Now showing items 184-203 of 508

  • Imaging with Terahertz Pulses 

    Dorney, Timothy D.; Johnson, Jon L.; Mittleman, Daniel M.; Baraniuk, Richard G. (2000-07-01)
    Recently, a real-time imaging system based on terahertz (THz) time-domain spectroscopy has been developed. This technique offers a range of unique imaging modalities due to the broad bandwidth, sub-picosecond duration, and ...
  • Imaging with THz Pulses 

    Dorney, Timothy D.; Johnson, Jon L.; Mittleman, Daniel M.; Baraniuk, Richard G. (2000-09-01)
    A real-time imaging system based on terahertz (THz) time-domain spectroscopy has been demonstrated. This technique offers a range of unique imaging modalities due to the broad bandwidth, sub-picosecond duration, and ...
  • Implementation of Channel Estimation and Multiuser Detection Algorithms for W-CDMA on Digital Signal Processors 

    Rajagopal, Sridhar; Xu, Gang; Cavallaro, Joseph R. (1999-08-20)
    Proposed algorithms for Third Generation W-CDMA communication systems have extremely high performance requirements. In this paper, we study the implementation issues involved for one of the proposed multiuser channel ...
  • An Improved Multifractal Formalism and Self Affine Measures 

    Riedi, Rudolf H. (1993-01-20)
    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 self-affine ...
  • An Improved Multifractal Formalism and Self Similar Measures 

    Riedi, Rudolf H. (1995-01-01)
    To characterize the geometry of a measure, its so-called 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 Time-Frequency Filtering of Signal-Averaged Electrocardiograms 

    Sayeed, Akbar M.; Jones, Douglas L. (1995-01-15)
    A recently proposed time-frequency filtering technique has shown promising results for the enhancement of signal-averaged electrocardiograms. This method weights the short-time Fourier transform (STFT) of the ensemble-averaged ...
  • Improved Type-Based Detection of Analog Signals 

    Goncalves, Paulo; Baraniuk, Richard G. (1997-04-01)
    When applied to continuous-time observations, type-based detection strategies are limited by the necessity to crudely quantize each sample. To alleviate this problem, we smooth the types for both the training and observation ...
  • Improved Wavelet Denoising via Empirical Wiener Filtering 

    Ghael, Sadeep; Sayeed, Akbar M.; Baraniuk, Richard G. (1997-07-01)
    Wavelet shrinkage is a signal estimation technique that exploits the remarkable abilities of the wavelet transform for signal compression. Wavelet shrinkage using thresholding is asymptotically optimal in a minimax ...
  • Improving the Resolution of Bearing in Passive Sonar Arrays by Eigenvalue Analysis 

    Johnson, Don; DeGraaf, Stuart (1981-08-01)
    A method of improving the bearing-resolving capabilities of a passive array is discussed. This method is an adaptive beamforming method, having many similarities to the minimum energy approach. The evaluation of energy ...
  • An Information processing approach to distributed detection 

    Lexa, Michael; Johnson, Don (2003-09-20)
    We apply the recent theory of information processing to a hybrid distributed detection architecture that combines the traditional parallel and tandem architectures. Central to this theory is the Kullback-Leibler discrimination ...
  • Information processing during transient responses in the crayfish visual system 

    Rozell, Chris; Johnson, Don; Glantz, Raymon (2003-06-01)
    We analyzed sustaining fiber responses in the crayfish visual system to light pulses using information processing techniques. The light pulse stimuli elicited a transient and a steady-state component in the EPSP input and ...
  • Information processing of linear block decoders 

    Lexa, Michael; Johnson, Don (2002-10-20)
    This paper develops a systematic method of studying the benefits of soft decoding for linear block codes by applying the concepts of information processing. We show that soft decoding uniformly improves decoder performance ...
  • Instantaneous Frequency Estimation using the Reassignment method 

    Odegard, Jan E.; Baraniuk, Richard G.; Oehler, Kurt L (1998-01-15)
    This paper explores the method of reassignment for extracting instantaneous frequency attributes from seismic data. The reassignment method was first applied to the spectrogram by Kodera, Gendrin and de Villedary and later ...
  • Integral Transforms Covariant to Unitary Operators and their Implications for Joint Signal Representations 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-06-01)
    Fundamental to the theory of joint signal representations is the idea of associating a variable, such as time or frequency, with an operator, a concept borrowed from quantum mechanics. Each variable can be associated ...
  • INTERFACIAL TENSION MEASUREMENT BY SESSILE DROP USING DIGITAL IMAGE PROCESSING 

    ELDER, JAMES EDWARD (1987)
    In enhanced oil recovery the displacement of oil is most effective at low interfacial tensions, usuall below 10$\sp{-2}$ dyne/cm. This condition can be achieved by surfactant or chemical flooding but requires accurate ...
  • Interpolation and Denoising of Nonuniformly Sampled Data using Wavelet-domain Processing 

    Choi, Hyeokho; Baraniuk, Richard G. (1999-03-01)
    In this paper, we link concepts from nonuniform sampling, smoothness function spaces, interpolation, and denoising to derive a suite of multiscale, maximum-smoothness interpolation algorithms. We formulate the interpolation ...
  • An introduction to multifractals 

    Riedi, Rudolf H. (1997-01-15)
    This is an easy read introduction to multifractals. We start with a thorough study of the Binomial measure from a multifractal point of view, introducing the main multifractal tools. We then continue by showing how to ...
  • Inverse Measures, the Inversion formula, and Discontinuous Multifractals 

    Mandelbrot, Benoit; Riedi, Rudolf H. (1997-01-20)
    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 

    Riedi, Rudolf H.; Mandelbrot, Benoit (1997-01-20)
    In a previous paper the authors introduced the inverse measure <i>µ</i><sup>â  </sup> of a probability measure <i>µ</i> on [0,1]. It was argued that the respective multifractal spectra are linked by the 'inversion formula' ...
  • Joint Compression and Speckle Reduction of SAR Images using Embedded Zerotree Models 

    Odegard, Jan E.; Guo, Haitao; Burrus, C. Sidney; Baraniuk, Richard G. (1996-03-01)
    We propose a new method for speckle reduction in synthetic aperture radar (SAR) imagery based on the embedded zerotree image compression algorithm. This new approach to denoising is inspired by the realization that the ...