trispectrum are used to detect and analyse non-linearities in high-order spectra (HOS) and the tricoherence and kurtosis functions are extended to their fourth-order equivalents.

266 citations

Journal ArticleDOI
TL;DR: The analytical modelling of physical phenomena so as to predict theoretical time-frequency distributions, with a view to offering insight into the signal generation mechanisms, is modeled.

178 citations

Journal ArticleDOI
TL;DR: In this article, a normalised bispectral measure is used in the analysis of vibration signals containing periodic components and noise, and practical considerations regarding the choice of sampling rate are considered.

99 citations

Journal ArticleDOI
TL;DR: The Gauss Newton method is used in setting up a two-stage iterative least squares algorithm and the usefulness of the algorithm is validated through its application to various simulated time histories from the hysteretic model.

85 citations

Journal ArticleDOI
TL;DR: A normalised bispectral measure is used in the analysis of vibration signals containing periodic components and noise, showing that there is potential for using these measures for machine condition monitoring.

67 citations


Cited by
More filters
Journal ArticleDOI
Leon Cohen1
01 Jul 1989
TL;DR: A review and tutorial of the fundamental ideas and methods of joint time-frequency distributions is presented with emphasis on the diversity of concepts and motivations that have gone into the formation of the field.
Abstract: A review and tutorial of the fundamental ideas and methods of joint time-frequency distributions is presented. The objective of the field is to describe how the spectral content of a signal changes in time and to develop the physical and mathematical ideas needed to understand what a time-varying spectrum is. The basic gal is to devise a distribution that represents the energy or intensity of a signal simultaneously in time and frequency. Although the basic notions have been developing steadily over the last 40 years, there have recently been significant advances. This review is intended to be understandable to the nonspecialist with emphasis on the diversity of concepts and motivations that have gone into the formation of the field. >

3,568 citations

Journal ArticleDOI
TL;DR: A tutorial review of both linear and quadratic representations is given, and examples of the application of these representations to typical problems encountered in time-varying signal processing are provided.
Abstract: A tutorial review of both linear and quadratic representations is given. The linear representations discussed are the short-time Fourier transform and the wavelet transform. The discussion of quadratic representations concentrates on the Wigner distribution, the ambiguity function, smoothed versions of the Wigner distribution, and various classes of quadratic time-frequency representations. Examples of the application of these representations to typical problems encountered in time-varying signal processing are provided. >

1,587 citations

Journal ArticleDOI
TL;DR: In this article, a review of the past and recent developments in system identification of nonlinear dynamical structures is presented, highlighting their assets and limitations and identifying future directions in this research area.

1,000 citations

Journal ArticleDOI
TL;DR: A systematic review of over 20 major time-frequency analysis methods reported in more than 100 representative articles published since 1990 can be found in this article, where their fundamental principles, advantages and disadvantages, and applications to fault diagnosis of machinery have been examined.

719 citations

Journal ArticleDOI
TL;DR: A review of the past, recent developments and implementations of the Bouc-Wen model which is used extensively in modeling the hysteresis phenomenon in the dynamically excited nonlinear structures can be found in this paper.
Abstract: Structural systems often show nonlinear behavior under severe excitations generated by natural hazards. In that condition, the restoring force becomes highly nonlinear showing significant hysteresis. The hereditary nature of this nonlinear restoring force indicates that the force cannot be described as a function of the instantaneous displacement and velocity. Accordingly, many hysteretic restoring force models were developed to include the time dependent nature using a set of differential equations. This survey contains a review of the past, recent developments and implementations of the Bouc-Wen model which is used extensively in modeling the hysteresis phenomenon in the dynamically excited nonlinear structures.

602 citations