Now showing items 339-358 of 1050

  • Gas Sensing using Terahertz Time-Domain Spectroscopy 

    Mittleman, Daniel M.; Jacobsen, R. H.; Neelamani, Ramesh; Baraniuk, Richard G.; Nuss, Martin C. (1998-01-15)
    A method for detection and identification of polar gases and gas mixtures based on the technique of terahertz time-domain spectroscopy is presented. This relatively new technology promises to be the first portable far-infared ...
  • A General Hardware/Software Co-design Methodology for Embedded Signal Processing and Multimedia Workloads 

    Brogioli, Michael; Radosavljevic, Predrag; Cavallaro, Joseph R. (2006-11-01)
    This paper presents a hardware/software co-design methodology for partitioning real-time embedded multimedia applications between software programmable DSPs and hardware based FPGA coprocessors. By following a strict set ...
  • Generalized Beamforming for MIMO Systems with Limited Transmitter Information 

    Mukkavilli, Krishna Kiran; Sabharwal, Ashutosh; Aazhang, Behnaam (2003-11-20)
    In this work, we investigate the outage performance of beamforming schemes in wireless systems equipped with multiple transmit and receive antennas. In particular, we analyze the outage performance of unit rank beamforming ...
  • Generalized Digital Butterworth Filter Design 

    Selesnick, Ivan W.; Burrus, C. Sidney (1996-01-15)
    This paper presents a formula-based method for the design of IIR filters having more zeros than (nontrivial) poles. The filters are designed so that their square magnitude frequency responses are maximally-flat at <i>m</i> ...
  • Generalized Digital Butterworth Filter Design 

    Selesnick, Ivan W.; Burrus, C. Sidney (1995-01-15)
    This paper presents a formula-based method for the design of IIR filters having more zeros than (nontrivial) poles. The filters are designed so that their square magnitude frequency responses are maximally-flat at <i>m</i> ...
  • Generalized Joint Signal Representations and Optimum Detection 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-01-20)
    Generalized joint signal representations (JSRs) extend the scope of joint time-frequency representations (TFRs) to a richer class of nonstationary signals, but their use, just as in the case of TFRs, has been primarily ...
  • Generalized likelihood ratio detection for fMRI using complex data 

    Nan, F.Y.; Nowak, Robert David (1999-04-20)
    The majority of fMRI studies obtain functional information using statistical tests based on the magnitude image reconstructions. Recently, a complex correlation (CC) test was proposed based on teh complex image data in ...
  • Generation of diffraction-free beams for applications in optical microlithography 

    Erdelyi, Miklos; Horvath, Zoltan L.; Szabo, Gabor; Bor, Zs.; Tittel, Frank K.; Cavallaro, Joseph R.; Smayling, Michael C. (1997-03-01)
    A new concept based on a Fabry–Perot interferometer for the generation of nondiffracting Bessel beams is described and proposed for potential applications in microlithography such as the fabrication of small isolated ...
  • Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer 

    Horvath, Zoltan L.; Erdelyi, Miklos; Szabo, Gabor; Bor, Zs.; Tittel, Frank K.; Cavallaro, Joseph R. (1997-11-01)
    A new concept for generating zero-order Bessel beams was studied theoretically. The spatial intensity distribution was calculated numerically using a wave optics model. Approximate analytical expressions were derived to ...
  • A Geometric Hidden Markov Tree Wavelet Model 

    Romberg, Justin; Wakin, Michael; Choi, Hyeokho; Baraniuk, Richard G. (2003-08-01)
    In the last few years, it has become apparent that traditional wavelet-based image processing algorithms and models have significant shortcomings in their treatment of edge contours. The standard modeling paradigm exploits ...
  • Geometric Methods for Wavelet-Based Image Compression 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2003-08-01)
    Natural images can be viewed as combinations of smooth regions, textures, and geometry. Wavelet-based image coders, such as the space-frequency quantization (SFQ) algorithm, provide reasonably efficient representations for ...
  • Geometric Tools for Image Compression 

    Wakin, Michael; Romberg, Justin; Choi, Hyeokho; Baraniuk, Richard G. (2002-11-01)
    Images typically contain strong geometric features, such as edges, that impose a structure on pixel values and wavelet coefficients. Modeling the joint coherent behavior of wavelet coefficients is difficult, and standard ...
  • Geometry Compression of Normal Meshes using Rate-Distortion Algorithms 

    Lavu, Sridhar; Choi, Hyeokho; Baraniuk, Richard G. (2003-06-01)
    We propose a new rate-distortion based algorithm for compressing 3D surface geometry represented using triangular normal meshes. We apply the Estimation-Quantization (EQ) algorithm to compress normal mesh wavelet coefficients. ...
  • Getting Real: A Naturalistic Methodology for Using Smartphones to Collect Mediated Communications 

    Tossell, Chad C.; Kortum, Philip; Shepard, Clayton W.; Rahmati, Ahmad; Zhong, Lin (2012)
    This paper contributes an intentionally naturalistic methodology using smartphone logging technology to study communications in the wild. Smartphone logging can provide tremendous access to communications data from real ...
  • Giant tunable Faraday effect in a semiconductor magneto-plasma for broadband terahertz polarization optics 

    Arikawa, Takashi; Wang, Xiangfeng; Belyanin, Alexey A.; Kono, Junichiro (2012)
    We report on a giant Faraday effect in an electron plasma in n- InSb probed via polarization-resolved terahertz (THz) time-domain spectroscopy. Polarization rotation angles and ellipticities reach as large as π/2 and ...
  • GNOMES: A Testbed for Low-Power Heterogeneous Wireless Sensor Networks 

    Welsh, Erik; Fish, Walt; Frantz, Patrick (2003-05-20)
    Continuing trends in sensor, semiconductor and communication systems technology (smaller, faster, cheaper) make feasible very dense networks of fixed and mobile wireless devices for use in many different sensing and ...
  • GPU Accelerated Scalable Parallel Decoding of LDPC Codes 

    Wang, Guohui; Wu, Michael; Sun, Yang (2011-11-01)
    This paper proposes a flexible low-density parity-check (LDPC) decoder which leverages graphic processor units (GPU) to provide high decoding throughput. LDPC codes are widely adopted by the new emerging standards for ...
  • A GPU Implementation of a Real-Time MIMO Detector 

    Wu, Michael; Gupta, Siddharth; Sun, Yang; Cavallaro, Joseph R. (2009-10-01)
    Multiple-input multiple-output (MIMO) is an existing technique that can significantly increase throughput of the system by employing multiple antennas at the transmitter and the receiver. Realizing maximum benefit from ...
  • GPU-based Acceleration of Symbol Timng Recovery 

    Kim, Scott C.; Plishker, William L.; Bhattacharyya, Shurva S.; Cavallaro, Joseph R. (2012-12-20)
    This paper presents a novel implementation of graphics processing unit (GPU) based symbol timing recovery using polyphase interpolators to detect symbol timing error. Symbol timing recovery is a compute intensive procedure ...
  • Gradient Estimation for Sensitivity Analysis and Adaptive Multiuse Interface Rejection in Code-division Multiple-access Systems 

    Mandayam, Narayan B.; Aazhang, Behnaam (1997-07-20)
    In this paper, we consider a direct-sequence code-division multiple-access (DS-CDMA) system in the framework of a discrete-event dynamic system (DEDS) in order to optimize the system performance. Based on this formulation, ...