Download or read book Coherence Estimation written by and published by . This book was released on 1980 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Estimation of Coherence written by Nigel Felix Nettheim and published by . This book was released on 1966 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherence is the frequency domain analog of the classical correlation coefficient. In recent years investigators have become aware that the usual procedure for estimating coherence may often be seriously inadequate; in particular, low estimates have appeared in cases where the true coherence is known to be high. A critical discussion of the usual estimates leads to the proposal of the so-called cross-regressive filter model. In spite of the naturalness of estimates of coherence obtained in this way, they have apparently not been used in the past. In testing whether the proposed model is satisfied one needs to test the hypothesis of identically zero coherence; a natural test is proposed, requiring a knowledge of the mean and variance of the estimated coherence under the null hypothesis.

Download or read book Coherence Estimation written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mathematics of the Discrete Fourier Transform DFT written by Julius O. Smith and published by Julius Smith. This book was released on 2008 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The DFT can be understood as a numerical approximation to the Fourier transform. However, the DFT has its own exact Fourier theory, and that is the focus of this book. The DFT is normally encountered as the Fast Fourier Transform (FFT)--a high-speed algorithm for computing the DFT. The FFT is used extensively in a wide range of digital signal processing applications, including spectrum analysis, high-speed convolution (linear filtering), filter banks, signal detection and estimation, system identification, audio compression (such as MPEG-II AAC), spectral modeling sound synthesis, and many others. In this book, certain topics in digital audio signal processing are introduced as example applications of the DFT"--Back cover

Download or read book Coherence and Time Delay Estimation written by G. Clifford Carter and published by Institute of Electrical & Electronics Engineers(IEEE). This book was released on 1993 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Engineering Studies Compiled 1979 Coherence Estimation written by G. C. Carter and published by . This book was released on 1979 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: On Generating Processes With Specified Coherence; Evaluation of the Statistics of the Estimate of Magnitude Squared Coherence; Some Practical Considerations of Coherence Estimation; Estimation of the Magnitude-Squared Coherence Function (Spectrum); Statistics of the Estimate of Magnitude Coherence; The Smoothed Coherence Transform (SCOT); Coherence Estimation as Affected by Weighting Functions and Fast Fourier Transform Size; A Digital Computer Algorithm for Estimation of the Power Spectral Density Matrix Using the Partitioned Modified Chirp Z Transform; Coherence Estimation Via the Partitioned Modified Chirp Z Transform; Approximation for Statistics of Coherence Estimators; Time Delay Estimation; The Role of Coherence in Time Delay Estimation; On the Variance of the Phase Estimate of the Cross Spectrum and Coherence; Positive Definite Spectral Estimate and Stable Correlation Recursion for Multivariate Linear Predictive Spectral Analysis; and Confidence Bounds for Magnitude-Squared Coherence Estimates.

Download or read book Some Practical Considerations of Coherence Estimation written by G. C. Carter and published by . This book was released on 1971 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given two processes the complex coherence spectrum is the complex cross spectral density function divided by the square root of the product of the two auto spectral density functions. Estimation of coherence in light of the fast Fourier transform (FFT) is investigated for synthetic data. The procedure used is to segment the given finite time histories to NSEG segments of size NNN. Each segment is multiplied by a weighting function (in this case a cosine bell) prior to computation of the FFT. Cross and Auto Spectra are then averaged over the NSEG segments prior to forming the coherence ratio. Practical conclusions drawn are that for non-flat auto spectrum, multiplication by a weighting function is necessary; that NSEG must be on the order of 64; that NNN must be large enough to insure sufficient spectral resolution.

Download or read book Coherence written by David Ramírez and published by Springer Nature. This book was released on 2023-01-01 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book organizes principles and methods of signal processing and machine learning into the framework of coherence. The book contains a wealth of classical and modern methods of inference, some reported here for the first time. General results are applied to problems in communications, cognitive radio, passive and active radar and sonar, multi-sensor array processing, spectrum analysis, hyperspectral imaging, subspace clustering, and related. The reader will find new results for model fitting; for dimension reduction in models and ambient spaces; for detection, estimation, and space-time series analysis; for subspace averaging; and for uncertainty quantification. Throughout, the transformation invariances of statistics are clarified, geometries are illuminated, and null distributions are given where tractable. Stochastic representations are emphasized, as these are central to Monte Carlo simulations. The appendices contain a comprehensive account of matrix theory, the SVD, the multivariate normal distribution, and many of the important distributions for coherence statistics. The book begins with a review of classical results in the physical and engineering sciences where coherence plays a fundamental role. Then least squares theory and the theory of minimum mean-squared error estimation are developed, with special attention paid to statistics that may be interpreted as coherence statistics. A chapter on classical hypothesis tests for covariance structure introduces the next three chapters on matched and adaptive subspace detectors. These detectors are derived from likelihood reasoning, but it is their geometries and invariances that qualify them as coherence statistics. A chapter on independence testing in space-time data sets leads to a definition of broadband coherence, and contains novel applications to cognitive radio and the analysis of cyclostationarity. The chapter on subspace averaging reviews basic results and derives an order-fitting rule for determining the dimension of an average subspace. These results are used to enumerate sources of acoustic and electromagnetic radiation and to cluster subspaces into similarity classes. The chapter on performance bounds and uncertainty quantification emphasizes the geometry of the Cramèr-Rao bound and its related information geometry.

