Browsing ECE Publications by Subject "Temporary"
Now showing items 150 of 50

An Adaptive OptimalKernel TimeFrequency Representation
(19951001)Timefrequency representations with fixed windows or kernels figure prominently in many applications, but perform well only for limited classes of signals. Representations with signal dependent kernels can overcome this ... 
Adaptive Wavelet Transforms via Lifting
(19990501)This paper develops new algorithms for adapted multiscale analysis and signal adaptive wavelet transforms. We construct our adaptive transforms with the <i>lifting scheme</i>, which decomposes the wavelet transform into ... 
Adaptive Weighted Highpass Filters Using Multiscale Analysis
(19980701)In this paper, we propose a general framework for studying a class of weighted highpass filters. Our framework, based on a multiscale signal decomposition, allows us to study a wide class of filters and to assess the ... 
Conditional and Relative Multifractal Spectra
(19970301)In the study of the involved geometry of singular distributions the use of fractal and multifractal analysis has shown results of outstanding significance. So far, the investigation has focused on structures produced by ... 
Detecting Periodic Behavior in Nonstationary Signals
(19981020)This paper presents results on the multiresolution analysis of nonstationary signals with the objective of detecting underlying periodic phenomena. Wavelet packet analysis with coefficient thresholding is the basis for the ... 
Detection of Target Speakers in Audio Databases
(19990115)The problem of speaker detection in audio databases is addressed in this paper. Gaussian mixture modeling is used to build target speaker and background models. A detection algorithm based on a likelihood ratio calculation ... 
Effect of Utterance Duration and Phonetic Content on Speaker Identification Usind Second Order Statistical Methods
(19950101)Secondorder statistical methods show very good results for automatic speaker identification in controlled recording conditions. These approaches are generally used on the entire speech material available. In this paper, ... 
Efficient Methods for Identification of Volterra Filters
(19960201)A major drawback of the truncated Volterra series or "Volterra filter" for system identification is the large number of parameters required by the standard filter structure. The corresponding estimation problem requires ... 
Empirical Mode Decomposition Based Frequency Attributes
(19991101)This paper describes a new technique, called <i>Empirical Mode Decomposition</i> (EMD), which allows the decomposition of onedimensional signals into intrinsic oscillatory modes. Each component, called <i>Intrinsic Mode ... 
Equivalence of Generalized Joint Signal Representations of Arbitrary Variables
(19961220)Joint signal representations (JSRs) of arbitrary variables generalize timefrequency representations (TFRs) to a much broader class of nonstationary signal characteristics. Two main distributional approaches to JSRs of ... 
Exceptions to the Multifractal Formalism for Discontinuous Measures
(19980115)In an earlier paper the authors introduced the <i>inverse measure</i> <i>Âµ</i><sup>â </sup>(<i>dt</i>) of a given measure <i>Âµ</i>(<i>dt</i>) on [0,1] and presented the 'inversion formula' <i>f</i><sup>â </sup>(<i>a</i>) ... 
Fast, Exact Synthesis of Gaussian and nonGaussian LongRangeDependent Processes
(19990115)1/<i>f</i> noise and statistically selfsimilar processes such as fractional Brownian motion (fBm) are vital for modeling numerous realworld phenomena, from network traffic to DNA to the stock market. Although several ... 
A Further Investigation on ARVector Models for Text Independent Speaker Identification
(19960101)In this paper, we investigate on the role of dynamic information on the performances of ARvector models for speaker recognition. To this purpose, we design an experimental protocol that destroys the time structure of ... 
Hybrid Linear / Bilinear TimeScale Analysis
(19990101)We introduce a new method for the timescale analysis of nonstationary signals. Our work leverages the success of the "timefrequency distribution series / crossterm deleted representations" into the timescale domain ... 
Image enhancement by nonlinear wavelet processing
(19941020)In this paper we describe how the theory of wavelet thresholding introduced by Donoho and Johnstone can successfully be applied to two distinct problems in image processing where traditional linear filtering techniques are ... 
An Improved Multifractal Formalism and Self Affine Measures
(19930120)This document is a six page summary of my Ph.D. thesis in which multifractal formalism based on counting on coarse levels (as opposed to a dimensional approach) is developed. This formalism is then applied to selfaffine ... 
