Now showing items 76-95 of 508

    • Contextual Hidden Markov Models for Wavelet-domain Signal Processing 

      Crouse, Matthew; Baraniuk, Richard G. (1997-11-01)
      Wavelet-domain hidden Markov models (HMMs) provide a powerful new approach for statistical modeling and processing of wavelet coefficients. In addition to characterizing the statistics of individual wavelet coefficients, ...
    • Contraction, Smoothness, and Low-Pass Filtering 

      Khojastepour, Mohammad; Aazhang, Behnaam; Baraniuk, Richard G. (2004-05-01)
      We introduce a generalized definition for "low-pass" filters that covers time-varying and nonlinear systems under the same umbrella. We show that the qualitative concept of signal smoothing can be made precise through the ...
    • Controlling False Alarms with Support Vector Machines 

      Davenport, Mark A.; Baraniuk, Richard G.; Scott, Clayton D. (2006-05-01)
      We study the problem of designing support vector classifiers with respect to a Neyman-Pearson criterion. Specifically, given a user-specified level alpha, 0 < alpha < 1, how can we ensure a false alarm rate no greater than ...
    • CORT: Classification Or Regression Trees 

      Scott, Clayton; Willett, Rebecca; Nowak, Robert David (2003-06-20)
      In this paper we challenge three of the underlying principles of CART, a well know approach to the construction of classification and regression trees. Our primary concern is with the penalization strategy employed to prune ...
    • CORT: Classification Or Regression Trees 

      Scott, Clayton; Willett, Rebecca; Nowak, Robert David (2003-04-20)
      In this paper we challenge three of the underlying principles of CART, a well know approach to the construction of classification and regression trees. Our primary concern is with the penalization strategy employed to prune ...
    • Covariant Time Frequency Representations Through Unitary Equivalence 

      Baraniuk, Richard G. (1996-03-01)
      We propose a straightforward characterization of all quadratic time-frequency representations covariant to an important class of unitary signal transforms (namely, those having two continuous-valued parameters and an ...
    • Data Driven Signal Detection and Classification 

      Sayeed, Akbar M. (1997-01-20)
      In many practical detection and classification problems, the signals of interest exhibit some uncertain nuisance parameters, such as the unknown delay and Doppler in radar. For optimal performance, the form of such parameters ...
    • Data-parallel Digital Signal Processors: Algorithm Mapping, Architecture Scaling and Workload Adaptation 

      Rajagopal, Sridhar (2004-05-01)
      Emerging applications such as high definition television (HDTV), streaming video, image processing in embedded applications and signal processing in high-speed wireless communications are driving a need for high performance ...
    • Decomposition of seismic signals via time-frequency representations 

      Tobback, Tom; Steeghs, Philippe; Drijkoningen, Guy G; Fokkema, Jacob T (1996-01-15)
      In this paper we discuss the use of a time-frequency representation, the Wigner distribution, for the decomposition and characterization of seismic signals. The advantage of the Wigner distribution over other representations, ...
    • Delay-Limited Throughput Maximization for Fading Channels using Rate and Power Control 

      Ahmed, Nadeem; Khojestapour, Mohammad; Baraniuk, Richard G. (2004-12-01)
      The fading channels seen in many wireless systems provide a particularly hostile environment for reliable communication. Current metrics for evaluating the performance limits of fading channels have shortcomings. Ergodic ...
    • Design of Adaptive Overlays for Multi-scale Communication in Sensor Networks 

      PalChaudhuri, Santashil; Kumar, Rajnish; Baraniuk, Richard G.; Johnson, David B. (2005-06-01)
      In wireless sensor networks, energy and communication bandwidth are precious resources. Traditionally, layering has been used as a design principle for network stacks; hence routing protocols assume no knowledge of the ...
    • Design of Linear Phase Cosine Modulated Filter Banks for Subband Image Compression 

      Odegard, Jan E.; Gopinath, Ramesh A.; Burrus, C. Sidney (1994-01-15)
      Wavelet methods give a flexible alternative to Fourier methods in non-stationary signal analysis. The concept of band-limitedness plays a fundamental role in Fourier analysis. Since wavelet theory replaces frequency with ...
    • DESIGN OF OPTIMAL DIGITAL FILTERS (APPROXIMATION, CHEBYSHEV, LINEAR PHASE, MINIMUM PHASE, COMPLEX DOMAIN) 

      CHEN, XIANGKUN (1986)
      Four methods for designing digital filters optimal in the Chebyshev sense are developed. The properties of these filters are investigated and compared. An analytic method for designing narrow-band FIR filters using Zolotarev ...
    • Design of Training Data Based Quadratic Detectors with Application to Mechanical Systems 

      Rizzoni, Giorgio; Sayeed, Akbar M.; Jones, Douglas L. (1996-01-20)
      Reliable detection of engine knock is an important issue in the design and maintenance of high performance internal combustion engines. Cost considerations dictate the use of vibration signals, measured at the engine ...
    • Detecting Periodic Behavior in Nonstationary Signals 

      Venkatachalam, Vidya; Aravena, Jorge.L. (1998-10-20)
      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 and estimation with compressive measurements 

      Baraniuk, Richard G.; Davenport, Mark A.; Wakin, Michael B. (2006-11-01)
      The recently introduced theory of compressed sensing enables the reconstruction of sparse or compressible signals from a small set of nonadaptive, linear measurements. If properly chosen, the number of measurements can ...
    • Detection of Target Speakers in Audio Databases 

      Magrin-Chagnolleau, Ivan; Rosenberg, Aaron; Parthasarathy, S. (1999-01-15)
      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 ...
    • Development of Digital Signal Processor controlled Quantum Cascade Laser based Trace Gas Sensor Technology 

      So, Stephen; Wysocki, Gerard; Frantz, Patrick; Tittel, Frank K. (2006-08-01)
      This work reports the design and integration of a custom digital signal processor (DSP) system into a pulsed quantum cascade laser (QCL) based trace gas sensor to improve its portability, robustness and operating performance. ...
    • Development of Japanese-language DSP Education Content in the Connexions Project 

      Frantz, Patrick; Yamada, Yoji (2005-10-01)
      Due to factors such as a small and fragmented market and rapid hardware development, the conventional textbook is inadequate for DSP lab education. Freely available open-content materials that enable and promote local ...