Download or read book A Comparison of Some Methods for Coherence Estimation for Application in the Analysis of EEG written by Helena Kadlec and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Issues in Multiple channel Coherence Estimation written by Scott E. Lloyd and published by . This book was released on 1992 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coherence Estimation as Affected by Weighting Functions and Fast Fourier Transform Size written by G. Clifford Carter and published by . This book was released on 1972 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given two wide-sense stationary random processes, the (complex) coherence function is the (complex) cross power spectral density function divided by the square root of the product of the two (real) auto power spectral density functions. Estimation of the magnitude square of the complex coherence (MSC) with fast Fourier transform (FFT) processing is investigated for synthetic data. The procedure used to partition the given finite time histories into n segments. Each segment, consisting of P data points, is multiplied by a smooth weighting function before computing the FFT. Cross and auto spectra are then averaged over a large number of segments before forming the coherence ratio. It is demonstrated that, when the magnitude of the first derivative of either the auto spectrum or the phase of the complex coherence is large, (1) multiplication by a weighting function is absolutely necessary and (2) P must be large enough to ensure sufficient spectral resolution. (Author).

Download or read book Confidence Bounds for Magnitude Squared Coherence Estimates written by G. Clifford Carter and published by . This book was released on 1978 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main emphasis of the talk was on explaining coherence and its usefulness. The paper given in the coherence record emphasizes how to estimate coherence and how accurately this can be done. In underwater acoustics where signals are digitally processed at the outputs of two or more receiving sensors, it is desirable to estimate the coherence spectrum, both for detection and position estimation. A processing technique for computing arbitrary confidence bounds for stationary Gaussian signals is presented. Now computationally difficult examples are given for 80-95 percent confidence with independent averages of 8, 16, 32, 64, and 128. A discussion of the computational difficulties together with algorithmic details (including the FORTRAN program) are presented.

Download or read book A Comparison of Some Methods for Coherence Estimation for Application in the Analysis of EEG written by Helena Kadlec and published by . This book was released on 1985 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimation of the Magnitude squared Coherence Function spectrum written by George Clifford Carter and published by . This book was released on 1972 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Statistics of Nonlinearly Transformed Coherence Estimates written by Albert H. Nuttall and published by . This book was released on 1981 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: An asymptotic relation for the average value of any nonlinear transformation of a magnitude-squared-coherence estimate is derived. It is utilized to determine the bias, variance, and mean-square error of the transformed coherence estimate. It is found that the arc tanh (x(1/2)) transformation is the only one with variance independent of the true coherence value to O(N( -1)), and that the 1n(x) transformation is the only one with zero bias, to exponential order in N. Here, N is the number of data pieces employed in the estimation of the coherence. Extensions to terms of O(N( -2)) are made and presented for a v-th law device also. (Author).

Download or read book Optical Measurement of Surface Topography written by Richard Leach and published by Springer Science & Business Media. This book was released on 2011-03-31 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: The measurement and characterisation of surface topography is crucial to modern manufacturing industry. The control of areal surface structure allows a manufacturer to radically alter the functionality of a part. Examples include structuring to effect fluidics, optics, tribology, aerodynamics and biology. To control such manufacturing methods requires measurement strategies. There is now a large range of new optical techniques on the market, or being developed in academia, that can measure areal surface topography. Each method has its strong points and limitations. The book starts with introductory chapters on optical instruments, their common language, generic features and limitations, and their calibration. Each type of modern optical instrument is described (in a common format) by an expert in the field. The book is intended for both industrial and academic scientists and engineers, and will be useful for undergraduate and postgraduate studies.

Download or read book Study of Parallel Implementation of Coherence Estimation on the Cell Broadband Engine written by Sushma Srikanta Murthy and published by . This book was released on 2010 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherence estimation is a fundamental and important tool that is widely used in the areas of signal and image processing, be it for segmentation of images, study of functional relationship between intracranial EEG signals from different parts of the brain, processing of language and reading impairs in dyslexic patients, and propagation of acoustic signals in liquids.