An Improved Multifractal Formalism and Self Similar Measures
(19950101)To characterize the geometry of a measure, its socalled generalized dimensions D(<i>q</i>) have been introduced recently. The mathematically precise definition given by Falconer turns out to be unsatisfactory for reasons ... 
Improved TimeFrequency Filtering of SignalAveraged Electrocardiograms
(19950115)A recently proposed timefrequency filtering technique has shown promising results for the enhancement of signalaveraged electrocardiograms. This method weights the shorttime Fourier transform (STFT) of the ensembleaveraged ... 
Inverse Measures, the Inversion formula, and Discontinuous Multifractals
(19970120)The present paper is part I of a series of three closely related papers in which the inverse measure m' of a given measure m on [0,1] is introduced. In the first case discussed in detail, both these measures are multifractal ... 
Inversion Formula for Continuous Multifractals
(19970120)In a previous paper the authors introduced the inverse measure <i>Âµ</i><sup>â </sup> of a probability measure <i>Âµ</i> on [0,1]. It was argued that the respective multifractal spectra are linked by the 'inversion formula' ... 
Joint Distributions of Arbitrary Variables Made Easy
(19981001)In this paper, we propose a simple framework for studying certain distributions of variables beyond timefrequency and timescale. When applicable, our results turn the theory of joint distributions of arbitrary variables ... 
Low Rank Estimation of Higher Order Statistics
(19951201)Low rank estimators for higher order statistics are considered in this paper. Rank reduction methods offer a general principle for trading estimator bias for reduced estimator variance. The biasvariance tradeoff is analyzed ... 
Multifractal Formalism for Infinite Multinomial Measures
(19950120)There are strong reasons to believe that the multifractal spectrum of DLA shows anomalies which have been termed left sided. In order to show that this is compatible with strictly multiplicative structures Mandelbrot et ... 
Multifractal Properties of TCP Traffic: a Numerical Study
(19971020)We analyze two traces of TCPtraffic recorded at the gateway of a LAN correÂ sponding to two hours at Berkeley and to eight hours at CNET labs respectively. We are mainly interested in a multifractal approach, which we ... 
Noise Reduction Using an Undecimated Discrete Wavelet Transform
(19950115)A new nonlinear noise reduction method is presented that uses the discrete wavelet transform. Similar to Donoho and Johnstone, we employ thresholding in the wavelet transform domain but, following a suggestion by Coifman, ... 
Nonlinear Wavelet Processing for Enhancement of Images
(19940520)In this note we apply some recent results on nonlinear wavelet analysis to image processing. In particular we illustrate how the (soft) thresholding algorithm due to Donoho and Johnstone can successfully be used to remove ... 
Nonstationary Signal Enhancement Using The Wavelet Transform
(19960320)Conventional signal processing typically involves frequency selective techniques which are highly inadequate for nonstationary signals. In this paper, we present an approach to perform timefrequency selective processing ... 
Numerical Estimates of Generalized Dimensions D_q for Negative q
(19960101)Usual fixedsize boxcounting algorithms are inefficient for computing generalized fractal dimensions D(<i>q</i>) in the range of <i>q</i><0. In this Letter we describe a new numerical algorithm specifically devised to ... 
On the Equivalence of the Operator and Kernel Methods for Joint Distributions of Arbitrary Variables
(19970420)Generalizing the concept of timefrequency representations, Cohen has recently proposed a general method, based on operator correspondence rules, for generating joint distributions of arbitrary variables. As an alternative ... 
Opitmal Phase Kernels for TimeFrequency Analysis
(19960501)We consider the design of kernels for timefrequency distributions through the phase, rather than amplitude, response. While phase kernels do not attenuate troublesome crosscomponents, they can translate them in the ... 
An Overview of the AT&T Spoken Document Retrieval System
(19980115)We present an overview of a spoken document retrieval system developed at AT&T LabsResearch for the HUB4 Broadcast News corpus. This overview includes a description of the intonational phrase boundary detection, ... 
Pseudo Affine Wigner Distributions
(19960501)In this paper, we introduce a new set of tools for timevarying spectral analysis: the pseudo affine Wigner distributions. Based on the affine Wigner distributions of J. and P. Bertrand, these new timescale distributions ... 
Pseudo Affine Wigner Distributions: Definition and Kernel Formulation
(19980601)In this paper, we introduce a new set of tools for timevarying spectral analysis: the pseudo affine Wigner distributions. Based on the affine Wigner distributions of J. and P. Bertrand, these new timescale distributions ... 
A PseudoBertrand Distribution for TimeScale Analysis
(19960301)Using the pseudoWigner timefrequency distribution as a guide, we derive two new timescale representations, the pseudoBertrand and the smoothed pseudoBertrand distributions. Unlike the Bertrand distribution, these ... 
Recent advances in Imaging and Spectroscopy with Trays
(19981201)Recent work in terahertz "TRay" imaging is reported. With the ongoing development of commercially viable THzTDS imaging system, opitmail signal processing strategies for the THz waveforms must be developed. Algorithms ... 
SCAN  Speech Content Based Audio Navigator: A Systems Overview
(19980115)SCAN (Speech Content based Audio Navigator) is a spoken document retrieval system integrating speakerindependent, largevocabulary speech recognition with informationretrieval to support querybased retrieval of information ... 
SecondOrder Statistical Measures for TextIndependent Speaker Identification
(19950820)This article presents an overview of several measures for speaker recognition. These measures relate to secondorder statistical tests, and can be expressed under a common formalism. Alternate formulations of these measures ... 
A Simple Scheme for Adapting TimeFrequency Representations
(19941201)Signaldependent timefrequency representations, by adapting their functional form to fit the signal being analyzed, offer many performance advantages over conventional representations. In this paper, we propose a simple, ... 
A Simple Statistical Analysis of Waveletbased Multifractal Spectrum Estimation
(19981101)The multifractal spectrum characterizes the scaling and singularity structures of signals and proves useful in numerous applications, from network traffic analysis to turbulence. Of great concern is the estimation of the ... 
Speaker Detection in Broadcast Speech Databases
(19980115)Experiments have been carried out to assess the feasibility of detecting target speaker segments in multispeaker broadcast databases. The experiemental database consists of NBC Nightly News broadcasts. The target speaker ... 
Tensor Product Basis Approximations for Volterra Filters
(19960201)This paper studies approximations for a class of nonlinear filters known as Volterra filters. Although the Volterra filter provides a relatively simple and general representation for nonlinear filtering, often it is highly ... 
Time Frequency Principal Components: Application to Speaker Identification
(19990101)In this paper, we propose a formalism, called vector filtering of spectral trajectories, which allows to integrate under a common formalism a lot of speech parameterization approaches. We then propose a new filtering in ... 
Toward an Improved Understanding of Network Traffic Dynamics
(19990620)Since the discovery of long range dependence in Ethernet LAN traces there has been significant progress in developing appropriate mathematical and statistical techniques that provide a physicalbased, networkingrelated ... 
Wavelet Analysis of Fractional Brownian Motion in Multifractal Time
(19990920)We study <i>fractional Brownian motions in multifractal time</i>, a model for multifractal processes proposed recently in the context of economics. Our interest focuses on the statistical properties of the wavelet decomposition ... 
Wavelet Based SAR Speckle Reduction and Image Compression
(19950401)This paper evaluates the performance of the recently published wavelet based algorithm for speckle reduction of SAR images. The original algorithm, based on the theory of wavelet thresholding due to Donoho and Johnstone, ... 
Wavelet Based Speckle Reduction with Applications to SAR based ATD/R
(19941120)This paper introduces a novel speckle reduction method based on thresholding the wavelet coefficients of the logarithmically transformed image. The method is computational efficient and can sinificantly reduce the speckle ... 
Waveletbased deconvolution for illconditioned systems
(20000201)We propose a hybrid approach to waveletbased deconvolution that comprises Fourierdomain system inversion followed by waveletdomain noise suppression. In contrast to other waveletbased deconvolution approaches, the ... 
WaveletBased PostProcessing of Low Bit Rate Transform Coded Images
(19941101)In this paper we propose a novel method based on wavelet thresholding for enhancement of decompressed transform coded images. Transform coding at low bit rates typically introduces artifacts associated witht he basis ... 
WaveletBased Transformations for Nonlinear Signal Processing
(19990701)Nonlinearities are often encountered in the analysis and processing of realworld signals. In this paper, we introduce two new structures for nonlinear signal processing. The new structures simplify the analysis, design, ... 
WaveletDomain Filtering for Photon Imaging Systems
(19990501)Many imaging systems rely on photon detection as the basis of image formation. One of the major sources of error in these systems is Poisson noise due to the quantum nature of the photon detection process. Unlike additive ...